Progressive cavity pump

The progressive cavity pump consists of a rotating cork-screw like sub-surface assembly which is driven by a surface mounted motor. Beam pump rods are used to connect the two. The flowrate achieved is mainly a function of the rotational speed of the subsurface assembly. There Is in principle very little that can go wrong with progressive cavity pumps. Progressive cavity pumps excel in low productivity shallow wells with viscous crude oils and can also handle significant quantities of produced solids. 

Rotary screw pumps (Progressing cavity pump moyno pump) for shear sensitive slurries particle diameter < 5 cm., temperature < 80 °C fluid viscosity, usually above 10 Pa.s head 0.2 to 300 m < 125 L/s self priming minimum foaming pulsation-free flow. Tends to be a constant volume device. 

Metering Pumps. For small flow rates, such as dosing chemical additives where precise control is requited, progressive cavity self-contained pumping units are used. These can often handle shear-sensitive fluids or Hquids containing abrasive particles. These pumps are not as widely pubHci2ed or generally as well known in the Hterature as other pump types. 

An emulsified fatty acid soap (e.g., magnesium or iron tallate, having between 8 and 18% metal content. This type of product is cationic and may exhibit some partial solubility in both oil and water. It can be fed by pump (usually a progressive cavity pump or a screw pump). 

The down-comer from the gas/liquid separator that collects the liquid slurry product is connected to the suction side of a moyno-type (Liberty progressive cavity) pump. The pump discharge is connected to a primary separation device (an inertial separator similar to a hydrocyclone). Since the slurry pump is a positive displacement device (i.e., no slurry slippage inside the pump), the total flow... 

Programming languages, 7 485-491 Progressive cavity pumps, 21 73-74 Progress, management systems to sustain, 10 166... 

Progressing Cavity Pumps, Downhole Pumps, and Mudmotors, Lev Nelik... 

A third type of pump is used largely for pumping at high rates, often with a white liquid color.This is a progressive cavity pump. Like the gear pump, it is very linear and can handle high viscosities. It has a convoluted tubular stator and a convoluted rodlike rotor, which intermesh, moving the liquid forward, much like an extruder screw. 

Figure 20.2, Typical liquid color pumps (a) peristaltic pump (b) detail of peristaltic pump head showing tubing (c) high-volume progressive-cavity pump. 

A similar system was already commercially available for a different application. A progressive cavity pump for feeding was placed in the bottom outlet of the feed reservoir [19]. It was claimed that the feeder delivered slurries of 0.5 to 6% (5-60 g/1) cellulose. This is remarkable because we were never able to suspend more than 30 g/1 of cellulose in a vessel no data were presented to support the claim. 

Finally, the progressive cavity pump uses a rotating member inside a molded cylinder that together form a cavity that moves from input to output as the centre is rotated. This pump can handle very viscous oils and debris, but is heavy and more expensive than other types of pumps. 

Positive displacement pumps. The minimal shear operation of progressing cavity or lobe pumps make them ideal for slurries. The non-pulsating flow is beneficial in most processes, but they are significantly more expensive and less portable than diaphragm pumps. 

Figure 18. Progressive cavity pump system. (Reproduced with permission from reference 25. Copyright 1991 Amoco Canada Petroleum Ltd.)...

The product classification in the elutriation leg is operated under flow rate control without automatic feedback from the product CSD. The rate of slurry discharge is set by the level control loop, responding to the differential pressure generated by the varying slurry-gas interface. A progressive cavity pump is the final control element to achieve the level control while providing minimal degradation of the crystals in the product slurry. 

To control dosing of the PAE resin to the papermaking system, metering pumps and mini magnetic flow or mass flow meters fabricated from 316L stainless steel and fitted with Teflon or Viton-wetted seals are most preferred. Progressive cavity or centrifugal pumps are preferred because they are low shear and impart less heat to the PAE resin. 

High-shear pumps will reduce the molecular weight of starch and thus its efficiency. Progressive cavity positive displacement pumps are recommended. Wet-end starch solutions are generally stored at 4% concentration, being reduced to below 1% concentration at the point of addition for fine paper and below 2% concentration for board and industrial grades. 

Progressing cavity pumps. These are self-priming positive displacement pumps which have a helical metal rotor lying inside a flexible tubular stator. The rotor maintains a continuous seal along the length of the stator and as it turns it forces the fluid through the stator to discharge. 

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