US2393868A - Heating system for refrigerator cars - Google Patents

Description

c. D. N|VEN HEATING SYSTEM FOR REFRIGERATOR CARS Jan. 29, 1946.

Filed July 9, 1942 s Sheets-Sheet 1 .INVEIVITOR C HARLLS 0 /V/ A rrokvsys 1946. c. D. NlV EN HEATING SY STEM FOR REFRIGERATOR CARS Filed July 9, 1942 s Sheets-Sheet 2- Jan. 29, c D NlV HEATING SYSTEM FOR REFRIGERATOR CARS Filed July 9, 1942 3 Sheets-Sheet 3 ATTORNEYS grammatic showing the control Patented Jan. 29,1946

I HEATING SYSTEM FOR REFRIGERATOR CABS Charles David Niven, Ottawa. Ontario, Canada, alsignor to The Honorary Advisory Council for Ontario, Canada Application July 9, 1942, Serial No. 450,31 6

This invention relates to improvements in heating systems for refrigerator cars of the type employing fuel heating means connected to coils on the interior of the car through which heating liquid is circulated. The objects of the invention -are to provide for more effective control of the temperature of the car through regulation of the circulating liquidand the heating means.

When refrigerator cars are used during cold weather it has been the practice for some time to provide for some form of-heating means. In my United States Patent No. 2,076,961, dated April 13, 1937, a convenient form of such heating means has been illustrated. It is desirable, however,

that in such a device means should be provided" for controlling both the circulation-of the heating fluid medium and the combustion of the solid fuel by means of which it is heated.

According to the present invention a thermostatic control is provided applicable to trucks. railway cars and the-like, adapted for the transportation of perishable products and equipped with fuel heating means located below the floor of the car. In its construction the invention comprises a double control consisting in the first place of a thermostat located on the interior of the car and designed to control the flow of the liquid in the heating coil whereby a portion or all of the circulating liquid may be caused to flow through a suitable by-pass pipe, and an auxiliary thermostat controlled by the temperature of the liquid in the by-pass pipe and adapted to control the solid fuel heating means, means-in the form of a thermal trap or traps being preferably provided to prevent undesirable back circulation of the heating liquid, all as hereinafter more fully set forth and described in the accompanying specification and drawings.

In the drawings:

Figure 1 is a diagrammatic top plan of a portion of a refrigerator car with parts removed 7 showing the heating system installed therein.

Figure 2 is a sectional side elevation showin certain portions of the system.

.mgure 3 is a sectional elevation of a thermal trap employed in the system.

Figure 4 is a sectionalelevation partly diameans operated by the main thermostat.

Figure 5 is a sectional elevation takenon the line 5-5 of Figure 4.

Figure 6 is a detail in elevation showing the link mechanism for operating the draught control from the auxiliary thermostat.

Scientific and Industrial Research. Ottawa,

Figure 7 is a perspective detail of one of the contact members of the valve.

Figure 8 is a section on the line 8-8 of Fi ure 4.

In the drawings like characters. of reference indicate corresponding. parts in all the figures.

Referring-to the drawings, A indicates a refrigerator car or truck, which may be of any convenient construction and "a portion only of 10 which is shown.

B indicates a solid fuel heater, conveniently located beneath the floor It of the-car and which may beof any convenient design, such as that shown in my aforesaid Patent No. 2,076,961,

the combustion in the heater being adapted to be controlled by a suitable damper H of any con-- venient design.

C indicates the heating coll connected in series with. the heater and through which heating liduid is circulated, this heating liquid being preferably a suitable antifreeze solution. The pipes C are suitably connected to'fiuid heating means forming part of the heater B, and the coils C are suitably arranged on the interior of the car to effect the desired heating thereof, the direction of flow of the liquid through the coil C being indicated by arrows. The heater B may be conveniently heated by charcoal contained in the usual firepot in the heater and supplied from a suitable hopper, as set forth'in my earlier patent.

D indicates the main controlling thermostat, which is situated inside thecar, preferably under the floor racks i2. It may be of any convenient design, that illustrated including a large bimetal- 86 he coil l3.

The thermostat D is designed to control a valve E, the construction of which is shown'in detail in Figures 4, 5, 7 and 8. I'his valve includes a casing It, the lower part of which is connected 40 to the riser pipe 15 which should be therznall insulated or lagged and which forms part of the circulating coil system C, and alternative outlet pipes l6 and H, the pipe I! forming part of the usual circulating system of the heating coils on- I the interior of the car, while the pipe 16 constitutes a by-pass for the return of the heatin fluid medium when the usual or main circulation is closed as hereinafter described. This by-pass ipe I! should be thermally insulated to prevent its heating up the car.

The function of the valveE is to direct the to should move with as little power as possible, and

in the embodiment illustrated it is constructed with a pivoted flap member l8 adapted to carry contact members l9 and 20 on opposite sides designed to control the outlet from the casing to the pipes H or H. To facilitate the control, conical reducing members 2| and 22 are provided on the ends of the pipes 16 andll having screw threaded or other suitable engagement with the ends of these pipes. The opening ends of these conical reducing pieces maybe quite small in diameter, say of the order of half an inch, and they are carefully machined to fit the contact members l9 and 20.

Each of the contact members 19 and 20 includes a triangular plate 23 loosely mounted on transverse posts 24 supported on the plate l8, which is fixed to and turns with the shaft 25, and which is suitably journalled in the casing I4. Springs 26 surround the posts 24 on .each side and hold the plates 23 in their outermost position against nuts 21. The plates 23 at the outer side carry contact pieces 28 of brass. By adjusting the nuts 21 the position of the contact plates 23 may beadjusted accurately so as to close exactly over one or other of the conical members 2| and 22. v

The plate I8.which constitutes the flap of the valve, is accurately balanced and designed to be moved from the thermostat by suitable link mechanism. In .the form of this mechanism illustrated the end of the shaft is provided with a crank 29, the outer end of which has sliding engagement with the end ,of a lever 30, mounted in a tubular extension 32 supported on the casing M. The opposite end of the lever 30 is connected through a coupling 3| to the end of the bimetallic coil l3 on the thermostat. The bimetallic coil l3 as it expands or contracts is adapted to move the lever 30 in a direction substantially at right angles to its axis, as indicated by the arrows in Figure 4. T0 guide this move:- ment and prevent excess movement stops 31a may be provided on the coupling 3| co-operating with corresponding spaced stops 3lb provided on a suitable base plate 3lc, which maybe conven iently connected to the floor of the car.

In order to permit free movement of the arm A of the lever 30 and to prevent escape of the heatthreaded adapter 34 to the extension 32 and having at its outer'end a connector 35 which is fastened to the lever 30. In this way the increas or reduction in curvature of the bimetallic c of the thermostat D is caused through the lever 30 and crank 29 to operate the flap plate I8 moving it into alternative positions in which one or other of the pipes 16 or H is closed or to some intermediate position in which the outlets to both p pes are open. 7 Y In order to prevent the circulation of a random v nature inside the pipe when the inlet to the main for adjusting the thermostat D from the exterior of the car. The means which I have illustrated for this purpose include a rod 3'! connected to pivoted arm 38 on the thermostat and designed to effect slight winding or unwinding of the coil l3, the outer end of the rod having screw threaded engagementwith a sleeve 39, the sleeve being rotatively mounted in a suitable support 40, and

being designed to be turned in its support by means of a rod 4! having a crank 42 at its outer extremity mounted in a suitable control box 43. The liquid passing into the by-pass pipe I6 is designed to be returned to the heater B through coils 44 and 44a leading to a connecting T 45 which joins with the return pipe 46 which should be thermally insulated or lagged and which is part of the main circulating system. The main and by-pass pipes thus meet at the T 45, and in order to prevent random circulation adjacent to this point a thermal trap 41 having a similar construction to the trap F as shown in Figure 3 but with the prong or dam extending upwardly is provided in the coil 44 adjacent to the T 45. It will be observed by reference to Figure 2 that the relatively long pipe legs 41a and'flb are provided on opposite sides of the trap 41 so that the fluid is caused to pass upwardly to and through Q the trap and then downwardly.

G indicates the auxiliary thermostat. connected to the by-pass pipe IS in such a way that it will be affected by the temperature of the liquid passing therethrough, this thermostat being operatively connected to the damper I I. The thermostat G may be of any convenient design, preferably including a bimetallic coil which, when heated by the hot liquid passing through the 'by-pass, will be moved with sufficient power to operate the draught control 'II and may be pro-' tectively surrounded by a metal box. The convenient form of connection is illustrated in which the arm 43 connected to the end of the thermostat passes through and has loose engagement with a lever 49 which is pivoted intermediate of means of a spring 55 fastened at one end'to the me is closed a thermal trap F is inserted in the pipe 11 adjacent to the valve E, Thistrap F, whichmay be of a form shown in Figure 3, is formed with a baiiie member 36 extending from the-top of the trap downwardly and designed to prevent the hot liquid from travelling along the with the upper end of the lever 49. The spring operating the thermostat G moving the damper 52 and 53. the latter stop having arranged at its inner face a pivoted contact piece 54 which -may be swung out of engaged position as indicated in dotted lines in Figure 6. Thiscontact piece 54 will normally liein position over the end of the stop 53 s6 that movement of the lever will be limited on one side by the stop 52 and on the other side by the contact member 54. When it is desired to cut off the 'fire completely, however, the contact piece 54 is swung upwardly and the lower end of the lever is moved against the stop a 53 as'shown in dotted line in Figure 6. The lever may be conveniently held in this position by 1 plate 50 and designed to be 'releasably engaged 55 should be strong enough to overcome any tendency of the thermostat to move it due to cooling.

It will thus be seen that when the main thermostat E moves on account of the car being too warm, it closes off the circulation in the main circulating pipe ll. This directs the heated liquid into the by-pass pipe l8, which then heats up,

control ll, which in turn reduces the firein the heater B. when the car cools the reverse of these operations takes place. v

is an automatic control both of the amount of liquid circulated in the=car and of the heating means.

The position of the thermal traps F and 41 has an important effect on the control of the circulating medium. The trap F should be located beyond the riser pipe IS in the usual circulation of the heating medium and also beyond the valve E which is conveniently placed at the point where the usual circulating pipe emerges from the thermally insulated box around E. It will be found 'liquid circulation while the trap 41 prevents random cold liquid circulation.

What I claim as my invention is: l. A heating system for refrigerator cars comprising in combination circulating coils extending in the interior of the car, heating means located outside the car, a connection adapted to feed a heating medium from the heating means to one end of the coils and a connection adapted to carry the return from the other end of the coils back to the heating means, a by-pass pipe engage the ports at the correct angle to completely close the same.

3. A heating system for refrigerator cars com-. prising in combination circulating coils extending in the interior of the car, heating means located outside the car, a connection adapted to 7 feed a heating medium from the heating means adapted to receive heating medium diverted from the coils and return it tothe heating means for recirculation, said by-pass pipe having a portion extending on the exterior of the car by which heat may be dissipated, valve means adapted to be positioned by thermostatic means responsive to the temperature inside the car to close ofl access of the heating medium either to the bypass pipe whereby the heating medium is circulated'through the coils to return, orto close of! access -to the coilswhereby the heating medium is diverted to the by-pass pipe and returned to the heating means for recirculation.

2. A heating system for refrigerator cars comprising in combination circulating coils extending in the interior of the car, heating means located outside the car, a connection adapted to feed a heating medium from the heating means to one end of the coils and a connection adapted to carry the return from the other end of the coils back to the heating means, a by-pass pipe-adapted to receive heating medium diverted from the coils and return it to the heating means for recirculation, said by-pass pipe having a portion extending on the exterior of the car by which heat may be dissipated, valve means adapted to be positioned by't hermostatic means responsive to the temperato one end of the coils and a connection adapted to carry the return from the other end of the coils back to the heating means, a by-pass pipe adapted to receive heating medium diverted from the 'coils and return it to the heating means for recirculation, said by-pass pipe having a portion extending on the exterior of the car by which heat may be dissipated, valve means adapted to be positioned by thermostatic means responsive to the temperature inside the car to closeoff access of the heating medium either to the bypass pipe whereby the heating-medium is circulated through the coils to return, or to close oil access to the coils whereby the heating medium is diverted to the by-pass pipe and returned to the heating means for recirculation, said valve means comprising a casing having an inlet for the heatingmedium, an outlet port leading to the heating coils, and an outlet port leading to said by-pass pipe, both of said ports having con-I members at the correct angle to completely close the respective ports.

4. A heating system for refrigerator cars comprising in combination circulating coils extending in the interior of the car, heating means located outside the car, a connection adapted to feed a heating medium from the heating means to one end of the coils and a connection adapted coils and return it to the heating means for reand a flap valve member swingable by the ther- 7 mostatic means to close one or other of the ports,

the valve memberhaving adjustable spring-supported contact pieces adapted automatically to to carry the return from the other end of the coils back to the heating means, a by-pass pipe adapted to receive heating medium diverted from the coils and return it to the heating means for recirculation, said by-pass pipe having a portion extending on the exterior of the car by which heat may 'be dissipated, thermostatic means responsive to the temperature inside the car-adapted to control mechanically the flow of. the heating medium by either directing the'heating medium to the coils in the interior of the car and thence back to the heating means, or diverting the heating medium from-the coils to the by-pass pipe to be returned to .t e heating means for recirculae tion, andan auxiliary thermostat responsive to the temperature of heating 'medium in the bypass pipe adapted, according to the temperature of such heating medium, to eifect control of the combustion oi fuelin said heating means.

5. A heating system for refrigerator cars comprising in combination circulating coils extending in the interior of the car, heating means located outside the car, a connection adapted to feed a heating medium from the heating means to one is end of the coils and a connection adaptedto carry the return from the other end of the coils back'to the'heating means, a by-pass pipe adapt-- ed to receive heating medium diverted from the circulation, said by-pass 'pipe having a portion extendingon the exterior of the car by which heat may be dissipated, thermostatic means responsive to the temperature inside the car adaptedto control mechanically the flow oi. the heating medium by either directing the heating medium to the coils in the interior of the car and thenceback to the heating means, or diverting the heating medium from the coils to the by-pass pipe to be returned to the heating means for recirculation, an auxiliary thermostat responsive to the temperature of heating medium in the by-pass pipe adapted, according to the temperature of such heating medium, to effect control of the combustion of fuel in said heating means,

a damper for said heating means, link mechanism.

between the second thermostat and the damper, and regulatable means adapted to limit movement of said linkmechanism beyond a predetermined point set to maintain a predetermined minimum opening on which the fire may be kept alive, said means being removable for complete closure of the damper as desired.

6. A heating system for refrigerator cars com prising in combination circulating coils extending in the interior of the car and including an approximately horizontal portion, a heater located outside the car, a connection adapted to feed heating liquid from the heater to one end of the coils and a connection adapted to receive the return from the other end of the coils and carry it back to the heater for recirculation, a by-pass Y pipe adapted to receive heating liquid diverted,

from the coils and return it to the heater for recirculation, said by-pass pipe' having a portion extending on the exterior of the car by which heat may be dissipated, valve means adapted to be positioned by thermostatic means responsive to temperature inside the car to close' 011 access of ing in the interior of the car and including at approximately horizontal portion, a heater located outside the car, a connection adapted to feed heating liquid from the heater to one end of the coilsand. a connection adaptedto receive the return from the other end of. the coils and carry it back to the heater for recirculation, a by-pass pipe adapted to receive heating liquid diverted from the coils and return it to the heater for recirculation, said by-pass pipe having a portion extending on the exterior of the car by which jacent to said valve and adapted to prevent the hot liquid from travelling along the top of the pipe andthe cold liquid returning along the bot- .tom to take its place sa id trap comprising a passageway for the heating liquid and a baflle member extending from one side of the passageway the heating liquid either to said by-pass pipe whereby the liquid is circulated through the coils to return, or to close 0115 access to said coils whereby the heating liquid is diverted to thebypass pipe and returned to the heating means for recirculation, and a thermal trap arranged in the approximately horizontal portion of the coils adjacent to'said valve. and adapted to prevent the hot liquid from travelling along the top of the pipe and the cold liquid'returning along the bot-' tom totake its place;

'7. Aheating system ior refrigerator carscomprising in combination circulating coils extendtowards the opposite side and defining with such opposite side a restricted passageway of a depth which is a small proportion of the total height of liquid in the immediately adjacent portions of the circulatingcoils,

8. A heating system as defined in claim 7 in which the by-pass pipe includes an approximately horizontal portion, and a thermal trap in the flow in such portion adapted to prevent hot liquid travelling along the top of the by-pass pipe and Q cold liquid returning along. the bottom to take its place,. said trap comprising a passageway for the heating liquid and a baffle member extending from one side of the passageway towards the opposite side and defining with such opposite side a restricted passageway of a depth which is a small porportion of the totalheight of liquid in CHARLES DAVID NIVEN.

the adjacent portions of the by-pass pipe.

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