Centrifugation standards

Standard Test Method for Determination of the Pigment Content of Solvent-Reducible Paints by High-Speed Centrifuging Standard Guide for Determining Volatile and Nonvolatile Content of Paint and Related Coatings... 

The water and sediment contents of crude oils is measured according to the standard methods NF M 07-020, ASTM D 96 and D 1796, which determine the volume of water and sediments separated from the crude by centrifuging in the presence of a solvent (toluene) and of a demulsifylng agent Table 8.13 gives the bottom sediment and water content of a few crude oils. 

Anotlier standard metliod is to use a (high-speed) centrifuge to sediment tire colloids, replace tire supernatant and redisperse tire particles. Provided tire particles are well stabilized in tire solvent, tliis allows for a rigorous purification. Larger objects, such as particle aggregates, can be fractionated off because tliey settle first. A tliird metliod is (ultra)filtration, whereby larger impurities can be retained, particularly using membrane filters witli accurately defined pore sizes. 

Example 3. A centrifugal pump moving a corrosive Hquid is known to have a time-to-failure that is well approximated by a normal distribution with a mean of 1400 h and a standard deviation of 120 h. A particular pump has been in operation for 1080 h. In order to plan maintenance activities the chances of the pump surviving the next 48 h must be deterrnined. 

The processing operations for fluid or manufactured milk products include cooling, centrifugal sediment removal and cream (a mixture of fat and milk semm) separation, standardization, homogenization, pasteurization or sterilization, and packaging, handling, and storing. 

Fat Content of Milk. Raw milk as well as many dairy products are routinely analyzed for their fat content. The Babcock test, or one of its modifications, has been a standard direct measure for many years and is being replaced by indirect means, particularly for production operations. The Babcock test employs a bottle with an extended and caHbrated neck, milk plus sulfuric acid [7664-93-9] to digest the protein, and a centrifuge to concentrate the fat into the caHbrated neck. The percentage of fat in the milk is read direcflv from the neck of the bottle with a divider or caHper, rea ding to... 

The pump-mounting feet are located close to the centerline. As a result, the pump thermal growth is uniform on both sides of the centerline, leading to minimal distortions. The design is governed by the American Petroleum Institute (API) standard 610, "Centrifugal Pumps for General Refinery Service" (30). 

The electric motors are often the noisiest component of the centrifuge assembly. Most standard motors in the 75—250 kW range develop noise levels of 85 dbA (weighted sound pressure level using filter A, per the ANSI standard). A quiet motor can reduce this level by 5 dbA and should be used whenever noise is of concern. 

Drying and Solids Separation. Separation of the polymer gel from the meth an o1 /methyl acetate Hquid is an important step, accompHshed by using standard pieces of equipment such as filters, screw presses, or centrifuges. 

Etibank is the sole producer of boron minerals and derivatives in Turkey, which is second in production only to the United States. The open-pit Kirka mine in the Eskisehir Province is the only source of Turkish sodium borate ore. A tincal concentrate is produced from ore that has been blasted and carried in tmcks to the concentration plant. The ore is screened and cmshed to reduce it to —100 mm and then hammer milled to —25 mm. The stockpiled material is further milled and screened to 6 mm. A fraction of +1 mm (+18 mesh, U.S. Standard) is washed and classified to remove fine clay. Clay is removed from the —1 mm faction bypassing it through cyclones and then through a classifier. This material is centrifuged and combined with the washed + 1 mm faction to produce a final product which is a —6 mm concentrate having 6—8 wt % moisture and 32% 2 3 1987 production was... 

Property Belt-filter Standard press Vacuum-a ssisted Filter Plates press Cloth Rotary vacuum filter Centrifuge... 

American Petroleum Institute (API) Standard 610, Centrifugal Pumps for Refinery Service... 

Fan Performance The performance of a centrifugal fan varies with changes in conditions such as temperature, speed, and density of the gas being handled. It is important to keep this in mind in using the catalog data of various fan manufacturers, since such data are usually based on stated standard conditions. Corrections must be made for variations from these standards. The usual variations are as follows ... 

A more economical alternative is found in a submersible pump where the pump, directly coupled with the prime mover, is slid into the tubewell through narrow pipes. Narrow pipes are easy to sink into rocky terrain or very deep water levels. They are less expensive and are easy to install due to the elimination of the need for a pump house. Once the unit is slid into the well it requires little maintenance. (See Figures 7.5-7.7.) Such pumps have a standard centrifugal multistage arrangement, and the motors are required to work under water or any other liquid. These motors have an exclusive application for submersible pumps. 

The majority of centrifugal pumps have performance curves with the aforementioned profiles. Of course, special design pumps have curves with variations. Eor example, positive displacement pumps, multi-stage pumps, regenerative turbine type pumps, and pumps with a high specific speed (Ns) fall outside the norm. But you ll find that the standard pump curve profiles are applicable to about 95% of all pumps in the majority of industrial plants. The important thing is to become familiar with pump curves and know how to interpret the information. 

This system requires a pump with a best effieieney point (BFP) of 94 feet at 300 gallons per minute. If this is a eonventional industrial centrifugal pump with a BFiP of 94 feet, the shut-off head should be approximately 110 feet. And if the motor is a standard NFMA four pole motor spinning at about 1800 rpm, the diameter of the impeller should be approximately 10.5 inehes. If this pump were bought off the shelf from local distributor stock, it would probably be a 3 x 4 x 12 model end-suction centrifugal back pullout pump with the impeller machined to about 10.5 inches before installing the pump into the. system. And that s the way it is done. 

P Standard 617, Centrifugal Compressors for General Refinery Ser m et, Sixth Edition, 1995, Wa.shington, DC American Petroleum Iii.sii tijte, 1979. 

The API mechanical standards for the rotary and centrifugal compressor have a test specified for proof of rotor insensitivity. This would normally be the test invoked at this point to ultimately prove the rotor. The fifth edition of API 617 expanded on this test and changed the acceptance criteria from those based on amplification factor to an acceptance level based on internal seal clearances. 

API Standard 617, Centrifugal Compressors for General Refinery Services, Fourth Edition, Washington, D.C. American Petroleum Institute, 1979,... 

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