US 3280586 A
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Description (OCR text may contain errors)
1966 TOYOMATSU FUNAKOSHI 3,280,585
PORTABLE COOLER INCLUDING HOLDOVER MEANS Filed May 18, 1965 2 Sheets-Sheet l INVENTOR 1966 TOYOMATSU FUNAKOSHI 3,280,586
PORTABLE COOLER INCLUDING HQLDOVER MEANS 2 Sheets-Sheet 2 Filed May 18, 1965 INVENTOR United States Patent 3,280,586 PGRTABLE tIOGLER INCLUDING HQLDOVER MEANS Toyomatsu Funakoshi, 72-3 Komukainishimachi, Kawasakishi, Japan Filed May 18, 1965. Ser. No. 456,639 3 Claims. (Cl. 62371) The present invention relates to a portable cooling apparatus in which materials which are to be kept cold can be kept and transported.
It is an object of the present invention to provide an apparatus for cooling material and keeping it at a substantially uniform low temperature, which apparatus is durable and not easily damaged.
It is a further object of this invention to provide an apparatus for cooling material and keeping it cool in which the apparatus can be made portable and yet which will keep the material in it at a preselected substantially uniform low temperature depending on the material which is to be cooled.
It is a still further object of the present invention to provide such an apparatus which does not require any such equipment as a fan, compressor, power source and the like, and yet Which has a large capacity and is substantially noiseless.
More particularly, the present invention relates to a portable container having inner and outer walls separated by insulation, the inner walls having brine boxes along the outside surfaces thereof through which run refrigerant circulation pipes. Cooling fins are mounted on the outside of the pipes within the brine boxes, and the boxes themselves are substantially filled with brine.
Fitted over the fins are fin caps which substantially prevent the brine from escaping from between the fins on the pipes. The ends of the pipes are connected in a refrigerant circultaing system which in turn has coupling means for coupling it to a refrigerant cooling system.
In use, the circulating system of the cooler of the present invention is connected to a refrigerant cooling system, and a refrigerant is circulated through the circulation pipes within the brine boxes so as to freeze the brine in the brine boxes. The circulating system is then disconnected from the refrigerant cooling system, and the material to be cooled is placed in the container. The container can then be transported, for example by automobile, and the materials will be kept cool for a long period of time, the heat Within the container being taken up by the brine in order to melt the brine. Of course the container can also just be allowed to stand and the same cooling effect will take place.
By using the apparatus in which the frozen brine is provided for cooling the interior of the container, the interior of the cooler is maintained at a substantially constant temperature, the heat being taken up by the brine to serve as the heat of fusion of the brine. Moreover, the temperature at which the container is to be kept can be controlled by the proper selection of a brine which melts at the desired temperature. The apparatus is efficient as well as being economical in operation, and is capable of being controlled to meet the conditions necessary for the particular materials being cooled.
Other and further objects of the invention will become apparent from the following specification and claims, taken together with the accompanying drawings, in which:
FIG. 1 is a transverse sectional view of the apparatus of the present invention;
FIG. 2 is an exploded perspective view of the inner walls of the apparatus of FIG. 1 showing the brine boxes and the circulation system for the refrigerant circulated to the brine boxes;
3,289,535 Patented Oct. 25, 1966 FIG. 3 is a longitudinal sectional view, on an enlarged a The apparatus according to the present invention composes a container 1 adapted to be used as a refrigerator and which can be installed in or separately mounted on a vehicle or which can remain stationary just like an ice box, has outer walls 3 surrounding a heat insulating material 2. Inner Walls- 4 are provided and have rows of v brine boxes 5 thereon extending longitudinally or laterally thereof. Refrigerant circulating pipes 8 are positioned within the brine boxes and have fins 7 thereon so as to improve the heat conduction from the refrigerant circulating pipes to the spaces within the brine boxes which contain freezing brine 9 which freezes at a temperatures depending on the type of goods to be stored in the container. By brine is meant a freezable liquid.
The refrigerant circulating pipes 8 extend through several brine boxes 5 and have coupling nuts 10, 10' on the ends thereof. A conduit 12 extends to an expansion valve 12 mounted on an end panel 11 from a one-way valve 14 mounted on an outside wall 3 of the container 1. Branching out from a distributor 16 connected to the expansion valve 12 are a number of branch pipes 17, 17' having couplings 18, 18 thereon for connection with said coupling nuts 10 so as to distribute refrigerant to the refrigerant circultaing pipes 8. The coupling nuts 10 on the other ends of refrigerant circultaing pipes 8 are cou pled with suction header 19 also mounted on the end panel 11. Header 20 is connected by conduit 20 to one- Way valve 15, also mounted on the outside of the container.
A refrigerant is led through the refrigerant circulting pipes 8 within the brine boxes 5 from the one-Way valve 14 through the expansion valve 12, the distributor 16 and the branch pipes 17. The refrigerant is collected in the suction headers 19 and fed through the conduit 20 to the one-way valve 15. The one-way valves 14, 15 are coupled to a conventional refrigerant cooling apparatus (not shown in the drawings) separately provided.
As the freezing brine within the brine boxes 5, water solutions of the following substances at the given concentrations can be employed depending on the freezing temperatures desired, as indicated:
Such brine materials, such as those as above, are suitable for producing cooling temperatures within the container and will be selected depending on the material to be cooled in the container. The brine materials are frozen by means of a cooling media such as a refrigerant gas. Denaturing of stored foods, for instance, can be prevented by using brine with a freezing temperature slightly lower than the best cold-storage temperatures of the said foods; e.g., if the temperature for cold-storage of a certain kind of food is l5 C., the brine can be a 22% ammonium chloride solution having the freezing tempera- 3 ture of about l6 C. so as to obtain a cooling temperature of -15.8 C.
With respect to the foregoing, a more specific illustration will be made: When a 23.07% sodium chloride solution is used as a refrigerant and is cooled down to -18 C. by a refrigerator separate from the container, its fluidity is retained because its freezing temperature of 21.8 C. is not attained, and the solution is passed through the brine boxes in the refrigerant circulating pipes 8, while a 22% ammonium chloride solution is used as brine 9 in said brine boxes 5, and said brine 9 will be frozen at -l5.8 C.
. As aforementioned, when inorganic brine is used, an extremely low temperature may be maintained, whereas, when a freezing temperature, e.g., of about -3 to 5 is desired, it is also possible to utilize organic brine solutions such as water solutions of propylene glycol or ethylene glycol.
Because temperatures suitable for storing foods will vary, as a rule, in practice depending on the kind of food, it is desirable to select a freezabie brine in accordance with the kind of food or other material to be stored, and
thus use the most suitable brine.
It is desirable to charge the freezable brine in an amount such that there is a void space 21 above the brine. The amount charged into the brine boxes 5 should be slightly less than the volume thereof, because the brine boxes 5 can become deformed or break accidentally due to expansion of the brine when it is overcooled. Moreover, the void space 21 should have the air removed therefrom until the pressure is reduced until the void space is at a vacuum of, e.g., the evaporation pressure of water, so that the inside of each of said boxes is in balance with respect to the expansion pressure caused by freezing of the brine and the negative air pressure, so that the internal pressure of the brine boxes is controlled so that the pressure on the wall of the box due to expansion during freezing is reduced whilealso the oxygen dissolved in the brine is decreased, thus effectuating the reduction of corrosion of the container as well as the fins.
As described above, fins 7 are positioned inside of the brine boxes 5 on the refrigerant circulating pipes 8. The fins 7 can be parallel individual fins or spiral fins and they act to better the thermal conductivity coefficient between the brine and the refrigerant. However, it may occur that when a vehicle carrying a container is running on a sloping road the container will tilt, and the brine in the brine boxes tends to flow toward the lower end of the brine boxes so that the upper end of the boxes is void while the lower end is filled with the brine. There is thus no void space, in the lower end and when freezing occurs and the volume of the brine in the filled-up portion increases on account of the freezing, the lower ends of the brine boxes are expanded and deformed. This condition is illustrated in FIG. 6 which shows the condition of the brine box in a conventional freezing container in which one of the brine boxes has tilted so that the end of the brine box has been filled up with the brine and the brine box has expanded and been deformed when the brine has frozen. These boxes can be expanded until an explosion occurs and they are damaged. This condition thus impairs their durability seriously.
In the present invention, short fin-caps 22 are tightly fitted over the tops of fins 7 on the circulating pipes 8, or long fin-caps, 23 are secured to the fins with an adhesive 25. By means of the fin-caps the inside of each of the brine boxes 5 is partitioned into independent chambers 24 at the tops of the fins 5, and the brine 9 charged into said brine boxes 5 is distributed into said chambers 24 leaving a void space 21 above the brine in each chamber, thereby enabling the aforementioned defect to be eliminated.
FIGS. 3 and 4 shows a preferred example thereof, in which box-like tin-caps .22 are formed by folding side plates 26 down from the edges of a flat plate and posi-.
tioning the fin-caps over substantially square fins 7 on the long, aluminum refrigerant circulating pipes 3. The side plates 26 fit tightly against the edges of fins 7. The inside of the brine boxes 5 are thus partitioned into independent chambers 24 by the engagement of the edges'of the fins 7 on the refrigerant circulating pipes 8 with the side walls 26 of the rectangular, box-like fin-caps 22. The freezable brine 9 in said brine boxes 5 is then prevented from running to one end of the box and deforming the boxes 5 even though the container tilts, as shown in FIG. 5, when a. vehicle carrying it is on a slope, so that damage such as deformation or breaking of the brine boxes 5 can be completely prevented.
Conventional freezers or refrigerators, the inside of which is directly cooled by means of regrigerant fed into circulating pipes therein, have had the disadvantage of a constant fluctuation of the temperatures of a freezing brine or gas used as the refrigerant, and also have had a high heat loss. On the other hand, the present invention can maintain the container at a certain temperature for a long time, as described in connection with the foregoing embodiment, because the heat loss from the container is,
with the disclosed embodiment of the present invention.
where the brine capacity of the brine boxes was kg., the total amount of heat of fusion would be 100 kg. 72K cal./kg.=7,200K cal.
where ammonium chloride is used. Where the amount of heat transferred out of the container to the brine was 360K cal./hr., the time during which the containercould be kept at l6 C. until the brine melted was 7,200K cal./36OK cal./hr.=20 hours or 20 hours where 100 kg. is being kept cool.
As aforesaid, the freezable brine in the brine boxes in the apparatus can be used for a long time after it has been detached from the container upon termination of the freezing of the brine by the refrigerant in the circulating pipes, and in the case of a refrigerant gas which may be employed and cooled by Dry Ice or the like, it will be kept cold during a long period of delivery, and itcan easily be, attached to a vehicle because it has a small size and a light weight.
With the construction of the present invention, it can be seen that the refrigerant coefficient can be augumented and the whole of the container can be maintained at a specified temperature. it possible to reinforce the structure of the container Walls while also avoiding a reduction of the volume of the inside of the container; The claimed apparatus-makes it possible as well to dispense with attached devices necessary for the fan cooler. Moreover, it requires no power source for a motor for working a fan cooler, although it can considerably diminish the heat loss, and, since the temperature difference between the freezing brine and the refrigerant will be great enough if it is about 2-5 G, the thermal coefficient will be improved. Hence the invention provides a suitable, effective portable cooler.
What is claimed is:
1. A portable cooler comprising a container having inner and outer walls, insulation between said walls, a plurality of brine boxes along the outside surfaces of said inner walls, a freezable brine .in said boxes, a refrigerant circulating pipe extending through each of said brine boxes, said refrigerant circulating pipes being coupled to Furthermore, this invention makes 5 each other in a refrigerant circulation system adapted to be attached to an outside cooling means for cooling a refrigerant and passing it through said circulation system and said refrigerant circulating pipes, a plurality of fins on said circulating pipes in each of said brine boxes, and fincaps fitting over the upper portions of the fins within said brine boxes and engaged with the edges of the upper portions of said fins for separating the spaces between the fins at the upper portions thereof from the spaces within the upper portion of the brine boxes, the brine within each brine box filling the spaces between the fins to a point within the fin-caps below the top edges of the fins 5 said fin-caps are lapped tightly onto the fins.
3. A portable cooler as claimed in claim 1 in which said fin-caps are adhered to the edges of the fins.
No references cited.
10 ROBERT A. OLEARY, Primary Examiner.
N. R. WILSON, Assistant Examiner.