US2255682A - Fluid control system - Google Patents

Description

' W. V. SAUTER ETAL Sept. 9, 194 1.

FLUID CONTROL SYSTEM Original Filed Ma y 18, 1935 I I: IN IN 4 5 I AI W Patented Sept. 9, 1941 UNITED STATE 2,255,682 FLUID CONTROL SYSTEM William V. Sa'uter and Howard F. Lawrence,

Philadelphia, Pa., assignors to American Engincering Company, Philadelphia, Pa., a corporation of Pennsylvania Original application May 18, 1935, Serial No. 22,217. Divided and this application June 16, 1938, Serial N0. 213,989

6 Claims.

This application is a division of our co-pending application Serial No. 22,217, filed May 18, 1935, now Patent No. 2,173,884, granted Sept. 26, 1939, and the invention herein involved relates more particularly to automatically operable damper mechanisms associated with the tuyere blocks of stoker furnaces.

It is the primary object of the present invention to provide an improved flow control damper for use in fluid control systems for 'stoker furnaces.

Other and further objects will become apparent as the description of the invention progresses.

Of the drawing, Fig. 1 is a longitudinal sectional view taken through one of the retorts of a stoker furnace.

Fig. 2 is a side elevational view partly in section of a plurality of tuyere blocks showing the fluid control elements associated therewith in open position.

Fig. 3 is a similar view showing the fluid control elements in closed position; and

Fig. 4 is a plan view, partly in section and with parts broken away, of a pair of superimposed tuyre blocks showing a damper element mounted on one of said tuyere blocks.

Referring to the drawing, the numeral 1 designates a stoker of the underfeed type having alternately disposed retorts 2 and tuyere rows '3. Fuel is supplied to retorts 2 from a hopper 4, and any suitable feeding device driven by a power mechanism indicated at 5 feeds the fuel gravitating in hopper 4 to the retorts2. A series of pushers 6 mounted in the bottom of each retort 2 is also operated by the power mechanism 5 through the connections 1. These pushers underfeed the fuel along the retorts and tuyeres to an extension grate 8, which in turn overfeeds the fuel to an ash pocket 9 disposed at the rear of the stoker.

It is to be understood that the invention hereinafter described is not to be limited to its application to underfeed stokers, since it is equally adaptable for use in connection with other types of stokers, as well asother apparatus wherein flow control is desired.

When the terms front and rear are hereinafter used in connection with the description of the elements of the stoker l and the associated fluid control, it will be understood that the portions of such parts extending toward the rear or ash pocket 9 of the stoker will be designated as rear, and those portions thereof extending toward the front or driving mechanism 5 of the stoker will be designated as front.

Referring more particularly to Figs. 1 and 2, each tuyre row 3 comprises a series of superimposed tuyere blocks 50, each having a rounded nose or rear portion H, and a substantially rectangular front portion l2. The upper surface l3 of each tuyere block is substantially flat and has a slightly beveled portion I4 extending around the nose portion thereof. I

The tuyre blocks l9 are supported in the usual manner upon the side plates l5 of adjacent retorts '2. The forwardly disposed ends [6 of. the tuyre blocks Hi extend between adjacent side plates I5. Draft air enters the tuyere locks from a common pressure or plenum chamber ll disposed beneath the stoker, which in turn is supplied with air from any suitable fan mechanism (not shown) in a well known manner.

The mechanism for controlling the flow of fluid from plenum chamber ll to the tuyere blocks [0 comprises a series of independently operable damper elements is, one for each of said tuyere blocks Hi.

As shown in Figs. .2 and '3, each damper element I3 is of arcuate construction; The forwardly-disposed end of each damper i8 is bent in the form of a loop, as shown at It, and a pin 20 extending through said loop pivotally supports the damper in position. The ,pin 25! extends through apertures provided in the forwardly extending projections 2i of the associated tuyre block [0. As shown in Fig. 2, the rearwardly disposed end of each damper it! rests upon the upper surface of the associated tuyere block l0, and extends between the ribs 22 of the next higher tuyere block of the series forming the inlet passage 23 thereof. These dampers operate on the airfoil principle and function when the 'velocity of the air passing thereov er reaches a the tuyre blocks and thus partially or completely shut off the air supply to the fuel bed overlying such tuyere blocks. In order to retain these damper members in open position until the air flowing through the tuyere blocks reaches a predetermined velocity, thedamper elements I 8 may be provided with weights W at the rearwardly disposed ends thereof, or the material of which the dampers are constructed may be sufficiently heavy to function in the desired manner. When the dampers !8 are in closed position, as shown in Fig. 3, a slight air leakage occurs past the upper surfaces thereof and accordingly the lifting efl'ect thereon is maintained. As a result the dampers remain in closed position until the condition of the fuel bed changes to impose a greater resistance to the flow of air through the associated tuyere blocks. It will also be noted that the dampers are disposed substantially longitudinally in respect to the direction of air flow to the tuyere blocks, and accordingly the impact head of the air flowing past the dampers has little or no effect upon the operation thereof.

From the foregoing description it is apparent that our fluid control mechanism is not only of simple construction, but is highly efficient in operation. Due to the simplicity of this construe-Q tion, the dampers may be readily assembled on the tuyre blocks, and when once assembled'in one end thereof and so arranged that when in fully open position lies adjacent one wall of said passage, said damper having a convex surface exposed to the fluid flowing in said passage,

wsaid convex surface being so disposed that an area of low pressure is produced thereon when fluid is flowing in said passage, the said pressure determined value the difference in pressures opn so produced being in inverse proportion to the velocity of the fluid passing thereover, whereby when the velocity of the fluid reaches a preerating at the opposite sides of said damper will to a dangerous extent to shut off the air supply to the tuyere blocks and thus immediately reduce the combustion rate at such points. The fuel feeding elements may then feed additional fuel to such portions of the fuel bed before the incandescent fuel has had the opportunity to cause any serious damage to the tuyere blocks. Blow holes which often occurin furnaces are thus practically eliminated by the use of the present invention. 7

While the embodiment herein shown is admirably adapted to fulfill the objects primarily stated, it is to be understood that it is not intended to limit the invention thereto, since it maybe embodied in other forms, all coming within the scope of the claims which follow.

What is claimed is: e

1. A damper adapted to control the flow of fluid in a passage, said damper being pivoted at one end thereof and so'arranged that when in fully open position lies adjacent one wall of said passage, said damper having one surface thereof in contact with the fluid flowing through said passage, the said surface of the damper in contact with the fluid beingso constructed and disposed that an area of low pressure is created on said surface when fluid is moving in said passage, the pressure so produced being in inverse proportion to the velocity of the fluid flowing in said passage, whereby when the velocity of the fluid reaches a predetermined value, the difference in pressures operating at the'opposite sides of said damper will cause it to move toward closed position to throttle'the flow of fluid in said passage.

2. A damper adapted'to control the flow of fluid'in a passage, said damper being pivoted at one end thereof and so arranged that when in fully open'position lies adjacent one wall of said passage, said damper having one surface thereof in contact with the fluid flowing through said passage, the said surface of the damper in contact with the fluid being so constructed and disposed that an area of low pressure is created on said surface when fluid is moved in said passage, the pressure so produced being in inverse proportion to the velocity of the fluid fiowingin said passage, whereby when the velocity of the'fluid reaches a predetermined value, the difference in pressures operating at the opposite sides of said damper will cause it to move toward closed position to throttle the flow of fluid in said passage, and weight means secured to said damper for holding the latter in open position until the fluid flowing in said passage reaches a predetermined velocity. v

3, A damper adapted to control the flow of fluid in a passage, said damper being pivoted at cause said damper to move toward closed position to throttle the flow of fluid in said passage.

4. A damper adapted to control the flow of fluid in a passage, said damper being pivoted at one end thereof and so arranged that when in fully open position lies adjacent onewall of said passage, said damper being substantially longer than the distance between the walls of the pas sage from and toward which it moves, and having a convex surface exposed to the fluid flowingin said passage, and said convex surface being so disposed that an area of low pressure is produced thereon, the said pressure so produced being in inverse proportion to the velocity of the fluid passing thereover, whereby when the velocity of the fluid reaches a predetermined value the difference in pressures operating at the opposite sides of said damper will cause it to move toward closed position to throttle the 'flow of fluid in said passage.

'5. A damper adapted to control the flowof fluid in a passage, said damper being pivoted at one 'end thereof and so arranged that when in fully open position lies adjacent one wall of said.

passage, said damper being longer than the distance between the walls of said passage from and towards which it moves and having an arcuate surface over which the fluid flowing in said passage passes, and said arcuate surface being so disposed that an area of low pressure is produced thereon, the said pressure so produced being in inverse proportion to the velocity of the fluid passing thereover, whereby when the velocity of the fluid reaches a predetermined value the differ ence in pressures operating at the opposite sides of said damper will cause it to move toward closed position to throttle the flow of fluid in said pas sage.

6. A damper adapted to control the flow of fluid in a passage, said damper being pivoted at the upstream end thereof and so arranged that when in fully open position lies adjacent one wallof said passage, said damper being substan- 1 't1ally longer than the distance between the walls of said passage from and toward which it moves, said damper having a convex surface exposed to the flllld flowing in said passage, and said convex surface being so disposed that an area of low pressure is produced thereon, the said pressure so produced being in inverse proportion to the velocity of the fluid passing thereover, whereby when the dlfference in pressures operating at the opposite sides of said damper is sufficient to overcome the weight thereof said damper will move toward closed position to throttle the fluid in said passage.

WILLIAM V. SAUTER. HOWARD F. LAWRENCE.

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