US1407136A - Vacuum breaker - Google Patents

Description

R. N. EHRHART.

VACUUM BREAKER.

APPLICATION FILED NOV, 6, 1917.

1,407, 1 3 Patented Feb. 21, 1922.

INVENTOR.

ATZLORNEYS.

7 part hereo I v UNITED s'r'rss AT -Q F CE5T RAYMOND N. EHRHART, ornnGEwoon-rARK, PENNSYLVANIA, ASSIGNORITO wnsr- INGHQUSE ELECTRIC 8: MANUFACTURING 00., A CORPORATION OF rENNs L- VANIA.

To all whom it may concern:

Be it known'that I, RAYMOND HART, a'citi'zen of the United States, and a resident of Edgewood Park,in thecounty of Allegheny and State of "Pennsylvania, have made a newand useful- Invention in Vacuum Breakers, of which the following .is aspecification. v

This invention relates to vacuum breakers andhas for an object to produce a new and improved vacuum breaker for effectively preventing the flooding of a condenser. or similar device. A further object is to produce a newand im roved vacuumj breakerwhich automatical y and effectively breaks the vacuum in'a condenser when the level of the water in' the condenser reaches a predetermined height; i

y A' further and 'more' specific object of invention is to produce a vacuum breaker which is not affected by variations in level of the water within a condenser untilthe water has risen'to a predetermined level, and which then opens quickly and is not affected by the diminishing vacuum within the condenser..

These and other objects are attained by means of a vacuumbreake'r embodying the. features herein described and illustrated in.

thedrawing accompanying and forming a The drawing is a diagrammatic sectional view of a; vacuum breaker embodying the 35 features of my invention.

A common trouble with vacuum breakers,

as heretofore constructed, is that theydo not completely break the vacuum and consev quently injection water continues" to be drawn into the condenser after the vacuum;

breaker has acted. This is especially'true if the lift from the source of injection to the condenser is low. A further .disadvam tage of some types of vacuum breakers is that the normal water level in the condenser must be kept well below the actuating float of the vacuum-breaker so that ordinary fluctuations in the water level within the condenser will not partially submerge the float and allow the vacuum breaker valve to open slightly'and admit air to the condenser. The disadvantages inherent in many vacuum breakers are due to the fact that the vacuum breaker float is located within the condenser shell itself, or in a Specification of Letters Patent. Patented 1922,

Application filed November 6, 1917. Serial No. 200,626. I

Y I float chamber in which the level of thewate'r N. EHR- varies directly with'the level of the water in the shell. 7 The vacuum breaker valve is normally held shut against the pressure of the atmosphere by the weightlof the unsubmerged float. When the float is sufliciently submerged, the weight is so reduced that the pressure of the atmosphere opens" the valve and presumably breaks the "vacuum. It has frequently been found that after the vacuum has been broken and th e pressure falls to approximately 10 of inercury,'the effective openingforc'e of-the atmospheric pressure is reduced, or balanced Q] by the pressure within the condenser, to such an extent that the valve begins to close with a partial vacuum still existing in the condenser. If the lift from the source, of injection to the condenser is low,' water continues to flow into the condenser; because of the partial vacuum still existing within the condenser and serious accidents" often result from condensers being flooded in this manner after the vacuum breakers have acted. I I

In thedrawingl have illustrated an embodiment of my invention in which thefloat' chamber 5 is located outside of the" condenser shell 6. As shown, this float chamber is in the form'fof a vertical cylinder and is;

connected near its upper end to the condenser shell 6 byfmeansof a port orpassage 7. Withinthe float chamber have; shown a "cylindrical float 8, which is nearly large enough-to fil lthe lower portion of the chamber. 7 v

The float 8 is suspended, by valve stem 10, from a vacuum breaker valve 9, located, in the upper part ofthe valve chamber 5. As shown, the valve9 is of the. balanced type being provided with two means of aj valve discs ll and 12. which cooperate with f valve seats in opposite wall of apocket or indent 13 in the valve chamber. The 'in dent l3 and therefore the space'between the discs 11 and 12 is open to the atmosphere so that the atmospheric pressure on one .disc is substantially counterbalanced by the atmospheric pressure on the other disc.

I have illustrated a drain pipe 14: connecting the bottom of the float chamber 5 with the condenser shell so that the chamber is normally drained. A check valve 15 is shown in this iping and is arranged to prevent water rom backing up the plpe from the condenser shell into the chamber 5. The check valve may be eliminated by connecting the drain pipe to the air pump of the condenser installation. I

The operation of .the vacuum breaker illustrated is as follows: The normal operating level of the water in the condenser shell 6 is such that ordinary fluctuations of the level will not cause the water to reach the port 7 so as to overflow into the float chamber 5n However, when the water does reach this port it overflows into the float chamber 5, causes the float S'to rise and open the valve 9 and to thereby break the vacuum in the condenser. As the float 8 nearly fills the lower part'of the float chamber 5 only a comparatively small amount ofwater is required to fill the remaining space around the float, and, as a result, the float is quick and positive in action. 7

The valve 9 is independent of atmospheric pressure, consequently it opens easily and is unaffected by changes in pressure as the vacuum is broken. The drain pipe lat is preferably so proportioned that the water is retained in the float chamber, and the valve 9 held open, long enough to completely break the vacuum. When the chamber 5 is drained, say in 30 seconds, the valve 9 is again closed and normal operation may be resumed.

The vacuum breaker illustrated is positive in action, remains tightly closed until opened by the float, then opens quickly, and remains open long enough to effectively break the vacuum. It is simple in construction and allows a maximum normal operating water level to be employed in the condenser, being unaffected by the normal varia tions in level until themaximum permissible level is reached. If desired, the weight of the float 8 may be partially counterbalanced so as to render the breaker more sensitive. Obviously the float chamber 5 may be located within the condenser, shell 6 if desired.

While I have described and illustrated but one embodiment of my invention, it will be apparent to those skilled in the art that various changes,modifications, additions and omissions may be made n the apparatus 1lchamber into the condenser shell below the 7 level of the bottom of said chamben'whereby the valve is held open until the liquid has receded in the condenser shell to a level at which the vacuum in the condenser shell may be safely reestablished, and means for preventing a return flow of liquid through the draining means. p

2. In combination with a condenser shell, a float chamber communicating with the condenser shell, afloat occupyingthe major portion of the float chamber and responsive to a relatively small amount ofliquid, means controlled by the float for admitting air to the condenser shell, and means for draining the float chamber and for, retarding said drainage. 7

8. In a vacuum breaker, into which liquid overflows from a condenser when a predetermined level is reached, means for admitting'an' into the condenser shell,

a float in the float chamber for controlling said means, means for draining saidffloat chamber,

means; r

4:. In combination withthe shell of a condenser, a float chamber communicating near;

a float chamber and means for preventing a' counterflow of l1qu1d through said draining float depending from said valve for. normally holding the valve closed andfor open ing the valve when the water Lin the condenser shell overflows into the float chamber, meansfor draining the float chamber and for retarding said drainage so'that the valve is held. open longenough to effectively break the vacuum in't'he condenser f shell, and meansfor preventinga return flow of water through the draining means, v

In testimony whereof, I have hereunto subscribed my name this 5th day of Novem-i' ber, 1917. f

"Witness: V

.C; VJ, MoGnnn,

RAYMOND N. HR HA T,

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