US2315179A - Pumping of liquids - Google Patents

Description

March 30, 1943.

S. S. ALLENDER PUMPING 0F LIQUID Filed Dec. 18, 1939 12k/yf,

2 Sheets-Sheet 1 @flee @y f March 30, 1943.

S. S. ALLENDER PUMPING OF LIQUID Filed DeC. 18, 1939 2 Sheets-Sheet 2 Patented Mar. 30, 1943 PUMPING OF LIQUIDS samuel s. Allende; New York, N. Y., assigner to Universal Oil Products Company, Chicago, Ill., a corporation of Delaware Application December 18, 1939, Serial No. 309,755

1 claim.

The invention relates more specifically to an improved method and means of absorbing shock and reducing the magnitude of pulsations in the discharge line of a reciprocating pump due to the intermittent nature of the flow of liquid from the pump cylinder or cylinders. It is adaptable to the Ipumping of all volatile liquids or liquids having constituents which are readily vaporized and is particularly advantageous in :pumping inflammable liquids and those to which the presence oi air may be detrimental.

It is, of course, common practice to provide an expansion chamber on the discharge line, manifold or outlet valve 'chamber of reciprocating pumps to assist in absorbing.pulsations and minimize shock resulting from the intermittent nature of the pumping. action. Heretofore, such devices have merely provided an entrapped body of air which is compressed and expands with variations in the pump discharge pressure and acts as a cushion. In the present invention this air cushion is replaced by a cushion comprising vaporized constituents of the liquid being pumped. This is accomplished by supplying suilicient heat to the upper portion of the expansion chamber to maintain a portion of the fluid in the expansion chamber in vaporous state.

Heating of the expansion chamber and vaporization therein may be accomplished, for example, by providing a closed coil within or a jacket or coil about the upper portion of he chamber and circulating a suitable heating medium therethrough. In case the pump is driven by-steam or other hot expanding gas, a portion thereof may be passed through the coil 'or jacket to supply heat to the upper portion of the expansion chamber and maintain a vapor cushion therein. The heating medium in such cases may be bled from the inlet or exhaust line of the pumping 4 the upper portion of the expansion chamber, particularly when the pump is electrically driven and/or lwhen other heating means are not readily available.

The use of a continuously maintained vapor cushion in place of an air cushion in the expansion chamber has numerous advantages, particularly as applied to specific pumping problems. A

In addition to eliminating the d-angers which sometimes result from the presence of air when combustible or inflammable liquids are being pumped, the features of the invention obviate the possibility of ultimate practical elimination of the cushion in the expansion chamber when the pump is in continuous service over a prolonged period of time. For example, nearly all liquids will dissolve varying amounts of air and over a prolonged period of operation the air cushion in the 'pumping cylinder may be thus dissipated. whereas with the present invention, although'va pors may also be dissolved from the cushion in the pumping cylinder and/or condensed by the liquid present, the continuous application of heat causes the evolution of additional vapor to replace that dissolved or condensed so that equilibrium conditions are established and a vapor cushion is continuously maintained, regardless of the length of time during which the pump is continuously operated.

The accompanying drawings dlagrammatically illustrate several specific forms of apparatus, each embodying the features of the invention and in which the improved method of operation provided by the invention may. be accomplished.

Fig. 1 illustrates a steam driven pump having an expansion chamber heated by steam supplied thereto from the inlet or from the exhaust line of the steam end of the pump.

Fig. 2 is an enlarged longitudinal elevation shown partially in cross-section, of the steam heated expansion chamber shown in Fig. 1.

Fig. 3 is a longitudinal elevation, shown partially in section, of a modified form of expansion chamber which may employ steam or 'other hot fluid as the heating medium.

Fig. 4 is an elevational view of an electrically driven reciprocating pump having an electrically heated expansion chamber.

Fig. 5 is an enlarged elevational view, shown partially in section of a portion of the expansion chamber shown in Fig. 4.

Fig. 6 is an elevational view, shown partially in section, of a portion of a modified form of electrically heated expansion chamber.

Referring to Fig. 1, the reciprocating type of steam drii en pump here illustrated has a steam cylinder I0 and a liquid pumping cylinder Il interconnected in the conventional manner, steam being supplied to the valve chest I2 through line i3 and exhausted therefrom through line i4.

The liquid to be pumped is supplied to the valve chamber of the iiuid .end of the Dump through suction line I5 and directed therefrom through discharge line I6. The expansion chamber Il\communicates with discharge line I6 and a closed coil I8 is provided in the upper portion of the expansion chamber. Steam may be supplied to coil I8 from the inlet steam line I3 through line I9 and valve 20 or exhaust steam from line I4 may be supplied to the coil through line 2|, valve 22 and line I9. Steam and any condensate formed in coil I3 are discharged therefrom through line 23 and valve 24. Valves and 22 are block valves and valve 24 is regulated to maintain the desired ilow of steam through the coil.

Exhaust steam may be utilized in coil I8 when its temperature is suiiicient to maintain a substantial portionof the liquid being pumped in vaporous state in expansion chamber I'I and when the back pressure in the exhaust steam line is sufficient to force steam through the coil at the required rate. In other instances, live steam from line I3 may be employed.

Referring now to Fig. 2, to facilitate the insertion of coil I8 in the upper portion of the expansion chamber and facilitate its removal for inspection and repair, whenever necessary,

the upper head of the chamber is a flanged bonnet removably bolted to the flanged substantially cylindrical lower portion oi the chamber as indicated at 26. Packing glands 21 are provided in bonnet 25 through which the inlet and outlet ends 28 and 29, respectively, of coil I8 extend.

Referring now to Fig. 3, the expansion chamber here designated by the reference numeral 30 of conventional form, except that a jacket 3| is provided at its upper end and spaced from the walls 32 of the chamber. Steam or other hot fluid of sutdcient temperature to maintain a substantial portion of the iiuid Within the expansion chamber in vaporous state is admitted to the space 33 between jacket 3I and the upper portion of walls 32 through line 34 and after transferring heat through Walls 32 to the fluid Within. the chamber, the spent or partially spent heating medium is discharged from space 33 through line 35.

With a pump driven by an internal combustion engine, the arrangement may be substantially the same as illustrated in Fig. l, except that an expansion chamber of the general type shown in Fig. 3 is preferably employed and only the combustion gas exhaust line, corresponding to line I4 of Fig. l, is connected with the steam jacket of the expansion chamber through line 34, which replaces lines 2I and I9. No valve will ordinarily be required in this line but a regulating valve` preferably of the gate or butteriiy type, may be employed in the outlet line 35 from space 33 in the same manner as valve 24 is employed in Fig. 1.

An expansion chamber of the general form shown in Fig. 3 may be substituted, in Fig. i, ior the type shown in Figs. 1 and 2 and is preferably employed when exhaust steam is utilized as the heating medium since it may be designed to offer less resistance to the iiow of steam.

Referring now io Fig. 4, the reciprocating pump here illustrated is of conventional form except for the heating means provided in the upper portion of the expansion chamber 40. A motor 4i. supplied with electrical energy through lines 42, is connected through pinion 43 with gear 44 and pitman 45 connects gear 44 with piston rod 46.

The valve chamber 4'I of the pump is mounted above the pumping cylinder 48, the inlet line for the fluid to be pumped communicating with the valve chamber on the opposite side of the pump from that here illustrated. The discharge line which communicates with the valve chamber is indicated at 49.

Expansion chamber 40, in the particular case here illustrated, is integral with bonnet of the valve chamber and an immersion type electrical heating unit 5I is provided in the upper portion of chamber 40. Electrical energy is supplied to heater 5I through lines 52 from lines 42, which supply electrical energy to motor 4l, and a suitable switch indicated at 53 is provided in one of the lines 52.

Fig. 5 illustrates how the immersion type heating element 5I may be inserted into the upper portion of chamber 40 through a threaded port 54 at the upper end of the chamber, the upper end of rod 5I being threaded to engage the threads of the port and seal the chamber. Resistance wires 55 of heater 5I are electrically insulated from the metal outer walls of the latter, preferably by a heat conductive material such as for example magnesium oxide, porcelain or the like, not illustrated.

The expansion chamber shown in Fig. 6 may be substituted for chamber 40 of Figs. 4 and 5 and is similar thereto except that instead of providing an internal or immersion type heating element, theheating element is disposed about the exterior surface oi the upper walls of the chamber. The heating element of chamber $0 comprises resistance Wires 6I encased in a substantially rigid body 62 of electrical insulating, heat conductive material such as magnesium oxide, for example. Resistance Wires 6I form a coil which is connected at its opposite ends to terminals 63 to which conductor wires 64, form a suitable source of electrical energy, are also attached. The rigid molded shape 62 conforms to the contour of the upper portion of the walls of chamber 60 and is encased in suitable heat insulating material 65.

It will be understood, of course, that it is within the scope of the invention to employ an electrically heated expansion chamber with pumps driven by steam or other expanding hot gases and also that an expansion chamber heated by steam or other hot iiuid may be employed on electrically driven pumps. Many speciiic forms of electrically heated or fluid heated expansion chambers, other than the specific forms illustrated, are, of course. also Within the scope of the broader aspects of the invention.

I claim as my invention:

In combination, a iiuid pump driven by an electrical power means, leads connecting said power means with a source of electricity, moans for equalizing the pulsations of said pump comprising a chamber mounted in the discharge line of said pump, means for heating said chamber comprising a casing mounted on the outside o said chamber, heat conducting electrical insu' `ting material within said casing, resistance ele.. ents in said casing mounted within said mateijh'l. and means for connecting said resistance "Ielemenis with said source of electricity.

SAMUEL S. ALLENDER.

Images