Pump, centrifugal circulation

Of the various extraction processes the decaffeination with supercritical CO2 exhibits the most commercial advantages for bulk production. The process is a discontinuous one. Fig. 1.4-3 shows a number of serially arranged extractors (5) charged with the supercritical CO2 feed by the centrifugal circulation pump (1). 

Primary Circuit (PC) X Reactor vessel, 4 steam generators, 4 centrifugal circulating pumps... 

The dilution loop consists of a centrifugal circulation pump with impervious graphite housing and impervious graphite heat exchangers. All pipework should preferably be of mild steel lined with polytetrafluoreAylene (PTFE) because of the corrosivity of the acid mixture, containing 80% sulphuric acid. 

Figure 9.36 In-line centrifugal circulation pump (GRASSEL).

The circulation pump should be a centrifugal type with a plastic or PVC impellor, or cast iron with adequate corrosion inhibitor. The acid tank, hoses, and other equipment should be connected to and from the boiler using suitable connection points. This usually is the bottom BD connection (with the valve removed) and the open manhole as the top point. 

In the saturator process (see Figure 12.7), neutralization and crystallization are carried out in the same vessel. The sulfuric acid is delivered to the suction side and the ammonia to the pressure side of the forced circulation pump. Crystallization of the metastable solution gives particle sizes generally between 0.5 and 3 mm. The salt is continuously discharged at the lower end of the saturator. The salt is separated in centrifuges, dried, and cooled. The mother liquor is returned to the saturator. Impurities in the sulfuric acid can adversely affect crystallization. Small quantities of phosphoric acid, urea, or inorganic salts are added to promote crystal growth295. 

It is required to estimate the amine-circulating-pump size in the separation process shown in Figure 5.4.1. The pump, which is a centrifugal pump, will be delivered six months after placing an order. In order to put the process on stream as soon as possible, a process engineer must place the order within three daj. ... 

Crystallisation theory is covered in Volume 2, Chapter 15, and in several other texts Mullin (1992), Van Hook (1961), Nyvlt (1971) and Janie and Grootscholten (1984). Descriptions and illustrations of the many types of commercial crystalliser used can be found in these texts and in various handbooks Perry and Green (1984), Schweitzer (1988). Procedures for the scale-up and design of crystallisers are given by Mersham (1984), (1988), (1995). Bamford (1965) includes details of the ancillary equipment required vacuum pumps, circulation pumps, valves, filters, centrifuges and dryers. 

In this method the fabric after padding with scouring solution is wound on to a perforated roller. The loaded fabric is then rotated in a treatment chamber provided with a liquid reception vat and a circulation pump. The liquor is circulated from inside to outside of the loaded beam by a centrifugal pump. The main advantage of this type of machine is that the scouring, bleaching and washing operations can be carried out on the same fabric roll. 

Feed solution enters the downpipe before the suction of the circulating pump. Mother liquor and crystals are drawn off through a discharge pipe upstream from the feed inlet in the downpipe. Mother liquor is separated from the crystals in a continuous centrifuge the crystals are taken off as a product or for further processing, and the mother liquor is recycled to the downpipe. Some of the mother liquor is bled from the system by a pump to prevent accumulation of impurities. 

An appliance that finds many uses in the laboratory is the Jena Circulation Pump 100 (Fig. 398), a centrifugal pump of the simplest type constructed entirely of glass. Its lift and capacity as a function of the number of revolutions per minute of the... 

The main circulation pump (pump) is intended for providing the sodium circulation in primary circuit. The pump is centrifugal, vertical arrangement, single-stage, console, sealed, electrically driven type. Motor — asynchronous, double-speed, vertical arrangement with squirrel-cage rotor. 

A Kryslai type of vacuum evaporator-crystallizer B Forced-circulation pump C Slurry-redrculation pump D Mother-liquor recycle pump E Mother-liquor tank F Continuous or batch centrifuge G Slurry concentrator H Drier conveyor I Rotary drier J Dried-product conveyor K Vacuum condenser-ejector unit... 

G. Materials of Construction. Evaporator materials of construction and their costs play a large role in determining the optimum compression ratio. Monel is a standard material of construction for brine evaporator bodies. Stabilized titanium (e.g.. Grade 12) is a frequent choice for heater tubing and Type 316 stainless steel for the circulating pumps. The evaporator normally will be of the forced-circulation type described in Section 9.3.3.2. It will either contain a number of effects or operate with vapor recompression. Salt-recovery centrifuges may be Monel or stainless steel. 

The main circulating pump is a canned, centrifugal, single-stage, vertical pump with a shielded, double-speed (double-winding) asynchronous electric motor. 

Alternatives to the present centrifugal mechanical pumps, such as natural circulation without pumps, or application of the lift-up pumps providing the introduction of gas bubbles into the coolant to increase the buoyancy force, would be further investigated in the future. The present development, however, makes an emphasis on a simple and feasible reactor concept with the requested functions being performed only with the use of conventional and reliable devices. 

Chemical pumps Built to handle abrasive and corrosive industrial materials. They can be of either centrifugal or positive displacement type. Circulator pumps Used to circulate fluid through a closed or looped system. They are usually centrifugal pumps, but a few use positive displacement technologies. 

The test loop consists of a circulating pump, pipe loop, and a pressur-izer. The circulating pump is a Westinghouse model lOOA canned-motor centrifugal type [5]. This pump delivers 100 gpm at a 250-ft-head and is constructed for operation at pressures up to 2500 psi. The loop and pressurizer are heated by means of electric elements cast in aluminum around the outside of the piping. 

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