US1407041A - Combined pressure and speed governor for steam-operated pumps - Google Patents

Description

A. PETERSON. COMBINED PRESSURE AND SPEED GOVERNOR FDR STEAM OPERATED PUMPS.

APPLICATION FILED APR. 5, 1920.

1,407,041 Patented Feb. 21, 1922.

JITORIVEY- UNITED STATES PATENT OFFICE.

ARVID PETERSON, OF TRENTON, NEW JERSEY, ASSIGNOR 'IO' DE LAVAL STEAK TURBINE COMPANY, OF TRENION, NEW JERSEY, A CORPORATION OF NEW JERSEY.

COMBINED PRESSURE AND SPEED GOVERNOR FOR STEAM-OPERATED PUMPS.

To all whom it may concern:

Be it known that I, ARV'ID PETERSON, a citizen of the United States, residin at Trenton, county of Mercer, and State of ew Jersey, have invented a new and useful Improvement in Combined Pressure and Speed Governors for Steam-Operated Pumps, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of this specification.

In pumping plants it is often desirable to maintain a constant discharge pressure with varying demands for water, and at the same time have the pumping unit under control of the speed governor. This is generally accomplished by introducing in the steam line a pump governor consisting of a valve, the movement of which is controlled by the water pressure acting upon a piston or a diaphragm, in such a way that when the pump pressure increases, the valve closes, thus re ducing the speed of the unit. In addition to the pump governor, the unit is equipped with a speed governor controlling a separate Valve.

This arrangement, however, is open to a serious objection. When the unit is operating under the control of the pump governor at capacities below normal (corresponding to speeds below normal) for long periods, the valve controlled by the speed governor stays in one position and is liable to become stuck due to scale formation. Should it now happen that the pump should lose water or that the demand for water should be so great that the pressure will drop down materially, the unit will start to speed up, and when governor speed is reached, the speed governor will not be powerful enough to close its valve, but the speed will continue to increase until the unit wrecks itself.

I The object of my invention is to prevent any such possibility by providing means whereby when the governor speed is exceeded the pump will be restrained from developing excessive speed regardless of the failure of the speed governor valve to operate. I accomplish this object by causing the governor as itspeeds up to operate not only the valve that it normally controls but Specification of Letters Patent. Patented Feb, 21, 1922,

Application filed April 5,

1920. Serial No. 371,273.

also the steam valve which, in the present A preferred embodiment of the invention A is shown in the accompanying drawing in which the figure is a vertical sectional view of an apparatus embodying my invention. j

The pump governor comprises mainly a special diaphragm a, a stem 12, a spring 0 and a casing (Z having an opening 6 through which the pump pressure acts on the dia-' phragm.

The governor valve in the steam line comprises a balanced valve f, within a casing 7" and a stem g. The stem 9 is in line with the stem 6 and movable downward thereby but is not attached thereto.

The valve casing f is provided with a head or closure f having a stufiing box through which the stem 9 extends. d is a housing mounted on the head f of the valve casing f. The upper end of the housing d 1 is provided with a flange on which is mounted a disc a and between which disc and a flange on the casing d is clamped'the dia phragm supporting plate a Z2 is a bearing for the valve stem 1), which bearing is supported between the flange on the housing and the disc a The spring a surrounds the stem 1) and is interposed between a fixed supporting plate d on the housing (1 and an adjustable nut 72 on a threaded portion of the stem I), so that the tension of the spring can readily be adjusted in accordance with the pressure to be maintained in the pump line.

A lever h is pivoted between its endsto a bracket on the casing 03. One end of lever h is attached to stem g. A spring i, secured between a bracket j and the other end of the lever it, tends to swing the lever h in the direction to cause the stem 9 of valve f to follow up the stem 2) of the pump governor when the latter is moved up by the of which is attached conveniently to the casing d, and from which depends a link p.

having a slot 9" engaged by a pins on the extremity of the spring-actuated end of the lever h.

Assuming now that the pump is operating at a speed below normal under control of the pump governor and that the pump pressure increases slightly, the diaphragm a will compress, moving down stem 6, together with stem 9 and valve f,thus reducing the steam flow and decreasing the speed or" the unit to suit the new conditions. When the valve stem 9 moves down, it rocks leverh, the pin .9 moving up through the slot r in link 7).

On the other hand, if the pump pressure decreases, the spring 0 lifts the stem Z) against the reduced pump pres ure, and the spring pulled lever 71, will lift the stem 9 and further open the valve f. This will increase the steam flow and consequently the speed to suit the new conditions.

Assume that a point has been reached where the pump is" operating at approximatelynormal capacity and normal pressure at a speed corresponding closely to governor speed, andthat a sudden great demand for water occurs, causing a drop in pressure which increases the speed. The speed governor. now comes into action, its sliding sleeve n and the link p moving up. After the bottom of the slot r in link p reaches the pin 8 in lever h, the lever will move with the'link, thus'moving valve f toward a closed position and holding the speed down. When the speed drops, the valve 7 will open, through the action of spring '5, as hereinbefore described.

The above described construction thereforeaccomplishes the purpose for which it was intended, in that it provides a steam admission which is normally operable from a pump governor, as heretofore, but which is also independently operable from a speed governor when conditions arise which make such independent operation advisable.

As the demand for water both in'municipal and industrial pumping plants frequently fluctuates, it is unlikely that the valve f will remain stationary in one position for any substantial length of time, and it will therefore always be free to move when the speed governor takes hold.

On boiler feed pumps it is often desirable to maintain a constant excess pressure over the boiler pressure rather than a constant pressure. This can be accomplished by the same arrangement simply by introducing the steam pressure below the diaphragm through anopening t.

Having now fully described my invention, what I claim and desire to protect by Letters Patent is":

1. In a steam operated pump, a combined pressure and speed governor comprising a governor controlled by the speed of the pump, a governor controlled by pump pressure, a valve controlling the admission of steam to the pump and operable toward a closing position by the pump governor, a pivoted lever connected with the stem of the steam valve, a spring connected with the lever and normally operating to cause the steam valve to move away from a closing position upon the recession of the pump governor, a lever movable by the speed governor, a link connected with the second lever, and a pin and slot connection between the link and the first lever, whereby the first lever is movable independently of the speed governor unless the speed of the latter is sufficient to move the link into position to actuate the first leverand thereby move the steam valvetoward a closing position.

2. A controlling device for pumps comprising a valve casing having a balanced valve therein for controlling theadmission of steam to the pump, a stem connected to the valve extending through the casing, a spring tending to open said valve to admit steam to the pump, a diaphragm chamber arranged to be connected to the pump, a diaphragm in said chamber arranged to be acted on by the pump ressure to move it in one direction, a spring or moving the diaphragm in the other direction, connections between the diaphragm and the valve for moving the valve against the action of its opening spring when the pump pressure rises beyond a predetermined limit but arranged to permit the diaphragm to be moved in the reverse direction by the action of its spring when the pump pressure falls without moving the valve towards its open position, a speed governor connected to the pump, and actuating connections between the speed governor and the valve arranged tomove the valve towards its closed position when the speed of the pump exceeds a predetermined limit to close the valve and reduce the speed of the pump regardless of the pump pressure, said diaphragm connections also being arranged to close the steam valve when the pressure exceeds a predetermined limit regardless of the speed governor.

3. A controlling device for pumps comprising a valve casing and a diaphragm casing connected to each other, a valve in the valve casing, a stem on the valve extending through the casing, a lever for actuating the valve connected to said stem, a spring for actuating the valve in one direction, 9. diaphragm in the diaphragm chamber, a stem arranged to be actuated in one direction by the diaphragm, the diaphragm stem being in alignment with the valve stem, a second spring for actuating the diaphragm stem against the action of the diaphragm and in a direction to permit the valve to be opened by the first spring, and a speed governor connection connected to the valve stem lever, there being lost motion in said speed governor connection to permit the first spring to open the valve if the speed of the engine is below a predetermined limit.

4. A controlling device for pumps comprising a valve casing and a diaphragm casing connected to each other, a valve in the valve casing, a stem on the valve extending through the casing, a lever for actuating the valve connected to said stem, a spring for actuating the valve in one direction, a diaphragm in the diaphragm chamber, a stemtion connected to the valve stem lever, there being lost motion in said connections to permit the governor connection to move a predetermined distance with relation to the valve stem before the valve stem is moved to close the valve.

5. A controlling device for pumps comprising a valve casing and a dia hragm casmg connected to the opposite en s of a housing, a valve in the valve casing, a stem on the valve extending through the casing, a lever for actuating the valve connected to said stem, a spring for actuating the valve in one direction, a diaphragmym the diaphragm chamber, a stem arranged to be actuated in one direction by the diaphragm, the diaphragm stem being in ali nment with the valve stem, a spring surroun ing the diaphragm stem for actuating the stem against the action of the diaphragm, an abutment for the spring supported on the housing, an adjustable abutment on the diaphragm stem for the spring, and a speed governor connection connected to the valve stem lever.

In testimony of which invention, I have hereunto set my hand, at Trenton, N. J on this 1st day of April 1920.

AltVID PETERSON.

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