Sharpies centrifuge

In the wet process, the clay is masticated in a pug mill to break up lumps and then dispersed with a dispersing aid and water to make a 40 percent solids slip of low viscosity. A hi -speed agitator such as a Cowles dissolver is used for this purpose. Sands are settled out, and then the clay is classified into two size fractious in either a Hydrosettler or a continuous Sharpies or Bird centrifuge. The fine fraction, with sizes of less than 1 [Lm, is used as a pigment and for paper coating, while the coarser fraction is used as a paper filler. 

Sharpies A continuous soapmaking process using centrifuges, invented in 1939 by A. T. Scott at the Sharpies Corporation, Philadelphia. 

This process uses a solvent mixture composed of ethylene dichloride and benzene and a special type of totally enclosed centrifuge developed by the Sharpies Specialty Co, and Max. B. Miller, Inc. The solvent is heavier than either the wax or oil to be processed, which permits discharge of the wax phase from the center of the centrifuge bowl without the use of a carrier liquid. 

To 50 gallons of juice were added 30 gallons of cold acetone. The precipitate which formed was removed by centifuging in a Sharpies centrifuge. This... 

Stop the growth by cutting off both air and agitation. Use a continuous centrifuge (e.g., Sharpies) to harvest the cells as quickly as possible. 

Centrifuges—For harvesting the 10-liter culture, a continuous-flow centrifuge such as a Sharpies is most convenient. For washing the cells, a refrigerated high-speed laboratory centrifuge (e.g., Sorvall RC-2B) is necessary. 

The Sharpies Centrifuge.—In this machine the bowl revolves from 20,000 to 40,000 r.p.m. and an effect is secured in separating solids, emulsions and matter in the colloidal state which is out of the range of the ordinary centrifugal separator. The formula for centrifugal force as given in the textbooks is F equals Wv /gr, If for v is substituted its equivalent and replacing the radius... 

High-speed centrifuges are of two types (1) the Sharpies type, which employs a long hollow bowl of small diameter and is rotated at a very high speed, and (2) the DeLaval type, employing a short disk bowl of large diameter. Such equipment is used largely for clarification and for separation of immiscible liquids. 

The dextrin is isolated from an enzymolysate of a 5% starch paste incubated for 5 to 7 days with macerans amylase. The enzymolysis is carried out in the presence of a precipitant such as toluene for precipitating the cyclic dextrin and an inhibitor such as thymol for inhibiting bacterial contamination. At the end of the enzymolysis period, the complex of -dextrin and toluene is collected by centrifugation in a Sharpies centrifuge and boiled in water to remove the toluene. The concentration of solids is adjusted to 20%. The -dextrin solution is heated to dissolve the dextrin, filtered to remove insoluble material and allowed to cool to room temperature. Large crystals of -dextrin are formed and these are collected on a filter and air dried. 

Figure 14-13. Solid bowl centrifuge. (Courtesy of Sharpies Corp.)...

Meanwhile, the Sharpies Corporation was patenting basket and tubular bowl centrifuge developments, and the Bird Machine Company had not yet been formed. So the relatively sudden appearance on the market of conical bowl decanters by both companies in 1945/1946. is, in retrospect, quite surprising. The Sharpies P-1000 decanter had quite a rapid impact on the whale and fish oil market, so much so that AB Separator (not yet called Alfa Laval) was forced to copy the Sharpies machine, or lose a good market in the Norwegian fishing industry. 

Specialist centrifuge manufacturer. The Sharpies Corporation, now part of Alfa Laval, was one of the world s first two major manufacturers of decanters... 

Ken Sutherland, for a time Technical Manager for Sharpies, has later been heavily involved with the marketing aspects of separation equipment, including centrifuges. 

The capacity of the Sharpies machine is from 25 to 55 bbl per day based on cylinder stock, each machine handling from 70 to 240 bbl of solution depending on the pour point desired, the properties of the stock, and the amount of dilution. The centrifuge operates at from 15,000 to 17,000 rpm and requires approximately 1 kw of power. The refrigeration requirement per machine per day is 5 to 10 tons. 

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