| 摘要 |
<p>An automatic pump control device for an injection pump used to inject flui d (typically methanol) into oil or natural gas wells to prevent freezing. The device enables the pump to operate at rates as low as one full stroke per 1.5 minut es (i.e., 0.67 stroke/min), substantially slower than current rates of approximately fifteen strokes per minute. The device comprises a main body; an extension air pilot ; a retraction air pilot; a toggle mechanism that actuates the extension air pil ot to extend the pump piston, that at the end of the extension stroke actuates a retraction air pilot to retract the pump piston, and that automatically continues the two stroke cycle; a drive mechanism for driving the toggle mechanism; an overstroke mechanism to prevent over driving the retraction air pilot at the end of its stroke; an optional stroke speed adjustment valve; a circuit to circulat e and transport a gas; and piston, spool, and sleeve for switching the path of the gas. The automatic pump control device operates over a wide range of flow rates and pressure ranges, thus enabling installation of the automatic pump control device to virtually all manufacturers' injection pumps.</p> |
