US2136688A - Fuel feeding means - Google Patents

Description

Nov. 15, 1938. G. E. HOUGHTON FUEL FEEDING MEANS Filed April 2, 1936 11M ill INVENTOR. .7

GEORGE E. HOUGHTU/V BY y ATTORNEY.

Patented Nov. 15, 1938 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to fuel feeding devices and has particular relation to devices for feeding pulverized fuel into a furnace for combustion liquid fuel are satisfactory in operation but it is a well known fact that the cost of the liquid fuel per heat unit is much greater than the cost of coal per heat unit. It is accordingly of substantial economical advantage to use coal in the firing of a heating plant.

There have been, consequently, various methods and devices employed to provide for the automatic feeding of coal to a furnace. These devices comprise stokers andpulverized coal burners and the like. However, stoking devices do not readily lend themselves to quick and positive control of combustion of the fuel in a furnace. In addition the residue of combustion in a stoker fired furnace usually takes the form of clinkers which are diflicult to remove from the fire box.

The use of pulverized coal does away with many of these difiiculties encountered in the use of stokers and approaches liquid fuel in ease of handling and in other advantages with the added advantage of lower fuel cost as compared to liquid fuels.

Devices adapted to feed pulverized coal constructed according to the teachings of the prior art and with which I am familiar, have had certain defects. In the first place many of the devices were designed primarily to be used with large furnaces and were consequently intricate and expensive and not applicable to the small heating plant. Others designed for use with small heating plants were unsatisfactory in many ways. Some did not provide for proper metering of the fuel and so did not provide for positive action for controlling the combustion of the fuel. In others proper provision was not madefor insuring that the pulverized fuel be finely divided before being injected into the fuel box of the furnace.

It is accordingly an object of my invention to provide a simple, compact and comparatively inexpensive device for feeding pulverized fuel into a furnace.

Another object of my invention is to provide a v pulverized fuel feeding device in which the feedfor positively controlling the amount of fuel fed into a heating plant.

A further object of my invention is to provide a pulverized fuel feeding mechanism which will insure the fuel being suspended in air in finely 5 divided particles.

According to my invention I provide a device that comprises a mechanism for withdrawing pulverized fuel from a hopper in fixed measurable quantities. The fuel is then led into a sysl0 tem of blowers and from there directed into the fire box of a. furnace where it is burned. An electric motor is employed to actuate the various mechanisms of the device.

The novel features that I consider character- 15 istic of my device are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation together with additional objects and advantages thereof, will best be un- 20 derstood from the following description of a specific embodiment of the invention when read in connection with the accompanying drawing, in which:

Figure l is a view in side elevation and as- ,25 sembled relation of a device constructed in accordance with the principles of my invention. Various parts are broken away to better illustrate the device.

Figure 2 is a top sectional view, taken along 30 line II of Figure 1, of a paddle mechanism employed in my device for distributing the fuel into the rest of the device.

Figure 3 is a detailed view in side elevation of the mechanism for controlling the amount of 5 pulverized fuel fed into the blower of the device.

Figure 4 is a detailed perspective view on larger scale of the gate-like device of the fuel discharging mechanism.

The device shown in Figure 1 comprises a 40 motor or actuating means Ill and a fuel feeding assembly indicated generally at H. The motor Ill and assembly l l. are mounted in close cooperative relationship on a base l2.

A housing l3 is secured on the base l2 and 5 the housing is designed to furnish bearing supports for a drive shaft M having a worm l6 integral therewith. The shaft is adapted to be driven by the motor l3 through the agency of a universal joint I5. 50

A second housing and supporting member I! is secured to the upper face of the housing 53. The upper portion of the support ll comprises a casing 18 which serves to house a fuel distributing device as hereinafter described. 55

The center of the support I1 comprises a bushing like member 2I which serves to enclose and to act as a bearing support for a shaft 22, indicated by dotted lines. The shaft 22 has a worm gear 20 at its lower end which is adapted to be driven by the worm IE on the shaft I4. A circular disk 23, illustrated in Figure 2, is suitably mounted on the upper extremity of the shaft 22 for rotation therewith. The disk 23 has paddle-like members 24 on its periphery and integral therewith. The paddle members 24 are set at an angle with the vertical axis of the disk 23 and serve as fuel distributing and metering means as hereinafter described.

A hopper 26 is provided and this hopper is mounted on and directly above the casing IS in which disk 23 is located. The topper is an integral part of a fuel supply bin which provides a supply of pulverized fuel immediately accessible to the distributing mechanism of the device.

The bottom of the hopper 26 is arranged with an opening therethrough (not shown). This opening corresponds in dimensions and location with the space enclosed between the paddles 24 on the periphery of the disk 23.

As the disk rotates with the shaft 22 the paddles 24 sweep by the above-mentioned opening and receive a definite amount of fuel from the hopper 26. The fuel is retained between the paddles 24 by the casing I8 and is swept by the paddles to an opening 21 in the lower face of the casing I8. At this point the charges of fuel carried between adjacent paddles 24 are discharged into the blower mechanism, the action of the paddles pressing a certain amount of fuel into the-blower mechanism each time a paddle passes over the opening 21.

Adjacent the opening 21 and immediately therebelow is a mechanism for controlling the amount of fuel discharged from the distributing disk 23 through the opening 21. This mechanism, better illustrated in Figures 3 and 4, comprises a gate-like device having cooperating plates 28 and 29. The plate 29, curved upwardly at the inner extremity as indicated at 3|, is secured in fixed relationship immediately below the opening 21 with the ear 3| extending within the opening and immediately adjacent one side thereof. The other plate 28 is designed to work cooperatively with plate 29 to permit increasing or decreasing the extent of the discharge opening and thus to regulate the amount of fuel passing therethrough. The plate 28 is slidably secured beneath the opening 21 at one portion and in a hanger 30 on the under surface of easing I8 and has an ear 32 at one extremity adapted to be closely engaged with ear 3| on plate 29. The other extremity of the plate is also formed in a lip 33 immediately adjacent the hanger 30 and a set screw 34 engages the lip 33 and is threadedly inserted in the hanger 3!]. Obviously, rotation of the screw 34 provides for adjustment of the plate 28 to bring the plate 28 in close engagement with plate 29 or to space the plates apart. The mechanism thus described provides an efficient means for controlling the flow of pulverized fuel into the blower mechanism hereinafter described.

Immediately below the gate and continuous therewith is a passage 36 forming a connection between the fuel distributing or metering mechanism and a housing 31.

The housing 31 is secured with and adjacent to housing I3 and is also secured to base I2. The housing 31 serves to enclose a fan 38 which is mounted on a portion of the through shaft I4 extending beyond the housing I3. This fan 33 may be termed an auxiliary fan as it serves to feed the main blower fan indicated at 39.

The main fan or blower 39 is also mounted on the shaft I4 at the outer extremity thereof. The main blower fan 39 is enclosed in a casing M which is secured to the outer face of the housing 31. A portion of the casing M is formed to provide a blower outlet indicated at 42. This outlet is adapted to communicate with the fire box of a furnace. The casing may be secured on the housing 31 in several positions, preferably five, to enable the blower outlet to be located in as many positions. This is accomplished by spacing the bolts by which the blower casing is secured to the housing at equal intervals about the periphery of the joint between these parts. The blower outlet may then be directed in any of five directions to thus provide a flexible arrangement for use with different type furnaces.

The auxiliary fan 38 has comparatively few blades and in the particular embodiment here shown comprises a four bladed fan. The main or blower fan 39 has a larger number of blades than the auxiliary fan 33, so arranged that the blades will not be in synchronous relation with the blades of the auxiliary fan. This arrangement insures that the pulverized fuel will be divided into fine particles well mixed with or suspended in air before injection into the fire box of the furnace thus assuring a proper combustible mixture.

The operation of the above described device may be set forth as follows. The motor 13 is engaged on base I2 in the usual manner and sets the rotating mechanism in operation through the agency of the universal joint I5 and the drive shaft l4. The worm IS on the drive shaft actuates the shaft 22 and in turn the fuel distributing disk 23 and paddles 24. The paddles 24 serve to meter the pulverized fuel fan hopper 26 with the blower mechanism of the device. The amount of fuel discharged into the blower mechanism may be regulated by the control gate formed by plates 28 and 29. This adjustment permits regulation of the rate of combustion in the fire box of the furnace.

The fuel is fed from the distributing device 23 through the air entering the furnace in the auxiliary fan 38 which is actuated by the shaft I4. The pulverized fuel is then discharged from the auxiliary fan through the main fan or blower 39 from which it is discharged into the furnace through outlet 42. The use of the auxiliary fan in addition to the main fan insures that the fuel will be mixed into the air entering the fur nace in fine particles.

It is obvious that the fuel feeding device here described is simple and positive in action and will thus insure good results in the use of pulverized fuel for all types of heating plants and the like.

Although I have shown and described a certain specific embodiment of my invention, I am fully aware that many modifications thereof are i possible.

My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and the spirit of the appended claims.

I claim as my invention:

1. In a device for feeding pulverized fuel into a furnace, a hopper for retaining a fuel supply, a housing below the hopper, a fuel distributing disk enclosed in the housing and having paddles at the periphery thereof adapted to take fuel from the hopper, a blower mechanism, means for controlling the discharge of the fuel from the distributing disk and housing into said blower mechanism comprising a gate-like device having a fixed plate curved upwardly at its inner extremity, and a movable plate slidably secured with relation to the fixed plate, a hanger for supporting the movable plate, the fixed and movable plates having ears on adjacent ends of the plates, said ears being curved upwardly toward each other with one ear higher than the other, aforesaid blower mechanism comprising an auxiliary fan and a main fan, and means for actuating the fuel distributing disk and the blower mechanism comprising a motor, a shaft adapted to be driven by the motor and having a worm integral therewith and the said shaft also having the main fan and the auxiliary fan mounted thereon, and a second shaft having the fuel distributing disk mounted thereon and adapt-ed to be driven by the first named shaft through the agency of the worm integral therewith, and a worm gear secured to the second named shaft.

2. In a pulverizing fuel feeding device, a fuel distributing and metering means comprising a disk having paddle-like members about the periphery thereof, a housing in which the disk is housed, the housing having an opening in the bottom thereof, below the paddles in an arc of their movement, a gate-like means for controlling the flow of fuel from the disk and including a plate having an upwardly curved ear at the inner extremity thereof and with the ear extending into the opening and immediately adjacent thereof, a second plate adapted to work co-operatively with the first named plate to permit increasing and decreasing at the extent of the discharge opening, the second plate being slidably secured beneath the opening and a hanger for supporting the second named plate, the inner end of the second named plate having an upwardly curved ear disposed in opposed relation to the ear on the first named plate, and the ears being arranged with one higher than the other to positively scrape fuel from beneath the paddles and discharge it through the opening, and a blower for discharging fuel from the fuel distributing means into the fire box of the furnace and means for actuating the fuel distributing means and the blower means.

GEORGE E. HOUGHTON.

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