US3464222A

US3464222A - Refrigeration arrangement

Info

Publication number: US3464222A
Application number: US694244A
Authority: US
Inventors: Harold E Gramse
Original assignee: Pullman Inc
Current assignee: Pullman Standard Inc; Pullman Inc
Priority date: 1967-12-28
Filing date: 1967-12-28
Publication date: 1969-09-02
Anticipated expiration: 1986-09-02

Description

H. E. GRAMSE REFRIGERATION ARRANGEMENT sept.' 2, 1969 2 s'nee'ts-sheet 1 Filed Dec. 28. l1967 .E mm

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INVENTOR. Harold EGr'omse Aftofneyv Sept. 2, 1969 H. E. GRAMSE REFRIGERATION ARRANGEMENT 2 SheetshSheet 2 Filed Dec. ,'28, 1967 mnofxm w v@ 5 l FNEQFNZ Soi m INVENIUR. Harold E. Gromse- [SY At'forney United States Patent O U.S. Cl. 62-45 6 Claims ABSTRACT F THE DISCLOSURE A refrigeration arrangement for a railroad refrigeration car including liquid nitrogen tanks mounted at one end of the car and provided with liquid nitrogen conduit means including a first conduit portion leading from the tanks to a heat exchanger and a second conduit portion leading to a nitrogen gas spray header conduit for spraying of nitrogen gas within the car for cooling, the second conduit portion having an orilice to reduce the cross sectional flow area to the heat exchanger, a heat exchanger for changing the liquid nitrogen to a gas for admitting the nitrogen gas under pressure of expansion to a nitrogen gas conduit, a pneumatic motor for driving an air intake fan coupled with the nitrogen gas conduit, an air inlet housing the fan and having a damper to introduce air into the car when the pneumatic motor is driven by the nitrogen gas, and temperature sensing means having mechanical trip to operate the nitrogen tank valve for introducing nitrogen into the liquid nitrogen conduit means when the temperature falls below a pre-determined value.

Cross-references This application is an improvement of my copending application having U.S. Ser. No. 669,819 and filed on Sept. 22, 1967.

BACKGROUND OF THE INVENTION Field of invention This particular invention relates to the eld of art concerned with the refrigeration of railroad cars and particularly to the type of refrigeration system supplying a cryogenic gaseous medium to the interior of the railroad car.

Description of the prior art The prior art heretofore has employed the use of liquid nitrogen which is introduced as a gas for cooling the interior of a refrigeration railroad car containing meats and vegetables or the like. However, refrigeration systems of this type usually require maintenance and require the use of a power source for operation. This results constant care of the system and results in delaying repairs which prevent use of the car during the time the repairs and maintenance are made. The subject invention eliminates the need for maintenance and repair of the refrigeration equipment so that the refrigeration car may remain in continuous service. It is also advantageous to introduce air with the gaseous nitrogen within the car to produce ran atmosphere that is a better environment for the transportation of meat and vegetables and the like.

Summary The invention provides a maintenance-free refrigeration arrangement for a railroad car employing a wholly automatic refrigeration system responsive to changes in temperature within the car. In particular, the invention takes advantage of the latent energy of nitrogen liquid and gas stored within the car tanks whereby the liquid nitroice gen, when exposed to a heat exchanger, goes to a gas and operates a motor for drawing outside air into the nitrogen car for environmental control while also allowing liquid nitrogen to expand to a gas for introduction into the car interior for cooling the car interior.

The invention has for its objects, purposes and advantages the introduction of nitrogen in the gaseous form within the car and also the introduction of gaseous nitrogen to a pneumatic driven motor for operating a fan to draw air from the outside through an inlet into the interior of the car for mixing with the gaseous nitrogen. These and other purposes, advantages and objects will become apparent from reference to the following description, drawings and appended claims.

Brief description of the drawings FIG. l is a plan view of the interior of a refrigeration car illustrating my novel and inventive refrigeration system;

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a sectional view taken along line 3--3 of FIG. 2; and

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3.

Description of the preferred embodiment With reference to the drawings and particularly with reference to FIGS. 1 and 2, there is shown a railroad box car 2 of the refrigeration

type having sides

4 and 6 and ends 8 and 10, all of which are provided with urethane insulation 12, and interior walls 14 of fiber .glass to insulate the interior 16 of the car from the outside. The roof 18 is also provided with the insulation 12 and the fiber glass 14. Depending from the upper cross structure 20 are meat rails or racks 22 provided with meat hooks 24 for carrying meat. The interiors of the

side walls

4 and 6 are provided with separator tracks 26 for carrying movable separator doors (not shown) for dividing the interior of the car into a number of compartments, as desired. The interior 16 of the car 2 at the end 8 is provided with a nitrogen tank storage compartment 28 provided with a set of nitrogen storage tanks 30` which contain liquid nitrogen 32. The liquid nitrogen tank compartment 28 is provided with an access door and control panel element 28a and the sides of the car are provided with the door openings 7 and doors 9. In the compartment shown there are two such sets of tanks 30, each provided with liquid nitrogen outlet conduits 34 for supplying of liquid nitrogen for the opposite ends of the car. Each liquid nitrogen bearing conduit 34 is provided with an outlet valve 36 controlled by a temperature sensing bulb means 38. Each temperature sensor means 38 generally comprises a lcopper element that expands or contracts with changes in temperature to operate mechanical linkage or temperature control cable 40 connecting with thermostat control means 42 connected with mechanical linkage 44 operating valves 36. The thermostatic control means 42 is set for, say, a temperature of 30 so that if the temperature falls below 30 the temperature sensing bulb 38 operates the

mechanical linkage

40 and 44 t0 open the valve to introduce liquid nitrogen 32 into the respective nitrogen conduit 34. This type of an arrangement is generally shown in my above referred to co-pending application.

The liquid Ibearing nitrogen line 34 branches into a spray header conduit or line 46 and a heat exchanger line 48. The spray header line 46 comprises an elongated copper tube provided with a plurality of orifice `spray means S0 disposed longitudinally of the spray header conduit for supplying nitrogen gas to the full length interior of the car exclusive of the nitrogen compartment 28. Each spray means 50 comprises a pair of laterally disposed orifices 52 in conduit 46 and each orifice 52 is disposed at approximately an angle of 30 to 35. This orifice angle is desirable for introducing nitrogen gas from the upper part of the car interior. The liquid nitrogen in the tube 46 turns to a gas approximately at each orifice 52 and is introduced into the car in the gaseous state for maintaining the temperature of the car interior at or below the temperature of 30 F. Should the temperature fall below approximately 30, the temperature sensing means would operate to close the nitrogen liquid admitting valve 36. Since each of the liquid nitrogen bearing conduits with their spray orifices 52 are disposed lengthwise of the entire car, uniform cooling of the -meat and vegetables and the like is maintained. The conduit 48 leading to the heat exchanger 56 is provided with orifice means 58 which is reduced in crosssectional area to reduce the return of flow of the nitrogen liquid to the heat exchanger 56 where the liquid nitrogen 32 goes to a gas, resulting in additional cooling of the car. The heat exchanger 56 is of the copper iin tubed type for effecting the fast change of liquid to gas. It is noted that the conduit 48 to the heat exchanger is joined to the main line 34 and to the header line 46 by a T-coupling 47, and an elbow element `49 provides for a bend in the header conduit means 46 to divide it into

portions

46a and 46b, the latter having the orifice means 50.

A gaseous nitrogen bearing conduit 60 extending from the heat exchanger `56 connects with an air motor 62 and is driven by the expansive nitrogen gas 33 to operate a fan means 64 for drawing in outside air through an air inlet structure 66.

With reference now in particular to FIGS. 4 and 5, there is shown the multiple fin construction 56a of the heat exchanger 56 that extends about the conduit 48 ex tending from the orifice means 58. The exiting portion of the conduit 58 by means of a coupling arrangement 61 is coupled to the nitrogen gas bearing tube leading toward the pneumatically or nitrogen gas-operated motor 62. The conduit 60, by means of a coupler 63, is attached to motor inlet tube 65 which is attached to the motor housing 67 of the motor 62. The motor housing or body 67 is mounted -by bolt means 68 to L-shaped bracket 69 mounted on arm 70 attached by bolt means 68a to the load divider track 26 mounted on the inside wall of the car. The gaseous nitrogen 33 is introduced from the inlet line 65 into the inlet port 72 of the motor housing 67 and flows parallel to the motor shaft 84 by passage 73 to the motor housing end plate passages 74 and travels through both end plate passages (only one of which is shown) to the motor housing end plate kidney-shaped ports (only one of which is shown) 75 and enters the appropriate rotor slot 76 of a plurality of rotor slots that registers with the kidney-shaped ports 75 and passes from the particular slot 76 pushing the vane 78 out and passes to chamber 80 as, for example in the drawing FIG. 4, charnber portion 88a acting on the exposed portions of the vanes 78 in passage portion 80a to turn the rotor 82 with the air exiting from the chamber 80, as indicated by the arrows in FIG. 4, out of outlet port 84 into the interior of the` car, resulting in rotation of the rotor shaft 86 attached to the rotor 84. This rotates shaft couple 88 and fan shaft 90 in the same direction as rotor shaft 86 and in turn rotating the blades 92 of the fan 94 for drawing air through the fan and into the interior of the car from the air intake tube 96 mounted in the openings 98 in the one side 4 of the car 2. The air intake tube is of L-shaped elbow construction and is provided with a dust filter 100 and a damper 102 having a damper plate 105 pivotally mounted on shaft 104 which (as seen in FIG. 2) is mounted above the center line of the air intake tube 96 to permit pivoting of the damper shaft 104 inwardly from the bottom of the damper, moving the damper lower end upwardly to permit introduction of outside air into the interior of the car. The damper 102 is carried by mounting bracket 106 on the shaft 104.

The invention provides for a novel refrigeration systern which is actuated -by changes in temperature to operate mechanical linkage for opening the liquid nitrogen supply to the interior of the car and wherein the liquid nitrogen is also converted to a gas for operating the pneumatic motor which in turn operates a fan for introducing air into the car interior. Any bearings that are used are of the self-lubricating type and there is no maintenance required on the various components used in the refrigeration system. The energy needed to operate the refrigeration system comes from the expansion of the nitrogen from a liquid to a gas. The refrigeration system and discharge of the nitrogen gas is from the top portion of the car so that it, being cooler than the air in the car, will descend to cool the entire interior of the car. The introduction of air into the car preserves the quality of the meat and produce therein.

`The foregoing description and drawings are given merely to explain and illustrate the invention, and the invention is not to be limited thereto, except insofar as the appended claims are so limited, since those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.

What is claimed:

1. In a railroad container, a refrigeration arrangement comprsing conduit means for supplying a cryogenic gas into the interior of the container from a source of a cryogenic liquid,

a heat exchanger for changing the cryogenic liquid to a cryogenic gas whereby the interior of the container may be cooled,

a conduit means including first conduit for connecting a source of cryogenic liquid with the heat exchanger for supplying the cryogenic liquid to the heat exchanger,

a perforated spray header means provided with a plurality of orifice means for discharging a cryogenic liquid as a gas at the orifice means whereby cryogenic gas may be discharged into the interior of the container,

a second conduit connecting the first conduit with the header means,

a pneumatically operated motor provided with a drive shaft driven by the cryogenic gas,

a third conduit connecting the heat exchanger with the pneumatic motor for supplying cryogenic gas to the motor,

an air intake means mountable on the container for communication with the interior, and

fan means disposed within said intake means and drivingly connected with the drive means of the motor for drawing air from the outside to the interior of the container for mixing with the cryogenic gas.

2. The invention according to claim 1, and

said second conduit connecting the conduit means with the heat exchanger being provided with a flow restricting orifice to reduce the rate of flow of cryogenic liquid from the conduit means into the heat exchanger.

3. The invention according to claim 1, and

said air intake means being provided with an eccentrically mounted damper within the air intake means and openable upon drawing of air into the container interior.

4. The invention according to claim 1, and

temperature sensing means responsive to changes of temperature within the container and operatively connected with associated cryogenic liquid emitting valve means through a mechanical connection to permit flow of cryogenic liquid within the conduit means to the heat exchanger and header means when 5 6 the temperature falls below a predetermined tem- References Cited Pefatlfe- UNITED STATES PATENTS 5. The invention according to claim 1, and

and a valve means openable by the temperature sensing means upon falling of the temperature below LLOYD L KING, Primary Examiner a predetermined value. 6. The invention according to claim 1, and said cryo- 10 U.S. Cl. X.R. genie liquid comprising nitrogen. 62-52, 239