Patent Application
20140056724
Exemplary embodiments pertain to the art of diaphragm metering pumps and, more particularly, to a diaphragm metering pump having a degassing system.
Diaphragm metering pumps generally draw in a fluid from a source to an inlet at a first pressure, and discharge the fluid through an outlet at a second pressure. Often times, gas entrained in the fluid, or developed as a consequence of pumping, may become trapped in a head portion of the pump causing a vapor lock condition. In such cases, fluid discharge may be reduced or even arrested. In order to alleviate vapor lock, many diaphragm metering pumps include a bleed valve that is manually or automatically activated to allow trapped gas to escape. In some cases, the trapped gas is discharged to ambient. In other cases, the trapped gas, along with a portion of discharged fluid, is passed back to the source through a piping system.
Disclosed is a diaphragm metering pump including a pump body having a head portion including a suction side and a discharge side defining a flow path. A valve seat is arranged at the discharge side and a check valve is arranged at the valve seat. A degassing system includes a check valve actuator operatively connected to the check valve. The check valve actuator is selectively activated to unseat the check valve from the valve seat to allow gases trapped in the head portion to pass through the discharge side.
Also disclosed is a method of degassing a diaphragm metering pump. The method includes drawing a liquid from a liquid source through a suction side of a diaphragm metering pump, passing the liquid from the suction side into a head portion of the diaphragm metering pump, guiding the liquid through a check valve from the head portion to a discharge side of the diaphragm metering pump, and initiating a check valve actuator to unseat the check valve allowing gases collected in the head portion to pass through the discharge portion.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
A diaphragm metering pump in accordance with an exemplary embodiment is illustrated generally at 2 in
Suction side 23 includes an inlet fitting 36 including a check valve 38 shown in the form of a check ball 40 that selectively rests upon a valve seat 43. The term “check valve” should be understood to mean a valve having a checking element configured to allow fluid to pass in one direction and arrest fluid flow in an opposing direction. Of course the particular form of check valve 38 may vary. Check valve 38 allows fluid to enter pump chamber 20 from fluid source 28 during a suction stroke and prevents fluid from exiting through inlet fitting 36 during a pressure stroke. A discharge fitting 56 is fluidically connected to discharge side 25 through a check valve 58. In the exemplary embodiment shown, check valve 58 is shown in the form of a check ball 60 that selectively rests upon a valve seat 62. Check valve 58 allows fluid to flow from pump chamber 20 toward fluid destination 32 during a pressure stroke and prevents fluid from being ingested into pump chamber 20 through discharge fitting 56 during a suction stroke.
In accordance with an exemplary embodiment, diaphragm metering pump 2 is provided with a degassing system 66 fluidically connected to discharge side 25 of pump chamber 20. As shown in
Degassing system 66 includes a check valve actuator 96 connected to mounting surface 75 though a mounting block 97. Check valve actuator 96 takes the form of a linear actuator 99 shown in the form of a solenoid 100. Solenoid 100 includes a coil 104 and a plunger 107. Plunger 107 acts upon an actuating pin assembly 109 that projects through second passage 79 along a path that is substantially parallel to discharge flow path 30. Specifically, upon application of an electrical current to coil 104, plunger 107 acts upon actuating pin assembly 109. Actuating pin assembly 109 extends along second passage 79, contacts and unseats check ball 60 allowing gases trapped within pump chamber 20 to pass from discharge flow path 30 to fluid destination 32. Degassing system 66 is also shown to include a sealing member 110 that takes the form of an isolation diaphragm or seal 113 that extends about actuating pin assembly 109 to prevent fluid from exiting second passage 79. In addition, check valve actuator 96 includes a return spring 115 that biases actuating pin assembly 109 into a ready position as shown in
Reference will now be made to
Degassing system 120 is also shown to include a check valve actuator 154 supported from second mounting surface 128. Check valve actuator 154 takes the form of a linear actuator 156. Linear actuator 156 is shown as a solenoid 158 having a plunger 161 that acts upon an actuating pin 162 through a spacer 163 and a diaphragm seal 164. Solenoid 158 is also shown to include a return spring 165 that biases actuating pin 162 into a ready position such as shown in
Reference will now be made to
Degassing system 170 includes a check valve actuator 204 mounted to third mounting surface 179. Check valve actuator 204 is shown in the form of a linear actuator 206. Linear actuator 206 is depicted as a solenoid 208 supported from third mounting surface 179 through a generally U-shaped bracket 210. Solenoid 208 includes a plunger 211 that is coupled to an actuating pin 214. Actuating pin 214 includes a first end section 216 mechanically linked to plunger 211 and a second end section 217 that defines a check valve 219 in the form of a check ball 220. Actuating pin 214 passes into second passage 191 through a sealing member 222 and is surrounded, in part, by a return spring 225. Return spring 225 is configured to bias actuating pin 214 into a ready position. Actuating pin 214 is configured to respond to pressure changes in pump chamber 20 to allow fluid to pass into first passage 190 and on through discharge fitting 56. Actuating pin 214 is also configured to be acted upon by solenoid 208 through plunger 211 to selectively unseat check ball 220 from valve seat 62 allowing gases accumulating in head portion 8 to pass through discharge fitting 56. In the exemplary arrangement shown, actuating pin 214 is selectively shifted along a path that substantially coincides with discharge flow path 30.
Reference will now be made to
Support member 232 houses a first passage 250, and a second passage 251. A third passage 252 is housed in second support element 234. First passage 250 includes a first end 256 that extends from discharge flow path 30 to a second end 257 that terminates at interface 235 and is selectively fluidically connected with check valve receiving portion 246. Second passage 251 includes a first end portion 259 that extends from interface 235 and fluidically connects with check valve receiving portion 246 to a second end portion 260 through an angled portion 261. Second end portion 260 terminates at and is fluidically connected with outlet 243. Third passage 252 includes a first end section 263 that extends from second mounting surface 238 to a second end section 264 that terminates at interface 235.
Degassing system 230 includes a check valve actuator 268 shown in the form of a linear actuator 270. Linear actuator 270 takes the form of a solenoid 272 mounted to second mounting surface 238 through a generally U-Shaped bracket 274. Solenoid 272 includes a plunger 277. Plunger 277 is mechanically linked to a coupler 279. Coupler 279 is mechanically linked to an actuating pin 282 that extends through third passage 252. Actuating pin 282 includes a first end 284 that extends to a second end 285. First end 284 includes a clip 286 that detachably engages with coupler 279. Second end 285 connects with a diaphragm valve 287 that serves as a check valve. A return spring 290 is linked to actuating pin 282 and is configured to bias actuating pin 282 into a ready position. With this arrangement, diaphragm valve 287 responds to pressure changes within pump chamber 20 to allow fluid to flow through first and second passages 250 and 251 and pass through discharge fitting 56. Diaphragm valve 287 also responds to changes in position of plunger 277 to selectively allow gases trapped within head portion 8 to pass through discharge fitting 56.
Reference will now be made to
A check valve actuator 329 is attached to support member 304 at second mounting surface 308. Check valve actuator 329 is shown in the form of an electro-magnetic actuator 331. Electro-magnetic actuator 331 takes the form of a solenoid 333 having a coil 334. Coil 334 is configured to generate an electro-motive force that acts upon a plunger 336. Plunger 336 includes an integral check valve 338 that takes the form of a check ball 340. Plunger 336 and check ball 340 return to a ready position under force of gravity. With this arrangement, check ball 340 responds to pressure changes within pump chamber 20 to allow fluid to flow from flow path 30, through first and second passages 317 and 318, and pass through discharge fitting 56. Check ball 340 is also unseated when electro-magnetic actuator 331 is energized drawing plunger 336 toward coil 334 to selectively allow gases trapped within head portion 8 to pass through discharge fitting 56.
Reference will now be made to
A check valve actuator 375 is supported at second mounting surface 358. Check valve actuator 375 takes the form of a linear actuator 377. Linear actuator 377 is shown in the form of a solenoid 379 including a plunger 380 operatively connected to a reservoir member 381 coupled to second mounting surface 358. Reservoir member 381 includes a reservoir 383 and a diaphragm 387. Diaphragm 387 is connected to plunger 380. With this arrangement, check valve 60 responds to changes in pressure in pump chamber 20. More specifically, check valve actuator 375 acts indirectly upon check valve 60. In the event of gas build up in head portion 8, solenoid 379 is activated to shift plunger 380 causing diaphragm 387 to deliver a pulse of liquid through second passage 365. The pulse of liquid unseats check ball 60 from valve seat 62 allowing any trapped gases to pass through first passage 364 and out from discharge fitting 56.
At this point it should be understood that the exemplary embodiments provide a system for alleviating gas build up in a head portion of a diaphragm metering pump. The exemplary embodiments include an actuator that acts directly upon a discharge check valve or indirectly on the discharge check valve to allow built up gases to flow to through an outlet. In addition, in contrast to prior art systems that bleed off a portion of the liquid to the liquid source to degas, the exemplary embodiments allow built up gases to flow through the pump outlet to the liquid destination. In this manner, the exemplary embodiments eliminate the need for additional plumbing, valves or other hardware and also ensure that all liquid passing though the discharge is passed from the outlet. Also, while described as using a linear actuator, the exemplary embodiments may use various actuators, including pneumatic actuators, hydraulic actuators, electric actuators, or actuators that are not linear, to unseat the check valve allowing gases to pass from the outlet.
Additionally, while the check valve is shown and described as a check ball and a diaphragm valve, other types of checking elements may be employed. For example, the exemplary embodiments may employ poppet valves, flapper valves, reed valves, wafer type valves or other elements that may be employed to allow fluid flow through a passage in one direction and to check or arrest fluid flow through the passage in an opposing direction. Further, while the mounting brackets are described as being generally U-Shaped, other types of brackets including a wide range of geometries may be employed. Still further, it should be understood that the accumulation of gases may be sensed using various techniques/devices and check valves may be unseated to alleviate gas build up based on these techniques and/or signals from these devices or, alternatively, the check valve may be periodically unseated on a time basis.
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims.
