US2007777A - Control mechanism for furnace blowers - Google Patents

Description

3! 1935.. R. G. STANDERWICK 2,U7,7W

CONTROL MECHANISM FOR FURNACE BLOWERS Filed Feb. 17, 1933 I %N 5 i. \N

Id G. Stanciervvic; k,

H s Attlorneg Inventor:

e ina i U Patented July 9, 1935 mm as '7 conrnonmnousmsivrlroa FURNACE ,BLOWER'S Reginald G; Standerwiek, Marblehead, esa, assignor to General Electric Company, a corporation of New York Application February 17,

1933; Serial No. 657,250

The'present invention relatesto furnaces such ,as Bessemer converters, and like consumers of air or gas wherein air for blowing the furnaces is supplied by a turbine driven centrifugal eempressor, and especially to control means for such rappara'tusr The control of such apparatus ofiers peculiar difficulties in that the furnace'or furnaces are located usually a considerable distance from the turbo-compressor, requiring along'pipe 'duringi'the operation of the furnace, the com- ;pressoi must be shut down, and started up again frequently. 1 V

' The object of my invention is to provide an "or thistype, and fora consideration ofivvhatl believe to benovel and my invention',,attention is directed to the following specification and'the claims appended thereto;

In the drawing, the figure is a diagrammatic view of an installation embodyingfmy invention, it being in the drawing shown'appli'ed to jtwo Bessemer converters receiving air from the same turbo-compressor set. i "Referring to V the drawing; the Bessemer converters I and'2are connected by conduits 3 and "4Qto a discharge conduit 5 of oentr'ifugal'c'om- 'pressor or blower 6 drivenby aneIastic' fluid turbine or prime mover 'I." In conduit 5, is a non-return valve 511 which serves to prevent back 'blow in conduit 5 toward the compressor; The converters l and 2 are indicated as beingf'located a considerable distance from the turbo compres- 501 set (this being the'condition met with usuf ally) which means that the pipe line comprising conduits 3,4 and 5 is relatively long and has a large volumetric capacity. The'turbinefT is provided with valve means 8 for controlling the v supply of elastic fluid to the turbine and with "a speed governor 9 driven from the turbine'shaft.

' it'being connected toa condenser I IJThe compressor is provided with an intake conduit l2 7 Connected to an end portion of the'discharge 5 conduit 5, that is in the vicinity of the compressor,

is a waste conduit or dumping pipe I3, in which is located a blow-ofi, dumping or wastevalve l4. Conduit 'l3 may discharge directlyto atmosphere or, as shown, it may be connected to'the com- ;50' 'pressor inlet conduit l2. Valve M has its stein connected'to 'a piston of a hydraulic motor, the cylinder of which'is indicated atlG. Admission of actuating fluid to cylinder l6 is controlled by a pilot valve I1, I8 being the supply condu t 65' to the pilot valve and IS the discharge conduit linetof relatively large capacity, and vin that ea governorlever 241 One end of lever 24 is pivotally connected to a lever 25 and the other i direction to move valve means 8 to closed posif therefroml The stem of pilot valve I! is con- 7 nected to avplunger 200i an electro-magn'et, the

winding of; which is indicated at 2|. Pilot valve 7 l1 hasonly two positions. 'When winding 2! is deg'energized, pilot valve l1 occupies a position to 5 "admitactuating fluid to the outer end of the cylinder l6,'thereby holding valve l4 closed, and 'when winding 2| is energized, the position of the ,pilotivalveis reversed, admitting actuating fluid to the inner end of cylinder [6 to force valve [4 10 7 to open position and hold it there. In other words, when winding 2| is deenergized, valve I4 is held closed and when winding 2| is energized, valve l4. is held open. improved control mechanism for an installation Inconduits 3 and 4 are manually controlled :15

.' valves 2tl'fandl23 bymeans of which the operator varies the quantity of air required during operation of the converters. 1

v Speedgovernor '9 has a spindle connected to end is connected" to the plunger 26 of an electromagnet, the winding of which is indicated at 21.

T Winding 2!v is normallydeenergized and when deenergized, a spring 28 holds the right hand end .25 of governor lever 24 against a fixed stop 29; One

n end of lever is connected to valve means 8 and the arrangement is such that when winding 21 is energized, it turns governor lever 24 in a v 30 tion, lever 24 pivoting on the spindle of governor 9. .It is desirable that this movement be retarded somewhat so that in operation valve M will be opened wide before valve means 8 is closed, In the present instance this is effected by Pa suitabledash pot 2'l which serves to retard upward movement of plunger 26.

It is desirable in an installation of this type [that evenwhen valve means 8 is closed, sufiicient Qe'lastic fluid flows by it to keep the turbine turning 40 The exhaust for the turbine is indicated at in,

over at a low speed. For this purpose, the valve lm'eans is provided with a small opening 39 through it, although any other suitable arrangement'rnay be used for this purpose.

" Electromagnet winding 2| and electromagnet ffi winding 21 are connected in multiple to a remote controlrhechanism comprising a switch 3!, one

terminal of which is connected to a suitable source of electrical supply indicated at 32. With is released, its right hand end being held in engagement with the stop 29. When switch 3| is 'clcsed, the windings of both electromagnets are 5 indicating the pressure therein.

energized, the energization of winding 2| serving to open valve l4 and the energization of winding 21 serving to close valve 8.

The left hand end of lever 25 is connected to a pressure responsive device 33 which in turn is connected by a pipe 34 to discharge conduit 5. In the present instance, the pressure responsive device which forms a part of the turbine governing mechanism is shown as comprising a casing 35 in which is located a corrugated bellows .36 having its stem 31 pivotally connected to lever 25. Pipe 34 connects to the lower end of casing 35. Surrounding stem 31, between the top of casing 35 and an adjustable spring plug 38 on stem 31, is an adjusting spring 39. .Spring 39 is a tension spring operating in a direction opposed to the pressure in casing 35. Spring plug 38 is threaded on stem 31 and may be adjusted by turning'it manually or by means of an electric motor 40 which is connected to .a gear 4|, which forms a part of spring plug 38, by means'of a bevel gear 42 and a spur gear 43. When motor 40 is operated in one direction or the other, it turns nut 4| to either increase or decrease the tension of the spring 39. The nut and spring plug travel along the threaded rod 31. The two windings of reversing motor 40 are connected to a switch 44. By means of switch 44, the pressure responsive device 33 may be adjusted or set for the desired pressure. p

The control switches 3| and 44 and the control 'means for valves 22 and 23 are located adjacent to the converters and to each other so that the operator at the Bessemer converters can manipulate them conveniently. Adjacent the operator is a pressure gage 45 connected to conduit 5 for The operation is as follows: When the molten stock is being poured into the converters to load the same, switch" 3| is closed, thereby energizing windings 2| and 21. This serves to open wide the blow-off or waste valve l4 and to close entirely valve means 8.

Closing valve means 8 shuts ofl the supply of elastic fluid to the turbine except for the amount which leaks through opening 30, this being suflicient to keep the turbine turning over at a relatively low speed. As soon as the converter is loaded, the operator opens switch 3| whereupon waste valve I4 is promptly closed and valve means 8 is thrown wide open. The turbine quickly comes up to maximum speed, this being the speed for which the governor 9 is set. Ordinarily,

the speed governor is set for a speed somewhat' ing valve means 8 to obtain the desired pressure in discharge conduit 5. In this connection, it will be seen that when the pressure in conduit 5 increases, the pressure responsive device closes valve means 8 somewhat to bring the pressure back to normal value and when the pressurein conduit 5 decreases below normal value, pressure responsive device. 33 serves to open valve means 8 to increase the speed and bring the pressure back to normal value. After the compressor pressure reaches normal value, the operator then .closing of the non-return valve.

manipulates valves 22 and 23 to supply the desired amount of air to the converters. After the blowing operation is completed, the operator closes the switch 3|, thus again bringing the turbine quickly to idling condition with the blow- 5 off valve I4 open and the valve means 8 closed. The cycle of operation canbe, then repeated.

The provision of dash pot 2! retards somewhat the closing movement of valve means 8 so that valve l4 will be opened wide prior to the 10 closing of valve means 8. As soon as valve |4 opens, the pressure in conduit 5 in advance of non-return valve 5 drops, thus effecting a quick By this arrangement, it is assured that there is a flow of 15 air through waste conduit 3 suflicient to pre vent pulsationbefore the closure of valve means 8 has caused the compressor to drop in speed.

The waste valve |4 serves to prevent pulsation of the compressor at times when the operator in 20 shutting down might close valves 22 and 23 before the turbine has appreciably dropped in speed.

By means of switch 44, pressure responsive device 33 can be adjusted to vary the pressurein-25 conduit 5 or it can be used to slowly shut down the turbine.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The combination with a gas compressor, "30 of a long conduit connected to the discharge of the compressor, the free conduit end portionincluding a valve for controlling the flow of gas, and means for dumping gas from the conduit for rapidlyinterrupting the flow of gas in the conduit to prevent pulsation of the compressor, said means comprising a pipe connected to'the conduit end portion adjacent the compressor, a dumping valve in the pipe andmeans for oper- I ating the dumping valve including an actuating 40 member located in proximity of the free conduit end portion. p 2. The combination with a gas compressor, of

a long conduit connected to the discharge of the ing a valve for controlling the flow of gas, and

means for dumping gas from the conduit for rapidly interrupting the flow of gas in the conduit .to prevent pulsation of the compressor, said means comprising a'pipe connected to the con- 50 duit end portion adjacent the compressor, a dumping valve in the, pipe, means for operating the dumping valve including an actuating member located in proximity of the free conduit endportion, and a non-retum valve in the conduit' behind its connection with said pipeas regards the direction of flow therein to minimize the pulsation of gas during the dumping operation.

3. The combination with a turbo-compressor of a. long conduit connected to the discharge of 60 tion, means for rapidly interrupting the flow of gas in'the conduit comprising a pipe connected to the conduit end portion adjacent the com-, pressor and a valve in the pipe for dumping gas I from the conduit,.and remote control means including a member adjacent the free conduit end portion for actuating the governing mechanism to efiect complete closing of the turbine valve.

4. The combination with a blower having a" discharge conduit of considerable length, of a control valve in the free end of the conduit for controlling the discharge of air from the conduit, a dumping conduit with a valve connected to the conduit adjacent the blower for dumping air from the conduit, and means including an actuating member adjacent the discharge end of the conduit for operating the dumping valve to prevent pulsation of the blower when the control valve is closed.

5. The combination with a blower having a discharge conduit of considerable length, of a control valve in the free end of the conduit for controlling the discharge of air from the conduit,

a dumping conduit with a valve connected to the conduit adjacent the blower for dumping air from the conduit, means including an actuating member adjacent the discharge end of the conduit for operating the dumping valve to prevent pulsation of the blower when the control valve is closed, and a non-return valve in the conduit behind the dumping conduit as regards the flow in the conduit tovprevent back flow in the conduit during dumping operation.

6. In a turbo-compressor, the combination of a compressor, a turbine for driving the compressor having an inlet valve with an opening in the valve member for by-passing elastic fluid to cause idle running of the turbo-compressor when said valve is shut, and a governing mechanism for normally operating the valve comprising a pressure governor connected to the compressor discharge conduit and remote control means for closing the valve.

REGINALD G. STAN DERWICK.

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