US1639014A - Means for supplying heated air to combustion chambers - Google Patents

Description

Patented Aug. 16, 19.27.

UNITED STATES PATENT OFFICE.

GEBRITA VAN DAAM, F BUFFALO, NEW YORK.

MEANS FOB SUPPLYING HEATED AIB. T0,COMBUSTION CHAMBERS.

' Application filed January 15, 1925. Serial No. 2,594.

. delivered to the combustion s ace, and means for automatically cutting o the supply of air when the said combustion space is cold or relatively cold and for automatically admitting heated air to the combustion ispace when said space becomes heated and for automatically regulating the amount of air delivered Vto said combustion space proportional to the temperature of said combustion space. l

Referring toV the drawings which illustrate merely by way of example suitable means for effecting my invention- Fig. 1 is a longitudinal sectional elevation.

Fig. 2 is a part section, part elevation on an enlarged scale of the automatic control.

Fig. 3 is a part section, part plan of same. e

Similar' numerals refer to similar parts throughout the several views.

LReferring to Fig. 1, the heating element proper comprises the chambered formation 5,`having the flat wall 6 adapted to be bolted to the inner wall 7 of the combustion chamber. This may be a part of the fire door of a furnace, or other suitable part.

The fiat wall 6 and the wall 7 of the combustion chamber are provided with the registering inlet ports 8. To the outer side of wall 7 is secured the automatic controlling device 9 as shown in Fig. 2. The parts are bolted together on each side of wall 7 by the bolts 10 as shown in Fig. 2.

The chambered body 5 is provided with the corrugated wall 11 presenting a series of annular projections extending into the combustion chamber and also into the chambered part of body 5. A series of screens or perforated disc partitions 12 are positioned transversely the chamber 5 and may if desired be held together by the central rod 13.

At the small end 14 of the chambered lbody i 5 is provided a series of air discharge ports or vents 15 for delivering air into the combustion chamber directly over the fire.

Referring to Figs. A2 and 3 the automatic control comprises the plate 16 bolted directly through the wall 7 to the wall 6, and if desired an asbestos sheet 17 is interposed between the plate 16 and wall 7. The plate 16 and asbestos sheet 1.7 are provided with ports 18 registering' with the ports 8. A bell formation 19 provided with the central sleeve 20 is mounted on the post 21 threaded into the plate 16 and its outer rim, as at 22, is nor- Inally held against the surface of plate 16 by the compression spring 23 acting 'between the head 24 of post 21 and the shoulder formation 25 of bell 19. The composite bar, composed of the strip 26 of brass, and the strip Y27 of steel fastened together at each end, is bolted securely to the flat plate 28 by the bolt 29 and is provided at the other end with the projection 30 adapted to engage the lug 31 on the lever 32 pivotally mounted at 33 to a lug secured at 34 tol plate 16.` The free end 35 of lever 32 engages the underside of lever 36 pivoted at 37 to lug 38-` The free end 39 of lever 36 is bifurcated and engages trunnions 40 on sleeve @20. A stirrup 41 is secured to' the top of bell 19 and is provided with a thumb screw 42 engaging the head 24 of post 21. By turning the thumb screw 42 the bell may be raised arbitrarily against the tension of spring 23.

In operation, when the furnace or the combustion chamber thereof is cold, the parts remain as shown in Fig. 2, that is the margin 22 of bell 19 in engagement with plate 16 shutting off access of air to the inlet ports 18 and 8. It is Well known that when the fire is low, or is just being started, it is not desirable for cold air to enter into the combustion chamber above the fuel bed, since this not only checks the draft but also tends to chill the lire and retard combustion. When however, the fire is well started and burning free it is desirable t'o have heated air enter the combustion `chamber above the fuel bed to mingle with the unburned gases and complete the combustion thereof. llor this purpose the arrangement shown in Figs. 2 and 3 is provided. rlhe composite bar 26-27 is a well known form of thermostat, as the combustion chamber becomes heated, heat is communicated to the chambered body 5 6, and thence through plate 16 to said composite bar. The brass having a greater ratio of expansion than the steel, the composite bar bends andthe end 30 acting on lever 32 which acts on lever 36 which engages trunnions a() causes the bell to move against tension of spring 23 so that the edge 22 moves from the surface of plate 16 and thus opens a passage to the ports 18 and 8. rlhe air now passing through these ports, being drawn into the chamber 5 by the natural draft of the furnace flue, becomes highly heated as it engages the highly heated corrugated walls of chamber 5 and also as it passes through the hot screens 12 and thus in a highly heated state delivers through the vents 15 to the combustion chamber.

As the fire burns more freely and becomes hotter a greater supply of hot air is desirable, and as the elements become hotter the distortion of the composite bar 26-27 increases to increase the opening movement of bell 9, so that the air control automatically adapts itself to the temperature conditions of the furnace.

is above stated the thumb screw 42 provides means for the arbitrary control of the u inlet ports.

Various forms of air heating chambers, and various forms of automatic thermostat control of the air inlets thereto may obviously be combined. rlhe forms herein illustrated and described are only given as examples.

l have shown in the drawings, as a preferred form, a system of inovement-amplifying levers, in order that a very slight liexing of the compound or composite bar will'give a wide opening movement of the element or bell 19. lt will be obvious however that, with the extended line of engagement between the rim of bell 19 and the surface of plate 16, a very slight separation of said rim from said surface will afford ample passage for the air to the inlet ports, and consequently, in many arrangements, the direct action of the end, or projection 30, of the bar .2G-27 upon the bell element,

vwill give ample opening movement, without the need of any intermediate elements, such as the movement-amplifying levers.

In many combustion chambers the temperature rises to a very high degree and it is important, in thermostats of the type herein shown, to prevent the metal ofthe compound bar 26-27, in which the differential of expansion of the two metals is utilized, to avoid excessive temperatures in said metal which would tend to give them a set and thus impair the efficiency of expansion. ln the present case the compound bar 26-27 is positioned outside the combustion chamber, the heat of conduction only being utilized in its operation. is a further protection the asbestos sheet 17 is shown, interposed between the furnace wall and the plate 16. rlhis however is not always necessary or desirable. l/Vhere the temperature in the combustion chamber is likely to be low, or where the space is ample, and the device may be y placedY suciently remote from the fuel bed, or for other reasons, the

compound bar Vor, similar device may even be placed within the furnace or Within the combustion chamber.

lWhat l claim is 1. ln combination with a.. combustion chamber provided with an inlet port in the wall thereof, a chambered body supported within the combustion chamber and in communication with said inlet and provided with a discharge to the combustion space, a post extending from the outer surface of the combustion chamber wall, a bell-shaped member provided with a central sleeve movably mounted on said post and having a periphery adapted to engage said outer surface and to surround said inlet port, and a thermostat mounted upon said outer surface for moving the bell away from said outer surface.

2. 1n combination with a combustion chamber provided with an inlet port in the wall thereof, a chambered body supported within the combustion chamber and Yin communication with said inlet and provided with a discharge to the combustion space, a post extending from the outer surface of the combustion chamber wall, a bell-shaped member provided with a central sleeve' movably mounted on said post and having a periphery adapted to engage said outer surface and to surround said inlet port and a thermostat secured upon said outer surface and within the bell for moving the bell away from said outer surface.

3. ln combination with a combustion chamber provided with an inlet port in the wall thereof, a chambered body supported within the combustion chamber and inV communication with said inlet and provided with a discharge to the combustion space, a post extending from the outer surfacev of the combustion chamber wall, a bell-shaped member provided with a central sleeve movably mounted and spring controlled on said post and having a periphery adapted to engage said outer surface and to surround said inlet port and a thermostat secured upon said outer surface for moving the bell in opposition to the spring.

a. In combination with a combustion chamber provided with aninlet port in the.'

wall thereof, a'ehambered body supported Within the combustion chamber and in communieaton With said inlet and provided with a discharge to the combustion space,

a post extending from the outer surface of the combustion chamber Wall, a bell-shaped member provided With a central sleeve movably mounted on said post and having a, pe-

riphery adapted to engage said outer surface and to surround said inlet port, and a thermostat secured upon said outer surface for moving the bell away from said outer surface, and a heat insulating body interposed between the combustion chamber and said thermostat.

GERRIT VANk DAAM.

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