FIELD OF INVENTION 
       [0001]    This invention is generally directed to metal parts quenching medium recycling apparatus. More specifically, the quenching medium recycling apparatus is to use the heat released from the quenching cooling process to evaporate the spray rinsing water in the quenching medium, in order to recover and recycle the quenching medium. 
       BACKGROUND OF THE INVENTION 
       [0002]    In the quenching process for shovel or other hardware that involve large amount of continuous operation, spray rising water and leaching/drip washing water converge into liquid storage tank. Over time, the concentration of quenching medium, as well as the liquid volume increase in the storage tank. In general, there are three temperature levels of liquid storage to recover the quenching medium by using temperature differential method. When the quenching medium concentration reaches a critical level, the medium will be crystallized in the bottom of storage tank. Because of the temperature difference among the levels in the liquid storage tank, medium crystals dominantly appear in in the third level of the tank that has the lowest temperature. To recover the medium crystal, the common practice is to take out the crystal from the tank manually, then dry the crystal out, in order to recycle the crystal. The disadvantage of this existing method is, first of all, large area is necessary for drying the medium crystal, and secondly, not only this manual taking out and drying process wastes human labor, also, it can be significantly interrupted by the influence of the natural environment such as unfavorable weather, limitation of space, and additionally, is can cause secondary pollution. 
         [0003]    The temperature of the quenching medium increases along with the continuous process of production, and cooling procedure is necessary to ensure the quenching quality. The existing technique involves installing water-cooling pipe to cool down the quenching medium in the quenching tank. The disadvantages of this existing technique are: first of all, water wasting, and secondly, pipeline blockage by scale deposition, which needs to be regularly maintained and repaired to ensure the quenching quality. 
       SUMMARY OF THE INVENTION 
       [0004]    This present invention is directed to a new a quenching medium recycling device for hardware. Contrary to the disadvantage of the existing techniques, the present invention provides a quenching medium recycling device with a novel structure that occupies small operating area, eliminates the water cooling process, abandons the manual work in taking out and drying the quenching medium crystal, has no secondary pollution, cools quenching medium and evaporates spraying and rinsing water at the same time, and recovers and recycles the quenching medium directly and automatically. 
         [0005]    Following technical strategy is applied to achieve the goal of invention: metal parts quenching medium recycling apparatus. This device is composed of a heating furnace, a spray rinsing chamber, an immersion cleaning tank and a washing chamber, a liquid storage tank that is used to collect the liquid from the spray rising chamber, from the immersion cleaning tank, and from the drip washing chamber, a circulation pump in the liquid storage tank. At one side of a thermal insulated door a liquid transportation pipeline is connected with the circulation pump in the liquid storage tank; at another side of the thermal insulated door, a pipeline that transports the spray rinsing water is connected with the spray rinsing chamber. It featured that the device includes a quenching tank and a molten and mixing tank with novel function. The molten and mixing tank is positioned above the quenching tank, and the molten and mixing tank is covered with a splash guard cover, and along the two edges of the molten and mixing tank with splash guard plates. The splash guard cover and the splash guard plates are overlapped. A spray rinsing water by-pass connects the molten and mixing tank through the spray rinsing water pipeline. A electromagnetic valve in the spray rinsing water by-pass is installed to connect a temperature controller, and the temperature controller is connected with the quenching tank: the quenching medium flows into the molten and mixing tank driven by the medium circulation pump in the quenching tank through the quenching medium transportation pipeline, the medium flows away the molten and mixing tank to quenching tank through the medium back flow pipeline. The medium transportation pipeline, the medium backflow pipeline, the molten and mixing, and the quenching tanks are looped, and serve the medium recover and recycle. 
         [0006]    Appling the above technical strategy, the present invention is different from the existing techniques. In the present invention, the quenching medium is automatically recovered and recycled from the molten and mixing tank, which is used to replace the existing method of taking out the crystal from the three temperature level storage tank, followed by drying out the crystal. The present invention not only has the advantage of small occupied area, also uses the definite amount of spray rinsing water mixing with the high temperature quenching medium (about 340° C.) in the molten and mixing tank, and after the evaporation of the spray rinsing water, the quenching medium directly merge into the medium circulation and flow back to the quenching tank, the quenching medium can therefore be recycled and reused. At the same time, the quenching medium is cooled down, the stable quenching quality can be ensured and the workload for recycling the quenching medium is minimized. Furthermore, the recovering and recycling of the medium are processed automatically in the molten and mixing tank under an enclosed structure, which provides a safe and harmless environment to the operator. In addition, no loss of the quenching medium ensures that the present device is environmental friendly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a schematic and work flow diagram of an embodiment of the metal parts quenching medium recycling apparatus of the present invention. 
           [0008]      FIG. 2  is a cross-sectional view of the structure of an embodiment of a_molten and mixing tank of the present invention. 
       
    
    
       [0009]    Elements in the figures are represented by the numbers as follows;  1 —heating furnace,  2 —burners,  3 —thermal insulation door,  4 —spray rinsing water transportation pipeline,  5 —temperature controller,  6 —quenching medium backflow  7 —electromagnetic valve,  8 —molten and mixing tank,  9 —by-pass,  10 —quenching medium delivery pipeline,  11 —medium circulation pump,  12 —automatic product delivery chain,  13 —tap water pipeline,  14 —rinsing chamber,  15 —immersion cleaning tank,  16 —spray washing chamber,  17 —liquid storage tank,  18 —quenching chamber,  19 —thermocouples,  20 —circulation pump,  21 —liquid deliver pipeline,  22 —stand,  23 —splash guard cover,  24 —splash guard plate. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0010]    The detailed information of present invention is further described below based on the figures. 
         [0011]    The present invention is metal parts quenching medium recycling apparatus. The preferred embodiments will apply in the production of shovels or other hardware that suits for continuous operation and requires abundant quenching. The design idea is: in order to reduce environmental pollution and medium loss during the metal quenching process, designing a novel functional molten and mixing tank  8 , where the spray rinsing water is evaporated by using the heat generated from cooling the quenching medium. The preferred embodiment includes the following steps: transporting the quenching medium in the quenching tank  18  to the molten and mixing tank  8  by using the medium circulation pump  11  and medium delivery pipeline  10 ; the electromagnetic valve  7  in spray rinsing water by-pass  9  is turn on based on the signal from temperature controller  5 , a definite amount of spray rinsing water flow into the molten and mixing tank  8  through spray rinsing by-pass  9 , the inflow water merges with the quenching medium through the tile-shaped splash guard cover  23 . The high temperature (around 340° C.) of the quenching medium causes water to evaporate, the remaining quenching medium is melted, and transported back to quenching chamber  18  through quenching medium backflow pipeline  6 . The medium circulation pump  11  forces the quenching medium in the quenching chamber  18  to circulate in the loop between quenching chamber  18  and molten and mixing tank  8 , the medium is therefore recycled. 
         [0012]    As shown in  FIGS. 1 and 2 , the whole device in metal products quenching includes a heating furnace  1 ; a spray washing chamber  16 ; a immersion cleaning tank  15  and a rinsing chamber  14 ; a liquid storage tank  17  is used to collect the liquid from the spray washing chamber  16 , from the immersion cleaning tank  15 , and from the rinsing chamber  14 ; a molten and mixing tank  8 ; and a quenching chamber  18 . There is a circulation pump  20  in the liquid storage tank  17 . There are multiple burners  2  in heating furnace  1 . At one side of a thermal insulation door  3 , a liquid transportation pipeline  21  is connected with the circulation pump  20  in the liquid storage tank  17 ; at another side of the thermal insulation door  3 , a pipeline  4  that transports the spray rinsing water is connected with the spray washing chamber  16 . The molten and mixing tank  8  is localized above the quenching tank  18 , and the molten and mixing tank  8  is covered with a splash guard cover  23 , and splash guard cover  23  is supported by a stand  22 . Along the two edges of the molten and mixing tank  8 , splash guard plate  24  covers the tank. The splash guard cover  23  and the splash guard plates  24  are overlapped. A spray rinsing water by-pass  9  from the spray rinsing water transportation pipeline  4  connects and inserts into the upper part of the molten and mixing tank  8 . An electromagnetic valve  7  is installed in the spray rinsing water by-pass  9  and connected with a temperature controller  5  to control the inflow of the spray rinsing water. The temperature controller  5  is connected with thermoelectric couple  19  in the quenching chamber  18 . When the temperature in the quenching chamber  18  is higher than a preset limit, the temperature controller  5  catches the signal and turns on the electromagnetic valve  7  automatically. The spray rinsing water by-pass  9  delivers the water to molten and mix tank  8 , and mixes with the medium there after passing the tile shaped splash guard cover  23 . The quenching medium flows into the molten and mixing tank  8  driven by the medium circulation pump  20  in the quenching tank  18  through the quenching medium transportation pipeline  6 , the medium flows away from the molten and mixing tank  8  to quenching chamber  18  through the quenching medium backflow pipeline  6 . The medium backflow pipeline  6 , the medium delivery pipeline  10 , the molten and mixing tank  8 , and the quenching chamber  18  compose the medium circulation loop. 
         [0013]    The spray rinsing water transportation pipeline  4  connects with the spray washing chamber  16 . 
         [0014]    The detailed procedure of the present invention: 
         [0015]    In the preferred embodiment, shovel is used as an example to illustrate the procedure. As shown in  FIG. 1 , automatic product delivery chain  12  hanging above the quenching chamber  18 , the spray washing chamber  16 , the immersion cleaning tank  15  and the rinsing chamber  14 . A passage is built above the spray washing chamber  16  and rinsing chamber  14  to facilitate the moving of the automatic delivery chain  12 . Shovels are hanged horizontally on the automatic delivery chain  12 , and sent to the quenching chamber  18  which is filled with nitrate as quenching medium. The shovels are isothermally quenched at the quenching chamber  18  by using nitrate. The used nitrate in the quenching chamber  18  is pumped to the molten and mixing tank  8  by medium circulation pump  11  through medium delivery pipeline  10 , When the temperature in the quenching chamber  18  is higher than a preset limit, the temperature controller  5  catches the signal and turns on the electromagnetic valve  7 , the definite amount of spray and rising water transportation by-pass  9  deliver the water to molten and mixing tank  8 , the water cool down the quenching medium as well as the molten and mixing tank  8 , and the influx water compensates the liquid loss in the molten and mixing tank  8 . 
         [0016]    Level 1 wash: quenched shovels are then under level 1 water wash. The water heated in the thermal insulation door  3  is transported to the sprayers in the spray washing chamber  16  through water transportation pipeline  4 . The shovels are under the level 1 melt spray cleaning: the hot water sprayed on the surface of the shovels, the nitrate on the surface of the shovels is quickly dissolved in the water, and the shovels are cleaned instantly. The washing water after cleaning is collected to liquid storage tank  17  through the collecting tube on the bottom of the spray washing chamber  16 . 
         [0017]    Level 2 wash: the washed shovels at spray rinsing chamber  16  are then transported by the automatic deliver chain to immersion cleaning tank  15  and are under level 2 wash. The immersion cleaning tank  15  is filled with used rinsing water, and the shovels are soaked and cleaned in the immersion cleaning tank  15  for about 3 minutes, and the surface of the shovels is washed with fresh water to dilute the coated nitrate. Then the automatic delivery chain  12  lifts the shovels up and brings the shovels to water rinsing chamber  14  for level 3 wash. 
         [0018]    Level 3 wash: the sprayers in the rinsing chamber  14  wash the shovels finally with vaporific water. The source of the spray water comes from tap water and the spray water flows to the reverse direction to the shovels&#39; moving direction. Because the rinsing chamber  14  is higher than the immersion washing tank  15 , the used spray water flow from the bottom of rinsing chamber  14  to the immersion washing tank  15 , the outflow from the immersion washing tank  15  flow to the spray washing chamber  16 , and then flew to the liquid storage tank  17  through used water collecting pipe. 
         [0019]    The liquid in the liquid storage tank  17  is pumped by the liquid circulation pump  20  to the thermal insulated door  3 , then to the molten and mixing tank  8  and spray rinsing chamber  16  through spray water transportation pipeline  4 , and then the liquid storage tank  17 . The circulation loop started from the storage tank, and the water back to storage tank  17  driven by the pump, make the water circulation and recycle. 
         [0020]    All the facilities and equipment are produced and arranged based on design requirements; the specification is matched with the design. 
         [0021]    Although shovels are exampled as the preferred embodiments, the present invention is not claimed to protect shovels only. Any modified and polished, or changed design by any people in this field based on present design idea should be protected under the present invention.
This invention is generally directed to a new metal parts quenching medium recycling apparatus. This device is composed of a heating furnace, a spray rinsing chamber, an immersion cleaning tank, a washing chamber, a liquid storage tank, a quenching chamber and a molten and mixing tank, in present invention, the recovering and recycling of quenching medium is carried out automatically in the molten and mixing tank, providing a minimized workload and safely procedure to recover and recycle the quenching medium. This procedure eliminates both the loss of the quenching medium, and the related environmental pollution.