US2040159A - Circulation of heating mediums in vapor heating systems for automotive vehicles - Google Patents

Description

May 12, 1936.

v S. VERNET CIRCULATION OF HEATING MEDIUMS IN VAPOR HEATING SYSTEMS FOR AUTOMOTIVE VEHICLES Filed NOV. 14, 1934 llll lllIllIIHHIHHIIH'IIHIIH II|lllllllHIHIIHIIHIIIIIII IlIlllIIIHHIIHHIIIIIHIIH ,lllllllllllllllllllllllllllllllll a l llllllIHIIIHIIHIHIlllllllllll l Patented May 12, 1936 Sergius Vernet, Brooklyn, N. Y., assignor to Foster Vernay Corporation, New York, N. Y., a corporation of New York Application November 14', 1934, Serial No. 752,947

15 Claims. (Cl. 237-123) UNITED STATES PATENT OFFICE My invention relates to an improvement in vapor heating systems for automotive vehicles, and concerns more particularly the circulation of heating medium between the vapor generator and the radiator condenser of such systems. This application is a continuation-in-part of my pg; application Serial No. 626,035 filed July 29,

In vapor heating systems of ,the type under consideration, the heating medium is trans formed from a liquid state to the vapor state in the vapor generator, and heat is radiated from the radiator so as'to condense the vapor therein to the liquid state again. The source of heat being the exhaust gases from the internal combustion engine driving the vehicle, which in the portion of the exhaust conduit adjacent the motor reach a temperature of 900 F. or

Moreover the system must operate without skilled supervision, and in the main without any supervision whatsoever in order to be practical, as it is intended to be sold to the public generally. It is, therefore, highly desirable that an amount of liquid commensurate with the maximum amount of heat desired from the system be introduced therein and the system closed. It will be noted that this is in contrast to the design of steam heating system customarily employed in dwellings, etc. wherein a valve functions, especiallyafter afresh charge of water is introduced into the boiler, to permit the escape of air. With the type of system dealt with in the present application, the system remains closed throughout the operation of the system; and operates by the circulation of vapor from the vapor generator 4 to the radiator condenser and of condensate back from the radiator condenser to the vapor generator, the amount of heat thus carried up to the radiator depending not upon the amount of heat in the exhaust gases primarily, but rather .45. upon the rate of return fiow of condensate to heating medium which is automatically enlarged or decreased as the temperature and pressure rise and fall.

Water because of certain advantageasuch as itscheapness and its inertness toward the walls of the radiator and vapor generator, is a desir- When the flow of exhaust gases from the engine ceases, the entire system cools oil, and'eventually substantially all of the heating medium gravitates into the boiler. If the temperature drops low enough during the winter months, as when the vehicle is placed in an unheated gara e or parked at the curb, the heating medium freezes to the solid state. So far as the boiler is concerned, such freezing isnot an insurmountable difficulty, as I have been able to provide in the boiler the necessaryexpansion space for avoiding damage from the expansion in freezing. It is of importance to note, however, that unless the total amount of liquid in the system is quite limited the boiler may become completely filled and be damaged by the expansion of the liquid in freezing.

Difliculty has, however, been encountered due to faulty operation when the heating system first starts up after being cold; Of course, when the denser may meet with such cold walls that until a substantial amount of steam is circulated,

there is a possibility of the steam depositing as ice; and in this way substantially the entire amount of heating medium may become deposited in thesolid state within theradiator condenser so as to put the system outof operation.

The second difliculty is peculiar to a system having a vapor line and a separate condensate line uniting the'vapor generator and the radiatcr condenser for the circulation of the heating medium. -While the one pipe system shown in my Reissue Patent No; 18,110, granted June 23, 1931, is entirely practical, and was used to a considerable extent, a heating system provided with circulating means including both a vapor line and a condensate line hasv proved more reliable and better adapted for quick and economical installation. In order to have the latter desirable attributes, the conducting means should be metallic, should be easily bent, and above all, the installation must not be susceptible to destructive vibration. This means that the pipes must be of small cross section; in other words, too small to permit the wall flow of condensate which is necessaryin a one-pipe system, where the condensate must fiow in the opposite direction to the vapor within the same pipe. Since the two-pipe system permits the use of pipes of smaller cross-section which stand up against the usual vibration in such installations, and thus are conducive of greater durability, it has been found more feasible commercially to use the twopipe system. Such a system when starting up from a cold condition after a considerable period of inaction does not possess an established circulation in a single direction. The liquid is substantially all in the boiler, and air or other nonconden'sing gas, which was entrapped when the system was closed, extends throughout the system. The high heat of the exhaust gases sets up, in a short time, a vigorous boiling off of heating medium, which passes up both the vapor line and the condensate line toward the radiator. The heating medium is pushed up these lines in surges by the pressure generated in the boiler. As the condensate returns back down,, substantially filling the small cross section of the conduit, it meets the heating medium driven off from the boiler so that there is considerable fluctuation of pressure and surging of heating medium --up and down both lines, a phenomenon known illustration merely, one embodiment which my away from the engine 8.

invention may assume; and in this drawing,-

Fi8.'-1 is a view showing more particularly the connection to the radiator;

Fig. 2 is a diagram illustrating the entire heating system; and

Fig. 3 is a view similar to Fig. 1 showing a modification of the connection.

The vapor heating system shown includes a vapor generator I and a radiatorcondenser 5, and is used in heat absorbing relation with the exhaust from the internal combustion engine of an automotive'vehicle. The vapor generator or boiler 4 is in-the formof a; tube arranged lon- .gitudinally in the exhaust conduit I which conveys the waste gaseous products of combustion A fan 9 may, if de-' sired, be employed for causing a forced circuiation of air through the radiator 5 to the interior of the compartment of the vehicle to be heated. The heatingmedium is circulated from the boiler I to the radiator 5 and back'again by con-' ducting means including. ingeneral, a vapor line or conduit l0 and a condensate line or conduit I I.

The vapor line is preferably considerably-larger than the condensate line.

The continued circulation of vapor to the radiator condenser and the building up of pressure 7 in the closed system causes the air or other noncondensing gas to become segregated in the control chamber l2 which leads off from the radiator 5. As disclosed in mycopending app ication Serial No. 29 8,242, filed August 8,1928, and Serial No. 737,791, filed July 31, 1,934, a continued increase in the pressure prevailing in the system causes heating medium to be forced into the control chamber as the air therein is further compressed, and there is an accumulation of liquid in an amount depending upon how high the pressure is driven. As this accumulation of liquid is withdrawn from active circulation, a nice balance is established to regulate the system. In ther words, the system is self-regulating, as increases in pressure cause the withdrawal of more The improvements to which the present application ismore particularly directed relate to the circulation of heating medium in a closed system, especially when starting up from a cold condition. The surging of heating medium up the conduits l0 and H as it boils off from the tube l or other boiler heated by the exhaust gases, is particularly troublesome when starting operation with the system cold. The vaporis condensed by the cold walls with which it comes in contact, and there is a return flow of condensate attempting to make its way down to the boiler 4, only to be driven back up the lines again with the next surge in pressure. The surges of pressin'e push up against a cushion or buffer constituted by the air driven into the radiator by the rising steam pressure. As the system is closed throughout its operation, that is, there is normally no communication with. the atmosphere, this air is expanding and recompressing with the surges of the heating medium along the conduits l0 and II as the heating medium boils oi! from the boiler 4. It will be clear that conduits of small cross section connecting the boiler and radiator condenser have but small internal volume orcapacity, even though fairly long. in other words, a slight differential in pressure in the boiler over the pressure'in the radiator condenser would, in consequence, not be evened up short of a surge extending through practically the complete length of the conduits. A chamber such as provided at l3 intermediate the vapor generator and the radiator condenser has an im- 'portant efiect in taking care of the objectionable blocking' and establishing unidirectional circulation ot heating medium. Thesurgesof vapor and liquid-up the two lines discharge in common into this chamber, and push forward along this chamber displacing the air. Meanwhile there- .follows a recession of pressure, which causes the condensate to return more particularly down thecondensate line II.

This chamber has the function both of bringing abouta separation of liquid from vapor, and also of providing a space into which the surges may extend without the heating medium being driven into the radiator 5. The volume of the chamber should be large enough to accommodate such heating medium as is driven up the lines from the boiler in the course of the surging incidental to the starting into operationof the system. Its

volume will of course depend upon the size of the system and the amount of heating medium therein. I have used a chamber whose volume is apvapor generator.

proximatelyhalf the volume of the liquid acering the invention from the point of view of its object of avoiding congealing of the heating medium in the radiator in cold weather. From the other point of view of its object of avoiding blocking, the effectiveness of the chamber is too much reduced when arranged immediately adjacent the Accordingly, the chamber should be spaced from the vapor generator a substantial part of the length of the conducting means.

Due to a primary circulation being established by way of conduit l0, chamber l3 and conduit Ii, the intermediate chamber has a tendency to suppress the surging or blocking set up by the starting of operation of the heating system. The chamber is far enough away from the vapor generator 4 so that by the time the surges of heating medium reach the chamber I3, considerable pressure has been built up in the system, and the air pressure in the radiator condenser E is acting as a buffer reacting against the surges of heating medium entering the chamber 13. With further increases in pressure in the' system the air is further compressed; and radiation of heat from the radiator.

condenser 5 due'to the condensing of vapor therein takes place according to the normal functioning of the system.

The chamber I3, furthermore, by its function of establishing a primary circulation in the conducting or circulating means only, acts toover come the dimculty with the depositing of ice on the walls of the radiator which has been above' referred to. lhe chamber l3 permits the first of the heating medium entering therein to circulate back to the vapor generator without entering the radiator 5 itself. During cold weather, the radiator 5, after a long period of idleness, may be so cold as to chill the heating medium, such as water, below its freezing point before the mass of the radiator is heated above such freezing point. Moreover, the blowing of cold air over the radiator by the fan 9 makes the chilling effect still more troublesome. The conduits l0 and II absorb so few calories, even though initially quite cold, that there-is practically nodanger of freezing of the heating medium if it thus be shortcircuited" before entering the radiator.

In Fig. 1 I have shown details of a preferred embodiment in which the chamber constitutes the connection for the vapor and condensateflines to the radiator condenser 5. As shown in this figure,

the connection is in the form of a tube with branches i4 and l5. The branch communicates with the vapor line l0, and the branch l5 delivers condensate to the condensate line H.

In the connection l3 which is common to both the vapor line l0 and the condensate line H, the

vapor is directed along the tube l3 toward the radiator 5 by an extension of theconduit 10. In the preferred embodiment shown, a tubular extension I9 projects-from the conduit I0 longitudinally of the connection I3. The connection l3 extends through the customary partition I 6 between the engine and the interior of the vehicle.

The portion of the conducting or circulating means which is on the same side of the partition l6 as the exhaust conduit 1, is in a somewhat heated atmosphere shortly-after the engine is started. Due to this fact, the circulation of heat ing medium within a part only of the conducting means so that circulation does not extend substantially beyond the partition [6 renders still more remote the possibility of a stoppage of flow due to ice formation when starting operation in extremely cold weather. As shown in Fig. 3 the connection l3a may be so related to the partition IE that the initial circulation is entirely on the engine side of the partition.

The difficulty with depositing of the heating medium as ice in the radiator condenser does not arise where the heat capacity of the latter is relatively small. In other words, the steam is not sufficiently chilled by the conduits l0 and II to be congealed therein; but in heating systems such as are here under consideration, the heat capacity of the radiator is large relative to the lines leading thereto so as to act effectively as a heat exchange element taking the heat from the steam and transferring it to the air to be heated. The circulation of the heating medium within the conducting means itself avoids bringing the heating medium into contact with the relatively large mass of the radiator. The conducting means, including the connection l3, which are not materially cooled by the air from the fan 9, thus become-rapidly heated. As the pressure increases, steam will make its way further and further into the radiator 5 until the heating system functions to its full extent. It;will thus be apparent that the initial circulation of heating medium in my improved heating system rapidly heats up the conducting means by reason of the short-circuiting" of the heating medium before it enters the radiator. Stea'm does not make its way into the radiator until the conducting means is hot, so that it is fairly dry steam which thus contacts the-cold walls of the radiator. Due to the pushing of the air ahead of the steam into the radiator,

and theincrease in pressure as the steam is a driven further and further into the radiator, a progressive warming of the radiator is effected. Thus the mass of the radiator is gradually warmed, with the advantage that sufiicient heat is practically never abstracted from the heating medium to cause congealing of the latter into the solid state.

While I have disclosed a preferred embodiment of my invention, it is to be understood that my invention is not so limited, but that various changes may be made in the construction and arrangements shown, as well as in the size and shape of the parts, without departing from the scope of my invention as defined in the following claims.

I claim:

1. A vapor pressure heating system for an automotive vehicle includingin combination with a conduit for the exhaust from the engine driving the vehicle a vapor generator arranged to absorb heat from the exhaust gases, a radiator con-v denser, conducting means uniting the vapor generator and the radiator condenser in a system which is closed throughout the operation of the system and which contains heating medium and non-condensing gas, said conducting means being adapted to circulate vaporized .heating medium from the vapor generator to the radiator condenser and condensate from the radiator condenser to the vapor generator and providing sepaheating medium, and a common chamber inter.

mediate the radiator condenser and the vapor generator for the flow in common of the vapor and the condensate said common chamber being spaced from the vapor generator a substantial part of the length of the conducting means.

2. A vapor pressure heating system for an automotive vehicle including in combination with a conduit for the exhaust from the engine driving the vehicle a vapor generatorarranged to absorb heat from the exhaust gases, a radiator-condenser, conducting means uniting the vapor generator and the radiator condenser in a system which is closed throughout the operation of the system and which contains entrapped non-condensing gas and a quantity of heating medium such that the vapor generator under normal running conditions operates substantially as a flash boiler, said conducting means being adapted to circulate vaporized heating medium from the vapor generator to the radiator condenser and condensate from the radiator condenser to the vapergenerator and comprising a vapor line, a condensate line and a common chamber intermediate the radiator condenser and the vapor generator placing the two lines in communication for permitting circulation of heating medium without entering the radiator condenser said common chamber being spaced from the vapor generator a substantial part of the length of the conducting means.

3. In a vapor pressure heating system, the combination with a conduit for the exhaust gases from the driving motor of an automative vehicle, of a vapor generator exposed to the heating effect of said exhaust gases, a radiator condenser, circulating means for heating medium operatively connecting the vapor generator and the radiator condenser in a system which is closed throughout the operation of the system and which contains heating medium and entrapped non-icondensing gas, said circulating means comprising a vapor line, a condensate line disposed closely adjacent the vapor line, and a connection intermediate the radiator condenser and the vapor generator and spaced from the latter a substantial part of the length of the circulating means for admitting heating medium from the vapor line into the condensate line at a-point spaced from the radiator condenser to establish initial circulation of heating-medium through a part only of said circulating means when starting operation of the system from a cold condition.

4. A vapor pressure heating system for an auto motive vehicle including in combination with a conduit for the exhaust fromthe engine driving the vehicle a vapor generator arranged to absorb heat from the exhaust gases, a radiator condenser, conducting means uniting the vapor generator and the radiator condenser in a system which is closed throughout the operation of the system and in which heating medium and noncondensing gas are entrapped, the quantity of heating medium being such that the vapor generator under normal running conditions operates substantially as a lash boiler, \said conducting means being adapted to circulateyaporized heating medium from the vapor generator to the radiator condenser and condensate from the radiator condenser to the vapor generator and comprising a vapor line and a condensate line connected intermediate the radiator condenser and the vapor generator by a common chamber spaced from the vapor generator a substantial part of the length of the conducting means for permitting circulation of heating medium without entering the radiator condenser.

5. A vapor pressure heating system for an automotive vehicle including in combination with a conduit for the exhaust from the engine driving the .vehicle a vapor generator arranged to absorb heat from the exhaust gases, a radiator condenser, conducting means uniting the vapor generator and the radiator condenser in a system which is closed throughout the operation of the system and in which heating medium and non-condensing gas are entrapped, the quantity of heating medium being such that the vapor generator under normal running conditions operates substantially as a flash boiler, said conducting means being' heating medium without entering the radiator condenser, said common. chamber being spaced from the vapor generator a substantial part of the length of the conducting means, and the volume of said chamber being at least one tenth the volume of the condensed heating medium in the radiator condenser when the system is cold.

6. A heating system as defined in claim 4 in which the chamber has a volume at least half the volume of the condensed-heating medium in the radiator condenser when the system is cold.

7. A vapor heating system for an automotive vehicle including in combination with an exhaust conduit for the waste gaseous combustion products of the engine driving the vehicle, a vapor generator or boiler in heat absorbing relation to said waste gases, a radiator condenser and fluid conducting-means connecting the vapor generator and the radiator condenser for the circulation of a heating medium in .a system which is closed throughout the operation of the system, said fluid conducting means comprising a vapor line, a condensate line and 'a chamber communicating with said vapor line and said condensate line, said chamber being intermediate the vapor generator and the radiator condenser .and spaced from the vapor generator a substanfrom the exhaust gases, a radiator condenser, a blower for establishing a circulation of air past hicle, a vapor generator arranged to absorb heat the radiator, and circulating means operatively connecting the vapor generator and the radiator condenser for the flow of vaporized heating medium to the radiator condenser and the return of condensate to the vapor generator in a system which is closed throughout the operation of the system, said circulating means including a vapor line and a condensate line provided with a connection ata point spaced from the radiator condenser for admitting heating medium from the vapor line into the condensate line to establish initial circulation of heating medium through i 2,040,159 a part of the heating system not materially cooled by the air from the blower, said point being also'spaced from the vapor generator a substantial part of the length of the circulating means.

9. A vapor heating system for an automotive vehicle including in combination with a conduit for the exhaust from the engine driving the vehicle, a vapor generator arranged to absorb heat from the exhaust gases, a radiator condenser, a

fan propelling coolingair past the radiator, and

circulating means for heating medium operatively connecting the vapor generator and the radiator condenser in a system which is closed throughout the operation of the system, there being heating medium and non-condensing gas entrapped in said closed system, said circulating means including a conduit for vapor and a conduit for condensate connected at a point spaced from the radiator condenserto establish initial circulation of heating medium through a part of the heating system not materially cooled by the air from the fan, said point being also spaced from the vapor generator a substantial part of the length of the circulating means.

10. In combination with a conduit for the exhaust gases from the driving motor of an automotive vehicle, a vapor pressure heating system comprising a vapor generator exposed to the heat of the exhaust gases, a radiator condenser, a fan cooperating with the radiator condenser for establishing a circulation of air past the radiator condenser, a partition between the exhaust conduit and the radiator condenser, and circulating meansoperatively connecting the vapor generator and the radiator condenser in a system which is closed throughout the operation of the system and which contains heating medium and entrapped non-condensing gas, said circulating means extending through the partition and comprising a vapor line, a condensate line, and a connection at a point spaced from the radiator condenser for establishing initial circulation of heating medium through a part of said circulating means not materially affected by the cooling fan, said connection being also spaced from the vapor generator a substantial part of the length of the circulating means.

11. A vapor heating system as defined in claim 1 in which the efiective flow area of the common chamber is at least as large as the combined flow area of the separate passages for the vapor and the condensate.

12. In a vapor. pressure heating system the combination with a conduit for the exhaust gases from the driving motor of an automotive vehicle, of a vapor generator exposed to the heating efiect of said exhaust gases, a radiator condenser, a partition between the radiator con denser and the exhaust conduit, circulating means for heating medium extending through said partition and operatively connecting the 'vapor generator and the radiator co'ndenserin a system which is closed throughout the opera- I tion of the-system, said circulating means including a vapor. line, a condensate line disposed closely adjacent the vapor line, and a connection for admitting heating medium from the vapor line into the condensate line at a point spaced from the radiator condenser to establish initial circulation of heating medium through a part of said circulating means not extending substantially beyond said partition, said connection being also spaced from the vapor generator a substantial part of the length of the circulating means.

13. In combination with a radiator, a branched conduit having a condensate line connected to one branch for draining condensate from the radiator, a vapor line connected to the other branch for supplying vapor to the radiator, and a tube extending toward the radiator but terminating shortof the radiator for. directing vapor from said vapor line toward the radiator.

14. A vapor pressure heating system-comprising a vapor generator, a radiator condenser and means operatively connecting the generator and the radiator condenser for circulating a heating medium in the system, said means including a vapor conduit, a condensate conduit and a common connection for the two conduits to the radiator condenser, the vapor conduit extending into said connection beyond the point where condensate flows out of the connection by way of the condensate conduit.

15. A vapor pressure heating system for an automotive vehicle including in combination with a conduit for the exhaust from the engine driving the vehicle a vapor generator arranged to absorb heat from the exhaust gases, a radiator condenser, and conducting means operatively connecting the generator and the radiator condenser in a system which is closed throughout the operation of the system and which contains a heating medium and non-condensing gas, said conducting means being adapted to circulate vaporized heatingmedium from the vapor genera- .tor to the radiator condenser and condensate from the radiator condenser to the vapor generator and comprising a vapor conduit, a condensate conduit and a common-chamber inter-" mediate the radiator condenser and the vapor generator for the flow in common of the vapor and the condensate, said common chamber being spaced from the vapor generator a substantial part of the length of the conducting means, the vapor conduit extending into said chamber above the level of the outlet through which the condensate flows to the condensate conduit.

SERGIUS VERNE'I.-

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