US2100373A - Heating apparatus - Google Patents

Description

' Nov. 30, 1937. v. s. BECK HEATING APPARATUS Filed May 29, 1936 5 Sheets-Sheet 1 v. s. BECK Nov. 30, .1937.

HEATING APPARATUS f5 Sheets-Sheet'Z Filed May 29, 1936 F|G.3. T

| l I l FIGS.

F'IG.8.

Nev. 30, --l 937. v. s. BECK HEATING APPARATUS Filed May 29, L936 -'5 Sheets-Sheet 3 FIG] min.

Patented Nov. 30, 1937 UNITED STATES PATENT OFFICE 7 Claims.

This invention relates to heating apparatus, and with regard to certain more specific features, to heating apparatus employing combustion of a fuel.

Among the several objects ofthe invention may be noted the provision of a forced-draft for supporting combustion in a furnace which is used in connection with a forced-draft circulating sys tern, in which furnace natural draft, as required,

is used for combustion when no heat is called for by the circulating system but wherein forced draft is used for combustion as required when heat is called for by the circulating means; the provision of simple means for maintaining a pre-' 16 determined maximum draft pressure under forced draft operation; the provision of means for preventing accumulation of dangerous gas in or near the combustion system; the provision of apparatus of the class .described hav- 20 ing means for adapting it for burning solid, liquid or gaseous fuels such as coal, oil, or gas; and the provision of apparatus of the class described which is simple in construction and operation.

1 Other objects will'be in part obvious and in part 25 pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter 30 described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which is illustrated one of various possible embodiments of the invention,

35 Fig. 1 is an isometric View, with parts broken away, showing certain features of the invention;

Fig. 2 is a cross-section taken on line 2-2 of Fig.1; Fig. 3 is a front elevation of a furnace and 40 radiator;

Fig. 4 is a right-side elevation ofFig. 3;

I Fig. 5 is a horizontal section taken on line 55 of Fig. 3;

Fig. 6 is a front elevation of a form of pit construction used for burning gaseous .fuel;

Fig. 7 is a horizontal section taken on-line l'| of Fig. 6;

Fig. 8 is a view similar to Fig. 6 showing a modification of the apparatus for burning liquid fuel, 50 and,

. Fig. 9 is a vertical section taken on line 9-4! of Fig. 2. Similar reference characters indicate corresponding parts throughout the several views of 55 the drawings.

Referring now more particularly to Fig. 1, there is shown in general at numeral I a jacket, spaced from, and surrounding a blower l and a furnace 3 which includes a radiator 5. The blower 11s driven from a motor 9 by way of a 5 drive I I, said motor 9 being energized and deenergized in response to temperature in the compartment under control, as is known. Likewise, the draft door I3 of the furnace 3 is energized to open or close from a motor apparatus I5 of 10 known type. The apparatus l5 responds to open or close the draft door It from thermo- 7 static means in the stack, as is known.

The jacket I is internally divided by a wall ll which forms a separate compartment I9 for said 15 blower l. The compartment l9 has an inlet duct 2i connected to the cold air return from the compartment controlled, or it may take in air from another source.

The jacket- 1 also has a second interior dividing wall 23 which forms a separate chamber 25 for the combustion apparatus 3, 5. The fan i in compartment is receives air from the cold-airreturn duct M. The blower, when operating forces air through the compartment 25 and out of 25 a warm-air duct 21 and to the compartment under control. It will be noted that the outlet 29 of the blower i is in the heater compartment 25 and the inlets it of the blower are in the suction compartment I9. Suitable screens 33 are used in 30 said suction compartment i9.

It will be seen from the above that a third or draft compartment is effected between the wall 23 and the front of the jacket I.

In the wall 23 (Fig. 9) is an outwardly swing- 35 ing door 31 which is normally closed and checked shut against pressure in the chamber 35 but which opens with excess pressure in the chamber 25. A limiting stop 39 is used to limit the amount of opening of the door 37 under pressure 40 in the chamber 25.

In the front wall of the jacket I are doors M and $3. The door ll is balanced normally to standopen inwardly as shown in Fig. 9. Un-

der super pressure in the chamber 35 thisdoor will shut.

The door i3 is normally closed, or nearly closed, and is adjustably weighted as shown at 45 to re-, sist opening under super pressure in the chamber 35. This door acts as an upper limiting means for the pressure in the chamber 35.

Opening 41 is used for screen replacement or' cleaning and is normally covered by suitable, cover. The door 49, which is normally shut, is for the purpose of reaching the firing door 5| in the furnace and the ash pit door 53. It is to be understood that suitable .air conditioning apparatus may be placed in the duct 21 such as a cooler'for summer use and a humidifier. Operation of the foregoing parts of the invention is as follows:

Assume that the compartmentconnected with the ducts 2| and 21 is warm. The draft door I3 is controlled by the stack temperature control switch which actuates the motor l5. Thus when the stack temperature is too low, the draft door I3 is opened. Then a natural, induced draft takes place from the outside of the casing I, through the normally open door 4|, compartment 35, and through the door |3 to the combustion chamber. When the stack temperature rises to a suitable degree, the draft door l3 recloses. It is to be understood that the ash pit draft door |3 may be made also responsive to compartment temperature, temperaturein the conduit 21 or a combination of compartment temperature, duct temperature and stack temperature, as is known. v

The blower is preferably responsive to compartment temperature. When the compartment temperature is high, the blower is actuated, and when the compartment temperature falls to a predetermined low point, the blower is not actuated. As soon as the blower comes into operation, .air is drawn in from the duct 2| and forced to the warm air duct 21 through the compartment 25, thereby placing a super-atmospheric pressure in the latter. This automatically forces open the door 31 to its predetermined limit, thereby by-passin'g some of the air from the duct-circulating system to the compartment 35 and into the draft door l3, provided the latter is open. The superior pressure in the compartment 35 automatically closes the natural draft door 4|. The door 43 by opening provides an upper pressure limit for the forced-draft pressure. This is adjustable at weight 45. Door 31 will hereinafter be referred to as a forceddraft door and door 4| as the natural-draft door.

From the above it will be seen that the natural-draft door 4| is normally open fornatural draft, should the stack switch call for draft at the door l3 when the blower is not operating. In the case of Fig. 6, the door 83 is the equivalent of door l3.

- The forced-draft door 31 is normally closed but opens due to air pressure when the blower starts, permitting air pressure to enter the front compartment 35, and if the draft door |3 is open, to enter into the ash pit, first closing the door 4|, the non-operating position of which is open.

The door 43, being adjustable, and having normal closed position, serves to 1 prevent the blower from delivering an air pressure into the compartment 35 which is greater than that desired for combustion purposes.

The forced-draft door 31may be fastened entirely closed by screwing down the limiting stop 39 when it is desired to use gas instead of coal for fuel. When gas is used for fuel it is desirable to use natural draft only. The draft will then take place through the normally open door 4| and the door l3.

The advantage of the above is that when solid fuel is used, the automatic forced draft reduces the period of smoking from the fuel under natural draft conditions and makes possible the use '{f'of lower grade fuel which requires higher drafts.

:Also, it is possible to operate with less natural draft than ordinarily required of a furnace of the same capacity. Furthermore, the same type of forced draft is provided by this device that is usually provided with stoker equipment and other forced draft devicesbut it uses the blower already available for circulation and does not employ an extra one. Thus this device makes it unnecessary to have an additional blower.

Another feature of the invention is shown in Figs. 3 and 4. The furnace 3 is of known type and has a connection 59 with the known type of radiator 5 which includes a bafile 55. The general idea of having a baflle 55 is known, but the relation at its upper end is believed to be new herein. Heretofore, the baflles such as 55 have been connected solidly at the top of the radiator 5, so as to positively cause the passage of combustion products to proceed from the up-' per end of the furnace 3 to the outlet 59, downwardly in one pass 51, upwardly in a second pass 58, and out through a flue 6|.

In cases where gas is used as a fuel (as is possible with the present apparatus and as will be described), it sometimes occurs that the flame goes out and a requirement for heat causes unburnt gas to be delivered to the combustion apparatus. This passes over through the outlet '59 and builds downwardly in the radiator and also in the furnace 3, until it reaches openings and leaks into the duct circulating system, or in the absence of leakage, gathers in the furnace 3 and radiator 5. The subsequent lighting of the apparatus is then liable to explode it.

I avoid the above difficulties by spacing the baffle 55 at 63 from the upper enclosure 65 of the radiator. This opening is not large enough to substantially interfere with the normal flow of products of combustion along the passes 51 and 58, but the opening 63 is large enough to permit the escape of the collecting unburned gases. The volume of gas unburned is much less than when burned and is accommodated by the relatively small opening 63.

The baffle 55 is slidably held between angle irons 61 and is enclosed in adjustable position by an adjusting screw 69 and thus is adjustable to suit various fuels, that is, to permit escape of the unburned gases without providing so much by-passing that the proper circulation in the radiator 5 would be interfered with.

Figs. 1 to 5 show coal burning apparatus. It is desirable that a coal burning furnace be rapidly convertible to gas or oil burning furnaces.

' This is accomplished by placing the ashpit door 53 on the front of a species of drawer H which provides an ashpit. Set into the top of this drawer or removable ashpit H are the grate bars 13 which are movable with the drawer 1|. The grate bars rest in notches 12 at the front and 14 at the back. A narrow cleaning door I5, by opening, permits raising of the drawer as it is fitted into position to move over holding clips 11. C- sure of the door after entry of the drawer effects a draft seal.

In Figs. 6 and 7 is shown a gas burning replacement unit for the 'coal burning unit shown in Figs. 3, 4 and 5. This gas burning unit is also in the form of a drawer 19, having a front 8| with a natural draft door 83. Running through the.

front 8| and supported thereon are pipes 85 emanating from a common header 81. The pipes 85 are valved as shown at 89 and a motor line valve 9| is shown at 9|. A union 93 connects the gas burning unit with the main gas line 95 so that it may be removed and replaced. Connected with that-all matter contained inthe above descripto the valve 9|, and arranging the connections so that when heat is required, gas is turned on and vice versal In Fig. 8 is shown a drawer front IIJI for an oil burning unit drawer J03. This drawer carries the refractory material surrounding the lower combustion region. This material may, if desired, be cemented to the refractory liner of the furnace. The portion of he unit I03 which extends into the furnace is supported in a hole through the front [0i and by outside legs I05, This unit may be slipped in and out of the bottom of the furnace, as may be the' coal fired and gas burning units. The same controls can be used for the oil burning unit but are arranged so that the blower always comes on when the oil burner comes on.

In order to change from one fuel to another, it is only necessary to disconnect the draft chain, disconnect the pipe union 93' when changing to solid fuel and reversing the action when changing to gaseous fuel, and open door 15 which frees the drawer unit for removal and replacement. After replacement the door 15 is again closed. This affords a quick change from one fuel to another without the necessity of special tools nor the requirement of the services of a special mechanic. The removal of a unit may also be effected for inspection, cleaning and repair of grates, pilot, manifolds, etc.

In view of the above, -it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be madein carrying out the above constructions without departing from the scope of the invention, it is intended tion or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a heating system, a heater having a combustion chamber and a draft intake, an enclosed heater casing about said heater, a blower constructed to receive cool air and force the same through said heater casing, a draft casing communicating with said heater draft intake, said heater casing and said draft casing having communicating means therebetween, means in said last-named communicating means automatically openable under super-atmospheric pressure in the heater casing to provide a super-atmospheric pressure in said draft casing available at said draft inlet, said draft casing also having an outside communication, and means in said outside communication normally standing open to permita natural draft to said draft opening but constructed automatically to close upon the attainment of super-atmospheric pressure in said draft casing. j

2. In a heating system, a heater having a com'- bustion chamber and a draft intake, an enclosed heater casing about said heater, a blower constructed to receive cool air and force the same through said heater casing, a draft casing communicating with said heater draft intake, said heater casing and said draft casing having communicating means therebetween, means in said last-named communicating means constructed to be automatically openable under super-atmospheric pressure in the heater casing to provide a super-atmospheric pressure in said draft casing available at said draft inlet, said draft casing also having an outside communication, means in said outside communication normally standing opento permit a natural draft to said draft opening but constructed automatically to close upon the attainment of a predetermined super-atmospheric pressure in said draft casing and means for limiting the super-atmospheric pressure in the draft casing.

3. In a heating system, a heater having an independently operated draft intake and a combustion chamber, an enclosed heater casing about said heater, a blower constructed to receive cool air and force the same through said heater casing, a draft casing communicating with said heater draft intake, said heater casing and said draft casing having communica ing means therebetween, means constructed to be automatically openable under super-atmospheric pressure in the heater casing to provide a super-atmospheric pressure in said draft casing available for said draft inlet; an outside, communication for said draft casing, means in said outside communication normally standing open to permit a natural draft to said draft opening but constructed automatically to close upon the attainment of a predetermined super-atmospheric pressure in said draft casing, a second outside communication for said draft casing, and adjustable means for resisting flow through said second outside communication. v

4. In a heating system, a heater having an independently operated draft intake and acombustion chamber, an enclosed heater casing about said heater, a blower constructed to receive cool air and force the same through said heater casing, a draft casing communicating with said heater draft intake, said heater casing and said draft casing having communicating means therebetween, means automatically openable under super-atmospheric pressure in the heater casing to provide a super-atmospheric pressure in said draft casing available for said draft inlet; an outside communication for said draft casing, means in said outside communication constructed to normally stand 'open to permit a natural draft to said draft opening but constructed automatically to close upon the attainment of a predetermined super-atmospheric pressure in said draft casing, a second outside communication for said draft casing, adjustable means for resisting flow through said second outside communication and means limiting the opening of the automatic means in the communication between the heater and draft casings.

5. A heating unit comprising a casing having an outlet warm-air duct and an inlet cold-air duct, a partition in said casing separating the same into a cold-air suction casing in communi-. cation with the cold-air duct and a warm-air pressure casing in communication with the warmto close upon super-atmospheric pressure occurtion therein forming a pressure casing, a blower in the cold-air casing having an outlet in the warm-air casing, a heater in the warm-air casing having a combustion chamber, a draft inlet in said pressure casing, communicating means between the pressure casing and the outside thereof constructed normally to stand open to permit natural draft to saiddraft opening and constructed automatically to close upon super-atmospheric pressure occurring in the pressure casing, communicating means between the pressure casing and the heating casing constructed automatically to open when said blower operates to provide superpressur'e in said pressure casing, and means constructed to independently control the draft through said draft inlet.

7. In a heating system, a heater having a combustion chamber and a draft intake,an enclosed casing about said heater, a warm-air duct from said casing, a blower adapted to receive cold air and force the same into said casing surrounding the heater, a second casing communicating with said heater draft intake, said heater casing and said second casing having communicating means therebetween, means constructed to automatically open upon occurrence of super-atmospheric pressure from said blower'in the heater casing to provide a super-atmospheric pressure in said second casing available for said draft inlet, a communication between said second casing and the outside thereof, means associated with said communication constructed normally to stand open to permit a natural draft to said draft opening but automatically to close upon the attainment of predetermined super-atmospheric pressure in said second casing, a second communicating means between said second casing and the exterior thereof and means associated therewith con- VERNON S. BECK.

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