US2249554A - All-weather hot air furnace - Google Patents

Description

July 15 194i. F. R. DALY ALL'WEATHER HOT `AIR FURNACE vFiled Feb. 24, 1959 July 15, 1941; F. R. DALY ALL-WEATHER HOT AIR FURNACE Filed Feb. 24. 1939 2 Sheets-Sheet 2 SIB Inventor;

Francis R. D015. M- M Bj lftor-neys;

Patented July 15, 1941 iUNITED-fisuras PATENT ortica v 12,249,554 v e Y e ALL-WEATHER Hor-AIR FURNACE v Francis Daly, Minneapolis, Minn. Application February 24, 1939, Serial No. 258,233 i ciw-2) 3 Claims.

My invention relates to all-weather hotair furnaces and has for its object to provide an `or-l ganization of elements whereby a forced air circulation through'the rooms to be heated is continuously maintained and heat exchanger means are provided of such a nature that heat will be delivered from the organization inraccordance with the demands for heat resulting from outside temperature. Thus, if the temperature is relatively'high, as in mild weather, but little heat will bedelivered tothe constantly-moving current of air; if the temperature is moderately cold a proportionately greater amount of heat willl beideli-vered to the constantly-moving stream of air, and if the temperature is low, as in severe cold weather. a maximum adequate amount of heat will be delivered to the moving stream of air.

I attain the Vabove objects by providing a furnace structure embodying a boiler with suitable means for delivering heat thereto", as an oil burner or the like; by providing a casing about said boiler with passages through which airv can circulate to be 'discharged to the rooms; providing a blower or 4air-moving device which'shall be continuously operative, that'is, will move a stream of air throughv the appliance and to and from the rooms at all :time's by carrying the exhausting furnace ga'sesfrom said boiler through heat exchangers exposed to incoming air so that said air will-be preliminarily heated by' heat exchange With the exhaustinggases ofi combustion; and providing means for passing 'said air around and over heat exchange surfaces of the 'boiler further to-"heatf the'air, and to' heat the air 'sunlciently" when the oil burner is-out of operation;y and nal' l ly toprovide radiators fadapted: to receive steamfrom the boiler whereby thefair' may be stillfurther heated whenI severeweather requires` a maximum or larger amount of heat.

It is a principal objectof my invention', therefore,l to provide a boilerand'heatin'g means' therefor entirely enclosedwithin "acasing, so that thejsurfaces of the boiler become heat exchange surfaces for a moving -stream of'air and :to cir-'- culate the air to and from the'rooms throughv said". casing and over said heat exchange'surfaces and to have such4 circulation at all times continuous,

taneously intermittent. l

Itis a further object of my invention to-provide a boiler for the purposes above outlined which shall embody a steaming chamber in combinaiion with a. radiator positioned in the path of f travel of the continuously circulating stream ofV air, whereby, when the demands for heat require it, the boiler will generate steam going to the A:radiator at such pressures and temperatures as may be requisite and the continuously circulating stream of air will be heated by contact with the Walls of said radiator in heat exchange with y :the said steam, in addition to being heated by l0' contact with the Walls of the boiler in heat exchange with the hot water therein.

It is a further object of my invention to carry .the gases of combustion to the bottom of the Achamber and pass them through heat exchangers at said bottom and to a'heat exchanger discharge smoke box at the rear of the casing and to causer the continuously moving stream of circulating air to pass over said heat exchangers, whereby V when the room thermostat calls for more heat and the oil burner or other` heating means is turned on the continuously moving stream of air will be preliminarily heated by Contact with the walls of said smoke-nue heat-exchangers and by heat exchange with the gases of combustion exhausting therefrom.

The full'objects and advantages of my inven# my invention in one formv e Fig. 1 is a longitudinal sectional elevation view taken through the center of my kair-'conditioning furnace Fig.'2 is a sectional'elevation view of a "part ofthe furnace taken on lineZ-Z of Fig. l.

Fig3 is a'sectional plan view of a portion'of the furnace taken online 3---3` of Fig. l. Fig. 4 is' a frontv part sectional elevation frontend View Fig'. 5.

f As illustrated, an outer casing I0, which may .u be insulated in acustomary manner, has support- 'ed therein a boiler II spaced from the side Walls of casing ID to form ascending air passages, asindicated at I2, I3 of Figs. 2 and 5. `The boiler IU'A may be specifically such a boiler as is disclosed' in my Patent No. 2,141,238v wherein there is an :outer shell I4 'of circular cross section surround# ing an inner shell I5. The outershell is closed by an end plate' Iand the inner shell is closed by an end plate i1 spaced from the end plate I6, as clearly shown in Fig. l.

nular chamber I8 about the inner shell I5 and There is thus an anan end chamber I9 formed continuous with said annular chamber I8. The chamber I8, I9 contains the water to be heated and from which when desired steam is generated, the desired level of said water being shown at 20 of Figs. 1 and 5. As clearly shown, the shell I has its center substantially below the center of the shell I4 so that the space above the shell I5, which constitutes the combustion .and heat 4chamber of the furnace, is substantially greater than the space below shell I5, with the Water level 29 controlled by a glass in the usual way low enough to leave a steaming chamber 2| in the space I8, I9.

Extending into shell I5, as shown in Fig. 1, -is an oil burner 22 of any well-known construction which discharges its flame into a primary combustion chamber 23 .and against a refractory baille 24. Operation of the oil burner is controlled by a thermostat shown conventionally at 1U and thermostat connections 1I, all of wellknown construction. The combustion gases .go from the chamber 23 to a second chamber 25 past a second baille 26 and down through a -third chamber 21 and a bottom passageway 28 to a smoke box chamber 29. The chamber 23l as clearly shown in Fig. 5, is provide-d with refractory side walls 30, 3l. Within the heat chamber in she-ll l5 are a multiplicity of U-tubes 32 which have portions extending along the top of the heat chamber and through the passageway 28 exposed to the heat of the llame and gases of combustion in the heat chamber, as clearly shown in Fig. l. These U-portions are connected by loops 33 with extensions 34 which go into the water abo-ve the shell I5, and by loops 35 with extensions 36 which go into the water below the shell I5, whereby cooler water in the lower part of annular chamber I 8 is caused to circulate through the U members 32 subject to the Vhigh hea-t within the combustion chamber in shell I5 and to discharge into the upper portion of the body of Water within the outer shell Il, all as fully described and -claimed in my aforesaid Letters Patent.

lOpening into the smoke box 29, as indicated at 31, Fig. 4, lare a multiplicity of smoke pipes 38 which discharge into a Vertical smoke box 39, as shown in Figs. 1, 3 and 6. The smoke box 39 extends upwardly in an air-inlet chamber 40 and discharges to the stack through a pipe 4I connecting with smoke box 39, as shown in Fig. l. While I have shown the passage of the gases of combustion as through a series of pipes 38 and smoke box 39, it will be understood that this is just one form of heat exchanger whi-ch may be employed, and I contemplate the use of other forms of heat exchangers which are capable of accomplishing the purpose of my invention.

The air-,inlet chamber 4|) is connected with main air-inlet trunk 42 which has therein a blower 43 whose outlet 44 discharges downwardly into chamber 4D past a transverse partition 45.

as shown in Fig. 1. The blower 43 may be of any desired construction, of any of the Wellknown forms of air-moving devices. and is operated by a motor 45. The arrangement is such that the motor 49 operates the blower 43 continuously, constantly ydrawing air from the rooms to be heated and deliveringit within the casing II) past the heating instrumentalities therein and through an air-delivery trunk 41, whence it goes to the various rooms to be heated. There is a continuous unchanging circulation of air to, through and from the rooms to be heated and through the casing and past the instrumentalities therein which exchange heat with said continuously moving stream of air.

It will be noted that the wall 48 of chamber 40 has the end plate I6 of the boiler protruding thereinto and cuts oft' said chamber 40 from within the main part of casing I0 except for ports 49 and 50, Figs. 2, 3 and 5. These ports, as clearly shown in Fig. 5, lead under the adjacent smoke pipes 38 so that the air being constrained to go beneath the smoke pipes by means of bafes 5I the incoming air thus is constrained to move about a heat exchanger formed of the smoke box 39 and the smoke ilues 38, from whence it passes through the spaces 52 and 53 between adjacent pairs of smoke ilues 38 directly beneath the shell II of the boiler, being con- K strained to pass around said shell, which, with .the hot water therein thus becomes a hot Water radiator or heat exchanger for said air.

From the passages I2 and I3 the air is caused to wrap around boiler II or the outer shell I4 thereof and pass Ithrough a steam radiator 54 located above the boiler II, as clearly shown in Figs. 1 and 5, ballles 55 and 56 in relation to discharge Iof m-ain air delivery duct 41 constraining the air to ow along the surf-aces of the elements making up the radiator 54. This radiator is supplied with steam from the steaming chamber 2l by a pipe 51, Figs.,1 and 5, and the return water goes back to the boiler preferably under the Water surface therein through a pipe 58. A protector member 59, pressurestat 60 and thermostat and connections, all of usual construction, control the operation of the oil burner 29 in a customary way.

For cleaning the combustion chambers the burner may be withdrawn and a brush introduced through the burner opening indicated at 6I, Fig. 4, or, if desired, additional sight holes closed by suitable plugs, not shown, may be employed.

The chamber 29 is closed by a casing member B2, which, as shown in Fig 4, embodies a ilange -63 secured by bolts 64 to the front of the casing IU. The smoke passageway 28 in the boiler and the several -flue members 38 under the boiler communicating with chamber 29 can thus be ex posed by removing the member 62, and accumulations of soot or other materials be readily brushed off of the inside of these passages. Some of this material will naturally gravitate to the bottom of upright smoke box 39, and at the bottom thereof I provide a lateral extension 65, Figs. 3 and 6, which is closed by a thimble door 66. When this is removed any accumulations of soot at the bottom of smoke box 39 can be removed and also the walls of smoke box 39 can be brushed to complete the cleaning of the smoke carrying passages.

The operation of the foregoing instrumentalities is as follows: The air at room temperature enters chamber 40 and wipes the surfaces of the smoke box heat .exchanger 39. From there this air goes through ports 49 and 50 and passes through and around the smoke pipes 38, thus preliminarlly heating the air by exhausting gases of combustion. This preheated air will then pass around shell I4 of heat exchanger with the water therein. In mild weather the burner will be on very little. The amount of heat necessary to keep the rooms warm will come mainly from heat exchange with the hot water in the boiler, being aided whenever the thermostat 10 calls for heat, at the time when such aid is most effective, by

heat exchange with the hot gases of combustion in the smoke ues and boxes. As the temperature drops outside and the need for heat increases the burner will be on for longer periods of time and the water in the shell I4 will be progressively made hotter and hotter. Up to a certain point suicient heat will be obtained without the generation of steam. When, however, that point is passed, by reason of lowered outdoor temperatures, theboiler will generate steam, which will pass into the radiator 54 and there be in heat exchange with the air moving over the surfaces'of the various parts of said radiator. In the event that a very great amount of heat is required because of excessive cold, the pressure of the steam, and its consequent temperature in heat exchange may be raised as determined by the setting of the pressurestat.

It follows that with a constant flow of air through the furnace arrangement and constant and continuous circulation of air through the rooms to be heated, there Will at all times be just enough heat, as indicated by the thermostat 10, to meet the requirements of the thermostat in heating the rooms. In that way, and this is one of the primary advantages of my invention, the undesirable and unpleasant effects of the turning on and oi` of the air circulation through starting and stopping the fan are entirely done away with and both the temperature and air movement conditions within the rooms may be kept constant. This also avoids the stratification of air in varying temperature zones through the elevation of the room which inevitably takes place where the air movement is interrupted from time to time along with termination of the action of the burner. All of this results in the air in living quarters being kept at all times in a uniform condition of movement and temperature which greatly increases the comfort and well-being of those Who are inhabiting such rooms.

I claim:

1. In a heating plant, a casing and conduits Aleading therefrom tothe rooms and from the rooms back to the casing, means for causing a continuous and constant current of air to move through said casing and conduits to and from said rooms, a boiler within said casing with means entirely within the inner Walls of the boiler for heating the Water in said boiler, the outer walls of said boiler being exposed to said current of air and constituting means for putting the air in heat exchange with the hot water within said boiler, and a steam radiator above said boiler the walls of which are in heat exchange with the continuously-moving current of air, said radiator adapted to be supplied with steam from the boiler when room temperature conditions call for more heat exchanged to the current of air.

2. In a heating plant, a casing and conduits leading therefrom to the rooms and from the rooms back to the casing, means for causing a continuous and constant current of air to move through said casing and conduits to and from said rooms, a boiler Within said casing with means entirely within the inner walls of the boiler for heating the water in said boiler, the outer walls of said boiler being exposed to said current of air and constituting means for putting the air in heat exchange with the hot water Within said boiler, a radiator adapted to be supplied with steam from said boiler when room temperature conditions require it and having its walls in heat exchange with said continuously-moving current of air, and means for taking the gases of combustion from the boiler constituting a heat exchanger for preliminarily heating the air before it goes-past the boiler.

3. In a heating plant having a casing and conduits leading therefrom to the rooms and from the rooms back to the casing, means for causing a continuously moving and uninterrupted current of air to move through said casing and conduits to and from said rooms, a boiler having all of its outside walls within the casing and exposed to the aforesaid current of air, said walls constituting a direct acting heat-exchanger, a steam radiator in the casing having connection with the steam chamber of the boiler forming a second heat exchanger, a burner, and a thermostat in the rooms for controlling operation of the burner according to room temperature, the said burner and thermostat being controlled by heat demands within the room so that when said heat demands are little the burner will continue to operate only long enough to heat the water in the boiler without generating steam until the heat requirements of the room are satisfied by heat exchange with the outer walls of the boiler and the burner will be caused to be heated to operate longer as the heat demands increase and will remain in operation long enough to generate steam and cause the steam radiator to act as a second heat exchanger when the heat demands of the room require it because of lowered outside temperature.

FRANCIS R. DALY.

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