Reciprocating pumps principles

The principle of operation of the hydraulic reciprocating pump is similar to the beam pump, with a piston-like sub-surface pump action. The energy to drive the pump, however, is delivered through a hydraulic medium, the power fluid, commonly oil or water. The power fluid drives a downhole hydraulic motor which in turn drives the pump. A separate surface pump delivers the hydraulic power. The power fluid system can be of the closed loop or of the open type. In the latter case, the power fluids are mixed with the produced fluid stream. The performance of the hydraulic pump is primarily monitored by measuring the discharge pressures of both surface and sub-surface pumps. 

Fig. 1.2 The principle of an air-driven reciprocating pump (V) a compressed-air distributor valve, and (C) one-way check valves. (Reprinted with permission from High Pres. Tech. (1977).)...

Depending on the principle of operation, we shall distinguish four categories of pumps pneumatic pumps, syringe-type pumps, reciprocating pumps and hydraulic amplifier pumps. The principles of operation of these four types are different and will be described briefly. 

Several commercial pumps are equipped with special feedback systems to control closely the constancy of the flow-rate and/or of the pressure. Basically, these pumps operate on the same principle as one of the above four types of pump (usually they are reciprocating pumps), but because of their sophistication and because the principles of feedback control are complex but similar for all pumps, the feedback systems will be considered in a separate section. 

Physical Methods. Although there are many methods (eg reciprocating pump, ball mill) to physically disrupt microbial cells, there have been few processes which are based on these principles proposed for the large-scale recovery of PHAs. A process in which a biomass suspension was heated to 220° C... 

The laser used to generate the pump and probe pulses must have appropriate characteristics in both the time and the frequency domains as well as suitable pulse power and repetition rates. The time and frequency domains are related through the Fourier transform relationship that hmits the shortness of the laser pulse time duration and the spectral resolution in reciprocal centimeters. The limitation has its basis in the Heisenberg uncertainty principle. The shorter pulse that has better time resolution has a broader band of wavelengths associated with it, and therefore a poorer spectral resolution. For a 1-ps, sech -shaped pulse, the minimum spectral width is 10.5 cm. The pulse width cannot be <10 ps for a spectral resolution of 1 cm . An optimal choice of time duration and spectral bandwidth are 3.2 ps and 3.5 cm. The pump pulse typically is in the UV region. The probe pulse may also be in the UV region if the signal/noise enhancements of resonance Raman... 

In the membrane pump, a disk brings the piston to a reciprocating movement. Special hydraulic oil passes the impulse from the piston onto the membrane. The functioning principle of the membrane pump is presented in Figure 2.24. 

The second governing principle relates to the simultaneous reciprocation of atrioventricular volumes during the cardiac cycle such that the four-chambered heart (i.e., the contents of the pericardial sack) operates as a near-perfect constant-volume pump [4]. That means that while the two ventricles eject and the closed atrioventricular valves move toward the apex, the two atria fill. This is accomplished by keeping the epicardial apical portion of the heart fixed in space within the pericardial sack, while the backs of the two atria are similarly anchored in the mediastinum by the pulmonary veins and cavae. The nearperfect constant-volume physiology by which the epicardial surface has minimal radial displacement in the normal heart provides the mechanism that relates diastolic transmitral flow to simultaneous, mandatory ascent of the mitral annulus. 

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