US2697450A

US2697450A - Alleviator

Info

Publication number: US2697450A
Application number: US125243A
Authority: US
Inventors: Walter T Knauth
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-11-03
Filing date: 1949-11-03
Publication date: 1954-12-21
Anticipated expiration: 1971-12-21

Description

W. T. KNAUTH Dec. 21, 1954 ALLEVIATOR 2 Sheets-Sheet 1 Filed Nov. 3, 1949 INVENTOR. Zer T. Km ulh If ATTORNEY Dec. 21, 1954 K AUT 2,697,450

ALLEVIATOR Filed Nov. 3, 1949 2 Sheets-Sheet 2 I I /II 12 l5 I4 15 16 -17 U INVENTOR.

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-ATTORNEY United States Patent ALLEVIATOR Walter T. Knauth, Houston, Tex. Application November 3, 1949, Serial No. 125,243

2 Claims. (Cl. 138-30) This invention relates to an alleviator, or shock absorber, particularly adapted for use in connection with fluid conducting pipe lines through which the fluid is forced, in pulsations, by means of reciprocating pumps or other, similar sources of pressure.

The present invention includes certain improvements over the type of alleviator disclosed in United States Patent No. 2,290,337, issued to applicant on July 21, 1942.

An object of the invention is to provide an alleviator adapted to be interposed between the pump and the conducting line, or incorporated into the line itself and which is effective to absorb excessive pressures and restore abnormally low pressure and to thus protect the line from the shocks due to variations in pressures.

Another object of the invention is to provide an alleviator of such construction that air or gas may be utilized as a dampening agent to absorb the shocks and which is also of such construction as to be adapted for use on lines carrying fluids containing abrasive materials or foreign matter.

A further feature of the invention is to provide an alleviator having an intermediate chamber containing clean operating fluid whereby a valve and seat employed will be operable in clean liquid and where the intermediate liquid acts as a damper.

A still further object is to provide an alleviator wherein the intermediate liquid dissipates heat from the diaphragm resulting from rapid flexing.

The diaphragm being located between two bodies of liquid, the migration of gas through the diaphragm will be prevented.

Other objects and advantages will be apparent from the following specification, which is illustrated by the accompanying drawings, wherein:

Figure 1 is a side view, partly in section, of the alleviator;

Figure 2 is an enlarged, fragmentary, vertical, sectional view showing the valve assembly;

Figure 3 is an enlarged, fragmentary, vertical, sectional view illustrating the mounting of the diaphragm.

Referring now more particularly to the drawings, the

numeral 1 designates the casing as a whole, which, in the present illustration, is formed with upper and

lower chambers

2, 3.

The lower end of the casing is composed of a separate casting, which is fitted to the adjacent part of the casing above and which is secured thereto by an annular clamp 4 which is screwed onto one of said sections and which has an inside shoulder 5 engageable against the corresponding external shoulder 6 carried by the other section of the casing 1. There is a circular diaphragm 7, which is preferably formed of rubber or similar material and which spans the lower chamber 3. It has a marginal rib 8 which is clamped between said separate sections of the casing, as shown in Figure 3, the abutting parts of said sections having grooves to receive said rib so as to anchor the rib against detachment and also to form a leak-proof joint between said parts. Any other suitable type of diaphragm may be employed such as an ordinary yieldable partition or a diaphragm in the general form of a bellows could be used.

The diaphragm is preferably annularly corrugated, as is indicated in Figure 3.

As is indicated in Figures 1 and 2, the casing is restricted approximately mid-way between its ends, and screwed into the restricted, internally threaded, walls of the restricted area there is an annular valve seat 9, whose upper end is, preferably, upwardly flared, as shown in Figure 2. This valve seat has a central bearing 10, and there is a valve stem whose upper end works through said bearing, and attached to said upper end there is an upwardly opening valve 12 which conforms, in shape, to the seating face of the valve seat so as to open and close said seat. The lower end of this stem is attached to said diaphragm.

Spaced beneath the valve seat and anchored to said seat by the tie rods 13 there is a disc 14 which is provided with openings 15 distributed through the area thereof and has a bevelled margin 16 which fits closely against the inner wall of the chamber 3 when the valve seat is screwed to home position.

The disc 14 has a central bearing 17 through which the piston rod 11 works.

The alleviator is connected with the pipe line through the connection 18 which is connected into the chamber 3 on the opposite side of the diaphragm 7 from the

valve mechanism

9, 12, and bridging the inlet of liquid through the connection 18 there is a disc 19, which is perforated throughout and whose margins are secured to the wall of the chamber 3.

The chamber 3 may be filled with a suitable liquid, and the chamber 2 may be filled with air or gas under the required pressure, which may be introduced into the said chamber through a suitable connection, as 20, which may be opened and closed by means of a valve 21 which is threaded into the connection 20. Under normal operating conditions, the liquid in the chamber 3, with the pressure of the air or gas in chamber 2 against it, will expand the diaphragm to its maximum capacity, thus completely filling the chamber 3 with liquid, which should rise above and cover the valve 12, as indicated in Figure 1.

When there is pressure in the line, the diaphragm 7 will be moved to positively open the valve 12 and to force part of the liquid from the chamber 3. through the valve seat 9 into chamber 2, and the valve 12 will be maintained open. When there is no pressure in the line, the diaphragm 7 assumes its normal position, as shown in Figure l, and the valve 12 seats on the seat 9 after substantially all of the liquid in the chamber 2 has returned into chamber 3. When the valve has seated on and closed the seat 9 the diaphragm 7 will be protected from the influence of any further pressure drop in the chamber 3.

The ordinary pump pulsations will be dampened by the diaphragm 7 acting against the liquid in the chamber 3 which in turn acts against the air, gas or other fluid under pressure in chamber 2.

The

perforated discs

14, 19 will tend to spread the liquid flowing through them, so that the pressure of the liquid through the disc 19 will be distributed substantially uniformly throughout the area of the diaphragm, and the liquid in the intermediate chamber 3 will be forced to pass through the perforated disc or damper 14 to break up any isolated currents in the liquid to the end that said liquid will be dampened and will flow uniformly through the valve seat against the diaphragm.

The type of alleviator herein described is of very simple construction and accurate in operation and is especially adaptable for use for dampening pulsations in liquid flowing through a line under pump pressure. The drawings and description are illustrative of what may now be considered a preferred form of the invention by way of illustration only and not by way of limitation, while the broad principle of the invention will be defined by the appended claims.

What I claim is:

1. An alleviator for absorbing pulsations and alleviating vibration in a pulsating, pressurized liquid line and comprising a casing including two vertically disposed, rigid walled chambers with the lowermost chamber adapted to be connected to said line to provide an inlet extending from the path of liquid flow in the line, perforate means across the intercommunication between chambers and a similar perforate means across said inlet, a flexible diaphragm dividing the lower chamber and forming with the casing a space on the inlet side of said diaphragm and communicating with said inlet, a body of liquid in said lower chamber in contact with the other side of said diaphragm and extending into said upper chamber. compressed gas in said upper chamber above said liquid, said chambers providing smooth, substantially spherical inner surfaces whereby, as line liquid flows into said inlet to urge the liquid above the diaphragm upwardly, said upper chamber has an increasing gasliquid contact area to dampen surging of said upper chamber liquid and of said diaphragm, and whereby, as said liquid recedes and liquid flows substantially uniformly through said upper and lower perforate means, billowing of said diaphragm is reduced as the horizontal cross-sectional area of said upper liquid around said diaphragm first gradually increases as said diaphragm recedes to pass the central horizontal plane of said lower chamber and then decreases as said diaphragm further descends as said line liquid flows downwardly through said inlet, a valve seat in said casing around said intercommunication above the perforate means therein, a valve to seat in said valve seat, and a valve stem connected at one end to said valve and at the other end to said diaphragm and of a length to limit downward travel of said diaphragm to a position above the perforate means in said inlet and to at least partially prevent said diaphragm from being drawn and urged into said inlet perforate means and into said inlet.

2. An alleviator for absorbing pulsations and alleviating vibration in a pulsating, pressurized liquid line and comprising a casing including two vertically disposed chambers with the lowermost chamber adapted to be connected to said line to provide an inlet extending from the path of liquid flow in the line, perforate means across the intercommunication between chambers and a similar perforate means across said inlet, a flexible diaphragm dividing the lower chamber and forming with the casing 21 space on the inlet side of said diaphragm and communicating with said inlet, a body of liquid in said lower chamber in contact with the other side of said diaphragm and extending into said upper chamber, compressed gas in said upper chamber above said liquid, said lower chamber providing a smooth, substantially spherical inner surface whereby after line liquid in a pulsation is forced through said inlet to force said diaphragm and the liquid thereabove upwardly and said liquid then recedes as the pulsation peak passes and said line liquid flows downwardly through said inlet, billowing and surge of said diaphragm is reduced as the horizontal cross-sectional area of said upper liquid around said diaphrarn first gradually increases as said diaphragm recedes to pass the central horizontal plane of said lower chamber and then decreases as said diaphragm further descends as said line liquid flows downwardly through said inlet, a valve seat in said casing around said intercommunication above the perforate means therein, a valve to seat in said valve seat, and a valve stem connected at one end to said valve and at the other end to said diaphragm and of a length to limit downward travel of said diaphragm to a position above the perforate means in said inlet and to at least partially prevent said diaphragm from being drawn and urged into said inlet perforate means and into said inlet.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,154,223 Wade Apr. 11, 1939 2,290,337 Knauth July 21, 1942 2,342,356 Mercier Feb. 22, 1944 2,394,401 Overbeke Feb. 5, 1946 2,417,256 Kremiller Mar. 11, 1947 2,446,358 Yates et al. Aug. 3, 1948 2,563,257 Loukonen Aug. 7, 1951 FOREIGN PATENTS Number Country Date 842,835 France June 20, 1939