The present invention provides a composition comprising an ion-trigger polymer coating joined to a water-sensitive substrate. When the composition is employed as a diaper outercover or a pantiliner baffle, for example, the ion-trigger coating is oriented toward the body and is exposed to bodily fluids. The coating inhibits the transport of the fluids to the inner, body-side water-sensitive substrate, maintaining the structural integrity of the composition. When the entire article is disposed of in a large volume of water, such as in the hydraulic flow of a toilet, both the water-sensitive substrate layer and the ion-trigger polymer coating layer mechanically weaken and break apart into small pieces.

The present invention relates to polymer compositions that are water stable on one surface and water-sensitive on the opposing surface. More particularly, the present invention encompasses flushable, barrier films that retain their integrity in the presence of body waste fluids, but which disintegrate and disperse in the hydraulic flow of a toilet.
Disposable products have revolutionized modern lifestyle and are of great convenience to society. Such products generally are relatively inexpensive, sanitary and quick and easy to use. Disposal of such products, however, increasingly is a problem as landfills close and incineration contributes to urban smog and pollution. Consequently there is an urgent need for disposable products that can be disposed of without dumping or incineration. An ideal disposal alternative would be the use of municipal sewage treatment and private residential septic systems. Products suited for disposal in sewage systems that can be flushed down a conventional toilet are termed xe2x80x9cflushable.xe2x80x9d An essential feature of flushable products is that they must have sufficient strength for their intended use, yet lose structural integrity upon contact with water. Meeting these dual criteria is particularly difficult for products that come in contact with body waste fluids, especially urine.
Numerous attempts have been made to produce flushable fibers, fabrics, films and adhesives that retain their integrity and wet strength in the presence of body waste fluids, yet can be disposed of via flushing in conventional toilets. One approach to producing a flushable product is to limit the size of the product so that it will readily pass through plumbing without causing obstructions or blockages. Such products may have high wet strength and would not disintegrate during flushing. Examples of this type of product might include wipes such as baby wipes. This approach to flushability suffers the disadvantage, however, of being restricted to small sized articles. Many of the current flushable products are limited to such small articles.
Another approach to producing a flushable product is to manufacture a product that is normally insoluble in water, but which disintegrates in the presence of alkaline or acidic aqueous solutions. The end user is provided with an alkaline or acidic material to add to the water in which the product is to be disposed. This approach permits disposal via normal plumbing systems of products substantially larger than wipes, but suffers from the disadvantage of requiring the user to perform the step of adding the dissolving chemical to the water. A further disadvantage is that the inadvertent or intentional disposal of such a product in a conventional toilet without the addition of the dissolving chemical can cause serious obstruction or blockage of the plumbing system. The latter disadvantage can, however, be overcome by incorporating the dissolving acid or alkali into the article but separate from the dissolvable material while in use. The dissolving chemical is only released upon contact with water during flushing.
Similarly, another approach to producing a flushable product consists of forming the product from a pH sensitive polymer and storing the product in the presence of a separate acid pH solution. When the product is placed in a large quantity of normal tap water, it disintegrates as a result of the pH shift. A disadvantage of this pH shift approach to flushability is that some acidic polymers lose wet strength at slightly alkaline pH in the range of 7-8. Because the pH of urine may be as high as 8.5, these flushable materials may not be well suited for use in, for example, diapers or incontinence pads.
Yet another approach to producing a flushable product is to form the product from material that is susceptible to attack by specific enzyme catalysis that breaks down the structural integrity of the material. In such a product the enzymes may be introduced into the disposal water separately. These systems suffer many of the same problems as acid or alkaline treatable materials.
Still others have attempted to make flushable products wherein a non-woven web is bound together with salt-sensitive binders. For example, some acrylic copolymers precipitate in the presence of high concentrations of calcium ions. The problem with calcium-dependent water soluble binders, however, is that across the country the concentration of calcium in normal tap water varies tremendously. Consequently, flushable products made with those binders may not, in fact, be flushable in regions with high calcium containing water.
None of the above approaches have proven completely satisfactory. Therefore, there is a need for a flushable barrier product which is stable in ion-containing bodily fluids, and which does not require special conditions of disposal.
The present invention provides a composition comprising a an ion-trigger polymer coating joined to a water-sensitive substrate. When the composition is employed as a diaper outercover or a pantiliner baffle, for example, the inner, body-side ion-trigger coating is exposed to bodily fluids, and acts as a barrier coating thereby inhibiting their transport to the lower water-sensitive substrate, maintaining the structural integrity of the composition. When the entire article is disposed of in a large volume of water, such as in the hydraulic flow of a toilet, both the water-sensitive substrate layer and the ion-trigger polymer coating layer mechanically weaken and break apart.
The present invention is, therefore, desirably designed to provide disposable compositions that can be flushed in a conventional toilet. It is also desirable to provide disposable compositions that act as fluid barriers, but are also capable of being flushed in a conventional toilet without the addition of a dissolving chemical. Additionally, it is desirable to provide flushable compositions that are insoluble in the presence of body waste fluids, but which are water dispersible in the presence of normal toilet water. Also, it is desirable to provide flushable compositions that disintegrate and disperse in normal toilet water regardless of geographic variations in toilet water salt concentrations. Additionally, it is desirable to provide flushable compositions that have sufficient strength for their intended use. Finally, it is desirable to provide flushable products, including, but not limited to, feminine care products, diapers and training pants, bandages, packaging, release films, and the like.
The present invention provides a composition comprising an ion-trigger polymer coating joined to a water-sensitive substrate. When the composition is employed as a diaper outercover or a pantiliner baffle, for example, the inner ion-trigger coating is exposed to bodily fluids, and acts as a barrier coating, thereby inhibiting their transport to the lower water-sensitive substrate, maintaining the structural integrity of the composition. When the composition is disposed of in a large volume of water, such as in the hydraulic flow of a toilet, both the water-sensitive substrate layer and the ion-trigger polymer coating layer mechanically weaken and break apart.
Therefore, one embodiment of the present invention provides a composite two-layer article comprising an ion-trigger coating on a water-sensitive substrate. In normal use, it is understood that the inner, ion-trigger coated side of the article will typically be exposed to bodily fluids, such as blood, menstrual fluid, vaginal exudate, urine and perspiration. The term xe2x80x9cinner sidexe2x80x9d, as used herein, means the side of the film closest to the skin of the wearer. Both the inner ion-trigger coating and the outer, water-sensitive substrate will be exposed to toilet water during disposal. The ion-trigger coating on the inner side acts as a barrier coating and inhibits the transport of body fluids from the wearer through the article, effectively providing a barrier between body fluids and the water-sensitive substrate.
In a further embodiment of the present invention, the composition may serve as a primer layer for additional coatings on the water-sensitive substrate, such as latex coatings or a second layer of an ion-trigger material. The primer layer provides enough water protection so that a water-based solution coating may be applied to the coated water-sensitive film, the water being subsequently removed prior to any degradation of the water-sensitive substrate layer. In most cases and applications, the coated water-sensitive film is flushable and dispersible because it will disintegrate rapidly when exposed to the flow of water such as in a conventional toilet.
Flushable articles of the present invention may be made up entirely of flushable components, or composed of a mixture of flushable and non-flushable materials. In the former case, the entire article disintegrates or disperses in the hydraulic flow of normal toilet water, while in the latter case the flushable components disperse in the presence of normal toilet water. The flushable article falls apart into pieces small enough to be flushed without causing obstruction.
The term xe2x80x9cflushablexe2x80x9d as used herein means capable of being flushed in a conventional toilet, and being introduced into a municipal sewage or residential septic system, without causing an obstruction or blockage in the toilet or sewage system, and does not adversely affect the microbiology of the septic or sewage treatment system. The term xe2x80x9cflushable articlexe2x80x9d as used herein includes, but is not limited to, feminine care products, diapers and training pants, bandages, packaging, release films, and the like.
Several formulations of the ion-trigger polymer coating may be used with the present invention. In order to be effective for use in flushable personal care products, the ion trigger coating must be functional in use, i.e. maintain integrity and act as a barrier in the presence of body fluids, yet dissolve or disperse rapidly in water found in toilets. The main component of the ion-trigger coating of the present invention is an ion-trigger polymer. An ion-trigger polymer is one whose strength and dispersibility in water is changed depending on a very slight difference in the concentrations of a salt. More specifically, an ion-trigger polymer loses strength and disperses in tap water, but maintains strength and is insoluble in an aqueous solution which contains not less than 0.5% by weight of a neutral inorganic salt comprising a monovalent ion such as NaCl, KCl and NaBr.
It is well known that addition of an inorganic salt to an aqueous solution of a water soluble polymer may force polymer precipitation through a salting-out phenomenon. For example, anionic polymers, such as sodium salts of polyacrylate and carboxymethyl cellulose, become insoluble in an aqueous solution of common salt having a concentration of 4 to 5% or higher; non-ionic polymers such as hydroxyethyl cellulose and polyvinyl alcohol (PVA) are insoluble in an aqueous solution only when the concentration of the salt is increased to about 10% or higher. This salting out of a water soluble polymer describes the change from a homogeneous polymer solution to a polymer precipitate.
While an ion-trigger polymer is certainly salt-sensitive, like the simple water-soluble polymers mentioned above, there are several significant differences in the behavior of an ion-trigger polymer for flushable applications. First, the ion-trigger polymer may be sensitive to changes in ion concentration at low levels, such as 0.5% by weight of a common salt. Second, in the aqueous ionic solutions of typical body fluids, the ion trigger polymer is expected not just to be insoluble, but is required to maintain integrity and strength and act as a barrier coating. Finally, the ion trigger polymer loses enough strength or integrity to disperse in tap water; but note that this dispersion does not necessarily require full dissolution, as would be typical with the simple salt-sensitive water-soluble polymers.
The feature of integrity and strength in use can be achieved by ensuring a proper xe2x80x9chydrophobic/hydrophilic balancexe2x80x9d throughout the polymer chain. As used herein, the term xe2x80x9chydrophobic/hydrophilic balancexe2x80x9d refers to a balance of hydrophobic and hydrophilic moieties along the polymer chain, which results in the polymer having a desired trigger property. By control of the hydrophobic/hydrophilic balance in the composition of the polymer, ion-sensitive polymers having desired in-use integrity and water dispersibility are produced. In contrast, for simple salt-sensitive, water-soluble homopolymers, like polyvinyl alcohol, the hydrophobic/hydrophilic character is fixed by the structure of the monomer, and cannot be adjusted.
In one formulation of the ion-trigger coating, the ion-trigger character is provided by a sulfonated polyester condensation polymer. The hydrophobic/hydrophilic balance can be controlled by choice of the monomers involved in the condensation reaction. The preparation of such polyesters is generally described, for example, in U.S. Pat. Nos. 4,910,292, 4,973,656 and 4,990,593, and European Patent Application No. EP 0 761 795 A2, all incorporated herein by reference.
In general, the ion-trigger material is a material that acts as a barrier coating thereby inhibiting the transport of fluids through the coating. Preferably, these materials are melt processable since they are easier to apply to a water-soluble substrate. Several different aqueous compounds have ion-triggerability, however, these compounds are not preferred. For example, U.S. Pat. Nos. 5,317,063 and 5,312,883 reveal acrylic acid or methacrylic acid copolymers that are ion-sensitive. Unfortunately, these materials are not melt processable, and so not amenable to melt coating. Coating an aqueous solution of ion-trigger polymers on water-sensitive substrate is difficult as the aqueous nature of these coatings tends to partially dissolve the water-soluble substrate. In addition, the acrylic or methacrylic functionality in the polymer is sensitive to physical crosslinking through divalent ions and therefore would not readily disperse in hard water.
In a desired embodiment of the invention, the ion-trigger polymer coating composition includes at least one water dispersible copolyester, present in an amount from about 25 to 100% by weight. Water dispersible copolyesters are those in which ionic moieties or water sensitive reactants are incorporated into the backbone.
Alternatively, the ionic moieties may be grafted onto the backbone. The structure of such copolyesters are described in Miller, et al., WO 95/18191, incorporated herein by reference. The xe2x80x9cEastman AQxe2x80x9d copolyesters, as taught by Miller, incorporate ionic moieties by copolymerizing 5-sodiosulfoisophthalate units into a polyester backbone. Due to certain deficiencies in the neat polymer, it is often desirable to add a second compatible polymer at concentration up to about 20% by weight to increase the cohesive strength, improve the sprayability, and/or reduce the cold flow tendencies. This second polymer may be any compatible elastomer, such as a thermoplastic block copolymer, an amorphous or crystalline polyolefin such as polypropylene, polybutylene or polyethylene; and ethylenic copolymers such as ethylene-vinyl acetate, ethylene-methyl acetate, and mixtures thereof.
Other useful ion-trigger polymers are described in U.S. Pat. Nos. 5,543,488 and 5,552,495, incorporated herein by reference, which disclose sulfonated copolyesters. Other useful polymer blends are available from National Starch and Chemical Company as NS70-4395 or NS70-4442.
In addition to the sulfonated copolyesters cited above, a variety of other trigger polymers are known in the art. U.S. Pat. No. 5,770,528 reveals methylated hydroxproplyl cellulose as an polymer with trigger controlled by temperature and ion concentration. Hydroxypropyl cellulose itself has some ion-sensitivity, but is more of a temperature trigger material. Indeed, U.S. Pat. No. 5,509,913 lists a variety of polymers, including poly vinyl methyl ether, polyvinyl alcohol and various cellulose polymers with temperature triggers modulated by ion concentration. While these temperature-trigger polymers may have some utility in an ion-trigger coating, these simple polymers themselves do not usually have the proper xe2x80x9chydrophobic/hydrophilic balancexe2x80x9d to provide the required integrity and strength in use.
In general, the thickness of the ion-trigger coating layer is dependent upon the product to be made. Preferably, the thickness is between about 0.1 to 3.0 mils. More preferably, the thickness is between about 0.5 to 2.0 mils. Most preferably the thickness is about 0.8 mils.
It may also be desirable to incorporate into the ion-trigger layer up to 20% by weight of certain other hydrophilic non-crystalline polymers such as hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl methyl ether, polyvinylpyrrolidone, polyethyloxazoline, starch or cellulose esters, particularly the acetates with a degree of substitution less than 2.5; the latter polymers function to increase the water sensitivity of the ion-trigger coating layer, which may be desired for some applications.
It may also be advantageous to blend the ion-trigger polymer coating composition with a hydrophobic polymer, such as polypropylene, polyethylene, or poly(lactic acid). The hydrophobic polymer can alter both the sensitivity of the ion-trigger composition to the differences between salt solution and pure water, and the time toward barrier failure when the composition is exposed to either salt solution or pure water.
Other hydrophobic compatible polymers include elastomeric polymers such as styrene containing block copolymers, e.g., styrene-isoprene-styrene, epoxidized polyisoprene, styrene-butadiene-styrene, styrene-ethylene butylene-styrene, styrene-ethylene propylene styrene may also be present at levels up to about 30% by weight. Of these polymers, those based on styrene-isoprene-styrene are most preferred. Among the applicable stabilizers or antioxidants which may be included herein are high molecular weight hindered phenols and multifunctional phenols such as sulfur and phosphorous-containing phenols. Representative hindered phenols include:
1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; n-octadecyl 3,5-di-tert-butyl-4-hydroxyphenyl) propionate; 4,4xe2x80x2-methylenebis (2,6-di-tert-butylphenol); 4,4xe2x80x2-thiobis (6-tert-butyl-o-cresol); 2,6-di-tert-butylphenol; 6-(4-hydroxyphenoxy)-2,4-bis(n-octylthio)-1,3,5-triazine; di-n-octadecyl-3,5-di-tert-butyl-4-hydroxybenzyl -phosphonate; 2-(n-octylthio)-ethyl 3,5-di-tert-butyl-4-hydroxybenzoate; and sorbitol hexa(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate). If used, the stabilizer may be present in levels of 0.1 to 3% by weight.
A plasticizer is broadly defined as a typically organic composition that can be added to thermoplastics, rubbers and other resins to improve extrudability, flexibility, workability, or stretchability. Plasticizers may be used in the ion-trigger layer at concentrations up to about 50% by weight. Preferably, the plasticizing agent is a solid at ambient temperature with a softening point above 60 degrees Celsius, and belongs to the class of plasticizers including cyclohexane dimethanol dibenzoate. Any plasticizer that will recrystallize in the compounded thermoplastic composition is suitable, for example, a 1,4-cyclohexane dimethanol dibenzoate compound commercially available from Velsicol Chemical Corp., Rosemont, Ill., under the tradename BENZOFLEX(copyright) 352. Other plasticizers that may be suitable for this purpose are described in EP 0422 108 B1 and EP 0 410 412 B1, both assigned to H. B. Fuller Company, incorporated herein by reference. When combined with the copolyesters, such as the Eastman AQ series, these plasticizers exhibit the unique ability to vastly improve the processability in the molten state, yet not interfere with the dispensability once cooled and solidified.
Other suitable plasticizers include hydrocarbon oils, polybutene, liquid tackifying resins, and liquid elastomers. Such oils are primarily hydrocarbon oils, and are paraffinic or naphthenic in character. The oils are preferably low in volatility, transparent and have as little color and odor as possible. The use of plasticizers in this invention also contemplates the use of olefin oligomers, low molecular weight polymers, vegetable oils and their derivatives and similar plasticizing liquids.
The ion-trigger coating layer may comprise a wax present in amounts up to about 20% by weight, more preferably in amounts ranging from about I to about 10% by weight. The wax is added to modify the viscosity, reduce the tack, and improve the humidity resistance. In one embodiment, the wax is polar in nature such as amide waxes. Other useful waxes include paraffin waxes, microcrystalline waxes, Fischer-Tropsch synthesis products, polyethylene and by-products of polyethylene.
As is known in the art, various other components can be added to modify the tack, color, and odor of a polymer. It is generally preferred that the other components or ingredients should be relatively inert and have negligible effects upon the properties contributed by the copolyester, tackifying agent, and plasticizer. Antioxidants and other stabilizing ingredients can also be added to protect the ion-trigger polymer from various heat and light induced degradation, but are not essential to the compositions of this invention.
Optional additives may be incorporated into the ion trigger polymer coating composition in order to modify certain properties thereof. Among these additives are colorants such as titanium dioxide, and fillers such as talc, clay or other silicates.
For a flushable composition of the present invention, such as a diaper outer cover or a pantiliner baffle, the inner side of the compositionxe2x80x94the side closer to the wearer of the articlexe2x80x94will typically be exposed to body fluids in use, while both sides will be exposed to toilet water in disposal. The ion-trigger coating on the side adjacent to the wearer of the article inhibits the transport of body fluids through the composition, and provides a barrier between body fluids and the water-dispersible substrate on the outer surface. However, the side of the article further from the wearer of the water-dispersible substrate is designed to quickly weaken in the flow of toilet water, and allows the entire composition to lose enough structural integrity to flush down a conventional toilet. Preferably, the wet substrate has a peak-load strength of less than 20 g/in, which is comparable to wet bathroom tissue.
Suitable polymers for the water-sensitive substrate layer include, but are not limited to, polyalkylene oxides, such as polyethylene oxide (PEO), ethylene oxide-propylene oxide copolymers, polymethacrylic acid, polymethacrylic acid copolymers, polyvinyl alcohol and vinyl alcohol copolymers, polyethyl oxazoline, polyvinyl methyl ether, polyvinyl pyrrolidone/vinyl acetate copolymers, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, ethyl hydroxyethyl cellulose, methyl ether starch, poly (n-isopropyl acrylamide), poly N-vinyl caprolactam, polyvinyl methyl oxazolidone, polyvinyl methyl oxazolidimone, poly(2-isopropyl-2-oxazoline), poly(isopropyl oxazoline), and poly (2,4-dimethyl-6-triazinyl ethylene). The water-sensitive substrate layer of the present invention may be made entirely of water-sensitive polymeric material or may contain water-sensitive as well as water-insoluble materials so long as the film disperses in water, such as in the hydraulic flow of a conventional toilet. Additionally, the water-sensitive substrate may also be made by mixing various different types of water-sensitive film materials. In some embodiments, it may be desirable to employ one or more additives into the water-sensitive substrate layer material including, but not limited to, compatibilizers, processing aids, plasticizers, tackifiers, detackifiers, slip agents, and anti-microbial agents, as fabricating agents or as modifiers depending on the specific properties desired in the water-sensitive substrate and the final product.
Desirably, the water-sensitive substrate of the present invention comprises a polyalkylene oxide film or a polyvinyl alcohol film. More desirably, the water-sensitive substrate of the present invention comprises a polyethylene oxide film, an ethylene oxide-propylene oxide copolymer film, a polyvinyl alcohol film or a film derived from a polyvinyl alcohol copolymer. Most desirably, the water-sensitive substrate of the present invention comprises a polyethylene oxide film or a polyvinyl alcohol film. The thickness of the water-sensitive substrate may vary greatly depending upon the end use of the film-containing product. The thickness of the water-sensitive substrate should be minimized when possible to reduce product cost and to reduce the time necessary for the substrate to disperse, especially in the case of flushable products. Desirably, the water-sensitive substrate thickness will be as thin as possible, depending upon the product to be made. Preferably, the thickness will be from about 0.1 to 3.0 mil.
In the uncoated form, when the water-sensitive substrate contacts water on either surface, it disperses. In the ion-trigger coated form, when only the outer side of the water-sensitive substrate contacts water, the composite two-layer structure will not immediately disperse, due to the transient structural integrity of the ion-trigger coating. However, the composite two-layer composition is dispersible when both the ion-trigger coating and the water-sensitive substrate have been exposed to water for some time.
The coating of ion-trigger polymer provides the required barrier to ion containing body fluids, yet weakens and disperses in relatively low-ion containing toilet water. In the presence of an aqueous salt solution, such as urine, the ion-trigger polymer is relatively inert. Water from the salt solution can reach the substrate only by a slow process of diffusion through the coating. However, the ion-trigger polymer rapidly weakens in tap water. The process of water penetration in the coating will differ with the ion content of the aqueous solution.
The ion-trigger layer may be joined to the water-dispersible substrate by standard methods known to those of ordinary skill in the art. As mentioned, the ion-trigger layer itself can provide enough tack to join the water-sensitive substrate layer thereto. Other suitable methods of joining the layers include, but are not limited to, solvent-based coating and holt-melt coating. Suitable solvent-based coating techniques include, but are not limited to, spray coating and ink jet printing. Suitable hot-melt coating techniques include, but are not limited to, slot coating, screen coating, spray coating, swirl coating and gravure coating. Another suitable method includes a transfer coating procedure.
The preferred coating process is a hot-melt slot die process. Molten ion-trigger polymer is delivered from a melting tank through a heated hose to a slot die. The temperature of the melting tank, hose and slot die may vary depending upon the melt rheology of the ion-trigger in the coating process. The molten polymer is uniformly applied directly onto the water-sensitive film, or alternatively, onto a carrier substrate and subsequently transferred onto the water-sensitive film (transfer coating process). Line speeds may vary depending upon the xe2x80x9copen timexe2x80x9d of the ion-trigger. As used herein, the xe2x80x9copen timexe2x80x9d of a polymer refers to the amount of time required for the polymer to lose its tackiness.
The polyethylene oxide film is the most desirable film for a transfer coating procedure, while the polyvinyl alcohol film is the most desirable film for a direct coating procedure.
In a transfer coating process, the coated carrier substrate moves further through the process and comes into contact with the water-sensitive film, which is properly aligned with the coated carrier substrate. The coating is transferred from the carrier substrate to the water-sensitive film under pressure as the film and carrier substrate pass through a nip roll. In practice, optimum coating thickness is achieved by adjusting processing factors which include, but are not limited to, the coating temperature, the resin flow rate, line speed, and the pressure applied at the nip roll.
In the transfer coating process or in a direct contact coating process, such as screen printing, the adhesion of the ion-trigger coating to the water-sensitive film should be greater than the adhesion of the ion-trigger coating to the screen (direct coating) or the carrier substrate (transfer coating). The choice of ion-trigger should take into consideration the desired characteristics and properties of the ion-trigger. The ion-trigger should have good adhesion to the water-sensitive substrate.
Those skilled in the art will readily understand that the ion-trigger coated water-dispersible films of the present invention may be advantageously employed in the preparation of a wide variety of products designed to be contacted with aqueous fluids. Although the coated water-dispersible film of the present invention is particularly suited for personal care products, the coated water-dispersible film of the present invention may be advantageously employed in the preparation of a wide variety of consumer products other than personal care products.

Compositions of ion-trigger polymer coatings on water-sensitive polymer films


A rotating electric machine for direct connection to all types of high-voltage networks, in which the magnetic circuit adapted for high voltage comprises a rotor, stator and windings. The winding comprising a conductor surrounded by a solid insulation system. The invention also relates to a method for manufacturing the same.

The invention relates to a rotating electric machine comprising a magnetic circuit with a magnetic core and a winding. Such electric machines comprise synchronous machines which are mainly used as generators for connection to distribution and transmission networks; commonly referred to below as power networks. The synchronous machines are also used as motors and for phase compensation and voltage control, in that case as mechanically idling machines. The technical field also comprises double-fed machines, asynchronous machines, asynchronous converter cascades, outer pole machines and synchronous flux machines.
The magnetic circuit referred to in this context comprises a magnetic core of laminated, normal or oriented, sheet or other, for example amorphous or powder-based, material, or any other action for the purpose of allowing an alternating flux, a winding, a cooling system, etc., and may be located in either the stator or the rotor of the machine, or in both.
The invention also comprises a method for manufacturing a magnetic circuit for a rotating electric machine.
In order to explain and describe the machine, a brief description of a rotating electric machine will first be given, exemplified on the basis of a synchronous machine. The first part of the description substantially relates to the magnetic circuit of such a machine and how it is constructed according to classical technique. Since the magnetic circuit referred to in most cases is located in the stator, the magnetic circuit below will normally be described as a stator with a laminated core, the winding of which will be referred to as a stator winding, and the slots in the laminated core for the winding will be referred to as stator slots or simply slots.
Most synchronous machines have a field winding in the rotor, where the main flux is generated by de, and an ac winding which is in the stator. The synchronous machines are normally of three-phase design. Sometimes, the synchronous machines are designed with salient poles. The latter have an ac winding in the rotor.
The stator body for large synchronous machines are often made of sheet steel with a welded construction. The laminated core is normally made from varnished 0.35- or 0.5 mm electric sheet. For larger machines, the sheet is punched into segments which are attached to the stator body by means of wedges/dovetails. The laminated core is retained by pressure fingers and pressure plates.
For cooling of the windings of the synchronous machine, three different cooling systems are available.
In case of air cooling, both the stator winding and the rotor winding are cooled by cooling air flowing through. The cooling air ducts are to be found both in the stator laminations and in the rotor. For radial ventilation and cooling by means of air, the sheet iron core at least for medium-sized and large machines is divided into stacks with radial and axial ventilation ducts disposed in the core. The cooling air may consist of ambient air but at powers exceeding 1 MW, a closed cooling is substantially used.
Hydrogen cooling is normally used in turbogenerators up to about 400 MW and in large synchronous condensers. The cooling method functions in the same way as in air cooling with heat exchangers, but instead of air as coolant hydrogen gas is used. The hydrogen gas has better cooling capacity than air, but difficulties arise at seals and in monitoring leakage. For turbogenerators in the power range of 500-1000 MW, it is known to apply water cooling of both the stator winding and the rotor winding. The cooling ducts are in the form of tubes which are placed inside conductors in the stator winding.
One problem with large machines is that the cooling tends to become non-uniform and that, therefore, temperature differences arise across the machine
The stator winding is located in slots in the sheet iron core, the slots normally having a rectangular or a trapezoidal cross section. Each winding phase comprises a number of coil groups connected in series and each coil group comprises a number of coils connected in series. The different parts of the coil arc designated coil side for the part which is placed in the stator and end winding for that part which is located outside the stator. A coil comprises one or more conductors brought together in height and/or width.
Between each conductor there is a thin insulation, for example epoxy/glass fibre.
The coil is insulated from the slot with a coil insulation, that is, an insulation intended to withstand the rated voltage of the machine to earth. As insulating material, various plastic, varnish and glass fibre materials may be used. Usually, so-called mica tape is used, which is a mixture of mica and hard plastic, especially produced to provide resistance to partial discharges, which can rapidly break down the insulation. The insulation is applied to the coil by winding the mica tape around the coil in several layers. The insulation is impregnated, and then the coil side is painted with a graphite based paint to improve the contact with the surrounding stator which is connected to earth potential.
The conductor area of the windings is determined by the current intensity in question and by the cooling method used. The conductor and the coil are usually formed with a rectangular shape to maximize the amount of conductor material in the slot. A typical coil is formed of so-called Roebel bars, in which certain of the bars may be made hollow for a coolant. A Roebel bar comprises a plurality of rectangular, copper conductors connected in parallel, which are transposed 360. degrees along the slot. Ringland bars with transpositions of 540 degrees and other transpositions also occur. The transposition is made to avoid the occurrence of circulating currents which arc generated in a cross section of the conductor material, as viewed from the magnetic field.
For mechanical and electrical reasons, a machine cannot be made in just any size. The machine power is determined substantially by three factors. The conductor area of the windings. At normal operating temperature, copper, for example, has a maximum value of 33.5 A/mm2. The maximum flux density (magnetic flux) in the stator and rotor material. The maximum electric field strength in the insulating material, the so-called dielectric strength.
Polyphase ac windings are designed either as single-layer or two-layer windings. In the case of single-layer windings, there is only one coil side per slot, and in the case of two-layer windings there are two coil sides per slot. Two layer windings are usually designed as diamond windings, whereas the single-layer windings which are relevant in this connection may be designed as a diamond winding or as a concentric winding. In the case of a diamond winding, only one coil span (or possibly two coil spans) occurs, whereas flat windings are designed as concentric windings, that is, with a greatly varying coil span. By coil span is meant the distance in circular measure between two coil sides belonging to the same coil, either in relation to the relevant pole pitch or in the number of intermediate slot pitches. Usually, different variants of chording are used, for example short-pithing, to give the winding the desired properties.
The type of winding substantially describes how the coils in the slots, that is, the coil sides, are connected together outside the stator, that is, at the end windings.
Outside the stacked sheets of the stator, the coil is not provided with a painted semiconducting ground-potential layer. The end winding is normally provided with an E-field control in the form of so-called corona protection varnish intended to convert a radial field into an axial field, which means that the insulation on the end windings occurs at a high potential relative to earth. This sometimes gives rise to corona in the coil-end region, which may be destructive. The so-called field-controlling points at the end windings entail problems for a rotating electric machine.
Normally, all large machines are designed with a two-layer winding and equally large coils. Each coil is placed with one side in one of the layers and the other side in the other layer. This means that all the coils cross each other in the end winding. If more than two layers arc used, these crossings render the winding work difficult and deteriorate the end winding.
It is generally known that the connection of a synchronous machine/generator to a power network must be made via a IE/Dconnected so-called step-up transformer, since the voltage of the power network normally lies at a higher level than the voltage of the rotating electric machine. Together with the synchronous machine, this transformer thus constitutes integrated parts of a plant. The transformer constitutes an extra cost and also has the disadvantage that the total efficiency of the system is lowered. If it were possible to manufacture machines for considerably higher voltages, the step-up transformer could thus be omitted.
During the last few decades, there have been increasing requirements for rotating electric machines for higher voltages than for what has previously been possible to design. The maximum voltage level which, according to the state of the art, has been possible to achieve for synchronous machines with a good yield in the coil production is around 25-30 kV.
Certain attempts to a new approach as regards the design of synchronous machines are described, inter alia, in-an article entitled xe2x80x9cWater-and-oil-cooled Turbogenerator TVM300xe2x80x9d in J. Elektrotechnika, No. 1, 1970, pp. 6-8, in U.S. Pat. No. 4,429,244 xe2x80x9cStator of Generatorxe2x80x9d and in Russian patent document CCCP Patent 955369.
The water- and oil-cooled synchronous machine described in J. Elektrotechnika is intended for voltages up to 20 kV. The article describes a new insulation system consisting of oil/paper insulation, which makes it possible to immerse the stator completely in oil. The oil can then be used as a coolant while at the same time using it as insulation. To prevent oil in the stator from leaking out towards the rotor, a dielectric oil-separating ring is provided at the internal surface of the core. The stator winding is made from conductors with an oval hollow shape provided with oil and paper insulation. The coil sides with their insulation are secured to the slots made with rectangular cross section by means of wedges. As coolant, oil is used both in the hollow conductors and in holes in the stator walls. Such cooling systems, however, entail a large number of connections of both oil and electricit,r at the coil ends. The thick insulation also entails an increased radius of curvature of the conductors, which in turn results in an increased size of the winding overhang.
The above-mentioned US patent relates to the stator part of a synchronous machine which comprises a magnetic core of laminated sheet with trapezoidal slots for the stator winding. The slots are tapered since the need of insulation of the stator winding is less towards the rotor where that part of the winding which is located nearest the neutral point is located. In addition, the stator part comprises a dielectric oil-separating cylinder nearest the inner surface of the core. This part may increase the magnetization requirement relative to a machine without this ring. The stator winding is made of oil-immersed cables with the same diameter for each coil layer. The layers are separated from each other by means of spacers in the slots and secured by wedges. What is special for the winding is that it comprises two so-called half-windings connected in series. One of the two half-windings is located, centered, inside an insulating sleeve. The conductors of the stator winding are cooled by surrounding oil. Disadvantages with such a large quantity of oil in the system are the risk of leakage and the considerable amount of cleaning work which may result from a fault condition. Those parts of the insulating sleeve which are located outside the slots have a cylindrical part and a conical termination reinforced with current-carrying layers, the purpose of which is to control the electric field strength in the region where the cable enters the end winding.
From CCCP 955369 it is clear, in another attempt to raise the rated voltage of the synchronous machine, that the oil cooled stator winding comprises a conventional high-voltage cable with the same dimension for all the layers. The cable is placed in stator slots formed as circular, radially located openings corresponding to the cross-section area of the cable and the necessary space for fixing and for coolant. The different radially located layers of the winding are surrounded by and fixed in insulating tubes. Insulating spacers fix the tubes in the stator slot. Because of the oil cooling, an internal dielectric ring is also needed here for sealing the oil coolant off against the internal air gap. The disadvantages of oil in the system described above also apply to this design. The design also exhibits a very narrow radial waist between the different stator slots, which implies a large slot leakage flux which significantly influences the magnetization requirement of the machine.
A report from Electric Power Research Institute, EPRI, EL3391, from 1984 describes a review of machine concepts for achieving a higher voltage of a rotating electric machine for the purpose of being able to connect a machine to a power network without an intermediate transformer. Such a solution judging from the investigation to provide good efficiency gains and great economic advantages. The main reason for considering it in 1984 to start developing generators for direct connection to power networks was that at the time a superconducting rotor had been produced. The large magnetization capacity of the superconducting field makes it possible to use an air gap winding with a sufficient insulation thickness to withstand the electrical stresses. By combining the most promising concept, according to the project, of designing a magnetic circuit with a winding, a so-called monolith cylinder armature, a concept where the winding comprises two cylinders of conductors con-centrically enclosed in three cylindrical insulating casings and the whole structure being fixed to an iron core without teeth, it was judged that a rotating electric machine for high voltage could be directly connected to a power network. The solution meant that the main insulation had to be made sufficiently thick to cope with network-to-network and network-to-earth potentials. The insulation system which, after z review of all the technique known at the time, was judged to be necessary to manage an increase to a higher voltage was that which is normally used for power transformers and which consists of dielectric-fluid impregnated cellulose pressboard. Obvious disadvantages with the proposed solution are that, in addition to requiring a superconducting rotor, it requires a very thick insulation which increases the size of the machine. The end windings must be insulated and cooled with oil or f reons to control the large electric fields in the ends. The whole machine must be hermetically enclosed to prevent the liquid dielectric from absorbing moisture from the atmosphere.
During the decades around 1930 a few generators with high voltages up to 36 kV were built, in order to develop a generator for direct connection to power networks. One project was based on using conductors of concentric type, with three layers of conductors enclosed in insulation, where each layer was connected in series and the inner layer was at the highest potential. In another version the electrical conductors were made of twisted copper strips that were isolated with special layers of mica, varnish and paper.
When manufacturing rotating electric machines according to the state of the art, the winding is manufactured with conductors and insulation systems in several steps, whereby the winding must be preformed prior to mounting on the magnetic circuit. Impregnation for preparing the insulation system is performed after mounting of the winding on the magnetic circuit.
The object of the invention is to obtain a rotating electric machine with such a high voltage that the 0/Y-connected step-up transformer mentioned above can be omitted, that is, machines with a considerably higher voltage than machines according to the state of the art to be able to perform direct connection to power networks. This means considerably lower investment costs for systems with a rotating electric machine and the total efficiency of the system can be increased. The rotating electric machine can be connected to a power network with a minimum of connecting devices such as circuit breakers, disconnectors or the like. In a system with a rotating machine directly connected to a power network without an intermediate transformer the connection can be made using only one circuit breaker.
A rotating electric machine according to the invention entails a considerably reduced thermal stress on the stator. Temporary overloads of the machine thus become less critical and it will be possible to drive the machine at overload for a longer period of time without running the risk of damage arising. This means considerable advantages for owners of power generating plants who are forced presently, in case of operational disturbances, to rapidly switch to other equipment in order to ensure the delivery requirements laid down by law.
With a rotating electric machine according to the invention, the maintenance costs can be significantly reduced because transformers and circuit breakers do not have to be included in the system for connecting the machine to the power network.
It is another object of the invention to achieve a synchronous compensator which is directly connected to the power network.
It is an additional object of the invention to be able to manufacture a rotating electric machine for high voltage without any complicated performing of the winding and without having to impregnate the insulation system after mounting of the winding.
To increase the power of a rotating electric machine, it is known that the current in the ac coils should be increased. This has been achieved by optimizing the quantity of conducting material, that is, by close-packing of rectangular conductors in the rectangular rotor slots. The aim was to handle the increase in temperature resulting from this by increasing the quantity of insulating material and using more temperature-resistant and hence more expensive insulating materials. The high temperature and field load on the insulation has also caused problems with the life of the insulation. In the relatively thick-walled insulating layers which are used for high-voltage equipment, for example impregnated layers of mica tape, partial discharges, PD, constitute a serious problem. When manufacturing these insulating layers, cavities, pores, and the like, will easily arise, in which internal corona discharges arise when the insulation is subjected to high electric field strengths. These corona discharges gradually degrade the material and may lead to electric breakdown through the insulation.
The present invention is based on the realization that, an increase in power of a rotating electrical machine in a technically and economically justifiable way, is achieved by ensuring that the insulation is not broken down by the phenomena described above. This can be achieved according to the invention by using as insulation layers made in such a way that the risk of cavities and pores is minimal, for example extruded layers of a suitable solid insulating material, such as thermoplastic resins, crosslinked thermoplastic resins, rubber such as silicone rubber or EP rubber, etc. In addition, it is important that the insulating layer comprises an inner layer, surrounding the conductor, with semiconducting properties and that the insulation is also provided with at least one additional outer layer, surrounding the insulation, with semiconducting properties. The inner semiconducting layer shall function in such a way as to even the potential of the electric field outside the inner layer and the outer layer shall on one part function in such a way as to evening the potential by connecting it to a selected potential and on the other part by enclosing the electric field around the conductors within the outer layer. Semiconducting properties in this context is a material which has a considerably lower conductivity than an electric conductor but which does not have such a low conductivity that it is an insulator. For example, the inner and outer semiconducting layers may have a resistivity within the interval 10-6 f2cm-100 kg2cm. By using only insulating layers which may be manufactured with a minimum of defects and, in addition, providing the insulation with an inner and an outer semiconducting layer, it can be ensured that the thermal and electric loads are reduced. The insulating part and the semiconducting layers should adhere along essentially the whole of its contact surfaces. Further, the adjoining layers should have essentially the same coefficient of thermal expansion. At temperature gradients, defects caused by different temperature expansion in the insulation and the surrounding layers should not arise. The electric load on the material decreases as a consequence of the fact that the semiconducting layers around the insulation will constitute equipotential surfaces and that the electrical field in the insulating part will be distributed relatively evenly over the thickness of the insulation. The outer semiconducting layer may be connected to a chosen potential, for example earth potential. This means that, for such a cable, the outer casing of the winding in its entire length may be kept at, for example, earth potential. The outer layer may also be cut off at suitable locations along the length of the conductor and each cut-off partial length may be directly connected to a chosen potential. Around the outer semiconducting layer there may also be arranged other layers, casings and the like, such as a metal shield and a protective sheath.
Other knowledge gained in connection with the present invention is that increased voltage load leads to problems with electric (E) field concentrations at the corners at a cross section of a coil and that this entails large local loads on the insulation there. Likewise, the magnetic (B) field in the teeth of the stator will, in the case of increased current load, be concentrated at the comers. This means that magnetic saturation arises locally and that the magnetic core is not utilized in full and that the waveform of the generated voltage/current will be distorted. In addition, eddy-current losses caused by induced eddy currents in the conductors, which arise because of the geometry of the conductors in relation to the B field, will entail additional disadvantages in increasing current densities. A further improvement of the invention is achieved by making the coils and the slots in which the coils are placed essentially circular instead of rectangular. By making the cross section of the coils circular, these will be surrounded by a constant B field without concentrations where magnetic saturation may arise. Also the E field in the coil will be distributed evenly over the cross section and local loads on the insulation are considerably reduced. In addition, it is easier to place circular coils in slots in such a way that the number of coil sides per coil group may increase and an increase of the voltage may take place without the current in the conductors having to be increased. The reason for this being that the cooling of the conductors is facilitated by, on the one hapd, a lower current density and hence lower temperature gradients across the insulation and, on the other hand, by the circular shape of the slots which entails a more uniform temperature distribution over a cross section. Additional improvements may also be achieved by composing the conductor from smaller parts, so-called strands. The strands may be insulated from each other and only a small number of strands may be left uninsulated and in contact with the inner semiconducting layer, to ensure that this is at the same potential as the conductor.
An advantage a of using a rotating electric machine according to the invention is that the machine can be operated at overload for a considerably longer period of time than what is usual for such machines without being damaged. This is a consequence of the design of the machine and the limited thermal load of the insulation. It is, for example, possible to load the machine with up to 100% overload for a period exceeding 15 minutes and up to two hours.
As synchronous compensators there are used, inter alia, synchronous motors without a connected mechanical load. By adapting the magnetization, the synchronous condenser may give either inductive or capacitive kVA. When the compensator is connected to a power network, it may compensate for inductive or capacitive load on the network within an interval. Since the synchronous compensator must be connected to certain power networks with voltages exceeding about 20 kV via a transformer, the range of the synchronous compensator within which it may provide the network with reactive power is influenced by the fact that the reactance of the transformer limits the angle of lag between current and voltage. With a rotating electric machine according to the invention, it is possible to design a synchronous compensator which may be connected to a power network without an intermediate transformer and which may be operated with a chosen under- or over-excitation to compensate for inductive or capacitive loads on the network.
The rotating electric machine according to the invention can be connected to one or more system voltage levels. This is possible due to that the electric field outside the machine can be kept at a minimum.
The connection to different system voltage levels, can be provided by having separate tappings on one winding or by having a separate winding for the connections to different system voltage levels or by combinations of these arrangements.
One embodiment according to the invention is that the magnetic circuit of the rotating electric machine comprises a winding of a threaded cable with one or more extruded insulated conductors with solid insulation with a semiconducting layer both at the conductor and the casing. The outer semiconducting layer may be connected to ground potential. To be able to cope with the problems which arise in case of direct connection of rotating electric machines to all types of high-voltage power networks, a machine according to the invention has a number of features which distinguish it from the state of the art.
As described above, a winding for a rotating electric machine may be manufactured from a cable with one or more extruded insulated conductors with a semiconducting layer both at the conductor and at the casing. Some typical examples are thermoplastic resins or crosslinked thermo plastic resins such as for example XLPE cable or a cable with insulation of rubber such as silicorie rubber or EP rubber, conductor may be composed of strands. It is possible to insulate the strands with respect to each other in order thus to reduce the amount of eddy current losses in the conductor. One or a few strands shall be left uninsulated to ensure that the semiconducting layer which surrounds the conductor is at the same potential as the conductor.
It is known that a high-voltage cable for transmission of electric energy is composed of conductors with solid insulation with an inner and an outer semiconductor part. In the process of transmitting electric energy it is required that the insulation should be free from defects. When using high-voltage cables for transmission of electric energy, the aim was been to maximize the current through the cable since space is no limitation for a transmission cable. Insulation of a conductor for a rotating electric machine may be applied in some other way than by means of extrusion, for example by spraying, figure moulding, compression moulding, injection moulding or the like. It is important, however, that the insulation should have no defects through the whole cross section and should possess similar thermal properties. The semiconducting layers may be supplied with the insulation in connection with the insulation being applied to the conductors. The semiconducting layers may be composed of a polymer comprising an electrically conductive element.
Preferably, cables with a circular cross section are used. Among other things, to obtain a better packing density, cables with a different cross section may be used. To build up a voltage in the rotating electric machine, the cable is arranged in several consecutive turns in slots in the magnetic core. The winding can be designed as a multi-layer concentric cable winding to reduce the number of end winding crossings. The cable may be made with tapered insulation to utilize the magnetic core in a better way, in which case the shape of the slots may be adapted to the tapered insulation of the winding.
A significant advantage of a rotating electrical machine according to the invention is that the E field is near zero in the end winding region outside the outer semiconductor and that with the outer casing at earth potential, the electric field need not be controlled. This means that no field concentrations can be obtained, neither within sheets, in end winding regions or in the transition in between.
The present invention also relates to a method for manufacturing the magnetic circuit and, in particular, the winding. The method for manufacturing comprises placing the winding in the slots by threading a cable into the openings in the slots in the magnetic core. Since the cable is flexible, it"" can be bent and this permits a cable length to be located in several turns in a coil. The end windings will then consist of bending zones in the cables. The cable may also be joined in such a way that its properties remain constant over the cable length. This method entails considerable simplifications compared with the state of the art. The so called Rocbel bars are not flexible but must be preformed into the desired shape. Impregnation of the coils is also an exceedingly complicated and expensive technique when manufacturing rotating electric machines today.
To sum up, thus, a rotating electric machine according to the invention means a considerable number of important advantages in relation to corresponding prior art machines. Firstly, it can be connected directly to a power network at all types of high voltage. High voltage in this respect voltages exceeding 10 kV and up to the voltage levels which occur for power networks. Another important advantage is that a chosen potential, for example earth potential, is consistently conducted along the whole winding, which means that the end winding region can be made compact and that support means at the end winding region can be applied at practically ground potential or any other chosen potential. Still another important advantage is that oil-based insulation and cooling systems disappear. This means that no sealing problems may arise and that the dielectric ring previously mentioned is not needed. One advantage is also that all forced cooling can be made at earth potential. A considerable space and weight saving from the installation point of view is obtained with a rotating electric machine according to the invention, since it replaces a previous installation design with both a machine and a step-up transformer. The invention requires no superconducting rotor with the problems associated therewith, such as maintaining the temperature, encapsulation, and the like. Since a step-up transformer can be avoided, the efficiency of the system is considerably increased.

Rotating electric machines with magnetic circuit for high voltage and method for manufacturing the same


A combined integrated apparatus for providing illumination and water that consists of a structural support that contains one pipe for transferring water and one pipe for conducting electricity. A light emitting device and a water-emitting nozzle are coupled to the structural support, and the apparatus is powered using electric and hydraulic energy.

1. Field of the Invention
The present invention relates to a combined system or apparatus for providing illumination and water.
2. Prior Art
The features of this invention arise out of daily observations of different problems that arise when the two systems (lighting systems and watering systems) are applied independently of one another. That is, when a lighting system is installed with the intention of illuminating a defined area, and it is later desired to install a watering system in the same area, or vice versa. Upon installation of the watering system in this scenario, the desired area must be dug up to install additional pipesxe2x80x94water pipes. Often the electrical pipes that were laid (typically subterranean) during installation of the lighting system are encountered during digging, posing an obstacle to the installation of the watering system.
Further, the laying of additional water pipes decreases the amount of land available for planting trees, plants, flowers, etc. This problem is further compounded when, in those parks and gardens possessing a variety of plants and bushes of different heights and which are relatively close together, it is necessary to increase the amount of water piping in order to increase the number of water-emitting nozzles provided. In addition, plants and bushes may pose an obstacle to watering in areas where the heights of plants and bushes are relatively high and the water-emitting nozzles may not clear the height of the plants and bushes.
The apparatus of the present invention comprises a combined system that includes a lighting system integrated with a watering system utilizing electric and hydraulic energy. The principal aim of the invention is generally directed towards public or private open areas such as parks, gardens, stadiums, plazas, greenhouses, buildings, homes, etc. The object of the invention is to unify and integrate two existing systems applicable to open areas, lighting systems and watering systems, in a novel and unique way, such that the utilization of these two systems is unified into one system.
Because in many cases a light is located near a water nozzle, one object of the invention is to integrate these two elements to avoid redundancy. This solution also creates the benefit of decreasing maintenance of the water nozzles (sprinklers, diffusers, fire sprinklers, etc.) because these fittings and fixtures can be adjusted at different heights to avoid obstacles, can be protected more easily, such as by a casing, and can be located such to avoid destruction and deterioration.
Another benefit is that the water nozzles, which are located and integrated with a light, can also serve to clean paths, rest areas, sidewalks, etc. using plain water or by adding a cleaning or disinfecting agent to the water being fed to the nozzles. In this case, the cleaning or disinfecting agent emitted would originate at a common cistern and be mixed at the apparatus of the invention or at the system providing electric or hydraulic energy to the apparatus of the invention.
Yet other benefits are the ability to regulate the temperature of the open areas, the ability to water dirt roads to quiet the surface, and the ability to combat fires in open or closed areas.
Yet another benefit includes the ability to control insects by using the apparatus of the invention as a fumigation device. In this case, the insecticide or insect repellant agent emitted would originate at a common cistern and be mixed at the apparatus of the invention or at the system providing electric or hydraulic energy to the apparatus of the invention with the purpose of decreasing the size of the infested area.
The apparatus of the present invention can be used in the agricultural industry, such as, by locating within homes, complexes or greenhouses to maintain and foster fruits, vegetables, flowers, etc. Alternatively, the apparatus of the present invention can be used in corrals or animal stables for illumination, cleaning or disinfecting. The apparatus of the present invention can also be used for aesthetic or public purposes.
Due to multiple uses of the apparatus of the present invention, as described above, additional components, such as manual or automatic controls, can be added to or integrated into the apparatus. These additional components can be barometers, photocells, microprocessors, motion sensors, etc. As an example, a system of the present invention can: A) automatically cease emitting water when the moisture level of the ground reaches a predetermined value due to a sensor that is coupled to a controller that controls the feeding of the water, B) more precisely control the reach or area being sprayed to coordinate an array of water nozzles with the water emitted by each to eliminate overlap and hence wasted water, C) emit different products via different water nozzles for the purposes noted above or others, D) provide fertilizer from remote parts of the system to the water nozzles, E) allow the automatic cessation of water emission at a given time either on a time basis or under the control of a controller and microprocessor responsive to a sensor, F) prevent the emission of water until a given time, etc.
The apparatus of the present invention can be structured and its elements combined in a variety of ways. For example, the main structure of the apparatus can be 1) a single, central structure, 2) expandable linearly as in a mesh form, 3) formed at the same time as the cable orifices, 4) formed of concrete for instances where the subterranean installation is impossible, such as areas having a large quantity of above-ground roots or agricultural areas, and 5) the water pipes and electric conduits can be installed above ground by suspending on suitable structural supports.
In an embodiment of the apparatus of the present invention, the apparatus can be used for fighting domestic, industrial or commercial fires by locating the apparatus near the ceiling and securing the apparatus to the ceiling, a column or the like. The apparatus shall be easily and simply mounted and dismounted in comparison with conventional installations of fire sprinklers or any other system to which the apparatus applies.
The following functions describe the apparatus of the present invention and any embodiment of the apparatus may manifest all or any combination of these functions:
1) the apparatus provides support and encases the water nozzle and the system utilizing electric and hydraulic energy
2) the apparatus may be formed of one piece
3) the interior and the exterior of the structure of the apparatus conduct electrical and hydraulic energy
4) the apparatus can be above or below ground
5) the apparatus can be attached to walls, roofs, etc.
6) the apparatus can be located indoors or outdoors
7) the apparatus integrates the lighting system and the watering system, wherein one system may be within another, or both systems housed within a common element or both systems housed within a third element
8) the apparatus is compatible with conventional lighting and watering systems
9) the apparatus operates effectively and precisely
The elements of the present invention comprise a structural support which includes, contains or supports the following elements: a light, a watering system or water nozzle, whether a sprinkler or a diffuser, a system for conducting electricity and water, which can be constructed of pipes, tubular bodies or laminates and controls for the same, whether barometers, photocells, microprocessors, water nozzles, etc.
The following advantages over the prior art are described. First, upon installation, the present invention reduces the total length of the trenches that must be dug to install water and electrical pipes and the amount of manual labor consumed. Second, in order to overcome a watering obstacle in the terrain, the height of the water-emitting nozzle can be adjusted to the same height as the light-emitting device, which can be 4.00 meters or more. The most common height of a light-emitting device is 2.40 meters. Third, maintenance of sprinkler nozzles due to footsteps or collisions with external objects is decreased since the nozzle is located at an increased height. Fourth, the effectiveness of the watering process is guaranteed without depending on the height of the grass.
In the manner described, the present invention will satisfy the illumination, watering and fertilizing needs of public and private open and closed areas using a unified system provided in one installation.
The foregoing objects of the invention are achieved by providing an apparatus for providing illumination and water that comprises a structural support, at least one pipe for transferring water, at least one pipe for conducting electricity, a light emitting device and
a water-emitting nozzle, wherein the apparatus is powered using electric and hydraulic energy. In the apparatus described, the structural support substantially encases the at least one pipe for conducting electricity and wherein the at least one pipe for conducting electricity is coupled to the exterior of the apparatus. Further, in the apparatus the structural support can substantially encase the at least one pipe for conducting electricity and wherein the at least one pipe for conducting electricity forms one piece with the apparatus.
In the apparatus, the at least one pipe for conducting electricity and the at least one pipe for conducting waterpower the apparatus can use electric and hydraulic energy. The structural support can substantially encase the light-emitting device and the water-emitting nozzle. Further, the structural support can substantially encase the light-emitting device and the light-emitting device substantially encases the water-emitting nozzle. Also, the water-emitting nozzle can be any one of a spray nozzle, a fire sprinkler, a fumigation nozzle and a nozzle that emits plain water or plain water with another liquid.
The apparatus can be configured so that the height of the structural support is independent of the height of the water-emitting nozzle and the light-emitting device. Further, the light-emitting device can be located in any one of the lowest region of the structural support, the middle region of the structural support, the highest region of the structural support and within the structural support.
The apparatus can be configured so that the water-emitting nozzle is located in any one of the lowest region of the structural support, the middle region of the structural support, the highest region of the structural support and within the structural support.
The apparatus of the invention may further comprises a lock for regulating opening of the apparatus, more than one water-emitting nozzle, more than one light-emitting device, an automation device, a solenoid, a sensor, a mixer, a dose regulator, a sound-emitting device, a water heating element, a laser light-emitting device, a fiber optic light-emitting device, a control module utilizing satellite radio frequencies, a control module utilizing high frequencies, a barometer, a transmitter, a receiver, a cistern and/or a water storage device. Further, the water-emitting device can located above or below ground and the light-emitting device can be located above or at ground.

Combined system for illumination and watering

Calle 27 Na1570 La Plata, Codigo Postal (1900)