Transfer pumps dual pumping system

The extrudable adhesives are supplied in the larger sized containers, 22-5 or 200 litres, which have been filled under controlled conditions to avoid the occlusion of air. The adhesive is distributed to the work locations from a centrally sited pump-house through a manifolded pipe network at moderate pressure. Care must be taken in the design of the pipework to ensure that there are no features which may lead to eventual partial or full blockages. A dual pumping system is normally used the adhesive is transferred from one container at a time and as the end is approached the system will automatically switch over to the other thereby providing a constant material supply. 

The Croy E series direct-drive dual extraction pump can be adjusted to pump from 5 to 60 gal/min during fluid transfer, and 500 actual cubic feet per minute during ground water/vapor extraction. The unit can be purchased for 20,000 and rents for 2000 per month. All units can be trailer mounted for mobility. Trailer costs are dependent on system size, number of axles required for transport, and other factors (D17804V, p. 17). 

Portable batch plants have also been built to melt and blend composites on-site. These are useful for larger applications where multiple batches of composite are required. One such unit, built and maintained in Canada, consists of two steam-heated vessels mounted on a common skid. They can be used to convert sulfur into composites or to melt preblended composite delivered to the site in solid form. The vessels have capacities of 1500 and 800 gal. The pump and manifold system has a dual function to transfer sulfur and composite to and from the vessels or to spray-apply composite directly from the tanks via heated hoses. 

In all cases, the pressure used should be the lowest which will do the work. This saves first cost, power and time. In many instances a part of an operation can be performed at low pressure, the finish only requiring high pressure. This dual system may be provided by a complete duplication of pumps, accumulators and piping, with manual or automatic transfer valves, or intensifiers may be used at points of fluid consumption. These are pumps using the low-pressure fluid as the actuating medium in what corresponds to the steam cylinder, to produce a local excess pressure. 

The sequence in the treatment of a core with a polymer gel system is similar to that just described and typically involves three steps. First, the initial permeability of the core sample is measured with brine. Then the core is treated with a polymer/crosslinker solution at a constant rate using a dual piston HPLC pump and a transfer cell (see Figure 5) while monitoring pressure with a differential pressure transducer. The core effluent is fractionated for analysis. This includes the determination of polymer and crosslinker concentration, the measurement of sample gelation tendencies, and the investigation of rock/polymer interactions. Finally, after a waiting period to allow gelation, the final permeability of the core is measured with brine to evaluate the effectiveness of the treatment. 

Important parts of well-designed tanks include proper dual pressure relief valves, a vapor absorption system, liquid level and pressure gauges, liquid and vapor transfer valves, and an adequate electrical ground. Pipes, fittings, pumps, gauges, and other equipment should be of steel, iron, or other material not subject to corrosion by the methylamines. Storage and... 

There are a number of types of polymer make-up system. The one represented in Figure 8.1 is the usual dual tank batch make-up system for solid-grade polymers. It basically comprises a powder hopper with a screw feeder, discharging into a stirred vessel. The volume of water is controlled by level probes in this vessel. The contents are stirred for a fixed time, to allow the polymer to dissolve and age to its full potency. After the required ageing time, it is automatically transferred to the polymer supply vessel when actuated by a low-level signal from this second tank. The polymer pump is controlled from the decanter control system. 

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