Centrifuges laboratory test

The incoming water should be pure deionized water. It could contain condensate from the various heat exchangers, or it could come from the water baths following the extruders. Still another source might be the wash water from the centrifuge. In this case the effect of recycled material upon the reaction would need to be determined. Since this would involve laboratory testing, the use of wash water will not be considered at this time. 

Laboratory wares, blood and centrifuge tubes, test tubes, beakers and pipette tips. .. 

Laboratory test tube centrifuges can determine if there is a sufficient density difference between the two phases to consider sedimentation as an alternative. If there is a sharp separation, one can anticipate the same in the field. One can also answer the following questions. Do the solids settle or float Is the solid phase granular or amorphous What is the moisture content The characteristics of the solids indicate the solids discharge design required, i.e., scroll in decanters, or in disk centrifuges, flow-through nozzles or wall valves. 

Cool the test tube by dipping it into cold water. Then centrifuge (Laboratory Methods J) the mixture. If the sample is still suspended, centrifuge again. If this still does not work, you may find it helpful to heat the sample in the water bath for a few minutes, thereby promoting formation of larger crystals of solid, which tend to centrifuge more easily. 

The MACT Model point values shown for vapor-suppressed resins applied manually, mechanically or by filament winding/centrifugal casting, are applicable for unfilled resin systems only. For filled resin systems, the non vapor-suppressed point values should be used whether or not the resin contains a vapor-suppressant. Point values shown for vapor-suppressed resins assume a 35% reduction in emissions when such resins are used in an unfilled resin system. Point values for a vapor-suppressed resin used to comply with a MACT standard would be obtained from an equation that uses results of a laboratory test conducted on that resin system. 

The centrifuge operates because two basic processes occur within its bowl. One is clarification, or die setding of solids from die mother liquid. The second is the successful movement of these solids out of die bowl. If either process is not performed successfully, (he centrifuge will not work. It is necessary (hen to measure in the laboratory test how a sludge will clarify as well as to estimate how well a sludge will be moved out of the bowl. 

The value of Z is really the area in m of a gravitational settler that will have the same sedimentation characteristics as the centrifuge for the same feed rate. To scale up from a laboratory test of q, andZj tOfjj (foru, = 0,2),... 

In actual practice, powdered activated carbon is added to the wine or the must in amounts equal to about 0.05 to 1 g. of activated to each liter of wine, but to avoid loss of quality, the smallest effective dose should be used. The dose can be determined by laboratory tests on the wine. A suspension of carbon in a small amount of wine is first prepared and then added to the rest of the wine (must) contained in a vat. The adsorptive purification can be enhanced by stirring the contents of the vat or by bubbfing air fed at the bottom of the vat. This process takes several hours, after which the spent-up activated carbon can be separated by sedimentation followed by filtration in a filter press or in a centrifuge. 

When Equation 10.120 holds, the cut size and the overall separation efficiency, in both cases, should be the same. Equation 10.120 can be used for sizing centrifuges from laboratory tests, or for predicting capacities of existing machines. 

Whereas an expert would be able to design and calculate the performance of most pieces of equipment from laboratory tests a word of warning should be sounded about centrifugally operated systems, which include hydrocyclones. In our experience these pieces of equipment are best tested on a pilot scale rather than on a laboratory scale. 

When a sample of sludge arrives in the laboratory for flocculant assessment, there are a number of common tests which are conducted. Its settling rate under gravity is observed and its pH is measured. A small sample, about 50 ml, is spun in a laboratory test-tube centrifuge for a fixed time, say 5 to 10 minutes. The g-level at the tip of the centrifuge will be of the order of 1500 to 2000 g. The volume of sediment will be recorded. 

The performance of laboratory tests by machines which are capable of carrying out some or all of the procedures which would otherwise have to be carried out manually. Such procedures include pipetting, centrifugation, measurement of optical density (or some other parameter) and calculations. 

The scale-up of filtration centrifuges is usually done on an area basis, based on small-scale tests. Buchner funnel-type tests are not of much value here because the driving force for filtration is not only due to the static head but also due to the centrifugal forces on the Hquid in the cake. A test procedure has been described with a specially designed filter beaker to measure the intrinsic permeabiHty of the cake (7). The best test is, of course, with a small-scale model, using the actual suspension. Many manufacturers offer small laboratory models for such tests. The scale-up is most reHable if the basket diameter does not increase by a factor of more than 2.5 from the small scale. 

A centrifuge on a crystallization process plant is to be scaled down for tests. If the plant centrifuge is 1.0 m diameter and rotates at 25 Hz at what speed should a 100 mm laboratory centrifuge run if it is to duplicate plant conditions ... 

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