Refrigerated produce transport

Fresh produce is loaded into an enclosed trailer, and the doors closed. Chilled water is pumped through overhead sprinkler pipes to chill the product to about 35 degrees Fahrenheit. Liquid nitrogen is used to maintain the trailer cold during transit and storage. Nitrogen tanks within the trailer are filled during the water chill operation. The nitrogen tanks are bled during the filling operation and the bled nitrogen extends through expansion tubes which are located co-axially within the water sprinkler tubes in the ceiling. From there the nitrogen is fed through exhaust pipes along the floor of the transport to purge the product of atmosphere and respiration gases. During transport, the liquid nitrogen is fed into the overhead expansion tubes for refrigeration and again the evaporated nitrogen is fed to the exhaust pipes along the floor to purge the product of respiration gases and to maintain the product oxygen-free.

BACKGROUND OF THE INVENTION 
(1) Field of the Invention 
This invention relates to fresh produce and more particularly to the 
transportation of said produce. 
(2) Description of the Prior Art 
Before this invention, fresh harvested produce such as radishes had been 
loaded into trailers and chilled by a water flood. The water was flooded 
into the trailer by inserting water pipes into the open doors of the 
trailer and leaving the doors open for the water to drain from the trailer 
after it had flushed the product. After the product was chilled, the 
normal atmosphere was purged from the trailer and from the produce by 
flooding the area with nitrogen gas as produced by liquid nitrogen. 
Thereafter the trailer was closed as tightly as possible and sent to its 
destination. During this time, conventional refrigeration units were 
provided to keep the contents as near as possible to 32.degree. 
Fahrenheit. 
Before filing the parent application, a search was made in the United 
States Patent and Trademark Office and the following patents were found: 
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JOHNSON ET AL 2,479,840 
ELLIS 3,153,917 
SNELLING 3,385,073 
LICHTENBERGER ET AL 3,421,336 
MAURER 3,525,235 
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JOHNSON ET AL discloses cooling a refrigerated car by the expanding of 
liquid air. As described in column 5, line 11 of that patent, the liquid 
air might contain more oxygen than the atmosphere itself, or it might 
contain less oxygen. 
ELLIS discloses discharging liquid nitrogen below floorboards within a 
compartment. Fresh food within the compartment would be chilled, but not 
frozen. 
SNELLING discloses a refrigeration system for shipping perishable 
commodities having a heat exchanger (evaporator) at the top of the 
compartment. The gaseous nitrogen is discharged to the outside of the 
compartment. SNELLING also discloses pulling outside air from outside of 
the compartment or container to within the compartment or container. 
Column 7, line 4 indicates that the nitrogen may be discharged within the 
container. 
LICHTENBERGER ET AL discloses coolant conduits extending under a covered 
floor or channels in the floor. 
It does not appear to applicant that MAURER is as significant as the above 
described patents. 
During the prosecution of the parent application, applicant became aware of 
the DIXON patents. They are as follows: 
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DIXON 3,239,360 
DIXON 3,269,133 
DIXON 3,365,307 
DIXON 3,487,769 
DIXON 3,563,757 
DIXON 3,962,477 
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These patents show that it is desirable to reduce the amount of oxygen 
present in a closed container carrying fresh produce. The DIXON references 
teach that it is desirable not to reduce the oxygen below 5%. Specific 
examples in DIXON indicate that the oxygen in certain cases may be reduced 
to as low as 1/4 of 1%. 
The following additional patents are of record in the parent application. 
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COYNER 2,751,882 
STOWASSER ET AL 3,672,182 
RHOAD 3,961,925 
WATERS 4,229,948 
SHAW 4,307,580 
______________________________________ 
However, applicant does not believe they are as pertinent as the patents 
specifically discussed above. 
SUMMARY OF THE INVENTION 
(1) New and Different Function 
I have invented a method for processing and transporting produce whereby 
the unusual and surprising results of maintained or enhanced freshness and 
flavor is achieved. 
I use a special trailer which has permanently installed sprinkler pipes in 
the top thereof. Therefore, the doors are closed during the chilling 
process, greatly increasing the thermal efficiency of this process. 
The produce is loaded into the trailer, or container, as soon as possible 
after harvest. Then the chilling process and the purging of all oxygen 
from the container occurs as soon as possible. 
Nitrogen bottles carried on the trailer are filled during the chilling 
process. The exhaust nitrogen from the bottles is used in aiding the 
chilling of the water. This is accomplished by placing the nitrogen 
expansion tubes inside and co-axial with the sprinkler pipe. This location 
had another advantage, because in maintaining the low temperature during 
transportation, the evaporation of nitrogen within the pipes often forms 
super chilled ice around the pipes. If this super chilled ice falls upon 
the produce, it damages the produce upon which it falls. However, by 
having the expansion tubes within the water sprinkler pipes, it prevents 
the super chilled ice from falling upon the produce. After the nitrogen 
has been expanded, the exhaust nitrogen, both during the chilling period 
and during the transport period, is exhausted beneath the produce to purge 
the produce of atmosphere so that it is oxygen free and also to remove 
respiration gases generated by the produce. 
Therefore, it may be seen that the total function of the combination of 
structure and steps of the method far exceeds the individual elements such 
as bottles, pipes, drains, etc. 
(2) Objects of this Invention 
An object of this invention is to process and transport fresh produce and 
other vegetation. 
Further objects are to achieve the above with a method that is versatile, 
ecologically compatible, energy conserving, rapid, efficient, and 
inexpensive, and does not require skilled people to adjust, operate, and 
maintain. 
The specific nature of the invention, as well as other objects, uses, and 
advantages thereof, will clearly appear from the following description and 
from the accompanying drawing, the different views of which are not scale 
drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The refrigerator transport 10, according to my invention, is illustrated in 
the form of a trailer for highway use. The main portion of the transport 
is container or body 12. The body 12 itself might be a railroad car or it 
might be a compartment or container suitable for loading aboard a ship, 
rail car, or highway truck. 
Describing the transport as a highway trailer, wheels 14 under the body 12 
are adjacent to the rear 16 of the body. Fifth wheel 18 is connected near 
front wall 20 of the body 12. The fifth wheel is for attaching the 
refrigerated transport unit to a tractor. The fifth wheel 18 and the 
wheels 14 form a means for transporting the container or body 12 from one 
location to another in this embodiment. In other embodiments, the means 
for transporting would take other forms such as railway trucks or skids 
and lifting eyes. 
The body 12 has side walls 22, top 24, and floor 26. Doors 28 over door 
openings will be at the rear of the body 12, which is opposite the front 
wall 20. The body, which is substantially air tight, will be insulated by 
insulation 29 in the walls, top, floor and doors of the body. 
Water sprinkler conduits or pipes 30 are attached to the top 24 of the body 
therein. According to present design, a sprinkler unit of ten sprinkler 
pipes extend from the back to the front of the body. A water header 32 is 
located at the rear of the trailer within the body. Water inlet pipe 34 
extends upward from the water header 32 through the insulated top 24 to 
cap connection 35 on top of the trailer. Each of the ten water pipes 30 
fluidly and structurally connect to the water header 32. Sprinklers 36 are 
connected to the water pipes 30. When water is pumped into the inlet pipe 
34 it flows through the water header 32 into the pipes 30 and out the 
sprinklers 36 which are sprinkler openings, flooding the body of the 
trailer with the water and particularly any produce which might be 
contained within the body 12. 
Water drain means 38 is located in the floor 26 at the rear 16 of the 
trailer. The drain has a small catch basin 40 to catch and gather the 
water. According to present design, two outlet pipes 42 are connected to 
the water drain 38. The catch basin is covered by a suitable grille 44. It 
may be seen that when chilled water is pumped into the inlet pipe 34 and 
sprinkled through sprinkles 36 that the water, after flooding and chilling 
the produce within the body 12, will run to the basin 40 and be drained 
through the water outlet pipes 42. This is done with the doors 28 closed. 
The doors have seals 46 upon them to prevent thermal transfer around the 
doors. The chilling of the produce can be performed very economically with 
a minimum of thermal loss. 
The water from the outlets 42 flows into a collection trough 48 outside of 
the body. The water is picked up by pumps 50 and pumped through water 
chiller 52 to be returned to the sprinkler pipes 30. Normally the produce 
will be chilled to a temperature which is above freezing. Normally the 
chilled water will be very close to freezing, to about 36.degree. 
Fahrenheit. For efficient operation, the chilled water will not be higher 
than 37.degree. Fahrenheit. For efficient operation, the volume of the 
water will not be less than 500 gallons per minute. 
In certain cases the best available chilling water will be spring water or 
ground water from wells. In any event, the vegetation within the trailer 
is chilled as soon as possible with water of the lowest temperature 
available provided that the temperature of the water is never lower than 
what the vegetation will tolerate. Those having skill in transporting 
vegetation will recognize that each different produce (e.g. tomatoes, 
corn, mellons, lettuce, radishes) will be able to tolerate different 
temperatures. Seldom will any vegetation tolerate a temperature lower than 
0.degree. Centigrade (32.degree. Fahrenheit). Some vegetation will not 
tolerate temperatures this low. 
Bottle means 54 suitable for carrying liquid nitrogen is located within the 
container body 12 adjacent to the front wall 20 thereof. Nitrogen 
expansion tubes 56 are located co-axially within the water sprinkler pipes 
30. According to present design, there are five expansion tubes. One end 
of each expansion tube 56 is connected to a nitrogen liquid header 58. The 
bottle means 54 is fluidly connected by connection 60 to the liquid header 
58. Each of the expansion tubes 56 enters a terminal end 62 of one of the 
water pipes 30 adjacent to the liquid header 58. The terminal ends 62 of 
the water pipe are adjacent or near the front wall 20 of the body 12. The 
expansion tube extends through the water pipe to the water header 32. Each 
expansion tube 56 makes a U-turn within the water header 32 and runs back 
as a back run through an adjacent water pipe 30. The expansion tubes are 
within the sprinkler unit. After the back run of the expansion tube 56 
extends through the terminal end 62 of the water pipe, and downward to one 
of five exhaust tubes or conduit or pipes 64. The exhaust pipes run along 
the floor 26 of the trailer. The exhaust pipes 64 run parallel to the 
water pipes, i.e. from the front to the back of the trailer. The exhaust 
pipes have exhaust openings or nozzles 66 therein. 
The expansion tubes 56 are held co-axially within the water pipes by spring 
positioners 68. These spring positioners are made of round spring wire and 
they make about a 360.degree. loop around the expansion tube 56 and have a 
terminal end 70 on each side of the expansion tube 56. The distance 
between the two terminals 70 is approximately the inside diameter of the 
water pipe 30. Therefore, the expansion tubes are held co-axially within 
the water pipe. 
As illustrated the exhaust pipes 64 have rectangular cross-sections. They 
are located within the floorboards 72 of the trailer. Specifically 
illustrated referring to the floor and floorboard construction there may 
be seen main crossbeam 74 forming a substantial part of the structural 
elements of the body 12. Wooden cross spacers 76 are located above the 
crossbeams 74. Outer skin 78 of the body 12 is located between the 
crossbeam 74 and spacers 76 as is customary in refrigerated trailer 
construction. Longitudinal I-beams 80 are attached above the wooden 
spacers 76. The floorboard or plate 82 is above the longitudinal I-beams 
80. At five regular intervals along the plate 82 there is a rectangular 
indentation or channel 84. The rectangular exhaust tubes or pipes 64 are 
located within the five rectangular indentations of channels. The nozzles 
66 extend to one side of the exhaust pipe so that they are protected from 
being plugged by debris. It is emphasized that the longitudinal I-beam 80 
and floor plates 82 as well as the crossbeam 74 and spacer 76 are designed 
for a general cargo carriage. 
The nitrogen bottles 86 forming the bottle means 54 are permanently affixed 
within the container or body 12 to the front wall 20. According to current 
government regulations they are limited to twenty pounds pressure and are 
provided with an insulation jacket and evaporative vent and cooling means 
to maintain the nitrogen liquid at this low pressure. A filling line 88 
extends from valve manifold 90 to outside the trailer through the 
insulation of either the front wall 20 or one of the side walls 22. Part 
of the connection 60 from the bottle means 54, extends to the manifold 90. 
Part of the filling operation is to vent the nitrogen bottles 86 during 
the filling process. This vented nitrogen is connected through the 
manifold 90 and connection 60 to the expansion tubes 56. According to 
present commercial practice, approximately one-third of the capacity of 
the nitrogen bottles 86 will be vented during the filling process. This 
will be chilled gas. The filling process is contemporaneous with the water 
chilling process. Since the expansion tubes 56 are co-axial with the water 
pipes 30, the water is further chilled by the vented gas from the filling 
procedures. 
Temperature control means 92 is connected to the manifold 90. After the 
produce is chilled and during transport to a second location, the 
temperature within the body is maintained at the desired level which is as 
low as the vegetation will tolerate, by the temperature control means 92. 
This is performed by opening valves to connect liquid nitrogen into the 
expansion tubes 56. The nitrogen will evaporate within the expansion tubes 
56 chilling this area. After the nitrogen has expanded, it passes to the 
exhaust tubes or pipes 64 so that it exhausts beneath the produce to 
continue to purge respiration gas which may be formed by the produce and 
to maintain an oxygen free atmosphere. 
Describing the operation, the doors 28 are opened and the produce, which is 
vegetation, for example radishes, is loaded within the body 12 of the 
trailer transport 10. Normally the produce is on pallets which are loaded 
by fork lifts. When the produce is loaded, the doors 28 are closed, and 
the seals 46 make the body 12 substantially air-tight. However, there are 
sufficient leaks or vents within the body to permit the escape of excess 
gas without forming undue high pressures within the body. 
In addition to the leaks within the body to permit excessive gas from 
forming undue high pressures in the body, there is also pressure relief 
vent 94 which will vent or release gasses from within the body, but not 
permit the entry of the gasses from outside to within the body. It is 
important to prevent outside gasses from entering the body since the 
outside gasses are the normal ambient atmosphere which contains oxygen. 
Thereafter, the trailer is positioned with the water drain 38 over or 
adjacent to the trough 48. Connections from water chiller 52 are made to 
the water inlet pipe 34 on top of the body 12. Then with the water chiller 
52 operating, and the pump 50 operating, water is flushed over the 
radishes to chill them. Also liquid nitrogen from an external source is 
connected to the filling line 88. Through proper setting of manifold 90, 
the nitrogen bottles 86 are vented to the expansion tubes 56 and the 
nitrogen bottles 86 filled. 
When the nitrogen bottles 86 are filled and when the produce (radishes) is 
chilled, the liquid nitrogen source is disconnected from the filling line 
88 and the water chiller 52 disconnected from the water inlet pipe 34. The 
inlet pipe is capped to maintain the body 12 substantially air tight, and 
the water outlet 42 also is capped for the same reason. 
Thereafter, liquid nitrogen from bottles 86 is released into the expansion 
tubes 56 where the liquid nitrogen vaporizes, chilling the tubes and 
through convection currents also keeping the body chilled also. The 
exhaust gas is exhausted through the exhaust nozzles 66 below the radishes 
to continue to remove expiration gas from them. The original atmosphere 
and the respiration gas present is removed from the radishes by the 
exhaust gas that is vented from the bottles 86 during the filling and 
chilling cycle so that the atmosphere in the container is oxygen free. 
It is particularly important that the produce or vegetation be placed in 
the container at a first location and chilled as soon as commercially 
feasible. In certain situations, it will be commercially feasible to first 
chill the produce by using natural, available water. For example, in some 
cases there will be cold spring water, or cold ground water such as from 
wells which can be used to chill the vegetation. Then after an initial 
chilling, the produce can be transported to a more convenient location 
where colder water and a nitrogen supply is available. At that time, the 
chilling process can be completed and the removal of the oxygen containing 
atmosphere can be effected. The temperature of the water and the 
temperature to which the vegetation is chilled will be as low a 
temperature as is available but under no circumstances will it be a 
temperature lower than what the vegetation will tolerate. The removal of 
oxygen is desirable and the container be maintained free of oxygen. After 
the vegetation is thoroughly chilled or cooled by water, the doors are 
closed and the transporation process begun. The container is maintained at 
a low temperature by nitrogen evaporation only. I.e. the evaporation of 
the liquid nitrogen will hold the contents at a low temperature as well as 
continue to maintain the container oxygen-free. During this time any 
excessive gasses within the trailer will flow from the leaks around the 
body of the trailer which are maintained to as low a level as possible. 
Additionally, there is the valve 94 by which excessive gasses from within 
the body may be exhausted. During the transportation, the temperature in 
the container is maintained as low as vegetation will tolerate. 
When the trailer with its load of produce reaches the second location, the 
doors 28 are opened, the liquid nitrogen turned off, so as to cease the 
chilling operation within the body 12. The produce is removed from the 
body. Thereafter the trailer 10 is used to backhaul any cargo available. 
The floorboards are made of sufficient structural strength to support 
general cargo and to withstand the rough handling to which they are 
subjected by the general cargo hauling. 
At the time the trailer is returned to the point where the produce is to be 
loaded, the described process is repeated. 
The embodiment shown and described above is only exemplary. I do not claim 
to have invented all the parts, elements or steps described. Various 
modifications can be made in the construction, material, arrangement, and 
operation, and still be within the scope of my invention. 
The limits of the invention and the bounds of the patent protection are 
measured by and defined in the following claims. The restrictive 
description and drawing of the specific example above do not point out 
what an infringement of this patent would be, but are to enable the reader 
to make and use the invention. 
As an aid to correlating the terms of the claims to the exemplary drawing, 
the following catalog of elements is provided: 
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10 transport 52 water chiller 
12 body 54 bottle means 
14 wheels 56 expansion tubes 
16 rear 58 nitrogen header 
18 fifth wheel 60 connection 
20 front wall 62 terminal ends 
22 side walls 64 exhaust pipes 
24 top 66 exhaust nozzles 
26 floor 68 spring positioners 
28 doors 70 spring terminal 
29 insulation 72 floorboards 
30 water pipes 74 crossbeam 
32 water header 76 spacers 
34 water inlet pipe 
78 skin 
35 cap connection 80 I-beams 
36 sprinklers 82 floorboard or plate 
38 water drain 84 channels 
40 basin 86 nitrogen bottles 
42 water outlet 88 filling line 
44 grille 90 manifold 
46 seals 92 temperature control 
48 trough 94 valve 
50 pump 
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