US2174901A - Combination coal-fed water heater - Google Patents

Description

Oct. 3, 1939. w. K. sTALl-:Y 2,174,901

COMBINATION COAL-FED WATER HEATER Filed July 22, 1938 3 Sheets-Sheet l INVENTOR TTOR Oct. 3, 1939. w. K. STALEY COMBINATION COAIrFED WATER HEATER :5 sheets-sheet 2 Filed July 22, 1938 .INVENTOR Y/f maar Oct. 3, '1939. w. K. STALEY COMBIATION COAL-FED WATER HEATER Filed July 22, 1938 3 Sheets-Sheet 5 INVENTCDF? z. mmf/ 6 762 5::

P .1 I n@ ATOR Promod oef. 3, 1939 i f 2,174,901

UNITED STATES PATENT OFFICE.,

COMBINATION COAL-FED WATER HEATER William K. Staley, Morton, Pa., assignor to Anthracite Industries, Inc., New York, N. Y., a corporation of Delaware Application July 22, 1938, Serial No. 220,615

4 Claims. (Cl. 126-344) The present invention relates generally to the air. All of these in association with the unit to automatic stoking and burning of coal and more which the burner was applied were the factors l particularly to a unitary apparatus for supplywhich led to success.

ing fuel to and maintaining combustion in a Some of the objects of the present invention burner or retort of smaller dimensions and ere to provide e coal burner and mechanical r capacity than any heretofore devised and which feed for use with a heater unit to 'suppllr hot functions in the open air instead of being coli- Welter for home 115e 01 the like; t0 provide e Cool ned in a combustion chamber, burning unit of the automatic type which will In heating apparatus as heretofore in use it eiiiciently burn barley size coal; t provide an m has been possible during the past several years, improved mechanical feed for a coal burning lo to more orV less successfully burn coal in a reunit; t0 provide en improved Control for a metort located in a furnace or enclosed Combustion chanical coal feed wherein the rate of feed bears chamber, such coal being supplied thereto autoa direct relation to the size of fuel and the heatmatically by means of a stoker from a bin or ing effect thereof; to provide o novel dual air hopper as the case may be. Where the burner is supply for a stolzer wherein a mein air supply 15 enclosed, as in the ordinary house heating boiler furnishes air for combustion purposes and a or furnace, quite efficient operating results have supplemental air supply furnishes air t0 temper been obtained provided the correct grade of anthe heated products end Ineke it DOSSlble to efthracite, such as buckwheat or rice gmdet` is fectively control the temperature of the water delivered to the bin or hopper. Such automatic or other medium being heated; and to provide 20 equipment, however, is applied to comparativelv other improvements eS Will .hereinafter appearairtight furnaces, all air supplied being furnished In the eeeolnpenying drawings, Figure 1 repby means of mechanical draft, and is furtherresents a side elevation of one form of the inmore adapted for the use of anthracite 0f larger vention in association with a hot Water heatingr size than barley. In consequence a wide field system; Figure 2 represents a. side elevation of 25 of commercial use has been forced to await the the burner and fuel feed mechanism; Figure 3 solution of the problem of open air use with represents an end elevation of Figure 2: Figure cheap fuel. This neld includes water heaters 4 represents a detail in plan of the burner; Figfor domestic use and no one heretofore has been ure 5 represents a sectional detail of one form of able to produce a coal stoking and burningr unit the thermostat; and Figure 6 represents a sec- 30 so associated. and combined with the ordinary tion 0n line 5-5 of Figure 1.

gas f uel type of water heater (minus the gas Referring t0 the drawings one form cf the burner) which is practical or commercial, It present invention consists of a coal burning unit j would seem a very simple thing to pattern a l0 arranged t0 be mechanically supplied with small burner yand its stoker after its well known fllei by a Stoker il from o SllDelDOSed hopper |2- 35 large counter-part so that the miniature device Theun-it l0 iS Shown in combination with a Coil could be used for water heaters, which are rela- Water heater i3 of the Well known ges heated tively small as compared to furnaces, boilers and type but from Which the ges burner has been like heating units, but this is not the case. When removed. In the illustrated form of the inven- -f o such reduction in size was tried, the result was tion the heater `lli maintains a supply of hot 4o failure. Thus the dwarf burner and Stoker rewater in a storage tank I4 which is connected fused to function with any grade of coal which by Circulating Pipes l5 and i5 With the coil IT had worked satisfactorily in the known types of. of the heater I3. It should be noted that the burners and stokers. This was surprising and burner unit Il) is not only located well below the baflling. Continued experiments finally gave a coil I1 but is exposed on all sides to the atmos- 45 clue to success in the use of barley size coal Dhere and hence operates Under Very unusual which has long since been abandoned as a precconditions. Furthermore since the casing of a tical fuel for mechanically red domestic burndomestic Water heater is of relatively Smell diers. Its use however did not come from a mere arneter, the diameter of the burner unit I0 must substitution of one fuel for another, but in conalso be restricted being therefore of the order of junction with a complete reorganization of the approximately seven inches. In effect it becomes coal feeding means including an ingenious bala miniature coal burner which through an nancing of rate of feed, control of feed by water l genious association with an inlet ue I8 has temperature. forced draft, and the mixing of the been made to operate under the most adverse gaseous products with a. supplemental supply of conditions for this type of equipment. As shown 55 the flue I8 is of truncate shape and is located between the coaxially positioned heater I3 and mingling fresh air with the burning products.v

top face of the base bowl 22.

the unit I2. The large diameter of the nue I8 is considerably larger than the diameter of the unit I in order to form an annular passage 20 about the rim of the 4unit I0 as a means for This te pering of the products `of combustion `has been' found to be one of the major requirements for efficient operation of the unit ID and heater I3 as a unitary combination.

Referring to the burner unit Il), a retort 2| in the form of a funnel shaped casting is provided having a circular flange which seats upon the The parts thus assembled are held in place by cotter pins 23. This is a simple and convenient assembly which is made possible by like material in the two castings whereby warping of one part with respect to the other is avoided. The funnel part of the retort 2l is provided with a plurality of circumferentially arranged rows of tuyres 24, those nearest the outlet end of the funnel part being of somewhat smaller diameter than the remaining rows.v This avoids undue loss of air near the surface of the burning fuel.

Vlhe -bowl 22 is provided with a fuel inlet 25 and an air inlet 26, the former leading directly to the inlet end of the retort 2I, and the latter discharging into a chamber 21 which'surrounds the inlet 26 and the perforated funnel part of the retort 2I. A removable plate 28 in the bottom of the bowl 22 permits the cleaning out of any collection fines or sediment when necessary.

For supplying air under forced draft to the air inlet 26, an air supply pipe 30 leads from the inlet 26 to the discharge side of a fan housing 3| which is located below the hopper I2 and adjacent a motor 32, the drive shaft 33 of whichV i I drives the blower fan 34.

For supplying fuel to the inlet 25, a conduit 35 leads from the inlet 25 to and communicates with the downwardly flared hopper bottom 36. A suitably mounted feed screw 31 of slow feed pitch is arranged within the conduit 35, and its shaft :it projects from the closed end of the conduit 35 to receive a driven ratchet wheel 40. A spring pressed pawl 4I is pivotally mounted to ride upon the ratchet wheel to thereby prevent lback lash.

In order to actuate the ratchet wheel 40 for vstep by step feed and to regulate the step quantity according to water temperature conditions, a work pawl 42 is pivotally mounted on the short I" arm of a rock lever 43 in position to engage the r being a fixed point 48 and the lever 43 to return the lever 43 after a ratchet working stroke.

is means for varying the stroke of the lever in accordance with the temperature of the water heated, a link chain 50 connects the lever i3 with a rock arm 5I which is fixed to a rock shaft 5E. An operating arm 53 is also fixed to the shaft 52 and is joined to one end of a suitable flexible cable or chain 54, the other end of which is attached to the long arm of a control lever 55 which is pivoted in a bracket 56 attached to the housing of an expansion type of thermostat 51. the thermostat housing to seat against an expansion member 58 for actuation thereby. The action of the thermostat can be varied by means of a weight 60 adjustable on the long arm of the control lever 55, and arranged to be set in a selac-ted position by a clamping screw 6|.

Attention is directed to the fact that the motor 32 is of the type which can be stalled for an indefinite periodwithout burning of the motor windings, for example a motor of the shaded pole type has been found to give satisfactory results. mechanical drive which is designed suciently strong to stall the motor in case of a jam to thus save the mechanical parts from injury. Such jams may be caused by foreign matter, such as nails, screws, nuts and the like, or large size coal accidentally entering the coal worm. By this construction it is unnecessary to use shear pins or similar devices to prevent injury when the feed becomes obstructed. Also it should be noted that the motor and gear box constitute a driving unit which can be replaced by simply removing the four holding capscrews. Furthermore the coal worm, thrust bearing and ratchet The short arm of the lever 55 enters Associated with this motor unit is the assembly form a complete driven assembly which has been devised wherein barley size coal can be successfully and efficiently used for heating water for domestic use. It should be noted that small quantities of coal in process of combustion possess no banking characteristics and therefore when once ignited must be kept replenished as consumed, which necessitates a continuously operating feeding means. Such continuous feed, even though regulated for a minimum and maximum feed, tends to overheat the water and in order to avoid too high water temperature (while at the same time maintaining efficient operation) a novel supplemental air supply means has been created to temper the hot products from the burner according to operating conditions.

Having thus described my invention, I claim: l. A combination of a water heater consisting of a water circulating coil'and a tubular casing enclosing said coil for the passage of products of combustion, said casing being arranged to discharge gases at its upper end and open to the atmosphere at its lower end, a burner unit co-' axially located below said casing, means for feeding coal continuously to said unit, a forced draft to supply air only to said unit, means to vary the rateof coal feed according to the water temperature, and an inlet for air at atmospheric pressure to said casing, said inlet being so associated with said casing and said unit that the quantity of supplemental air traversing said inlet is controlled by the pressure of the gaseous products in said casing whereby under pilot conditions of said burner unit the efficiency of heat transfer from the products of combustion is reduced.

2. The combination with an enclosed water heater having an open bottom to receive products of combustion to heat the water, of a continuously operable coal burning unit to produce the products of combustion, means for feeding fuel to said unit at a varying rate in accordance with heat demand of the water to be heated,.a forced draft mechanism to supply a non-variable volume of air to said unit, and means to vary the thermal emciency of the products of combustion in the heater to maintain combustion in the burner unit under pilot conditions without overheating the water including a supplementary supply of air under atmospheric pressure fed directly into said heater at a point above and in non-eombustive relation to said unit.

3. A replacement burnerunit foia gas fired water heater consisting of a coal burning retort, means for feeding coal continuously to said retort, a forced draft to supply air to said retort, means responsive to the temperature of the water being heated to vary the rate ot fuel feed, and means including a supplemental air supply delivered directly into said heater at a point above and in non-combustive relation to said retort to prevent overheating of the water when said fuel feed is functioning at a. minimum rate.

4. The combination of a water heater and a coal burning unit, said heater including a casing forming a combustion chamber open at the bottom and a water coil in said chamber, said unit being disposed coaxially below said bottom, means forming an annular passage about said unit to admit air to said chamber according to pressure conditions in said chamber to vary the efficiency of heat transfer from the products of combustion to the water in said coil, means for feeding fuel to said unit, and a forced draft mechanism to supply air only to said unit to support combustion.

WJLLIAM K. STALEY.

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