Static filling operations

Dump fill, instantaneous addition of waster water into the reactor is rarely used in the field but is implemented practically by including a static fill in the operating strategy. The mathematical representation for the SBR with dump fill is the same as that for the plug reactor at steady state, where the hydraulic residence time in the PFR compares to the time for react in the SBR. 

A static fill, an effusive beam or a supersonic nozzle can be used for the introduction of the gas sample,. The supersonic nozzle has the advantage of refrigeration, and one may study rotationally and vibrationally cold molecules, or even stabilize otherwise inaccessible van der waals molecules. Finally, when operated in a pulsed mode, the nozzle cycle can be matched to the duty cycle of the laser to optimize the measuring conditions and improve the background vacuum. 

A number of accidents have occurred as a result of the discharge of static electricity. The latter can be generated even by the flow of fluids. To provide additional protection against explosion or fire due to the discharge of static electricity, determine what temperature an acetone drum filling operation would have to maintain so that flammable mixtures would not be produced by vapor-air mixtures in equilibriurr with the liquids. The lower flammable limit (LFL) for acetone vapor in air is 2.55 percent by volume. 

Once a uniform blend has been obtained, it is essential that the particles in the blend cease movement to allow the system to exist in a state of static equilibrium without segregation occurring. From a practical point of view, this is not possible as subsequent material transfer during the compression or filling operations involves material How. Therefore, care must be exercised to ensure that the impact each subsequent handling step has on the equilibrium achieved for the blend at the conclusion of the blending operation is minimized. The mechanisms by which powders can segregate, as well as means to control it, will be discussed later in this chapter. 

Both containers must be physically interconnected to eliminate any static electricity which may cause a spark and ignite the flammable liquid vapors. Physically connecting the containers equalizes the difference in the static charge which may be present between the two object. Therefore, a bond wire between containers during flammable liquid filling operations must be provided, unless a metallic path between them is already present. 

Aseptically prepared collection plates are placed in the sampling apparatus. Petri dishes used must be sterilized prior to filling. Verify the adequacy of petri dish dimensions so that the operational characteristics are maintained according to the manufacturers specifications. Plastic petri dishes are not recommended because static changes are likely to be present in plastic that will reduce the collection efficiency. 

Because of its very low friction coefficient, PTFE is used for bearings, ball- and roller-bearing components, and sliding bearing pads in static and dynamic load supports.11 Piston rings of filled PTFE in nonlubricated compressors permit operation at lower power consumption or at increased capacities.12... 

Britton, L.G., and Smith, J. A., Static hazards of drum filling Parts 1 and 2, Plant/Operations Progress, 7, No. 1, January 1988. 

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