US800194A - Pressure-controlling mechanism for turbines. - Google Patents

Description

11, 10. 800,194. 'PATENTED SEPT. 26, 1905. J. WILKINSON.

' PRESSURE CONTROLLING MECHANISM FOR TURBINES. APPLICATION FILED me 1 04.

r ff u I/ /26 39 d9 26 F; 1. 4 33 39 g 76 79 22 3/ I attozmut Working passage,which from a point of economy or safety would demand the immediate UN ITED STATES JAMES WILKINSON, OF BIRMINGHAM, ALABAMA.

PRESSURE-CONTROLLING MEICHANISM FORITURBIINES.

Specification of Letters Patent.

Patented Sept. 26, 1905.

Application filed August 24, 190*. Serial No. 221,987.

To all ivhom it may concern:

Be it known that 1, Loans WILKINSON, a citizen of the United States, residing at Birmingham, in the county of J elferson and State of Alabama, have invented new and useful Improvements in Pressure-Controlling Mechanism for Turbines, of which the following is a specification.

My invention relates to an improvement in pressure-controlling mechanism for elasticfluid turbines. I

In turbines where the motor-fluid pressure passes through an extended working passage in one or more casings, whether the turbine be of the impact or expansion type, conditions .may arise at intermediate points in the reduction or complete stoppage of the supply of motor fluid. This is true in connection with multicellular turbines,where theflowof the motor fluid is controlled by valves disposed at different points in the Working passage, and particularly true where a speedgovernor is used to regulate the action of the supplyor stage valves, or both, for the turbines will run for long periods even after pressure is cut off, and it follows that diminution of speed consequent to such disturbances could not be relied upon to economically control the supply. Should any trouble arise with the condenser or exhaust or with any of the intermediate pressure-controller means, it would cause the motor fluid to bankup in the working passages in a manner which would not only occaslon a loss in the economlcal operation of the turbine, but would also subject the turbine shell or shells to an un-- preferably utilize a fluid-pressure controller mechanism comprising a piston movable in a cylinder which is exposed at one end to the pressure existing at an intermediate point in the Working passage and from which lead a plurality of conduits adapted to be successively opened to said pressure by the movement of a piston which is set to operate at any desired pressure and to move in accordance with the excess of pressure. mission of pressure to the conduits aotuates means to close the supply-nozzles independently of theirnormal controller mechanism. I have illustrated my invention as applied to a compound turbine comprising two separate shells or casings connected by asuitable conduit with which the controller-cylinder is in communication, so that its piston is exposed to the pressure existing in the conduit.

The ad-' My invention is capable of various applications, its broad principle consisting in the utilization of means sensitive to excessive intermediate or internal pressures to reduce the volume of motor-fluid supply or cut it off entirely independently of the controller mechanism, which latter may be operated by a speed-governor or by hand or in any desired manner.

My invention comprises the details of construction and arrangement of parts hereinafter described and claimed, reference being had to the accompanying drawings, in which- Figure lis a side elevation of a compound turbine provided with my invention applied between separate shells. Fig. 2 is a sectional view through the supply-head, partly broken away to show the nozzles and valve mechanism in elevation. Fig. 3 is a vertical sectional view'through the automatic controller-chamber.

Similar reference numerals refer to the same parts throughout.

-I have illustrated my present invention applied to a compound multiple-shell turbine, the high-pressure turbine 1 and the low-pressure turbine 2 being of any preferred type, such as shown and described in my Letters Patent Nos. 761,865 and 761,866. The turbine 1 has an exhaust-head 3, which communicates through conduit 4 with the low-pressure turbine 2. These turbines drive a common shaft 5, the bearings 6 for which, together with the turbines, are mounted upon a common bed-plate 7 Turbine 1 comprises a supply-head 8 and a plurality of diaphragms, which divide its interior into any desired number of stages, within each of which rotates a bucket-Wheel 9, carrying a row of bucket elements 10. The inner. casing of the turbines are surrounded by annular shells 11, each of which is internally recessed to form an annular superheating and supply chamber for the turbine, to which motor fluid pressure is admitted IIO 8 be described in detail herein.

through port 12 in the side of the shell for turbine 1 and through a similar port 13 in the shell of turbine 2. The pressure from the supply-chamber is admitted to supply-valve chambers 14, formed in head 8, through ports 15. The valves 16, which control the admission of fluid-pressure to the supply-nozzles, l

are operated by pistons 17, which move in the valve-chambers as cylinders, being exposed below to pressure admitted through ports 15. Screw-plugs 18 close the open end of these chambers, being recessed to provide a seat for springs 19, which engage the pistons, tending to move them downwardly to close the valves. Thus far the construction and operation of my turbine responds to the disclosure in the patents aforesaid. A restricted passage 20 leads through each piston 17, for the purpose hereinafter described. Controller-pressure from any suitable form of governing mechanism is admitted to each valve-chamber 14 through pipes 21, which communicate each with a passage 22, leading through an extension 23, integral with each plug 18. This passage 22 leads to an auxiliary-valve chamber 24, which communicates by a port with the piston-cylinder 14, and within which is disposed a valve 25, operated by a stem 26, leading outwardly through a suitablypacked opening in the extension 23 and connected at its outer end to a corrugated diaphragm 27, similar in construction to the diaphragm disclosed in my Letters Patent No. 7 61,865. These diaphragms are suitably mounted in casings 28, being exposed below to the atmosphere and above to a pressure-tight chamber in each casing. The casings are mounted on supports 29. These diaphragms normally maintain the valves in their open position, so that controller fluid entering the valve-cylinders through pipes 21 will control the supply-valves in the usual manner, opening and closing them in accordance with the volume of pressure required and in the manner described in the patent last referred to. It will be evident when I admit controller fluid, which is of equal pressure with the fluid-supply, above the pistons 17 they will be balanced between even pressures, when the springs 19 will close the supply-valves. In like manner when valve 25 is seated and chambers 14 above the pistons are cut off from the fluidpressuregoverning mechanism, the pressure below the pistons will flow through passages 20, and becoming balanced the valves will be closed by the springs.

The controller mechanism for the turbinevalves may be of any desired constructionsuch, for instance, as that shown in my Letters Patent aforesaidand as it constitutes no part of my present invention it will not Its operation, however, is controlled by a speed-governor 30, mounted ona shaft 31 and driven by suitable gearing 32 from the turbine-shaft, the shaft 31 being supported in a bearing 33, integral with bed-plate '7. The governor-collar 2-34 operates a bell crank lever 35, pivotally mounted on a standard 36 and conneclaal by a rod 37 to the controller device ol the lluidpressure-governingmechanism. (Notshowlr) The pressure admitted by the governing mechanism under normal conditions ilows in through suitable working passages, through the several compartments of turbine 1 to its exhaust-head, and thence through conduit 4 to the annular sup ily-chamber of turbine 2, from which it passes into the supply-nozzles therefor and through working passages to the exhaust-head 38 thereol, thence to the atinosphereof condenser. Valves may be used in the nozzle-passages between stages in turbines 1' or 2, or in both, any suitable controller mechanism being used to operate the stage-valves in correspondence with the supply-valves. hen the supply ol lluid admitted to turbine l is in excess of that being utilized by or flowing through turbine 2, either by reason of an oversupply or a restricted exhaust from turbine 2, due to trouble with the condenser or interruption of the flow between any of the stages in turbine 2, pressure .will bank up in the conduit 4 and in the working passages. Such a condition will not only interfere with the proper action of the turbine, but will also materially all'ect its economy in operation, and it is my purpose to obviate this by providing a pressure-:wtuated controller mechanism which will act automatically and independently of the governing mechanism to reduce or shut oil the supply of motor fluid. This coin prises a casi ng in, communicating at its lower end by pipe 41 with the conduit 4 and open at its upper end through port 42 to the exhaust or atmosphere. A screw-plug 43 is in threaded engagement with the enlarged end 44 of the casing 40 and is recessed for the reception of a spiral spring 45, which at its other end bears against the head of piston 46. This piston has a stem 47, which projects through an opening in the plug 43, passing upwardly through the spiral spring 45. The lower face of the piston 46 is beveled to seat against a reduced beveled seat 48, into which pipe 41 enters. The piston and seat are beveled, to el'lect a delinite and positive opening action of the piston when the pressure admitted through pipe 41 exceeds the pressure of the spring 45, which latter may be adjusted by screwing the plug 43 up or down in the head 44. I provide the plug with a handle 49 for the purpose of elfecting this adjustment. From aside of casing40 lead a plurality of ports 50, arranged equidistant and in vertical alinement and threaded at their outer ends. A pipe 51 is screwed into each of these ports and leads to one or more of the dia 'ihragm-casings 28, entering chambers 52 therein above the dia- \Vhcn pressure phragms through ports 53.

lOO

I tion.

however, the pressure exceed the desired point in the conduit, piston 46, which is exposed thereto, will be moved from its seat to a position where it will open a port to the high pressure admitted through pipe 41. This pressure will flow through the pipe 51, communicating with the open port, to the chamber or chambers 52, with which it communicates, and will force the diaphragm or diaphragms controlled thereby to a lowered position, where the auxiliary valve or valves 25 under their control will be closed. Bythus closing one or more auxiliary valves the turbine valve or valves controlled thereby will be withdrawn from the control of the governing mechanism and in the manner hereinbefore described will move to a closed posi- As the pressure in the conduit 3 increases the pipe 51 will be successively opened to the high pressure and will successively withdraw the turbine-valves from the control of the governing mechanism until they are all maintained closed and the supply of fluid entirely cut off. This controller mechanism will therefore cooperate with the governing mechanism in regulating the supply of motor fluid and will increase the efliciency of the governors control of multicellular turbines by making it sensitive to intermediate or final pressures throughout the working passages.

My invention is equally applicable to compound turbines formed in a single casing, when the pipe 41 or a corresponding conduit may communicate with the pressure in or between any of stages or compartments succeeding the initial stage or compartment.

I have illustrated a preferred embodiment of my invention; but I do not desire to limit myself thereto, it be ng my purpose to cover and protect by this application any character of controller mechanism responsive to pressure conditions arising in a working passage for the motor fluid which cooperates. with the governing or controller mechanism for the supply by closing the fluid-admission ports independently of the governing mechanism when intermediate pressure exceeds predetermined points.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a turbine having a regulated supply of motor fluid, the combination of emergency means controlled by abnormal conditions of pressure in the turbine to reduce or stop the trol to automatically regulate the supply of motor fluid. under normal conditions.

2. In a turbine, the combination of a speedresponsive device, means controlled thereby for regulating the supply of motor fluid to the turbine, with means controlled by the pressure of the motor fluid during its active service in the-turbine or turbines which act to vary the volume of the fluid-supply independently of said speed-responsive device, as and for the purposes described.

3. In a turbine having a valve-controlled working passage,the combination of governore'ontrolled means to regulate the admission of fluid-pressure thereto in accordance with the load on the turbine, with means, controlled by abnormal pressures in said passage, which are adapted to assume control of the admission of fluid-pressureindependently of said first-mentioned means.

4. The combination with a turbine, of a controller means sensitive to speedor load, and a controller means sensitive to internal-pressure conditions, both of which cooperate under determined conditions to regulate the supply of motor fluid.

5. In a turbine, the combination of gov: ernor-controlled means to regulate thesupply of motor fluid, with automatic pressure-actuated means to cause a reduction in the motoramount.

6., In a turbine having a plurality of fluidadmission passages, acontroller means to vary the volume of the fluid-supply in accordance with the load,and meansoperated by excessive internal pressure to out said passages successively out of service.

7 In a multiple-nozzle turbine, valves for said nozzles, agoverning means to operate said valves, and means to out said valves out from the control of said governing mechanism and close all or part of them, when the pressure in the turbine banks up or becomes excessive from any conditions.

8. In a turbine, a working passage for the motor fluid, a supply-valve for said passage, means responsive to load conditions which operate said valve, a conduit leading from an intermediate point in said working passage to conduct fluid-pressure therefrom to effect the closing of said valve, and a valve in said conduit which is opened by abnormal pressures in said working passage to admit fluid-pressure to close said supply-valve, substantially as described.

9. In a compound multicellular turbine, a plurality of supplynozzles, fluid-actuated valves therefor, a controller mechanism for said valves, and a controller-chamber communicating with the interior of the turbine and having a plurality of conduits leading therefrom, means controlled by the pressure in said conduit to cause said valves to open or close independently of said governing mechanism, and a valve in said chamber which maintains said conduits closed until exposed to predetermined pressure when it successively admits said pressure to said conduits to close the valve or valves under their control.

10. In a multiple-nozzle turbine having fluid-actuated valves, and a governing mechanism therefor, an automatic pressure-controlling mechanism comprising a chamber communicating at one end with the interior of the turbine and at the other with a 10W pressure, a springpressed piston-valve therein held to its seat against any but excessive pressures in the turbine, and a plurality of conduits leading from said cylinder to conduct fluid-pressure therefrom to close said valves.

11. In a compound multicellular turbine having a plurality of Working passages, val vecontrolled nozzles admitting pressure to said passages, and means to control the operation of said valves comprising a fluid-pressure-governing mechanism and an automatic pressurecontrolled mechanism which interrupts the control of said governing mechanism when the pressures in said Working passages become abnormal, said controller mechanism acting subject to said abnormal pressures to close one or all of said nozzles.

12. In a plurality of turbines operating in series, a conduit connecting them, a chamber communicating With said conduit and with means to vary the supply of motor fluid to the turbines, a valve in said chamber, and adjustable spring means to hold said valve to its seat until a predetermined pressure exists in said conduit, when said valve is unseated thereby and admits pressure to said first-mentioned means to cause a reduction in the volume of fluid-pressure supply for the turbines.

13. In a turbine, a nozzle supply-passage, a piston-actuated valve there-for, a cylinder for said piston exposed to said supply-pressure below and a governed pressure above, spring means cooperating with one of said pressures to cause said valve to close, and means controlled by the interior pressure of the turbine to interrupt the admission of governed pressure above said piston, for the purposes described.

1 In a turbine, a nozzle, a valve therefor, a fluid-motor for actuating said valve comprising a cylinder and piston, means to admit a governed pressure to said cylinder tocontrol the operation of said piston, and valve means to interrupt the admission of said pressure to the cylinders, said valve means being actuated by pressure under the control of an interior pressure-actuated safety device, and said pistons being adapted to move to a valve-cl osed position when said governcdpressure is interrupted.

15. In an elastic-fluid turbine, the combination of a plurality of wheel-compartments, conduits connecting said compartments, and rotatable buckets against which said conduits discharge motor fluid, valve means to control the supply of motor fluid to the first wheelcompartment, means to control the operation of said valve means, and means exposed to the motor-fluid pressure in one of said conduits between said \vheel-compartments, said latter means operating responsive to predetermined conditions of said pressure of said motor fluid and being adapted to reduce or out 01f the supply of motor fluid to said first wheel-compartment.

In testimony whereo t' .l have hereunto set my hand in presence of two subscribing witnesses.

JAMES \VILKINSON.

Vitnesses:

NOMIE \VELsH, H. M. HORTON.

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