GB2083900A - A refrigerating apparatus - Google Patents

Abstract

A refrigerating apparatus comprising a cooling chamber (1), means (14, 15, 16) for cooling the cooling chamber, cooler boxes (2) arranged in the cooling chamber for storing food in the cooler boxes, heat medium passages (9) with inlets (9a) and outlets (9b), provided on the peripheries of the cooler boxes, means (10, 11, 12) for feeding a cooled heat medium into the heat medium passages, a humidified air supply pipe (22) having ports (23) which open into the cooler boxes, and a humidifier (20) connected to the humidified air supply pipe for supplying a humidified air to the humidified air supply ports. Food can thus be kept at a temperature of 0 DEG C +/- 1 DEG C, with a humidity of 60-100%, preferably 80-95%. Moisture-collecting plates (30) are provided in the boxes (2) adjacent to ceilings. <IMAGE>

Description

SPECIFICATION A refrigerating apparatus This invention relates to a refrigerating apparatus for keeping food and particularly perishable food such as marine products, meat of domestic animals, or vegetables and fruit, in cold storage, without freezing them. This invention relates in particular to a refrigerating apparatus which can keep perishable food in cold storage at temperature of OOC + 1 OC and humidity of 60 N 100%, for a long period of time.

The freshness of perishable food, for example, the freshness of meat of domestic animals or marine products usually decreases due to rigor mortis, decomposition of protein by autolytic enzyme, and putrefaction by breeding of the microorganism, all of which appear in that order. The autolysis of meat is generally called "ageing", which softens the tissue and improves the flavor thereof.

However, in case of marine products, since their tissues are originally soft, the autolysis spoils the taste. In particular, spoiled taste of slices of raw fish is fatal. Therefore, it is very important to prevent the freshness of marine products from being decreased.

In order to restrain such an autolysis or putrefaction of food it is well known to keep food in cold storage thereby making enzymes of the microorganism inactive. For this purpose, the storage temperature is preferably kept below -1 00C in a freezing storage system. However, the freezing storage system causes the tissue of food to be broken, the colour of food to be changed and the good taste of food to be lost, due to freezing. It is, therefore, most desirable to keep food in cold storage without freezing it, in order to prevent the composition of food from being changed. However, it has been considered that the storage period of time in a refrigerating storage system without freezing food is relatively short, in view of the capacity of a refrigerating apparatus.

The inventor of this invention has experimentally found that not only the storage temperature itself but also the fluctuation of the storage temperature have a great influence on the freshness of food. It has been also experimentally found that when the storage temperature fluctuated over 30C, the storage period was extremely decreased. According to the inventor's experiments, the optimum environment for storing perishable food is as follows; at a temperature of OOC i 1 OC, the humidity being 60 N 100% and preferably 80 N95%.

However, in conventionally known refrigerating apparatuses (refrigerators), the storage temperature in the refrigerator varies between 50C N 1 OOC affected by the open air temperature and by the opening and closing operations of the door of the refrigerator. Furthermore, in the known refrigerators, the humidity therein cannot be controlled, which tends to make the inside of the refrigerators dry. That is, it is impossible or next to impossible for conventionally known refrigerators to establish the above mentioned optimum.

It is therefore desired to provide a refrigerating apparatus in which the fluctuation of the temperature is extremely small and the humidity can be controlled.

It is also desirable to provide a refrigerating apparatus which can establish an optimum storage environment in which the temperature is OOC + 1 cc and the humidity is 60 N 100%.

Still another desirable feature is to provide a refrigerating apparatus which can store perishable food for a long period of time by considerably restraining the activity of enzyme, breeding of the microorganism, or oxidation, without freezing the food.

Still another desirable feature is to prevent the freshness of food from being decreased by maintaining the water contained in the food as it is, without drying the food.

Furthermore, a clear guiding principle is required for the dimensional limitation of a cooler box for storing food and providing a circulation system of coolant to maintain the fluctuation of the temperature within a range of about +1 cc.

Still another desirable feature is to provide a refrigerating apparatus in which dew-drops produced on the upper wall of the cooler box by humidifying the inside of the cooler box do not drop onto the food in the cooler box.

Finally, still another desirable feature is to provide a a refrigerating apparatus in which, when it is used with a quality stabilizer which is adapted to improve the quality of food to be kept in cold storage, such a stabilizer can be easily fed in the cooler box.

According to the present invention, a heat medium directly flows around a cooler box in which food is stored, a humidified air is fed in the cooler box, and the cooler box is located in a cooler chamber.

Means for treating dew-drops are provided on the ceiling of the cooler box so as not to be an obstacle for the flow of cold air and so as not to produce a harmful temperature gradient. Means for feeding a quality stabilizer are provided at a humidified air feeding port to feed a gaseous stabilizer together with a humidifed air into the cooler box.

Other features, additional objects, and many of the attendant advantages of this invention will readily be appreciated as the invention becomes better understood by reference to the following detailed description of the preferred embodiments when considered in connection with the appended drawings in which:: Fig. 1 is a longitudinal sectional view of an embodiment a refrigerating apparatus according to the present invention, Fig. 2 is a sectional view taken along the line Il-Il in Fig. 1, Figs. 3A and 3B are side sectional views of a cooler box with a cover and with the cover removed, respectively, Fig. 4 is a partially sectioned perspective view of means located on the ceiling of a cooler box for receiving dew-drops, Fig. 5 is a perspective view of means for feeding a quality stabilizer, Fig. 6 is a partially sectioned side elevational view of a part of Fig. 5, Fig. 7 is a sectional view taken along the line VIl-VIl in Fig. 6, and, Fig. 8 is a sectional view similar to Fig. 7, showing a different embodiment of a quality stabilizer feeding means.

A refrigerating apparatus, according to the present invention has a cooling chamber 1 and cooler boxes 2 located in the cooling chamber 1. The cooling chamber 1 is defined by a cover box 3 which can be made of a heat insulating material, such as urethane or the like. Each of the cooler boxes 2 is in the form of a hollow square tube with a bottom made of a metal plate 4 having a high thermal conductivity.

The cooler boxes have at their front ends, inlet openings for food to be stored therein. At the front ends of the cooler boxes 2 are provided inner doors 5 and outer doors 6 which can open and be closed, the outer doors 6 being made of a heat insulating material.

Each of the upper and lower cooler boxes 2 has a spirally wound separation plate 7 which surrounds the respective box and which is secured to the metal plates 4 of the respective boxes by welding or the like. The separation plates 7 form a spiral passage 9 of a heat medium (coolant) on the outer periphery of each cooler box 2, together with outer casings 8 which cover the respective separation plates 7.

The cooler boxes 2 have lower inlets Ya of the coofant pa-ssagès 5which are connected to a discharge port of a pump 1 2 by means of a feed pipe 11 having flow rate control valves or electromagnetic ON-OFF valves 10 therein. The cooler boxes 2 have an upper outlet 9b of the coolant passages 9 which are connected to a suction port of the pump 12 by means of a return pipe 13 and a chiller tank 14. In the chiller tank 14 is arranged an evaporator 1 6 of a refrigerator 1 5 to cool the heat medium in the tank 14. The cooled medium is fed into the spiral passages 9 surrounding the cooler boxes 2 by means of a circulation circuit having the pump 12 and is then returned to the chiller tank 14.

The heat medium is cooled to OOC u --30C and preferably to --20C in the chiller tank 14, in order to keep the temperature in the cooler boxes 2 at OOC + 1 "C. in the cooler boxes 2 are arranged temperature sensors 1 7 which sense the temperature in the cooler boxes and which feed a control signal to the electromagnetic valve 10 so that the valve 10 increases and decreases the flow rate of the heat medium when the sensed temperature is above or below OOC. respectively.

It has been experimentally found that in order to keep the temperature in the cooler boxes 2 at OOC + 1 cc without any undesirable temperature gradient, it is necessary to limit the height 1 of the cooler boxes 2 to a predetermined value. According to the experiments, the best result was obtained when the height 1 was 200 N 230mm.

As a heat medium there can be used a liquid which cannot be frozen even when the temperature is below --30C, suich as glycerin, propylene glycol, or mixture of ethyl alcohol and water (organic brine).

The refrigerator 1 5 has a stop valve (not shown) provided on the output side of the condenser (not shown) in the refrigeration cycle of the refrigerator to control over-cooling of the heat medium, thereby minimizing the difference in the cooling temperatures. The evaporator 1 6 of the refrigerator 1 5 is connected, in the cooling chamber 1, to a cooler 18 consisting of a helically wound uncovered tube located in the cover box 3. The cooler 1 8 inside the cooling chamber 1, connected to the downstream side of the evaporator 16 maintains the temperature in the cooling chamber 1 at 2 C n- OOC.

As is well known, in order to keep the temperature of the heat medium constant even when the outside air temperature is below the temperature in the cooler boxes 2 or the temperature of the heat medium, a heating means such as a heater can be provided in the chiller tank 14 or a switching means for switching the operation of the refrigerator 1 5 to function as a heat pump can be provided in the refrigerator 1 5.

In the cooling chamber 1, there is arranged an ultrasonic humidifier 20 which produces a clean mist (1 N 5 micron particles) which is fed into the cooler boxes 2 by means of a multivane fan 21, main duct 22 and humidified air inlets 23 provided on the respective cooler boxes 2. The humidified air is discharged from the humidified air outlets 24 into the cooling chamber 1, after the air circulates in the cooler boxes. Humidity controllers 25 are located in the vicinity of the outlets 24, to detect a relative humidity of the humidified air at the outlets 24, thereby to make the humidifier 20 ON or OFF or to control the time during which the humidifier 20 operates, by a timer, so that the relative humidity is a predetermined value, for example 60 N 100%.

The ultrasonic humidifier 20 has an ultrasonic radiator (not shown) located on a water tank 20a to generate ultrasonic waves, as is well known. The ultrasonic humidifier 20 can provide a high quality mist of 1 N 5 microns. Preferably, the humidifier 20 is arranged in the cooling chamber 1 so that the temperature of the water in the tank 20a is substantially the same as that in the cooler boxes.

Preferably, the humidifier 20 has a heating means such as a heater therein to prevent the water in the tank 20a from being iced when the temperature in the cooling chamber 1 is below 0 C. The heating means operates to heat the water when the temperature in the cooling chamber 1 is at a predetermined value.

The cooler boxes 2 are provided, on their tops (ceiling), with dew-drop collecting plates 30 which are slightly smaller than the ceilings of the cooler boxes 2 and which are held by a plurality of supporting projections 31 provided on the peripheral walls of the cooler boxes 2. The collecting plates 30 can be inserted in the cooler boxes 2 when the doors 5 open so that the receiving plates 30 are located on the projections 31. When the receiving plates 30 are put on the projections 31, there are provided predetermined peripheral gaps between the peripheries of the collecting plates 30 and the peripheral walls of the cooler boxes 2. The collecting plates 30 have upwardly bent peripheral edges 32 so as to provide a dish shaped receiver. On the flat plate portions of the dishes are formed a plurality of holes 33 through which the cold air flows.On the periphery of the cold air holes 33 are provided upwardly bent peripheral walls 35 having trumpet shaped sections for preventing the dew-drops from entering the cold air holes 33. The dew-drops collected in the plates 30 are discharged from water conduits 35 connected to the humidified air outlets 24. For this purpose, preferably, the collecting plates 30 are slightly inclined so that the dew-drops on the plates 30 can be collected into the water conduits 35. A water drain (not shown) can be advantageously provided on the bottom of the cooling chamber 1.

To the humidified air inlets 23 are removably attached quality stabilizer feeding devices 40 for feeding a medicine or medicines, for stabilizing the quality of food, for example, for bacteriostasis or sterilization of microorganisms generated in food, or for antioxidization of food, or the suppression of denaturation of protein. The device 40 has a mixing tube 41 and a quality stabilizer holder 42, as shown in Figs. 5-7. The tube 41 has at its one end a flange 43 which is adapted to bear against the peripheral wall of the inlet 23*when the tube 44 is inserted in the inlet 23. The tube 41 has therein a separation plate 44 located on a diametral plane of the tube to divide the tube into two sections. The holder 42 has a flat housing 45 corresponding to the upper section of the tube 41 and secured to the tube 41.The upper section of the tube 41 and the inside of the housing 45 are interconnected by means of an opening 46 formed in the tube 41. The housing 45 contains therein a hygroscopic filler 47 which is made of absorbent cotton, or filtering materials is also located in the upper section of the tube 41. The housing 45 has an end cover 48 which is opened or removed when the filler 47 is put in the housing 45.

In the upper section of the tube 41 are arranged netting 49 located at extensions of the opposed front and rear walls of the housing 45.

The quality stabilizer is a vaporizable medicine having characteristics, such as a microorganism bacteriostasis or sterilization action, an antioxidization action, and/or a antiprotein denaturation action.

The vaporizable quality stabilizer can be, for example, a mixture of 100 parts by weight of ethyl alcohol having a sterilizing property, 0.02 N 50 parts by weight of an anti-oxidation and reducing agent, and 5 N 30 parts by weight of a sequestering and anti-protein denaturing agent. A good experimental result was obtained by the use of such a mixture. The anti-oxidation and reducing agent may be one or more components selected from L-ascorbic acid, an ester of L-ascorbic stearic acid, sodium L-ascorbate, erysorbic acid, sodium erysorbate, erysorbic acid, sodium erysorbate, L-fryptophane, tocopherni, vanillin, rutin, butylhydroxy anisole, and dibutylhyadroxy toluene.The sequestering and anti-protein denaturing agent may be one or more components selected from sodium metaphosphate, sodium pyrophosphate, sodium polyphosphate, and phytic acid.

For foods capable of resulting in enzymolysis, such as marine products or meat of domestic animals, 1 N 10 parts by weight of burnt alum and 1 N 20 parts by weight of sodium 5'-libonucleotide can be added to a stabilizer having a composition as mentioned above, to provide a better quality stabilizing effect.

According to the present invention, the temperature in the cooling chamber 1 can be kept -20C N O"C by means of the cooler 18 consisting of the uncovered tube, and, accordingly, there is substantially no possibility that external heat which can be transmitted from the outside to the inside of the apparatus through the cover box 3 is transmitted to the cooler boxes 2.Furthermore, since the heat medium having a temperature of OOC u --30C directly flows in the passages 9 on the outer peripheries of the cooler boxes 2, the temperature in the cooler boxes 2 can be kept at OOC 1 1 cc. It should be noted that the passages 9 have the lower inlets 9a located on the bottoms of the respective cooler boxes 2, and, accordingly, the heat medium which is fed to the lower inlets 9a from the chiller tank 14, through the pump 12, the feed pipe 11 and the ON-OFF valves 10 flows in the helical passages 9 while expelling the air existing in the passages 9 and is then discharged from the upper outlets 9b located on the upper portions of the respective cooler boxes 2.The heat medium thus discharged from the outlets 9b is returned to the chiller tank 14 through the return pipe 1 3. Therefore, substantially no bubbles are produced in the passages 9, which results in a good heat transfer between the heat medium and the wall surfaces of the cooler boxes 2, thereby providing a good homeothermism. The numeral 26 designates air vent cocks located at the outlets 9b of the passages 9.

The ultrasonic humidifier 20 keeps the humidity in the cooler boxes 2 at 60 N 100%. The freshness of the perishable foods can be maintained for a long period of time by the control of the humidity and the temperature in the cooler boxes 2, in the above mentioned way.

Furthermore, since the humidified air is fed into the cooler boxes 2, the dew forms on the upper walls of the cooler boxes which are in a cold state and drops therefrom. However, the dew-drops are all collected in the collecting plates 30 and are then discharged outside of the cooler boxes 2, through the conduits 35 (see Fig. 4). Therefore, food in the cooler boxes 2 and, in particular, soft food such as "sea urchin" is free from dew-drops, so that such food cannot be damaged.

The cold air holes 33 enable the cold air in the cooler boxes 2 to flow therethrough, resulting in the occurrence of no temperature gradient. In view of this, the number and the total area of the holes 33 can be determined. Furthermore, as mentioned before, since the holes 33 are surrounded by the upwardly bent peripheral walls 34, no dew can drop down from the holes 33.

The dew-drops collecting plates 30 can be made of metal such as stainless steel. However, the plates 30 are preferably made of non-metal, such as synthetic resin, to decrease the possibility that the dew will form on the plates 30.

When the humidified air fed from the inlets 23 passes through the quality stabilizer feeding device 40, the part of the air that flows in the upper section of the mixing tube 41 is mixed with the evaporated quality stabilizer, during the passage of the air through the filler 47. The mixture of the humidified air and the evaporated quality stabilizer stabilizes the quality of food in the cooler boxes and increases the storing property of the apparatus. The density of the quality stabilizer can be determined, in view of the density of the hygroscopic filler 47 and the length of the passage of the humidified air, etc.

The quality stabilizer which is absorbed in the filler is properly supplied to the device 40. Normally, it is enough that the quality stabilizer is supplied every one week or ten days, in accordance with how many times food is put in or taken out of the cooler boxes. Alternatively, it is also possible to provide a liquid reservoir 50 on the lower portion of the housing 45 to decrease the number of times of the additionai supply of the quality stabilizer, as shown in Fig. 8. The filler 47 is partially put or dipped into the liquid of the quality stabilizer contained in the reservoir 50.

The technical effects of the present invention have been experimentally proved. The experiments have used two refrigerating apparatuses according to the present invention, having substantially the same storing temperature of OOC + 1 cc and substantially the same humidity of 60 N 100%. The quality stabilizer which comprises mixture of 70 ml of ethyl alcohol with a solution of 20 parts by weight of Lascorbic acid, 1 5 parts by weight of sodium metaphosphate, 5 parts by weight of 5'-libonucleotide and 5 parts by weight of burnt alum in 30 ml of water was fed to only one of the two apparatuses. The perishable food stored in the cooler boxes is shown in the following tables.

For the purpose of comparison, these items of food were also kept in cold storage at OOC N and at OOC ,v10 C, respectively, with the use of two refrigerators on the market.

The tables show the result with respect to colour, texture, putrefaction (browning, tastelessness), and mold, slime (breeding of bacteria), under different storage conditions. They were judged by eighteen experts including fish dealers and meat dealers, brokers of perishable food, and cooks, etc. The judgement was established when it was supported by over fifteen experts.

0-- very good -good A- slightly changed X -- Wrnedbrnwn, untasty, putrefied 0-- molded. slimy TABLE. 1 Item of food: Defrosted tund

I present The present invention invention Prior Art Prior Art FJcllir sabilizer pcilalistabier ( O"C - 70C) (OOC - -100C) is splied) is supplied) ococ3o)oOxtDjì3 CD U) -- 4:,a,: -- - U) 1 CD 03 0 3 0' 3' 0' 3' CD CD CD q 3 q CD 1 O O O O OO oo oo Qo 2 O O oo O t t n ~ OAA o 300 O AX 4 0 O O O X X A .0 5 0 ~~~~ Qo 0 6 O O Qo A 7 O O ~ 0 O O ~ ~ 00 8 O O IOr 00 9 O O O O 10 0 O ~ O 11 0O n O O A 1200 oA ~ ~ A 1300 AAA n 1400 A A < A ~ ss 1 5 0 0 AXX 0 1 6 0 0 1 ------- 7 --- ------- ---ii----- 0 0 1 8 O A 1 9 0 A 20 t Onoo A 0 ~ 0 #...very good #...good #...slightly changed X...turned brown, untasty. putrefied #...molded, slimy TABLE 2 Item of food:Bonito

The present The present invention invention Prior Art Prior Art ,Quality sinbilizer mqaliy'd' (Ot"' 7oC) (oOC -10 C) is applied) is supplied) s 3 o3 0 30 -x 0 Cx C xao 0 - a. E O E"dpoa E 0 - O CD x o ',,,'Dc o x ;PSL 3' 0 3' 0' 3' 0' 3' CD CD CD 1 O O ~ O O on n QO 2 O O 00 O ~ ~~OO~ oo 00 300 QO xA Ao 400 -O 500 O O t 6 -O ~- --O X oO 7 0 0 0 0 8 O O t O 9 00 AA 10 O O A A 11 00 A 1 2 0 0 I 1 3 A O A 14AA A A 15 A A n x ~ X ~ xO 16 A A A 17 X X A 18 A 19 A I 20 A 0 #...very good #...good #...slightly changed X...tuyned brown, untasty, putrefied #...molded, slimy TABLE.3 Item of food:Raw prdwn

The present The present invention invention Prior Art Prior Art iality stabili r 5) wditydnhilizer ( oec ~ 7oC) (oOC -10 C) is suXied) is supplied) 0 g - .3 CL A g a A 3 A 2 3 " W 30 3 0 - E 0 E ;I E 0 C rs C C Yi c ;- B CD (I1 CD -fl 0' 3' -. -. 0 3' 0' 3' o CD CD CD 1 O O O O O O O O 200 Qo AO o0 3 O O O xA 4 O O ~ O o0 oO 0 5 OQ O O O ~ X O 5 O 00 ~ oO 0 7 C)O~~ 00 AO 8 O O ~ ~ A O ~ 0 AO 9 0 0 AO 10 A 0 A 0 11 A.o AA 12 X A 'A A 13 X A ~ X A )CA A 14 A A A 15 'A A 16 A 17 x6 18 19 20 0 #...very good #...good #...slightly changed X...tuyned brown, untasty, putrefied #...molded. slimy TABLE.4 Item of food:Saurei

The present The present invention invention Prior Art Prior Art ,4-lality stabilizer walilystabili l ( roc 7oC) (oOC 0 C) is supplied) is supplied) OxCD o CL OoxCD3OoxrD3 0 xCD3o "' 0 - 0C ?ii c E 0, C E cpC t "'CD"' U)"' CD"' a "'CD ~ 0' 3' 0' 3' a 3' 0' 3 03 CD CD CD 1 O O Qo Qo 00 20 0 Qo 0 0 0 0 O~ 3 O O O loo 4 O O O O O t O O 5 00 0o A$AoA 6 OQ 00 ~ 0A 7 0 O O O 8 O O O O A 9 0 -O - a 0 0 A tO O O O O t 1 1 O nun A ~~~ 0 0 1 2 O ~- t- t t O v ~ 13 O O t X t 14AA A A 15 A A 16 AA 17 A A A 18 19 20 0 #...very good #...good #...slightly changed X...turned brown, untasty, putrafied #...molded, slimy TABLE. 5 Item of food:Paste of sed ulchin eggs

The present The present invention invention Prior Art Prior Art quality stabilizer calityW (Ot q 70C)( ) ( 0 C - -10 C) is sppplied) is supplied) - 0 0 /a CL CD 0 'V 0 - ac 0 0 - ~ 0 E 0 - C C C C C CL W ~ MT Wô E -c O CD 3 CD 3 CD CD 1 40 00 00 ~~ O O ~ ~ O O O000 2 2 O O ~ 00 00 AA OOtm 3 0 o 0 0 )( A X A A t t t O o' 4 X~Xx 4 O O O O X)c 5 O 0 ~ ~ 0 00 00 6 O -O = ~ rr 7 00 8 O O O O 00 00 9 100 o T 10 O;;o oo 1 11 1 1 CO 3 0 X 14 0 0 A 15 -O - o ~A 460 1 7 O 1 18 & O O 1 9 0 A 0 20 oA O O #...very good #...good #...slightly changed X...turned brown, untasty, putrefied #...molded, slimy TABLE.6 Item of food:Cockle

The present The present invention invention Prior Art Prior Art ality stubilizer cualitystabili r (Ot"" 7 C) (OoC --10 C) is supplied) is supplied) 0c' - o 0 8-,3 - ce '6 0 0 'V 0 o Oc E CL o CC gocOoa, C C t C ('1 U) ac I n ~ 2 3 CD |0 3 0 3 0' 3 a 3 D 3 rp CD CD CD 1 O O ~ O 00 ~00 0'0 0 0 2 00 00 oo 00 3 o QO o O a n n zoo o 00 4 0 QO O x X 5 O O O O 00 00 6 O O = 00 00 AA 7 0 0 0 0 XA 8 0 0 0 0 x 9 0 0 0 0 10 O O O A 11 O O AA 1 2 O O A A A 13 n x A 14 XO x 15 AA 16 1 A 17 A 18 19 20 A == A,A #...very good #...good #...slightly changed X...turned brown, untasty, putrefied #...molded, slimy TABLE.7 Item of food: cuttlefish

&verbar; The present The present invention invention Prior Art Prior Art ,quality stabilizer c,ualityMbili ( O"C - 7oC) (OoC * -1 0 C) is supplied) is supplied) o - 3 - 3 C' C' 0 CD o 0 S s xCD x o 'V - 0 - VI-r 0 o'0 E0 C CL CL C C C C - ~ t . X . t E c"; & BR< 'V 03 CD CD 1 O O O O O O 0o Qo 200 QO () O O O o O QO 3 O O O O O 00 00 O O 4 O O ~ O Qo 00 at 00 5 O O O O ~ ) < X X O A0 6 00 O O O X 7 O -O- 0o O O 00 8 0 0 0 O 9 O O 0 ~ 10 O 0 0 0 0 11 O O O O 1 2 O A A 0 4 3 0 0 A 0 14 A 0 x A 5 A O AA 16 A O OA00 X x 17 ~ 18 x A 19 20 #...very good #...good #...slightly changed X...turned brown, untastyl, putrefied #...molded, slimy TABLE.8 Item of food:Mackerel

The present The present invention invention Prior Art Prior Art sulity stabilizer cn[ity slabiF (Ot 7oC) (OOC 0 C - OOC) is supplied) is supplied) n fD S; o o 00-0 CL S1 0x'Vo0x'V0x'VC0xC 0 - oa. E 0 O E 0C a o C0 t o ,"'C o "' 2 0 c 'p"' R "' 'p ('1 'V ~ 03 o 3' D 3 ~ 0' 3 'V Irp 'V CD 1 O O ~ O 00 or 00 0o 2 o O LLO .0 300 ~ O 00 4 0 O O O t x A O 5 O O O O X 0X v(- O 0Q x 6 QO 0o 00 7 O O 0Q 00 800 QO 9 O O (D leo ~ A 10 QO 00 )( 1 1 00 1 2 O O O 0 13 4 O O O 1 4 010 0 5 O O O t O O O 16 AoA X AA 17 A A A 'A 18 X )( X 19 20 #...very good #...good #...slightly changed X...turmed brown, untasty, putrefied #...molded, slimy TABLE.9 Item of food:Oyster

The present The present invention invention Prior Art Prior Art stabilizer ystabili r (Ot" stabiIii?er PC 3 - 7oC) (oOC "'00C) is supplied) is supplied) 4 O ~ o o xCD3 a o - a "- s! r ~ o fl' I I'"e 300 11 o n 400 QO 500 O 600 QO A 7 o0 Qo 8 O O ~ ~ O O ~ 0 zap ~ C, v 9 0 0 10 00 oo 11 II ^ C > L 4 O O ~~ O O ~~~ ------ 0 5 O O O O O 6 O O t A A A 17 00no X K 18 00 A 1 9 0 0 20 0000 00 #...very good #...good #...slightly changed X...turned brown, untasty, putrefied #...molded, slimy TABLE.10 Item of food:Beef

The present The present invention invention Prior Art Prior Art lityslabilizer bc,tulitystbilizer ( 0 C- 7 C) (oOC * "-100C) is supplied) is supplied) C' c- C'- rC7-3 C' - 3 On'do OcroOc 3 9 CLoE e, C O ZL - a,iPce C ~ vr 1 (n t Ff I 3 0' Isl=~~p 5' 3' 'p 'p 'p CD 1 O O ~ O O O O 00 2 q 00 00 O ~~O ~ 00 3 O O 00 o 0 0 400 O O O 0 0 5 QO xao C) 00 600 QO === t t O O O ~~ 7 O O O o x X 8 O O o O O 9 00 oA 00 10 00 ~ A A I O -O 1 1 O A A X A A0 1200 X X X ~ ~ t ~ AA 1 3 O 0 1 4 0 0 1 - 5 ~ 0 1 6 0 0 17 at 17 A A 19 A A 19 nn 20 X X t o 00 #...very good #...good #...slightly changed X...turned brown, untasty, putrefied #...molded, slimy TABLE.11 Item of food:Chicken

The present The present invention invention Prior Art Prior Art litytcibilizer cilitycibW (Ot"' 7oC) (oOC -10 C) is s4Wied) is supplied) C' - C' C'-3 OxCDo 0xCD 0 OxCD 0 %L'o'0ccE cC c EC b O t 3 o t D o ~ 0 ; o t or 3 O'p3' 1 O O ~ O O 00 00 O O O 200 00 00 30 O O O o 4 00 aon ~ ~ A O AoA 5 00 ~00 Xoxooo 6 ~-0 ~ ~ O QO ~ oo t 7 QA t X O O 8 00 O t t c 00 9 X A 0 )cXA 00 1000 OA 11 nn~~ 12 o O A?C 1 3 0 0 1 4 0 0 1 5 0 0 0 160 A A 17 n X ~ o 18 X A A 19 x 20 ~~~ 00 #...very good #..good #...slightly changed X...tuned brown, untasty, putrefied #...molded. slimy TABLE 12 Item of food: Pork

The present The present invention invention Prior Art Prior Art lity stabilizer cpclily abil' (O0C 70C) (O"C --100C) is supplied) is supplied) - O = e 3 ffi rr ssoso, '1, O4cCLOcC-Occ EOc O a iI d t a r C a 0' 3' 0' 3 0 3' 0' 3' 1 0Q 00 00 00 2 O O o O ~oo~ 3 O O ~ O 00 00 O O O O 4 -O- O ~ O O 00 Ao 40 5 O O O C no o )( AA00 6 0 0 0 0 X 0 0 7 00 O ~ A oiI 8 00 Ax A O O ~00 9 QO 'K X O O 10 0 0 1 1 O O ~ ~ A A 12 E O 00 1 3 O A ~ ~ X O 14 ~~ A A is A A, 16 X A X 16 'A 19 20 #...very good #...good #...slightly changed X...turned brown, untasty, putrefied #...molded. slimy TABLE.13 Item of food:Hamburg

The present The present invention invention Prior Art Prior Art :plolity stabilizer roGalitystbili r (Ot"" 7cC) (oOC --100C) is supplied) is supplied) 0 CD 3 ~ o ! 2 0 0 3 3-.0 CD CD CL x 0xO 0-xO - 7i! or ;il 'CL-C - s c -, U1. n D CD 0. ~ SD -, Uk, n fD -, Do 3 n 3 & ' 8 3 a 3 0' 3' CD CD CD 1 0Q -O -=-0 O 0 2 00 oc O 0 300 O AA o A O O00 4 o o ~ ~ O xx A o 0 5 AA 600 AAA o c 7 Oo x x oA 8 O O 00 9 o -O- ~~~~ ~ ~ c, x o 10 0 0 1 1 O O 12 -O 2 0 0 1 3 O ~ ~ = 1 4 A 0 C > 16 AAA 17 A A X 18 )C 19 20 1 Ao #...very good #...good #...slightly changed X...tuned brown, untasty, putrefied #...molded, slimy TABLE.14 Item of food:Mushroom

The present The present invention invention Prior Art Prior Art IcJity stabilizer c'aliystabiF (Ot - 7oC) (()oC --lOOC) is supplied) is supplied) o - C'- " o o C 10- 'D 0 o o 'D CL -0x 0 izo fic - 'CLOc a 5' 3' 5' 3' 3' 5" 3' ID 0 ID ID 1 O O ~~ O O QO O O O 2 0 0 0 0 O O O ~~X X ~ O 3 O O O O O O ~ v 3 ~ ~ ~ ~ ~ 00 00 4 00 00 AAA 5 0 0 O O XXX x A 6 O O ~ ~ A t t AAA 700 xxx a O QO 9 0 0 10 00 11 00 1 2 ~ ~ 1 3 0 0 1 4 0 0 15 O O 1 6 0 0 A I 7 0 A A 16 A)c A 19 )( 20 x0 #...very good #...good #..slightly changed X...turned brown, untasty. putrefied #...molded, slimy TABLE.15 Item of food:Strawberry

The present The present invention Inn invention Prior Art Prior Art (quality stabilizer nocJaliyObil' (O0C"" 7oC) (oOC -iC) is isPPIL3 i73 Quality supplied) is - 70C ) ( supplied) o 0 0 o CD 0 OxCDo oCD x 0 -x C -x t X o / > ,',;;cC c " C o C CD ", CD ~ CD ('1 CD fl 5' 3' 5' 3' 0' -' 0 CD CD 0 CD 1 O O O O ~ QO QO o 00 200 QO O 0 X X ) < 3 00 0 x Y 4 -O -O 5 0 O ~ =t t t AAA 600 Axx 7 00 8 QO ]10 00 .~~ =~~ ~ ~~~~~~~ ~ ~ 10 0 0 Ii 00 I 2 0 0 13C I 4 0 0 1 5 0 0 1 6 0 0 #...very good #...good #...slightly changed X...turned brown, untasty, putrefied #...molded, slimy TABLE 16 Item of food: Broccoli

The present The present invention invention Prior Art Prior Art krJaity stnbilizer rotNalitystab (Ot 7DC) (oOC --10 C) is supped) is supplied) c iR ffi '3 O &commat; o =g oc a 0 TT o H: t 3~ I 5 a $ a n, ~ a S' C 3' 3'D' S' 3' 1 ~ = ~ 0 0 Ox 20 0~ 00 00~~X 3 00 60 oo 4 oo oo~~nn s 00 oo nnn~~ 6 0 0 0 0 A K 7 O O O O 00 00A 8 O onrx 1190 0-x 3 0 0 1 4 0 0 1 5 0 0 1 6 0 0 17 18 (3/ 0 0 1 9 0 A 20 A A A =~~ 4jz = c ~ ~~ #...very good #...good #...slightly changed X"'turned brown, untasty. putrefied #...molded, slimy As can be seen from the Tables 1-1 6, the refrigerating apparatus and the quality stabilizer highly contributed to the maintenance of the freshness of perishable food.

In the illustrated embodiments, the heat medium flowing through the passages on the peripheries of the cooler boxes and the cooling chamber are cooled by a common refrigerator, which makes the refrigeration cycle simpler. However, the heat medium and the cooling chamber can be, of course, independently cooled by their respective refrigerators. The number of the cooler boxes arranged in the cooling chamber is not limited to two. However, the number is preferably four or five, in view of the dimensional limit as mentioned before. In such a multilayer cooler box arrangement, each cooler box: has preferably a separate inner door 5 and an outer door 6 so that the opening-closing operation of the doors 5 and 6 of one cooler box does not have any thermal influence on the remaining cooler boxes.

Claims (22)

1. A refrigerating apparatus comprising a cooling chamber, means for cooling the cooling chamber, at least one cooler box arranged in the cooling chamber for storing food in the cooler box, at least one heat medium passage provided on the outer periphery of the cooler box and having an inlet and an outlet, means for circularly feeding a cooled heat medium into the heat medium passage from the inlet to the outlet, at least one humidified air supply pipe having a port which opens into the cooler box, and a humidifier connected to the humidified air supply pipe for supplying a humidified air to the humidified air supply port.

2. A refrigerating apparatus according to claim 1, wherein said heat medium passage comprises a lower inlet located on the bottom of the cooler box and an upper outlet located on the top of the cooler box.

3. A refrigerating apparatus according to claim 1, wherein it further comprises a single refrigerator with an evaporator for cooling both the heat medium and the cooling chamber.

4. A refrigerating apparatus according to claim 3, wherein it further comprises a chiller tank for cooling the heat medium, in which the evaporator is located, and a cooler in the cooling chamber, consisting of an uncovered tube connected to the evaporator.

5. A refrigerating apparatus according to claim 1, comprising a plurality of cooler boxes which are put on one another.

6. A refrigerating apparatus according to claim 5, wherein each cooler box has a separate double door construction comprising an inner door and an outer door.

7. A refrigerating apparatus according to claim 1, wherein said cooler box and the heat medium passage are made of metal, and the cooling chamber is made of a heat insulating material.

8. A refrigerating apparatus according to any one of the preceding claims 1-7, wherein it comprises means for controlling the temperature of the heat medium which is cooled to -30C N o0c before the heat medium enters the heat medium passage of the cooler box, so that the temperature in the cooler box can be controlled at OOC + 1 OC by controlling the flow rate of the heat medium having a controlled temperature.

9. A refrigerating apparatus according to claim 8, wherein it comprises means for controlling said humidifier to keep the humidity in the cooler box at 60 N 100%.

10. A refrigerating apparatus according to any one of claims 1-4, wherein it comprises means for maintaining the temperature in the cooler box at --20C N OOC.

11. A refrigerating apparatus according to claim 1, wherein said humidifier comprises an ultrasonic humidifier located in the cooling chamber.

1 2. A refrigerating apparatus according to any one of claims 1-4, wherein said cooler box has a vertical width of 200 N 230 mm.

1 3. A refrigerating apparatus comprising a cooling chamber, means for cooling the cooling chamber, at least one cooler box arranged in the cooling chamber for storing food in the cooler box, at least one heat medium passage provided on the outer periphery of the cooler box and having an inlet and an outlet, means for circularly feeding a cooled heat medium into the heat medium passage from the inlet to the outlet, at least one humidified air supply pipe having a port which opens into the cooler box, a humidifier connected to the humidified air supply pipe for supplying a humidified air to the humidified air supply port, and means provided on the top of the cooler box for receiving and collecting dew-drops from the top of the cooler box.

14. A refrigerating apparatus according to claim 13, wherein said means for receiving and collecting dew-drops comprises a plate having a plurality of cold air holes with upwardly bent peripheral walls.

1 5. A refrigerating apparatus according to claim 14, wherein the number and the diameter of the cold air holes are such that no temperature gradient occurs in the cooler box.

1 6. A refrigerating apparatus according to claim 14 or 1 5, wherein said plate is made of a heat insulation material, such as synthetic resin.

1 7. A refrigerating apparatus comprising a cooling chamber, means for cooling the cooling chamber, at least one cooler box arranged in the cooling chamber for storing food in the cooler box, at least one heat medium passage provided on the outer periphery of the cooler box and having an inlet and an outlet, means for circularly feeding a cooled heat medium into the heat medium passage from the inlet to the outlet, at least one humidified air supply pipe having a port which opens into the cooler box, a humidifier connected to the humidified air supply pipe for supplying a humidified air to the humidified air supply port, and a quality stabilizer feeding device which is located at the port of the humidified air supply pipe and which carries a vorizable quality stabilizer having a property or properties, such as a microorganism bacteriostasis or sterilization action, an antioxidization action, and/or an antiprotein denaturation action, to feed a vaporized quality stabilizer, together with the humidified air into the cooler box.

1 8. A refrigerating apparatus according to claim 1 7, wherein said quality stabilizer feeding device comprises a housing which is mounted to the humidified air supply pipe and which houses therein a hygroscopic filler which is partly located in the humidified air supply pipe, at least a part of the quality stabilizer being absorbed by the hygroscopic filler.

1 9. A refrigerating apparatus according to claim 1 7, wherein said quality stabilizer feeding device comprises a housing which is removabiy attached to the humidified air supply pipe.

20. A refrigerating apparatus according to claim 1 7, 1 8, or 19, wherein the quality stabilizer is a liquid mixture of 100 parts by weight of ethyl alcohol, 0.02 N 50 parts by weight of an anti-oxidation and reducing agent, and 5 N 30 parts by weight of a sequestering and anti-protein denaturing agent.

21. A refrigerating apparatus according to claim 20, wherein the quality stabilizer further contains 1 N 10 parts by weight of burnt alum and 1 N 20 parts by weight of sodium 5'-libonucleotide, which are added to the liquid mixture.

22. A refrigerating apparatus substantially as described herein with reference to the accompanying drawings.