US2138654A - Pressure equalizing arrangement for reciprocating pumps - Google Patents

Description

Nov. 29, 1938. J. H. DORAN 2,138,654

' PRESSURE EQUALIZING ARRANGEMENT FOR RECIPROCATING PUMPS Filed Dec. 29, 1957 I -lllll John H. Do an,

y W 6/3 M 4 is Abcovneg.

Patented Nov. 29, 1938 r PRESSURE EQUALIZING ARRANGEMENT FOR RECIPROCATING PUDIPS John H. Doran, Scotia, N.'Y., assignor to GengralkElectric Company, a corporation of New Application December 29, 1937, Serial No. 182,280 6 Claims. (01. 103224) This invention relates to fluid pressure equalizlower or bottom portion thereof communicating ing arrangements and devices. Such devices are with the conduit l8 through a connecting pipe provided, for example, in connection with recipor member2l in close proximity to the pump I0. rocating pumps to equalize, reduce or minimize An electric heater 22 is disposed in the upper fluctuations or pulsations in pressure of the fluid portion of the cylinder and during normal opera discharged by reciprocating pumps. The pulsation is immersed in the fluid therein. The heater tions of the fluid discharged by reciprocating is connected with the electric supply circuit 23 by pumps have an intensity depending upon the a circuit 24 having therein a-control switch 25 number of cylinders of the pump. For instance, which is normally biased to a closed circuit posi- 10 with a five cylinder pump, the variation in flow tion by a spring 25'. As soon as the pump is 10 is of the order of about 8% of the normal or started, part of the fluid discharged thereby is average flow. The fluctuations tend to increase forced through the connecting pipe 2| and into with a decreasing number of cylinders, reaching the cylinder 20. Immersed in this fluid, the heata maximum in the case where but a single cyliner 22 will vaporize part of it forming a vapor l5 der is provided for forcing the fluid through a cushion in the upper part of the cylinder. This conduit. These fluctuations or pulsations are un-- vapor cushion clamps the pressure fluctuations of desirable and often lead to considerable vibration the fluid discharged by the pump, that is, as long of the conduits which may result in the breakas the pressure near the connection between the ing thereof. pipe 2! and the conduit 18 increases, fluid is 20 The object of my invention is to provide an forced into the cylinder 20 causing compression 20 improved construction and arrangement of presof the vapor cushion in the upper portion of the sure equalizing devices whereby fluctuations or cylinder. Thereafter as the pressure in the conpulsations in pressure of a fluid forced through a duit I8 near its connection with the pipe 2| deconduit are substantially reduced, damped or creases, fluid is forced out of the cylinder 20 by equalized. the expansion of the vapor cushion. 25

For a consideration of what I believe to be As the elastic fluid generator or steam boiler novel and my invention, attention is directed to 9 reaches its normal operating condition, elastic the following description and the claims appended fluid or steam is fed therefrom to any suitable thereto in connection with the accompanying consuming apparatus through the feed main 21.

drawing. A conduit 28 in communication with the supply 30 Referring to the drawing, the arrangement of the generator l9, as through the main 27, has comprises a reciprocating pumping means or a continuous looped portion 29 thereof disposed pump l0 having a cylinder II and a piston l2 within the upper end of the cylinder 20. This movably arranged within the cylinder. This pisloop, which passes through the openings in the top ton is connected toastem l3 which is reciprocated of the cylinder 20 and is sealed thereto as by 35 by any suitable means, not shown. The cylinder welds 30, is partly immersed in the fluid in the has an inlet or suction conduit M with an inlet cylinder and forms a second heating unit therefor. or suction valve I5 and an outlet or discharge Thus, assuming that the elastic fluid generator conduit IS with an outlet or discharge valve l1. I9 is of the superheating type, as it reaches its The outlet I6 is connected to a conduit l8 which normal operating condition, suflicient vaporiza- 40 communicates 'with the elastic fluid generator, or tion of the fluid in the cylinder 20 is caused by steam boiler l9. During operation, upward movethe heating unit 29 to maintain a sufiicient vapor ment of the piston l2 creates a vacuum in the cushion in the upper portion of the pressure cylinder whereby fluid, such as water, flows equalizer. When such a condition obtains, prothrough the inlet conduit l4 into the cylinder, the vision is made for the deenergization of the elecvalve l5 being open during upward movement tric heater 22. Connected with the switch 25 in whereas valve" is closed. As the piston I2 is the control circuit for the electric heater is a moved downwardly, the inlet valve 15 closes and temperature responsive switch actuating mechathe discharge valve l1 opens whereby the fluid is nism 3| having connected thereto a bulb 32 conforced throughthe outlet l6 into the conduit l8. taining thermo-expansible fluid arranged in ther- 5 In order to reduce pulsations in pressure of the ma] communication with the elastic fluid outlet fluid discharged from the reciprocating pump, I 26. So long as the temperature of the elastic provide, in accordance with my invention, means fluid circulating through the elastic fluid heater for equalizing the pressure fluctuations. This unit 29 is too low to properly maintain a sufiicient means includes a cylinder or chamber 20, the vapor cushion in the upper portion of the cylinder,

reaches the normal operating temperature, the

switch operating mechanism 3! acts to deenergize the electric heater 22.

While I have described above a pressure equaling system which is thoroughly satisfactory in operation, in the preferred embodiment I add an additional electric heater 33 disposed around or adjacent to the elastic fluid conduit 28 near the inlet thereof to the cylinder 23. Though I have shown in this instance this heater as comprising a resistance unit encircling the conduit 28, of course, it is obvious that any heating means might be employed. This heater is conected to the electric source of supply 23 by a control circuit 345 having a switch 35 disposed therein. Switch 35 is normally biased to a closed circuit position by a spring 35 and has connected thereto a temperature responsive actuating mechanism Bl which has connected thereto a bulb 38 containing thermo-expansible fluid arranged in thermal communication with the conduit 28 between the elastic fluid generator 19 and the heater 33. Before the elastic fluid generator 89 reaches its normal operating condition of temperature and pressure, that is, before the temperature of the elastic fluid flowing through the heating coil 29 reaches a sufliciently high value for maintaining a proper vapor cushion in the pressure equalizer, the elastic fluid flowing through the conduit 28 is superheated by the auxiliary heater 33 to raise the temperature thereof a predetermined amount. As soon as the superheated elastic fluid discharging from the heating coil 29 reaches a predetermined temperature during which condition prevailing a proper vapor cushion will be maintained in the pressure equalizer, the relatively large electric heater 22 will be deenergized by the operation of the thermal responsive device 3i. The vapor cushion within the pressure equalizer will then be maintained solely by the heating coil 29 as augmented by the superheater 33 which superheater will in turn be deenergized as the elastic fluid generator is reaches its normal operating condition. Thus, during the transition of control of the pressure equalizer from the electric heater 22 to the elastic fluid heater 29 a substantially constant condition of the vapor cushion is maintained with a minimum consumption of electrical energy.

In the event that the pressure equalizer is used in conjunction with an elastic fluid generator which is not of the superheating type, it is obvious that the temperature of the elastic fluid generated thereby will be below the temperature required for forming steam in the chamber 20 the pressure in which is greater than in the boiler [9. In such case the heater 22 will be deenergized, as before, as soon as the elastic fluid flowing through the coil 29 superheated by the heater 33 reaches a temperature sufliicient for maintaining the proper vapor cushion in the pressure equalizen. But because the relatively low temperature of the boiler output during normal operation requires the continual energization of the superheater 33, the switch 35 will not be opened and may in fact be dispensed with or be substituted by any other suitable type of control switch.

Having described the method of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In an elastic fluid generator plant, a pulsating fluid pump. an elastic fluid generator, a conduit for conveying fluid from said pump to said generator, a chamber in communication with said conduit adjacent said pump for equalizing fluctuations in pressure caused by said pump, a conduit for conveying elastic fluid from said generator to heat fluid in said chamber to form a vapor cushion in the upper portion of said chamber, auxiliary heating means associated with said chamber, means for controlling said auxiliary heating means upon a predetermined temperature obtaining in said elastic fluid conduit adjacent said chamber.

2. The combination of a reciprocating pump, a conduit connected to the outlet of the pump for conducting liquid to an elastic fluid generator, :1. device connected to the conduit in close proximity to the pump [or equalizing fluctuations in pressure of the liquid discharged by the pump into the conduit, said device comprising a closed chamber communicating with the conduit, a conduit extending from said elastic fluid generator for conveying elastic fluid therefrom, a loop of said elastic fluid conduit disposed within an upper portion of said chamber and partly immersed in the liquid in said chamber. during normal operating conditions, an electricalresistance heater disposed around said elastic fluid conduit adjacent the inlet to said chamber for heating the elastic fluid passing through said loop, an electric circuit for said heater having a switch therein biased to closed position, means for opening said switch in response to a predetermined temperature of the elastic fluid in said conduit between said heater and said steam generator, an electrical resistance heater disposed within an upper portion of said chamber and partly immersed in the liquid in said chamber during normal operating conditions, an electric circuit for said heater, a switch biased to closed position in said electric circuit for said last mentioned heater and means for opening said last mentioned switch in response to a predetermined temperature of the elastic fluid in said conduit adjacent the outlet end thereof from said chamber.

3. The combination of a reciprocating pump, a conduit connected to the outlet of said pump for conducting liquid to an elastic fluid generator, a device connected to the conduit in close proximity to the pump for equalizing fluctuations in pressure of the liquid discharged by the pump into the conduit, said device comprising a closed cylinder communicating with the conduit, a conduit extending from said elastic fluid generator for conveying elastic fluid therefrom and having a looped portion thereof disposed within an upper portion of said cylinder and partly immersed in liquid during normal operating conditions, an electrical resistance heater disposed within an upper portion of the cylinder and partly immersed in liquid during normal operating conditions, an electric supply circuit for said heater, a switch in the electric supply circuit for said heater and means responsive to a predetermined temperature of the elastic fluid in said conduit for actuating said switch.

4. The combination of a reciprocating pump,

a conduit connected to the outlet of said pump for conducting liquid to an elastic fluid generator, a device connected to the conduit in close proximity to the pump for equalizing fluctuations in pressure of the liquid discharged by the pump into said conduit, said device comprising a closed chamber communicating with said conduit, a conduit for conveying elastic fluid from said elastic fluid generator having a looped portion disposed within an upper portion of said chamber and'partly immersed in liquid therein during normal operating conditions, an electrical heating means adjacent the inlet of said last mentioned conduit to said chamber for heating the elastic fluid within said conduit, an electrical supply circuit for said electrical heating means having a switch therein, means responsive to a predetermined temperature of the elastic fluid within said conduit between said heating means and said elastic fluid generator for actuating said switch.

5. The combination of a reciprocating pump,

' a conduit connected to the outlet of said pump portion of said chamber and partly immersed in the liquid in said chamber during normal operating conditions, an electrical supply circuit for said heating means, a switch in the supply cir- 4 cuit for said last mentioned heating means and means responsive to a predetermined temperature of the elastic fluid in saidconduit adjacent the outlet portion thereof Irom said chamber for actuating said last mentioned switch.

6. In a boiler teed liquid pumping system, a pulsating feed liquid pump,.an elastic fluid generator, a conduit for conveying feed liquid under pressure from said pump to said elastic fluid genaerator, a pulsation damping chamber in communication with said conduit adjacent said pump. electric heating means associated with said chamber'for forming a vapor cushion in the upper portion thereof upon the starting of said system, a conduit for conveying elastic fluid from said generator for heating liquid in said chamber, means for superheating the elastic fluid in said conduit for maintaining the vapor cushion in said chamber, and means responsive to a predetermined superheated condition of the elastic fluid in said conduit for deenergizing said electric heating means.

JOHN H. DORAN.

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