Pad filters

Sediment. Sediment is most commonly used as an operational check of filter efficiency and leakage, although some customers, especially those who iatend to melt the sugar iato clear solutions, write sediment restrictions. The measurement is normally done by passiag the 50% solution used for the color determination through a half black—half white filter pad and visually counting the white and black specks. 

The foregoing procedure is commonly employed in reverse to determine or confirm fiber target efficiencies from the experimentally determined efficiencies of fibrous filter pads. 

Air-Filter Types Air filters may be broadly divided into two classes (1) panel, or unit, filters and (2) automatic, or continuous, filters. Panel filters are constructed in units of convenient size (commonly 20- by 20-in or 24- by 24-in face area) to facilitate installation, maintenance, and cleaning. Each unit consists of a cleanable or replaceable cell or filter pad in a substantial frame that may be bolted to the frames of similar units to form an airtight partition between the source of the dusty air and the destination of the cleaned air. 

Panel filters may use either viscous or dry filter media. Viscous filters are so called because the filter medium is coated with a tacky liquid of high viscosity (e.g., mineral oil and adhesives) to retain the dust. The filter pad consists of an assembly of coarse fibers (now usually metal, glass, or plastic). Because the fibers are coarse and the media are highlv porous, resistance to air flow is low and high filtration velocities can be used. 

Norite, is heated to boiling by introduction of steam, filtered through a Norite filter pad by suction, and cooled in an ice-salt bath. The muconic acid is precipitated by the addition of a large excess (1500 ml.) (sp. gr. 1.18) of concentrated hydrochloric acid to the cold solution. The acid is added in a thin stream to the well-stirred solution. After 2 hours the muconic acid is filtered, washed first with two 400-ml. portions of cold water and then with 200 ml. of methyl alcohol, and dried at 85°. The yield of nearly colorless product melting at 296-298°, with decomposition, amounts to 165-195 g. (37-43%). 

The flasks are then placed on a reciprocating shaker (120 one and one-half inch cycles per minute) and mechanically shaken at 25°C for 3 days. The contents of the flasks are then pooled and, after the pH of the culture is adjusted to about 4 0.2 with sulfuric acid, filtered through Seitz filter pads to separate the mycelium from the fermented medium. 

Chrambach this indicates that the effective protein size for gel filtration is larger than the effective size for gel electrophoresis. They concluded that this could not be accounted for by gel swelling, pH, or ionic strength effects. Biefer and Mason [36] found the constant a in Eq. (93) to be 0.93. They measured the conductance of cellulose acetate filter pads with porosities from 0.5 to 0.9 in solutions of 10 M KCl. 

Plant material. Weigh 25 g of the chopped and frozen sample into a blender jar. To check recoveries, spike the fortification samples with the appropriate volume of metabolite standard at this point. Add 200 mL of acetonitrile-water (4 1, v/v) to the jar, and blend the sample at medium speed for 5 min. Filter the extract through a Buchner funnel fitted with a glass-fiber filter pad into a 500-mL round-bottom flask containing 10 drops of Antifoam B and 3 mL of 10% aqueous Igepal CO-660 (nonionic surfactant). The flask is connected to the Buchner funnel by means of an adapter suitable for applying vacuum to the system. 

During operation, samples of all flows were taken for suspended solids analysis. These tests were performed by a qualified local analytical laboratory. Procedures for this analysis were as outlined in standard methods.47 Glass fiber filter pads with a particle size retention of 1.2 pm were used. 

Remove the insoluble dicyclohexyl urea (DCU) by-product by filtration using a glass fiber filter pad and vacuum. 

The NHS-palmitate may be purified by recrystallization using ethanol. Dissolve the activated fatty acid in a minimum quantity of hot ethanol. Immediately upon dissolving, filter it through a filter funnel containing a fluted glass fiber filter pad, both of which have... 

Filter the solution through a glass-fiber filter pad and slowly add, with stirring, 600 ml of petroleum ether (bp 35-60°C). 

If N-succinimidyl chloroformate was used, filter out the white precipitate of 4-(dimethylamino) pyridine hydrochloride using a glass fiber filter pad. Collect the supernatant. 

The filter pad was prepared by compressing Celite (4 cm) onto a layer of sand (1.5 cm) in a fritted glass funnel (10-cm diameter). 

Also used in wire or cable coatings impregnants in cotton and asbestos braided insulation coating on glass air filter pads, metal mesh to filter air and gas streams (Monsanto, 1960). 

ASTM units, the fuel is considered to be unstable. After the fuel color has been measured, the test fuel is filtered through a standardized filter medium such as Whatman or Millipore filter pad. The filter pad is preweighed so that the total weight of insoluble compounds can be collected and measured. 

A 50-mL sample of distillate fuel is immersed in a 300°F (149°C) oil bath for 90 minutes. After removalfrom the bath and cooling to room temperature, the color of the fuel is measured and compared to the initial color. The fuel is then vacuum filtered through two 1 Whatman filter pads and rinsed with heptane. The color of the pad is compared to a standard color chart and rated. The color of the pad may also be measured by a light reflectance meter. 

Add approx 5g of the prepd sample into a previously tared clean, dry, medium porosity crucible, contg a filter pad. Reweigh crucible and contents on an analytical balance and record die total wt to the nearest 0.0002g. 

Filter the syrup through T1500 filter pads (8 to 10) washed with purified water. Collect the syrup in clean stainless steel tank. Avoid any loss of syrup quantity. 

Filter through 100-micron filter and then through filter pads. 

Quality control audit of incoming process materials such as filter powder, organic acids, cleaning agents, filter pads, fining agents, etc. 

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