Fluid handling

One essential part of downstream processing is the movement of fermenter broths, supernatant fluids and whole cell slurries around the production plant. In the pharmaceutical industry, this has been traditionally achieved by pressure or gravity feed. In general, these methods are slow and unsuitable for large scale and continuous bioprocesses. The use of pumps is now the preferred method for most fluid transfer operations. 

Pumps for use in the biotechnology industry have been reviewed by Matthew Hall. The types thought to be suitable are summarised as follows. 

Sliding vane. Positive displacement pumps in which a multi-bladed impeller rotates inside an eccentric pump cavity. They are self-priming and deliver a non-pulsating flow. 

Rotary positive displacement pumps. These have two or more impellers in the form of toothed gear wheels or lobed cams which rotate with an extremely small clearance between each other and the pump casing. They have to be primed and they produce a pulsed output. 

Peristaltic. These have a flexible tube set in a curved track in the pump head. A rotor carried three rollers which compress the tube against the outside of the track as they rotate. Fluid in the tube is pushed forward by positive displacement. 

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BE-7398 Advanced and preventative diagnostics of fluid handling rotating machinery Dr. F. C. Visser BW/IP International B.V. PUMP DIVISION... 

Teflon PEA 440 HP is a chemically modified form of PEA 340 that provides additional benefits such as enhanced purity and improved thermal stability. This product is suitable for producing tubing, pipe linings for production of ultrapure chemicals, semiconductor components, and fluid handling systems for high performance filters (31). 

For lubricated plug cocks, the lubricant must have limited viscosity change over the range of operating temperature, must have low solubility in the fluid handled, and must be applied regularly. There must be no chemical reaction between the luBricant and the fluid which... 

Tilting-Disk Check Valves These valves (Fig. 10-160) may be installed in a horizontal line or in hnes in which the flow is vertically upward. The pivot point is located so that the distribution of pressure in the fluid handled speeds the closing but arrests slamming. Compared with swing checkvalves of the same size, pressure drop is less at low velocities but greater at high velocities. 

Valve Trim Various alloys are available for valve parts such as seats, disks, and stems which must retain smooth finish For successful operation. The problem in seat materials is fivefold (1) resistance to corrosion by the fluid handled and to oxidation at high temperatures, (2) resistance to erosion by suspended solids in the fluid, (3) prevention of galling (seizure at point of contact) by differences in material or hardness or Both, (4) maintenance of high strength at high temperature, and (5) avoidance of distortion. 

Cement-Lined Steel Cement-hned steel pipe is made by lining steel pipe with special cement. Its use prevents pickup of iron by the fluid handled, corrosion of the metal by brackish water, and growth of tuberculation. Threaded pipe in sizes from to 4 in is stocked however, cement-lined pipe in sizes smaller than in is not considered practical for common use. 

Orifice plates. Either the concentric orifice, eccentric orifice, or segmented orifice-type. Choice depends on the quality of the fluid handled. Venturi tubes. These consist of a well-rounded convergent section at the entrance, a throat of constant diameter, and a divergent section. Their accuracy is high however, installation, unless planned for in advance, is very difficult in the field. 

The polymer, like many fluorine-containing polymers has very good weathering resistance and may also be used continuously up to 150°C. Outside of the electrical field it finds use in fluid handling, in hot water piping systems, in packaging and in chemical plant. A widely used specific application for PVDF is in ultra-pure water systems for the semiconductor industry. 

The fluid handled must be all vapor at the valve inlet. 

Reliability analysis of fluid handling practices, ship to shore, and store to road vehicles and pipelines... 

Reliability of a Solids-Fluid Handling Ore Processing Failure modes and failure rates covering 829 kiln, leaching tank, screwfeeder, and associated ... 

Reliability of a Solids-Fluid Handling Process Plant... 

Figure 3-1B. Sealless canned centrifugal pump, primary and secondary leakage containment. See Table 3-2. (Courtesy Sundstrand Fluid Handling Co.)...

Figure 3-12. Single-stage, high speed (>5000 ft) centrifugal process pump. Pumps are high speed, gear driven, and especially suited for applications in light hydrocarbon liquid service. (Courtesy Sundstrand Fluid Handling, Inc.)...

Figure 12-39C. Single-stage gas compressor with integrally geared drive shaft. (Used by permission Bui. 1.10, Jan 1994. Sunstrand Compressors, Sunstrand Fluid Handling.)...

Figure 12-56. Estimates of process gas seal leakage using nitrogen as sealing gas for single-and tandem-gas seal arrangements. (Used by permission Sundstrand Compressors Bui. 450 April 1995. Sundstrand Fluid Handling Corporation.)...

Sundyne Sunstrand Compressors, Sunstrand Fluid Handling, Bui. 450, April (1995). 

Shaft seal requirements and two common types of seals, packed stuffing boxes and simple mechanical seals, are described and discussed in this section. A packed box typically is used on slow- to moderate-speed machinery where a slight amount of leakage is permissible. A mechanical seal is used on centrifugal pumps or other type of fluid handling equipment where shaft sealing is critical. 

Miniaturized fluid handling devices have recently attracted considerable interest and gained importance in many areas of analytical chemistry and the biological sciences [50], Such microfluidic chips perform a variety of functions, ranging from analysis of biological macromolecules [51, 52] to catalysis of reactions and sensing in the gas phase [53, 54], They commonly consist of channels, valves and reaction... 

Among the most important fluid handling components in an LOC are pumps and valves. There are two main methods by which fluid actuation through microchannels can be achieved pressure driven and electroosmotic flow. In pressure driven flow, the fluid is... 

A-9.1.3 Slip-On Flanges. The need for venting the space between the welds in double-welded, slip-on flanges should be considered for fluid services (including vacuum) that require leak testing of the inner fillet weld, or when fluid handled can diffuse into the enclosed space, resulting in possible failure. 

Extruded tubing, pipes, hoses, fittings, fluid handling, profiles. .. 

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