Process centrifugal operation

Froth from the hot-water process may be mixed with a hydrocarbon diluent, eg, coker naphtha, and centrifuged. The Suncor process employs a two-stage centrifuging operation, and each stage consists of multiple centrifuges of conventional design installed in parallel. The bitumen product contains 1—2 wt % mineral (dry bitumen basis) and 5—15 wt % water (wet diluted basis). Syncmde also utilizes a centrifuge system with naphtha diluent. 

It should be noted that the separation factor for the centrifuge process is a function of the difference in the mol wts of the components being separated rather than, as is the case in gaseous diffusion, a function of their ratio. The gas centrifuge process would therefore be expected to be relatively more suitable for the separation of heavy molecules. As an example of the equiUbrium separation factor of a gas centrifuge, consider the Zippe centrifuge, operating at 60°C with a peripheral velocity of 350 m/s. From equation 68, OC is calculated to be 1.0686 for uranium isotopes in the form of UF. ... 

Cascade Design. The efficiency of a Zippe-type centrifuge, separating uranium isotopes when UF is the process gas, operating at a peripheral speed of 350 m/s and at a temperature of 320 K A = 2.85), would be expected to be... 

Landis, D.M. Process Control of Centrifuge Operations, Chemical Engineering Progress, Jan. 1970, P-51. 

Many process machines operate at speeds different from the one of their drivers. Typical of cases where the machine rotates slower than the driver are reciprocating compressors typical examples of machines rotating 5f than the drivers are centrifugal compressors driven by electric motors. In either case, gears are used to match the two speeds. Gears can also be designed to accommodate shafts that... 

To reliably perform qualitative and quantitative analyses on body fluids and tissue, the clinical laboratorian must understand the basic principles and procedures that affect the analytical process and operation of the clinical laboratory. These include the knowledge of (1) the concept of solute and solvent, (2) units of measurement, (3) chemicals and reference materials, (4) basic techniques, such as volumetric sampling and dispensing, centrifugation, measurement of radioactivity, gravimetry, thermometry, buffer solution, and processing of solutions, and (5) safety. ... 

The yeast produced by continuous culture techniques is separated from the liquid medium and solvent washed by centrifugation or filtration techniques. After drying, a protein supplement is obtained, which contains 65-68% protein and is suitable for addition to animal feeds. This protein content compares very favorably with that of dry fish meal, which contains about 65%, and dry skim milk powder with about 32%. The SCP processes have operated on the thousands of tonne/year scale in the U.K., France, and Italy, but regulatory problems with facilities operating on unpurified gas oil feedstocks have caused some shutdowns [64]. Nevertheless, because of a cell mass doubling time of 2.5-3 hr and the efficient carbon conversion to protein of this technology, these developments deserve to be explored further. 

The majority of CFF processes are operated in a closed configuration which minimizes vapor emissions. Some traditional techniques such as centrifugal processes may generate aerosol foaming in the air (e.g., pathogens) which is highly undesirable. 

With these data summarized, one can now discuss the application with vendors or consultants with expertise in centrifuge operations to help simplify the selection process. Pilot plant testing can be done with 10-25 gallons at the vendor s facility or with a rental unit for an in-plant trial. If sufficient material is available, semiworks tests are recommended as more data can be taken for scaleup. Equipment manufacturers should be questioned about how they are scaling up, whether it is based upon volume, filtercloth area, etc., and what accuracy can be expected. Critical to a trial s success is how representative... 

PP is produced by a variety of processes, most of them by a diluent phase propylene polymerization utihzing a Ziegler-Natta-activated titanium trichloride catalyst in the presence of low- to high-boiling hydrocarbons. Residual catalyst removal followed by hydrocarbon slurry centrifugation is the immediate upstream operation prior to thermal drying. Hexane is the solvent used in the major PP processes in operation today. As a result these polymers are solvent wet. 

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. 

---