US2025695A - Domestic heating process and apparatus therefor - Google Patents

Description

Dec. 24, 1935. R. M. STEWART DOMESTIC HEATING PROCESS AND APPARATUS THEREFOR Filed June 15. 1934 5 Sheets-Sheet 1 Dec. 24-, 1935. R. M. STEWART DUMESTIC HEATING PROCESS AND APPARATUS THEREFOR Filed June 15, 1934 3 Sheets-Sheet Dec. 24, 1935. R. M. STEWART DOMESTIC HEATING PROCESS AND-APPARATUS THEREFOR -Filed June 15, 1934 5 Sheets-Sheet 5 a W a A? w 553 m? Patented Dec. 24, 1935 PATENT OFFICE R DOMESTIC HEATING PROCESS AND APPARATUS THEREFOR Richard M. Stewart, Montclair, N. J., assignor to Ellis-Foster Company, a corporation of Ne Jersey Application June 15, 1934, Serial No. 730,711

4 Claims.

This invention relates to a method of generating and dispersing heat throughout the interior 5 of heat transference, such as radiators, together with the apparatus for that purpose.

This process may be applied to heating by any of the usual means such as steam, hot water, either with open or closed expansion tank, warm air, or by heating employing a pressure lower than atmospheric. The invention may also be used to furnish hot water for any purpose such as the supply of buildings.

The application of this method will be illustrated by a domestic heating plant of small proportions, but the invention is not limited to such use and may be applied to large installations or industrial heating of any nature where the usual means of heat transference may be employed. The fuel used in this example is illuminating gas, that is city or town gas, either natural and/or artificial, but this does not preclude the use of fuel oil, coal tar,'powdered coal, still residues, or other more valuable fuels or any combination of these.

As the supporter of combustion I may use ordinary air, or air which has been dried or humidified or air enriched by'the addition of oxygen, although satisfactory operation may be obtained except under severe service conditions without such means. Preheating may be employedeither for the fuel or supporter of combustion but its use is not essential to the process unless a low grade of fuel is employed and this is not illustrated 'in the method shown here. p

The pressure required for the operation of the process may. be greater than atmospheric as in the case of steam or hot water, atmospheric as shown in the example here, or less than atmospheric as in the case of vapor systems.

The medium of transfer used in this example is water, but this does not preclude the use of other heat-stable liquids which may be suitable for the purpose.

When applied to heating as described herein, submerged combustion has many advantages, tending to simplify the equipment necessary for the generation-of heat, increase the efficiency of the process, and decrease the cost of the equipment required.

Since the exhaust-gases from the burner pass directly through the medium of heat transfer, they are removed at the temperature of the liquid through which they pass. The gain in efiiciency resultant from this method is, of course, large, 5 the thermal eificiency shown by this method is well above per cent. Furthermore,- since these exhaust gases are forced from the system by the differential air density between the gases andthe medium of transfer, a. draft is'not required 10 and the necessity for a flue is dispensed with.

In this process an ordinary malleable iron pipe of, say, an inch diameter, is all that is required to replace the .usual expensive chimney. When the pipe is used as a heat exchanger for the preheating of the fuel supply, even the small heat waste, represented by the extremely small difference between the temperature of the medium of transfer and the temperature of the air used to support combustion, may be reduced to a negli-.

. gible amount. I prefer, however, to' omit such additional apparatus in domestic heating systems as described herein.

Inasmuch as I may put the heating unit at the top of the system, as in Fig. 1, instead of at the 25 bottom, as is the usual case, thecellar is left entirely free of all heating equipment, and it is not necessary to heat that portion of the building unless it is desired to do so.- The heating plant may then be placed in space which is usually 30 wasted and is of such compact design that it occupies far less room than the conventional type of unit with the same equivalent radiation. There may, however, be cases where it would be preferable to place the heating unit on the same horizontal plane level as the radiators or other means of heat dispersion. Such a system is illustrated in Fig. 3, where the heating unit is placed in a small enclosure outside the main dwelling. If desired, the heating unit may be placed within the building in, say, a closet and operation will be equally satisfactory.

' Under certain conditions it may be desired to place the heating unit below the radiating 5 elements of the system. I prefer not'to do this because of the more elaborate compressors required to force the fuel into the burner against this larger water pressure, but if so desired the unit may be utilized in this manner. When the 50- heating unit is placed at the bottom of the circuit, circulation is of course extremely rapid, since it is impelled by the combined forces of convection and pressure at the mouth of the burner. Circulation in this system is due to the pressure of the burner g'ases impinging on the liquid at the mouth of the burner and not to the lifting effect of the entrapped gas particles over a large vertical distance. Because of this it is not essential that the burner be placed under considerable water pressure with the disadvantages of injection mentioned above.

Since the heating system as shown here is entirely sealed with the exception of the air intake and exhaust, which are outside the building, there is no possibility of leakage of noxious fumes or gases inside thestructure. Inasmuch as the heating unit itself requires no floor space, it may be hung from the wall or placed in accessible dead air spaces. 0

Whengas is used as a fuel, there is no need of bins or storage tanks and the supply of fuel is entirely automatic. When the system as described here is combined with a thermostat placed within the structure or material to be heated, the control of heat becomes self-regulating.

Since the elements of the heating unit are'principally of tubular shape and of relatively small dimensions, the apparatus may be made entirely of malleable iron or corrosion resisting material without making the cost of the system prohibitive.

Due to the fact that the circulation of the medium of transfer is caused by the pressure of the exhaust gases at the mouth of the burner, thereby producing a considerable pressure head, the circulation is not dependent on a large difference in elevation of the heater and radiating units as .40 is the case when circulation is due" to convection currents. 0n the other hand, the head produced by this method is suflicient to support circulation over any height feasible with the usual systems.

This is of particular value in one-story cone struction, since it is not necessary to place the heating unit lower than the balance of the structure.

Aside from the heating unit as described herein, the piping and units for radiation are of the.

conventional type and do not necessitate any special equipment, or particular methods of piping, so that this heating unit may readily be adapted to systems which have formerly utilized some other type of heating unit. Because of the extremely'small amount of water which is required in the heating unit, practically the entire amount of water is in the radiators and piping circuit, thus lessening the amount of water which must be heated and so greatly reducing the time which is required to bring the system to full heat.

'Due to the fact that the movement of the medium of heat transference is not due to convec- ,tion but to a pressure head circulation starts immediately when the burner is lighted, thus making this a most flexible source of heat.

The entire unit is free from small orifices, com- 'plex mechanical devices, and other trouble-making features. r The cost of this system both fromthe standpoint of installation and equipment should be far less than that of any other comparable apparatus of equal heating effect and the operating cost will also-be-less than that of other systems using 7 the same The invention is illustrated by the appended drawings, in which similar reference numbers de- .note similar parts.

The general elevation, Figure 1, represents an installation using hot water as the medium of heat 5 transference together with the usual radiators employed in such as'ystem;

It will be seen that the usual methodof double piping from headers'is employed, the only variation from the conventional system being that the 10 heating unit is placed in waste space at the top of the structure instead of in the cellar. The direction of circulation through the system is indicated by arrows, but it is of course possible to oper ate any one or any combination of radiators if so 15 desired. The method of leading the exhaust gases to the roof vent, consisting merely of a length of piping, is also shown.

Figure 2 illustrates the heating unit in detail. Illuminating gas and air, the components of the 20 combustible mixture chosen for this example, are drawn into the apparatus through the needlevalves at I and 2 respectively. These valves are adjusted to give the proper mixture when the apparatus is first installed and it is not necessary-to 25 set them thereafter. In the mixing chamber, 3, the gas and air are thoroughly intermingled to give an intimate mixture and they then pass through the supply line, 4, to the compressor, 5,

where they are raised to a pressure slightly above 30 atmospheric. In this example a rotary compressor of the gas booster type maybe used but a compressor capable of giving greater pressures may be used if required.

The .pipe, 6, leads the compressed mixtureto 35 the nozzle, 1, where it is discharged into the burner at a velocity greater than the rate of backfire. The burner casing is lined with some heat-resistant substance, either of refractory or metallic through the burner mouth, 8. This opening may 45,

be covered by a small perforated plate designed to break up the gases into a large number of minute bubbles which give up their heat to the water in the region of heat transfer, 9, between the burner mouth, 8, and the exhaust pipe, II. or other circulating medium, is forced through the burner casing in the direction indicated by the arrows under the impetus of the pressure of the gases leaving the burner mouth. The general water level is shown in Figure 2, but this is of 5 course only approximate since the level will be 'higher at ll than at l5 by the amount representing the head tendency to circulate the water. I

At the water level the gases separate from the liquid, while the water passes down the header, 60

l0, and so to the heating system. Liquid returns from the radiators by the header, l2, and so passes through the heater again, flowing in the annular space between the burner and the casing 65 o the heating unit. Since it is'possible that from timeto time a small amount of gas should pass up the annular space, an air trap might form at the junction, [5, if it were not for the. bypass, l6, which removes any such gas which might 0011866. This is only an incidental feature, however, and not essential to the operation of the burner, Under certain conditions it may be desirable to preclude the'possibility of noise traveling to the-radiating elements from the heating unit. This may 76 Thewater, 50 j be done by the use of rubber fianges, 48, as shown.

Although I may operate the heating unit under a considerable head of water, I prefer to so place the burner so its highest point is just at the water level, thus completely surrounding the burner with liquid and still keeping the pressure within the burner at a minimum. The level of liquid within the burner is kept at the correct point by the use of a tank, I 3, equipped with a float valve and supplied from the water'mains by the feed pipe, M. This tank serves both to compensate for the expansion of the liquid upon heating and also to supply the system with water as needed.

This arrangement of the supply and expansion tank is not essential for, as in Figure 4, Imay greatly enlarge the heating unit at the point I8,

where the gases escape from the liquid, and use this for the purposes of supply and expansion.

As shown in Figure 2, I may light the burner by passing a spark from the contact, II, to some point within the burner, such as the orifice I, but

under some conditions it might be preferable to ignite the mixture by means of a glow bar or by a pilot light.

Figure 3 illustrates another method'of placing the heatingsystem. In this case the level of the water in the burner may be placed as low as the tops of the radiators in the circuit. The details of the heating unit used here are identical with those illustrated in Figure 2. Again I prefer to operate the burner with the minimum head, as explained above.

Figure 4 illustrates an adaptation of this burner to the method of warm air heating. The heating unit again is similar to that shown inFigure 2, except as to the arrangement of the supply-expansion tank, as explained above. In this case, however, the radiator, I9, is placed within a duct which is supplied with air entering at 23. Circulation of the air is secured by convection'but a fan, 2|, may be used to increase'the velocity of flow, if desired. A screen, 22, may be used to clean the air of dust particles and a spray, 20. falling into the catch basin, 25, represents a possible means of humidifying the air. After passing over the heating element, l9,'the air is then led through the duct, 24, to the points to be heated, where it is discharged through registers or grilles. Figure 5, illustrates a means by which submerged combustion may be adapted to the heating of water or other liquid for useother than heating purposes. The tank, 29, may be the sole method of storage or the liquid may pass through the outlet, 28, to another tank used for storage purposes. Heating is accomplished by surrounding the heating unit with fins, 26, to create a large heating area and submerging the unit in the liquid to be warmed. Cold water from the supply I line is supplied at 21. The supply-expansion tank as well as the apparatus .for the supply of fuel is omitted in this figure for the sake of clarity. Numbers 6, l6, and II have the same significance as in Figure 2.

Figure 6 shows an adaptation of submerged combustion to vapor heating. Operation here is identical with that of Figure 2, except that there is no circulation of water. .The water level shown is maintained by the storage tank, 30, and the burner raises the temperature of the liquid contained in the heating unit to a point such that the liquid vaporizes and is carried up with the exit gases from the burner to the radiators, 4 I, through the header, 41. The radiators are equipped with valves, 44, to permit shutting off unnecessary units. If desired valves, 43, may be placed on each radiator either to maintain a certain pressure within the system or else to maintain the heat within the radiators at the best point. The condensed vapor runs back through the piping to the chamber, 40, containing a deflector not shown, 5 so that this liquid is bypassed into the annular space between the burner casing and the walls of the heating unit. The exit gases which contain no excess vapor are then allowed to escape through the header, 46, to the roof vent, 42.

In both this figure and in the following figure,

"7, the fuel supply apparatus has been omitted.

Figure-"l illustrates a method of using other submerged combustion heating units for both space heating or water supply heating.

-With valves 33 and 35 closed and valves 34 and 36 open, operation is the same as in Figure 2. When valves 33, 34, and 36 are closed and valve 35 open, the unit may be used to heat the water in tank 29 by means of the radiator 32. Cold water 20 enters the tank at 21 and the warm water may be drawn off at 26. When valves 34, .35, and 36 are open, and 31 is closed, the unit may be used simultaneously both for space heating and for the heating of water. supply. Circulation of the 25 medium of heat transfer to radiators is through the supply header, Ill, and the return header, l2, as in Figure 2.

For certain purposeswhere hot water is required, this may be drawn directly from the sys- 30 tem through valve 33. Fuel supply is identical with that shown in Figure 2. y

In some cases it may be found desirable to use a. pump to aid the circulation of the liquid through the system. Such a device is not shown 35 in the drawings, since in general its use is not necessary. or advantageous, but such use is not precluded.

What I claim is:

1. The process of heating and circulating a 40 liquid medium of heat transfer within a heating systemwhich comprises the ejection of the products of combustion from a burner submerged in the liquid into the liquid in the direction of cir-- culation' of the liquid, said burner being so ar-'- 4 ranged that the hydrostatic head is greater at the point of entry of the exhaust gases into the liquid medium of heat transfer than at the point of introduction of the combustible mixture into the combustion chamber. 2

2. The process of heating, and circulating a liquid medium of heat transfer within a heating system which comprises the ejection of the prodnets of combustion from a burner submerged in the liquid into the liquid in the direction of citculation of the liquid, said burner being so arranged that the point of entry of the combustible gases into the burner chamber is not under pressure due to hydrostatic head of the liquid medium of heat transfer. 0

3. The process of heating and circulating water within a heating system which comprises the ejection of the products of combustion from a burner submerged in the water into the water in the direction of circulation of the water, said burner being so arranged that the hydrostatic head is greater at the point of entry of the exhaust, gases into the water than at the point of introduction of the combustible mixture into the combustion chamber. I

4. In a heating system a portion of thei'watercontaining circuit comprising two tubular units joined at an'angle of less than 180to form an erect V-shaped structure and containing within one ofthe membersa downwardly directed bum- 4 2,025,090 er submerged within the liquid medium of transthe hit due to gas entrapped in the medium of fer in such a manner that the liquid withinthis transfer and then, after the removal of exhaust portion is impelled, directly following the appligases from the liquid, flows downward to supply cation of heat, in an upward direction in the heat to the balance of the circuit. opposite arm due to the combined impetus ol the 5 pressure of the exit gases from the burner and RICHARD M. STEWART.

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