US1513982A - Safety shut-off valve for condenser systems - Google Patents

Description

J. F. GRAGE sAFgTY SHUT-OFF VALVE FOR CONDENSER SYSTEMS Filed Dec. 22 h 1920 l2 25 45% 22 W E. 8 2 I 1 M i W J m l h l lnnwl w 7p 2 5 1 z 2. z y W F A! T Q. 0

Patented Nov. 4, 1924.

UNITED STATES ATENT OFFICE.

JOHN F. GRACE, OF KEARNY, NEW JERSEY, ASSIGNOR TO WOETI-IINGTON PUMP AND MACHINERY CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF VIRGINIA.

SAFETY SHUT-OFF VALVE FOR CONDENSER SYSTEMS.

Application filed December 22, 1920.

To all whom it may concern:

Be it known that I, J OHN F. Gimme, a citizen of the United States, residing at Kearny, county of Hudson, and State of New Jersey, have invented certain new and useful Improvements in Safety Shut-Off Valves for Condenser Systems, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to improvements in safety shut-off valves for condenser systems.

It is the especial object of the present in vention to provide improved automatic means for preventing the flooding of condensers provided with hydraulic vacuum pumps or ejectors, such means operating on stoppage or inefiicient pump or ejector action, to shut off the condenser from backfiow of the pump liquid and thus permit continuous operation of the condenser. The invention is especially applicable to high vacuum condensers in which the air and uncondensed vapors are taken off separately from the water of condensation, but is of general application in condenser systems.

It is a further object of the invention to so arrange such shut-off valve and its operating mechanism that the valve is normally wholly or substantially outside the air passage and will not, therefore, obstructor choke such passage under normal operating conditions, such valve only obstructing the air passage to shut ofi back-flow.

For a full understanding of the invention, a detailed description of a preferred embodiment of the same will now be given in connection with the accompanying drawings, and the features forming the invention then specifically pointed out in the claims.

In the drawings:

Figure 1 is a side elevation, partly in section, of a condenser system embodying the invention in a preferred form;

Figure 2 is a longitudinal section of the shutoff valve and operating mechanism therefor, and t Figure 8 is a similar section of a modified form of shut-off valve and its operating mechanism, looking in a direction opposite from that of Figs. 1 and 2.

Referring now to the drawings, and particularly to Fig. 1, the letter A indicates a Serial No. 432,477.

condenser of the surface type provided with the usual hot-well B and condensate pump C and connections therefor; D indicates the air and uncondensed vapor connection between the condenser and a hydraulic vacuum pump indicated generally by the letter E, and F is the centrifugal circulating pump therefor delivering through connection G to such pump, the latter discharging through nozzle H to supply tank I provided with vent pipe at. The general system illustrated is the same as shown and described in Let ters Patent No. 1,255,869, dated February 12, 1918, and the hydraulic pump that of Letters Patent No. 1,031,143, dated July 2, 1912, but it will be understood that the invention maybe applied in connection with other systems and hydraulic pumps or ejectors of other types.

In order to prevent flooding of the con denser A, due to subnormal water pressure in plpe G supplying the air pump E, which may be due to various causes, such as centrifugal pump trouble or shortage of pressure supply water, there is interposed in the connection D, between the condenser A and the air pump, an automatic shut-off valve 10 (Fig. 2) hinged at 10 and held open under normal working conditions by one arm 12 of a rocking lever pivoted at 11, such arm being suitably shaped for engagement with the edge of the valve 10, while the other arm 12 of said rocking lever enters groove 13 in a floating piston 14 in a cylinder 15 suitably mounted on the valve casing.

In order that the pressure on each side of the piston 14 may operate to hold the valve 10 open under normal working conditions, as shown in Fig. '2, one end of the cylinder 15 is in communication by pipe 16 having valve 9 therein, with the pressure water supply connection Gr between the supply pump F and the hydraulic air pump E, the pressure in such cylinder end being opposed by a spring 17 acting on'the opposite side of the piston'lt, which spring, through the medium of a regulating screw 18, may be adjusted so that its pressure will b overcome by the normal working water pressure in the opposite end of the cylinder, which thus holds the valve 10 open through the medium of latch arm 12 engagthe edge of the valve, as shown in full lines in Fig. 2. Handle 20 (Fig. 1) on the exterior of the valve casing, secured to valve-pivot 11, is provided to reset the valve in open or working position, after it has been allowed to close by gravity on a 'diminution of pressure in the connection Gr, communicated by pipe 16 to the vlave tripping mechanism in cylinder 15, it bevalv to prevent shock, and fluid pressure controlled means for restoring the valve to normal or open position. In this view, the valve and seat are indicated, respectively, by the numerals 21, 22, the valve being mounted on a spindle 23, an extension of which 24 passes through a stufling box to a guide bracket 26, in which it slides. The lower end of the valve spindle 23 terminates in a piston 27 working in a cylinder 28 filled with drainage water and acting as a water dash-pot to absorb shock incident to sudden closing under high pressure. Overflow from the space 28 to the condenseris prevented by drainage pipe 0 to the hot-well or waste. The valve 21 is assisted in its closing movement by a coil spring 29. which, with the back-flow liquid holds the valve on its seat thereafter until normal operating conditions have been resumed, when the valve is opened in the manner hereinafter described.

The automatic means for causing the modified form of valve .shown'in Fig,

to close on a diminution ofwater supplypressure below a predetermined safe mini.- mum, comprise a cylinder 1 having positioned therein floating piston 3, springpressed by a coil spring 4, the spring abutment preferably being a movable piston 2 for adjustment of the spring pressure,

and on the opposite side of the piston 3 is a coil spring 5, exerting its pressure against that of the spring 4. In practice, the pressure of the spring at plus the water pressure of the hydraulic air pump, conveyed from the connection G to the cylinder 1 by pipe 6, is sufficient to slightly overbalance the. pressure of the spring 5 and thereby cause the piston stem 7 to contact with the underside of a cone-shaped latch I 8 on the valve spindle extension 24,-such regulation being accomplished through the medium of screw 7 bearing aga nst piston 2. It will be noted that the connection to the cylinder 1 from pipe 6 is by fanshaped openings, to avoid complete closure in any position of the pistons.

From the construction so far described, it will be seen that any drop in pressure in the supply pipe to the air pump, trans mitted through pipe 6 to cylinder 1, will reduce the pressure between pistons 2 and 3, whereupon piston 3, under'the influence of spring 5, will move to the left and, through disengagement of piston stem 7 with the cone-shaped latch 8 on valve spindle extension24, permit th valve 21 to drop to its seat by gravity and pressure of spring 29, shock being prevented by'the water dash-pot scribed.

In order to re-set, or open, the modified form of'valve shown in Fig- 3,. when normal working conditions are attained, Iiprovide fluid-operatedmeans controlled. by a' hand-valve, such meanscompri singa cylinder b in. the bottom of the shut-off valve casing, in. which cylinder is-a piston. with stem a normally held in the position shownby a coil spring (Z, into which cylinder-pres sure water from. a city supply connection controlled by valve f may be admitted, The three-way valve h controls a connection for this cylinder 6 and for both ends of cylinder 1 and pipe6' through pipes g, It, the connection is being fordrainage.

It will be obvious from the foregoing that when the three-way valve h is moved to a position to open communication from .cyl inder Z) through pipe 9 to pipe'fl and close connection is to cylinder 1, andcity water; or other pressure is admitted to cylinder 5 by opening valvewf, the piston stem 0 will be raised against the pressure-of the spring (Z and abut againstthe'dash-pot piston 27,- thereby opening the valve 211 and atthe same time movingthe cone-shaped'latch -8 on valve spindle extension. 2 1 past the end of the pistonstem 7 when thepressure between the pistons 2, 3 will move the stem 7 to the right undertheangularedge of such latch and lock the :valve 21 in open position, where it will remain until the pressure again falls below a predetermined minimum, or it: is desired for other reasons to close the shutoff valve, which latter can readily be done by shutting the hand valve mIin pipe'6. The valve. f, of course, is closed by hand as soon as the valve 9 is locked in its open position.

arrangement above de-' It will be, understood that various changes" densers, and in other relations where;shut- 130 off Valves adapted to be closed at predetermined pressures to prevent back-flow are useful.

hat is claimed is:

1. The combination with a condenser system having an air discharge pump or the like, of a valve on the condenser connection to said air discharge pump, and pressure controlled mechanism for closing said valve to prevent back-flow to the condenser.

2. The combination with a condenser system having a hydraulic air discharge pump or the like, of a valve on the connection between the condenser and said air pump, means dependent on the pressure in the water supply to said air pump for holding said valve open, and means controlled by said pressure for closing said valve at predetermined supply pressures.

3. The combination with a condenser system having a hydraulic air discharge pump or the like and a water supply pump therefor, of a shut-off valve on the connection between the condenser and said air pump, means dependent on the supply pump pressure for holding said valve open, and means for causing said valve-holding mechanism to release said valve for closing at predetermined supply pressures.

4-. The combination with a condenser system having an air discharge pump or the like, of a valve on the condenser connection to said air discharge pump, pressure controlled mechanism for closing said valve to prevent back-flow to the condenser, and fluid operated means for returning the valve to open position.

5. The combination with a condenser system employing a hydraulic air discharge pump or the like, of a shut-0E valve on the air pump connection to the condenser, pressure controlled valve trip mechanism normally holding said valve open, a connection from the air pump pressure supply to said trip mechanism for tripping the valve to close it when the pressure in the air pump supply connections falls below a predetermined minimum, and dash-pot mechanism for cushioning the closing of said valve.

In testimony whereof, I have hereunto set my hand.

JOHN F. GRACE.

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