Industrial piston-type

After all the previous statements, it would seem very difficult to select a piston. speed. For someone without direct experience, the following guidelines can be used as a starting point. Actual gas compressing experience should be solicited when a new compressor for the same gas is being eonsidered. These values will apply to the industrial process type of compressor with a double-acting cylinder construction. For horizontal compressors with lubricated cylinders, use 700 feet per minute (fpm) and for nonlubricated cylinders use 600 fpin. For vertical compressors with lubricated cylinders, use 800 fpm and for nonlubricated cylinders use 700 fpm. 

Although die compaction is used most widely in applications (such as tableting in the pharmaceutical industry) requiring strict specifications for the agglomerate, there are a few applications in which piston-type machines are used simply to compress particulates into a larger size suitable for further processing without regard to fine detail. 

Scorim Process or SP (Cinpres-Scorim), Rheomolding Process or RP (Thermold s), and the Press Alpha Process or PAP (Sumitomo Heavy Industries and Sankyo Chemical Engineering of Japan) processes are examples of this method. The SP multi-live feed molding process where two packing pistons oscillate 180° out of phase and eliminate weld lines, etc. The RP system provides 3-D orientation based on the concept of melt rheology as a function of vibration frequency and amplitude as well as temperature and pressure. The equipment utilizes piston/type melt accumulators set up adjacent to the melt stream of the plasticator. Piston oscillates back and forth. The PAP system uses compression pins that are... 

The hydrostatic pressurization equipment (Pmax 6000 atm, Mitsubishi Heavy Industries, Ltd., Type 471-046, Hiroshima, Japan) used in the present study consisted of a pressure container and a pressure cell, with approximately 120 mL capacity. The pressure cell was maintained at a constant temperature with a thermo-controlled water bath (Hakke GH, Germany). Pressure was applied by operating a piston with an oil hydraulic motor, that is used in the high pressure equipment. The time required to build up pressures of up to 4000 and 6000 atm was about 30 and 40 sec, respectively. The time required to return to atmospheric pressure was about 5 sec. 

The most widely used pumps in the oil and gas industry are reciprocating displacement pumps (in particular piston plunger type), the rotary displacement pump, and the centrifugal dynamic pump. Only these pumps will be discussed in detail. 

There are four (4) major es of pumps (1) positive displacement, (2) dynamic (kinetic), (3) lift, and (4) electromagnetic. Piston pumps are positive displacement pumps. The most common centrifugal pumps are of dynamic type ancient bucket-type pumps are lift pumps and electromagnetic pumps use electromagnetic force and are common in modern reactors. Canned pumps are also becoming popular in the petrochemical industry because of the drive to minimize fugitive emissions. Figure 10-24 shows pump classification ... 

As the piston is in direct contact with the mobile phase, it must be made from some type of material that is resistant to chemical attack (see above). For most purposes, pistons made from industrial grade ruby or sapphire are used. 

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