US2254573A - Shaft packing - Google Patents

Description

Sept. 2, 1941. A. w. HUBBELL SHAFT P CKING Filed June 5, 1939 3 Sheets-Sheet 1 INVENT 'R AW. HUBBELL 4 A. w. HUBBELL Sept. 2, 1941.

' I SHAFT PACKING Filed June 3, 1939 3 Sheets-Sheet 2 INVENTOR 'A. W. HUBBELL S pt. 2, 1941.

A. w. HUBBELL SHAFT PACKING Filed June 5, 1939 3 Sheets-Sheet 3 INVENTOR A. W. HUBBELL TI'O NEY Patented 'Sept. 2, 1941 sum PACKING Alfred W. Hubbell, Bartlesville, kla., assignor to Phillips Petroleum Company, a

Delaware corporation of Application June 3, 1939, Serial No. 277,278

2 Claims.

The present-invention relates to a fluid sealing device for resisting a flow of fluid along a shaft, rod or similar member passing into a container or casing storing or handling liquids under superatmospheric pressures.

Although the present invention is useful in a relatively large number of devices, its present principal utility is in high pressure oil pumps and more particularly a centrifugal or reciprocating pump handling fluids. Accordingly, it is believed that the invention may be best exemplified by disclosing an embodiment thereof particularly suited to thisuse.

Heretofore, in the operation of centrifugal pumps handling all grades of gasoline and oils, it has been both necessary and-customaryto pass a certain portion of the fluid handled around the shaft through the packing in order to prevent the packing from overheating. The gasoline, when released into the atmosphere from the packing gland, evaporates and although some of the material is returned to the line, about flfty per cent of the gland leakage is never recovered. The leakage of such liquids through the pump packing not only constitutes a high percentage of loss of material handled through the pump, but in the case of material containing abrasives, the shaft is short lived.

Thus, the primary object of the present invention is to overcome the above defined defects, and briefly described, I accomplish this object by introducing into the lantern gland of the pump a liquid other than the fluid which is being pumped, the liquid acting as a cooling medium for the packing, and maintaining substantially the same pressure on each end of the packing next to the pump impellers, thus preventing the exit of the fluid flowing through the pump or the entrance of the cooling medium into the pump.

Further objects and advantages of the present invention will be apparent from the following description taken in connection with the accompanying drawings.

Referring to the drawings which are for illustrative purposes only,

Figure 1 is a view of a conventional four-stage centrifugal pump to which the present invention is applied.

Referring to the drawings in detail, numeral [0 designates the pump generally, herein shown as a conventional centrifugal pump. The pump comprises a casing ll within which oil is pumped at a superatmospheric pressure, or a pressure in excess of that outside the casing II. The

'numeral 12 designates a shaft passing through the casing and I3 the sealing gland between the shaft and the casing. The sealing gland comprisesthe packing material l4 and a lantern gland l5 intermediate the length of the packing l4. Formed in the wall of the casing is an inlet port I6 to which the pipe I! is connected, the purpose of which will be hereinafter described.

An outlet pipe l8 extends from the casing at the inner end of the packing material l4 and is connected to an inlet l9 at the upper end of apressure equalizer tank generally designated by the numeral 20.

Referring more specifically to Figure 2 wherein the pressure equalizer is shown in detail, the equalizer 20 has a lower plate 2| suitably connected thereto, as by bolts 22, said plate having an inlet port 23 and a valve controlled outlet port 24. Mounted within the equalizer is a float 25 pivotally secured to a supporting arm 26 by means of a link 21. Pivotally secured to the link 21 is a valve 28, movable to open and close the outlet. port upon movement of float 25.

As seen in Figure 1, the pressure equalizer 20 is so mounted with respect to the pump that the fluid level of the liquid within which member 25 floats is at approximately the same level as the pump shaft I 2. The gasoline inlet I9 is connected to the pump through, pipe .I 8 as previously explained, thus permitting gasoline to pass from this point of the pump into the upper end of the equalizer. Pipe H, which leads into the lantern gland I5, is connected to the inlet port 23 and is also connected to a small high pressure pump 29, through line 30, said pump supplying the present device has been described in connection with the introduction of water into the lantern gland, it is to be understood that any 5 cooling fluid other than that which is being pumped may be used within the scope of the present invention.

It should be understoodthat the sealing rangement described above is applied to both sides of the pump, with like numerals designating like parts. As seen in Figure 1, a separate equalizer is provided for each side of the pump, said equalizers being mounted in series, but it is readily apparent that the same may be mounted in parallel. A description of the operation of one of the sealing glands will sufilce as a description of the operation of both glands.

The operation of the sealing device of the present invention is as follows:

The small pump 29 will supply clear water to the lantern gland II and to the water inlet 23 of equalizer 20, until the float 25 lifts the valve 28 from its seat. Gasoline from the pump it enters the equalizer through-inlet I! and there will be a point where the water level will be constant and the pressure at the point of contact of the gasoline and water will be equal to the pressure existing on the inside of the packing in the pump. As the pressure fluctuates in the pump, the pressure must necessarily fluctuate the same in'the float chamber, which could in some of are representative of other parts or elements which may be used in substantially the same manner to accomplish substantially the same results. Therefore, it is to be understood that the invention is not to be limited to the exact details described herein, but is to be accorded the full scope and protection of the following claims.

Having thus described the invention, what is claimed is:

1-. In a system for handling fluid under pressure, the combination comprising a casing; fluid under pressure within the casing; a shaft supported in each end of the casing; a packing unit surrounding the shaft in each end of the casing; a pair of pressure equalizer tanks, each tank including an inlet in its upper portion, an inlet and an outlet in its lower portion, a sealing liquid in its lower portion, and means for maintaining the level of the liquid in the tank in substantially the same plane as the shaft; means for supplying fluid from the casing to the inlet in the upper portion of each tank; means for transmitting sealing liquid from the outlet of one of the tanks to the outer end 01' oneof the packing units; means for transmitting sealing liquid from the outlet of the other tank to the outer end of the other packing unit; and means for placing the inlet in the lower portion of one of the tanks in communication with the outlet in the other tank.

2. In a system for handling fluid under pressure, the combination comprising a pump including a casing, a shaft supported in each end of the casing, and a packing unit surrounding the shaftin each end of the casing; a pair of pressure equalizertanks, each tank including an inlet in its upper portion, an inlet and an outlet in its 7 lower portion, a sealing liquid in its lower portion,

and a floatcontrolled valve cooperating with the outlet for maintaining the liquid level in the tank in substantially the same plane as the shait; a conduit for supplying fluid from the casing to the inlet in the upper portion of each tank; a conduit for transmitting sealing liquid from the 'outlet of one of the tanks to the outer end of one of the packing units; a conduit for transmitting sealing liquid from. the outlet of the other tank to the outer end of the other packing unit; and a conduit for placing the inlet in the lower portion of one of the tanks in communication with the outlet of the other tank.

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