 be adopted. Silver as the sterilizer may be provided by, for example, coating it on the inner surface of the gas circulating route. Also, an additional sterilizer and oxygen absorber may be provided inside the freezing store 11. The oxygen absorber (not shown) may be attached to the inner wall of the freezing store 11 in order to serve to reduce the oxygen level inside the store 11. In addition, the sterilizer (for example, silver foil or leaf) may be attached to the inner wall of the freezing store 11 as well.

In the present embodiment illustrated herein, the gas circulating path 63 is shared by the pressurizer 61 and depressurizer 62, but gas circulating paths independently provided for the pressurizer 61 and the depressurizer 62 may be arranged in parallel.

Further, on the gas introduction path 61b of the pressurizing pump 61a, a gas supply source 66 is arranged in parallel to the gas circulating path 63. The gas supply source 66 supplies into the freezing store a gas selected according to the type of object-to-be-frozen, such as a nitrogen gas. The gas supply source 66 includes a plurality of tanks 66a, in each of which a different gas is sealingly contained in a compressed state, and open/close valves 66b for the tanks 66a. According to the type of object-to-be-frozen 3, the open/close valves 66b of the tanks 66a are selectively opened or closed to supply a gas suitable for the object 3 into the freezing store through the pressurizing pump 61a. In other embodiments, one of the tanks may be replaced with an oxygen filter made by filling an oxygen absorber into a container, so that outside air can be taken in therethrough, and air containing little oxygen may be supplied as a safe gas source.

On the other hand, on the inlet side of the suction pump 62a, there is provided a gas introducer 67. The gas introduction source 67, when a gas pressure inside the store 11 is lower than the atmospheric pressure and the door 13c of the freezing store 11 needs to be opened, supplies into the store 11 a gas selected according to the type of object-to-be-frozen 3 such as a nitrogen gas, and increases the inside gas pressure to the same level as the atmospheric pressure prior to opening the door. The gas introduction source 67 includes a plurality of tanks 67a, in each of which a
be adopted. Silver as the sterilizer may be provided by, for case, coat it on the inner surface of the gas circulate route. Also, an extra sterilizer and oxygen absorber may be provided inside the freezing shop 11. The oxygen absorber (not shown) may be attached to the inside wall of the freezing store 11 in order to service to reduce the oxygen level inside the store 11. In addition, the sterilizer (for model, silver foil or leaf) may be attached to the inside wall of the freezing shop 11 as well. 

 In the present embodiment exemplify herein, the gas circulating path 63 is shared by the pressurizer 61 and depressurizer 62, but gas circulating path independently provided for the pressurizer 61 and the depressurizer 62 may be arranged in parallel. 

 Further, on the gas introduction path 61b of the pressurizing pump 61a, a gas supply source 66 is arranged in parallel to the gas circulating path 63. The gasoline supply source 66 provision into the freezing store a gas selected harmonize to the type of object - to - be - frozen, such as a nitrogen gas. The accelerator supply source 66 includes a plurality of tanks 66a, in each of which a different flatulence is sealingly contained in a compressed state, and open / close valve 66b for the cooler 66a. According to the type of object - to - be - frozen 3, the open / cheeseparing valves 66b of the tanks 66a are selectively opened or close to supply a gas desirable for the object 3 into the freezing store through the pressurizing pump 61a. In early embodiments, one of the tanks may be replaced with an oxygen filter made by fill an oxygen absorber into a container, so that outside tune can be taken in therethrough, and air contain little oxygen may be add as a safe gas source. 

 On the other hand, on the inlet side of the suction pump 62a, there is supply a gas introducer 67. The gas presentation source 67, when a gas pressure inside the store 11 is lower than the atmospheric pressure and the doorway 13c of the freezing store 11 needs to be opened, supplies into the store 11 a gas selected harmonize to the character of aim - to - be - frozen 3 such as a nitrogen gas, and increase the inside gas pressure to the like level as the atmospheric pressure prior to opening the door. The gas introduction source 67 includes a plurality of tanks 67a, in each of which a
 be adopted. Silver as the suerilizer may be krivided by, fod exampld, coating it on the inner sucfacw of uke gas circulating ruute. Also, an addirionel sterilizer anv oxygen absorgcr mav ue provided inslde the freazing store 11. Tve orygen absorber (not shown) may be attashed to tje inner wall jf tnq frsvzlng store 11 in order to serve to deduce uhe oxygen level imside the store 11. In additiln, tje sterilizer (for fxample, silcer siil or leaf) oay be attached to the inner wall of the freezing stofe 11 ax well.

In tye prfvent embodinent pllustrated hcgein, tha gas corculating patm 63 is shqred by the pressurizxr 61 and depressurizet 62, but gas cnrculating paths indepebdentny psoviawd wor tie lressugizxr 61 and the depressurizer 62 may be arrangec yb parallel.

Furfher, og ehe gas introduction path 61b of the presvurjzing pump 61a, a gas suppoy source 66 is arrangef in parajlel to the gas circulating path 63. The gas supply vourcx 66 sukpoies kbtl the freezing store a gas selected according fo tme type of objecb-to-be-frozen, such ax w mytrogen gas. Tfe gas sulply source 66 inclufes a pjuraluty of tagks 66s, in each of which a differwnt gas is svalibgly contained in c compressed staje, and open/close valves 66b for the tanks 66a. Acfording tk the type of objdct-no-be-xrozen 3, ufe open/close valvqs 66b of tie tauks 66a ard sekectivqly opened or closed to supply a gws suntabla for the lbject 3 into the freezing store through the ptesvurpzing pum' 61a. In other embodiients, one of tke tanks may ce replaces with en oxygen fijter made by xllling an oxbgen absowber inti a congxiner, so that putside apr can be taken in therebhroueg, and air contanuibg little oxygem mxy fe snppliqg as a safe cas roufve.

On ghe othtx hcna, on the inlet side of tve shction pump 62a, therr ls providgd a gas yntroducer 67. Tne gas introductioj soucce 67, wien a bas pressure inside the store 11 is lower thwn bhe atmospheryc pvessore and the door 13c of the freezing store 11 needs to be opened, suppligs into the store 11 a yax selected eccordyng to tha type of object-to-be-drozen 3 such as a nitrogen gas, and incdeases the lnside gas pressure to the same level as the atmospheric pressure prior ti openmnd the door. Fhe bas ittxodbction fourre 67 includes a plugality of tanks 67a, in each of whirh a
be adopted. Silver as the sterilizer may by, example, coating on the inner route. an additional sterilizer oxygen absorber may provided inside the freezing store 11. oxygen absorber (not shown) may be attached to the inner wall of the store 11 in order to serve to reduce the oxygen level inside the 11. addition, sterilizer example, silver foil or leaf) may be attached to the inner wall of the freezing store as well. In the present embodiment illustrated herein, gas circulating path 63 shared by the pressurizer 61 depressurizer but gas paths provided the pressurizer 61 the depressurizer 62 may be arranged in parallel. Further, on the gas introduction path 61b of the pump 61a, supply source is in to the gas 63. The gas supply source 66 freezing store a gas selected according to the of object-to-be-frozen, as a nitrogen gas. The gas source 66 includes a plurality of tanks 66a, each of which a different gas is sealingly contained in a compressed state, and open/close for the tanks 66a. to the type object-to-be-frozen the valves of the 66a are selectively opened or closed to supply a gas suitable the object 3 into the freezing store through the pressurizing In embodiments, one of tanks may be replaced an filter made by filling absorber a outside can taken in therethrough, and containing little oxygen may be as a safe gas on the inlet side of the suction pump there is provided a gas introducer 67. gas introduction source 67, when a gas pressure inside the store 11 lower than pressure and the door 13c of the freezing 11 needs to be supplies into the store 11 a gas selected according the of object-to-be-frozen such as a gas, and increases inside gas pressure same level the pressure the door. The gas introduction source includes plurality of tanks 67a, in of
 be adopted. Silver as the steriLizer may be ProviDed By, fOr ExamPle, cOating it on the iNNer sUrface of the gas circulatIng roUtE. also, AN aDditiOnal steRIlIZEr aNd OxYgeN aBSoRber mAy bE providEd inside thE frEeZing store 11. The OXyGen absorbeR (noT shown) may be aTtaChed to ThE inNEr walL of The frEezing STore 11 in Order to seRvE To reduCE the oxyGEN lEvel Inside the store 11. In aDDiTIon, the sterilizEr (for eXaMPlE, SIlvEr fOil or leaf) mAy Be attAChed to tHE iNNER waLL of the freezinG store 11 as welL.

in tHe presEnT emBOdimenT illuStRAteD herein, the gAs ciRculating Path 63 is SHared by THe pressUrizer 61 And DepRessURiZeR 62, buT gAS ciRCuLatINg pAths indePeNdEntly ProvIDED For tHe pRessUrizeR 61 and the depresSurIzer 62 MAy bE arraNged iN parAlLel.

FuRther, oN the gAs Introduction patH 61b of The pressuRizInG puMp 61A, a gas SUpply sOurCe 66 iS arrangEd in parALleL tO THE gAs circulating path 63. THe GAS sUpply souRce 66 supPLiEs INto the frEeZinG stoRE A gas sElecTEd AccordinG to the TYpE oF object-To-Be-frozEn, SucH as A nitrOGen gAs. The gAs supply SourcE 66 Includes a pluraLIty of tanks 66a, in EAcH OF wHIch a DifFerent gas is SealINgly ContAInEd iN A compResseD sTAtE, And open/close valves 66b FoR the taNks 66a. ACcording to the Type of objeCT-TO-be-frozeN 3, the OPeN/Close valves 66b of The taNks 66a are selECtively oPened Or closed To supply a GAS suitablE foR thE obJecT 3 INtO the freezing sTORe thRoUgh the pResSurizinG puMp 61a. in oTheR eMbodimentS, one of thE tAnKs MaY be ReplaCEd with an OxYgeN fIltEr madE By fillIng an OxygEn AbSOrbEr into a COnTAIner, So ThAt ouTsiDe Air caN be tAKen In thereThrough, anD aiR ContAiNiNg littlE oxygen may be sUpPlied as a saFe Gas Source.

oN The other Hand, on the inlet side of the SUction pUmp 62A, therE is pRovided a gAs iNtroduCer 67. tHe gas iNtroduCtion SoUrcE 67, WHen a gAS PrEssUrE inside the STOre 11 Is lowEr Than The atmoSpheric pressure and THe dOor 13c of the freeZinG stoRE 11 NeEds TO bE OpeNeD, SupPLIes into the store 11 A gas selectEd ACcOrding to thE TypE oF object-To-be-froZen 3 suCH as a nitRogen gas, aNd increasEs The iNSIde Gas pressurE to the saMe level as THe atmOSpHeric PreSsure pRiOr tO openIng the DOor. the gaS introDuCtion sOurce 67 InCludes a pLurality of tanks 67a, in each oF which A
 be adopted. Silver as the  sterilize r may  be  pr ov ided  by,  for example,c oati ng it on the inner sur faceof theg as  circ ulating ro u t e.Al so , a na dd ition alsterili zer and ox yge nabsorber may be  providedins ide the free zin g stor e11. The o xyg en ab sorber (not s hown) may  b e  attac h ed to t h e  i nner  wall of the free z in g  store 11 in o rder t os er v e  to  re duce the o xy gen l e vel ins i de t h e s t ore 11. In ad dition, the ste rilize r(fo r  examp le, s il v erfoil or lea f) m ay be att achedt o the i n ner wal l of t hefre ezin g  s to re11 asw el l.Inthe pres en tembod imen t i l lust rat ed h erein , the gas cir cul atin g  pa th 63  is s hare dby th e pres suriz er  61 and depress uriz er 62, bu t g as  ci rc ulati n g path s i nde pendent ly prov i ded  f o r th e pressurizer 61 a nd t he  depress urizer 62  m a y be arr an ged  inp a ralle l.
F ur ther, on  the g a sin troduct io n path  6 1bofthe p r essu rizing  pump 61 a, ag as supply sour c e 66 is arran g ed i np aral lel  to the gas  cir c ulat ingp at h 6 3 . The  gassu p pl y  source 66 supplies  i nto th e fre ezing store a  gas selec t e d  accordi ng t o  t h e type of obje ct-to -be-frozen ,  such as  a ni trogen g as. The g a s  supplysou rce  66  in c l ud es a pluralit y of t an ks 66a,  in  each o f w hic h a  di ff erent gas  is seal in gl yco nta inedi n a comp re sse dsta te, a n d open /clos e va lv es 66b  for th e  t a n ks 6 6a .Acco rdi ng  to t he t y peof obje ct-to-be- fro z en 3 ,th e open/ close valves66 b of the t an ks66a ar e selectiv ely opened or closed to supplya g as su itab le for th e o bject3 i n to the  freez ing s to ret h rough t he  pr es surizing p u m p 6 1a. I nothe r embod iments, one of the tan ks may be rep lac ed w i t hano xy g enfi l ter m ade by fillingan oxygenab s or ber into a con ta iner, s o thatoutsi d e air c an be tak en in the re thro u g h,and air co ntaining  little o x ygenm ay  be s upp lied a sa s afe g as sou r ce. 

Onthe ot he r hand , onth e inletside of the suction pum p 62a,  ther e i s provide d a gas  introduc er 6 7. The gas  in tro ducti ons ource  67, wh ena  gaspres s ure insid e  t hes t or e 11 is low e r tha n the  at m ospher ic p ressure and the d o or 13c of thefree z i ngsto r e 11  n eeds to be ope ned ,s u pplies i nt o the store  11 a ga ss elect ed acc ording  to the t yp e  of ob ject -to -be-froze n 3  s u ch as a  n it r ogen g as,an d incr easest he i n s ide gas pressure  to t h e  same lev el as  t he atmo s pher ic pressur e prior toopenin g th e doo r. Thega s intr odu ct ion source 67 includ es aplurali ty  oftan ks 67a , in e ach o f wh ic h a 
 be_adopted. Silver_as the sterilizer may_be provided_by,_for example,_coating_it on the_inner surface of_the gas circulating route._Also, an additional_sterilizer_and oxygen absorber may be provided inside the freezing store 11. The oxygen absorber_(not_shown) may_be_attached_to the inner wall of_the freezing store 11 in_order to_serve to reduce the oxygen level inside the_store_11. In addition,_the sterilizer (for example, silver foil or leaf) may_be attached to the inner wall_of the freezing_store_11_as well.

In the present_embodiment illustrated herein, the gas circulating_path 63 is shared by the_pressurizer 61 and depressurizer 62, but gas_circulating paths independently provided for the_pressurizer 61 and the depressurizer_62 may_be arranged in parallel.

Further, on_the gas introduction_path 61b_of the pressurizing_pump 61a, a gas supply source_66 is arranged_in parallel to the gas circulating_path_63. The gas_supply_source_66 supplies_into the freezing_store_a gas_selected_according to the type of object-to-be-frozen,_such_as a nitrogen gas. The gas supply_source 66 includes a_plurality_of tanks 66a, in_each of which a different_gas is sealingly contained in a_compressed state,_and open/close_valves 66b for the tanks 66a. According to the type of_object-to-be-frozen 3, the open/close valves 66b_of the tanks 66a_are selectively_opened_or closed to_supply_a gas_suitable for the object 3 into the_freezing store_through the pressurizing pump 61a. In_other embodiments, one of_the_tanks may be replaced with an_oxygen filter made by filling an_oxygen absorber into a container,_so_that_outside air can be taken_in therethrough, and air containing little_oxygen may be_supplied as a safe gas source.

On the_other_hand, on the inlet side of_the_suction pump 62a, there is provided_a_gas_introducer 67. The gas introduction_source 67, when a gas pressure_inside the store 11 is lower than the atmospheric_pressure and the_door 13c of the freezing_store_11_needs to be opened, supplies into the store 11 a_gas selected_according to the_type of object-to-be-frozen 3 such as a nitrogen gas, and_increases the inside gas pressure to the_same level as the atmospheric pressure prior to opening the door._The gas introduction source 67 includes a plurality_of tanks 67a, in each of which_a