Filter fixed

Fixed Granttlar-Bed Filters Fixed-bed filters composed of granules have received considerable theoretical and experimental study [Thomas and Yoder, AMA Arch. Ind. Health, 13, 545 (1956) 13, 550 (1956) Knettig and Beeckmans, Can. J. Chem. Eng., 52, 703 (1974) Schmidt et al., J. Air Pollut. Control Assoc., 28, 143 (1978) Tardos et al.,y. Air Pollut. Control Assoc., 28, 354 (1978) and Gutfin-ger and Tardos, Atmos. Environ., 13, 853 (1979)]. The theoretical approach is the same as that used in the treatment of deep-bed fibrous filters. 

Figure 10.4 Representative HPLC chromatograms (a) excipient placebo for the high dose active IR portion of the bilayer tablet (b) excipient placebo for the low-dose active sustained release portion of the bilayer tablet (c) Amicon Ultra-4 filtered fixed combination tablet sample. Annotation 1 = low-dose active ingredient 2 = high-dose active ingredient = pregelatinized starch-related peak = HPMC-related peak = filter-related peaks.

As an example of thin-foil analysis in the SEM, samples of the mineral standard kaolinite (<2 pm fraction, KGa-2, Source Clay Minerals Repository) were dispersed on TEM grids and analyzed using a JEOL JSM 6400 SEM under the control of an automated Noran Voyager EDS system equipped with a thin-window EDS detector.93 For comparison, EDS spectra were also collected using the same instrument for the kaolinite size fractions deposited on polycarbonate filters, fixed to SEM... 

The DNA is first transferred from the gel to a membrane by capillary action. Fluid wicks from the gel through the blotting membrane to several layers of absorbent paper, but the nucleic acids stick to the membrane. Baking the filter fixes the DNA or RNA to the filter. 

The technique of the filtration of hot solutions has already been described in Section 11,28. The filtration of cold solutions will now be considered this operation is usually carried out when it is desired to separate a crystalline solid from the mother liquor in which it is suspended. When substantial quantities of a solid are to be handled, a Buchner funnel of convenient size is employed. The ordinary Buchner fimnel (Fig. 11,1, 7, a) consists of a cylindrical porcelain funnel carrying a fixed, flat, perforated porcelain plate. It is fitted by means of a rubber stopper or a good cork into the neck of a thick-walled filtering flask (also termed filter flask, Buchner flask or suction flask) (Fig. 11,1, 7, c), which is connected by means of thick-walled rubber tubing (rubber pressure tubing) to a similar flask or safety bottle, and the latter is attached by rubber pressure tubing to a filter pump the safety bottle or trap is essential since a sudden fall in water pressure may result in the water sucking back. The use of suction renders rapid filtration possihle... 

Dissolve 180 g. of commercial ammonium carbonate in 150 ml. of warm water (40-50°) in a 700 ml. flask. Cool to room temperature and add 200 ml. of concentrated ammonia solution (sp. gr. 0 88). Introduce slowly, with swirling of the contents of the flask, a solution of 50 g. of chloroacetic acid (Section 111,125) in 50 ml. of water [CAUTION do not allow chloroacetic acid to come into contact with the skin as unpleasant burns will result]. Close the flask with a solid rubber stopper and fix a thin copper wire to hold the stopper in place do not moisten the portion of the stopper in contact with the glass as this lubrication will cause the stopper to slide out of the flask. Allow the flask to stand for 24-48 hours at room temperature. Transfer the mixture to a distilling flask and distil in a closed apparatus until the volume is reduced to 100-110 ml. A convenient arrangement is to insert a drawn-out capillary tube into the flask, attach a Liebig s condenser, the lower end of which fits into a filter flask (compare Fig.//, 1) and connect the... 

Wien analyzer. A velocity filter with crossed homogeneous electric and magnetic fields for transmitting only ions of a fixed velocity. 

If the Polaroid filters are held fixed and the sample rotated between them, the Maltese cross remains fixed because of the symmetry of the spherulite. 

Figure 9.22 illustrates how a CARS experiment might be carried out. In order to vary (vj — V2) in Equation (9.18) one laser wavenumber, Vj, is fixed and V2 is varied. Here, Vj is frequency-doubled Nd YAG laser radiation at 532 nm, and the V2 radiation is that of a dye laser which is pumped by the same Nd YAG laser. The two laser beams are focused with a lens L into the sample cell C making a small angle 2a with each other. The collimated CARS radiation emerges at an angle 3 a to the optic axis, is spatially filtered from Vj and V2... 

Recovery of Ammonia. The filter Hquor contains unreacted sodium chloride and substantially all the ammonia with which the brine was originally saturated. The ammonia may be fixed or free. Fixed ammonia (ammonium chloride [12125-02-97]) corresponds stoichiometrically to the precipitated sodium bicarbonate. Free ammonia includes salts such as ammonium hydroxide, bicarbonate, and carbonate, and the several possible carbon—ammonia compounds that decompose at moderate temperatures. A sulfide solution may be added to the filter Hquor for corrosion protection. The sulfide is distilled for eventual absorption by the brine in the absorber. As the filter Hquor enters the distiller, it is preheated by indirect contact with departing gases. The warmed Hquor enters the main coke, tile, or bubble cap-fiUed sections of the distiller where heat decomposes the free ammonium compounds and steam strips the ammonia and carbon dioxide from the solution. 

Optimization of Cycle Times. In batch filters, one of the important decisions is how much time is allocated to the different operations such as filtration, displacement dewatering, cake washing, and cake discharge, which may involve opening of the pressure vessel. Ah. of this has to happen within a cycle time /. which itself is not fixed, though some of the times involved may be defined, such as the cake discharge time. 

The Sweedand filter, a significant departure from the standard end-opening design, has the cylindrical shell spHt in a horizontal plane into two parts, where the bottom half can be swung open for cake discharge. The upper half is rigidly supported and both the feed and the filtrate piping are fixed to it. 

The product stream contains gases and soflds. The soflds are removed by using either cyclones, filters, or both in combination. Cyclones are devices used to separate soflds from fluids using vortex flow. The product gas stream must be cooled before being sent to the collection and refining system. The ALMA process uses cyclones as a primary separation technique with filters employed as a final separation step after the off-gas has been cooled and before it is sent to the collection and refining system (148). As in the fixed-bed process, the reactor off-gas must be incinerated to destroy unreacted butane and by-products before being vented to the atmosphere. 

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