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Productivity pressure filters

The fundamental case for pressure filters may be made using equation 10 for dry cake production capacity Y (kg/m s) derived from Darcy s law when the filter medium resistance is neglected. Eor the same cycle time (same speed), if the pressure drop is increased by a factor of four, production capacity is doubled. In other words, filtration area can be halved for the same capacity but only if is constant. If increases with pressure drop, and depending how fast it increases, the increased pressure drop may not give much more capacity and may actually cause capacity reductions. [Pg.393]

The pressure versions of the nutsche filter, which falls into this category, are either simple pressurized filter boxes or more sophisticated agitated nutsches, much the same in design as the enclosed agitated vacuum filters described eadier. These are extremely versatile, batch-operated filters, used in many industries, eg, agrochemistry, pharmaceuticals, or dyestuff production. [Pg.402]

Following carbonation, the product can be further purified by screening. This screening, also used to control the maximum size of the product, is followed by dewatering (qv). Rotary vacuum filters, pressure filters, or centrifuges are used in the mechanical removal of water. Final drying is accompHshed as with natural calcium carbonate in either a rotary, spray, or flash dryer. Products having mean particle sizes from submicrometers (- O-OS fiTo) to several micrometers are available. [Pg.411]

The dry methosulfate, dissolved in about 30 ml. of water, is made alkaline with 2-3 ml. of 10% sodium hydroxide, and the solution is then extracted exhaustively with successive 15-ml. portions of chloroform until no more blue substance is remov ed from the aqueous solution (Note 12). The combined chloroform solutions are extracted three times with 20-ml. portions of 5% hydrochloric acid. The combined acid extracts are made alkaline to phenolphthalein with 10% sodium hydroxide and reextracted exhaustively with 25-ml. portions of chloroform until no more blue substance is removed from the aqueous solution (Note 12). The combined chloroform solutions are dried over anhydrous sodium sulfate and decanted, and the chloroform is removed by distillation under reduced pressure. The blue crystalline residue is recrystallized by dissohnng it in the least possible amount of water at 60° and then cooling the solution in an ice bath. The product is filtered on a 5-cm. Buchner funnel and dried in the dark in a v acuum desiccator over calcium chloride. The yield is 1.35 g. (58%) of dark blue needles that melt at 133° (Note 13). [Pg.88]

A. Triphenylcinnamylphosphonium chloride. A mixture of 40 g. (0.26 mole) of (3-chloropropenyl)benzene (Note 1) and 92 g. (0.35 mole) of triphenylphosphine (Note 2) in 500 ml. of xylene is heated at reflux for 12 hours with stirring. The mixture is allowed to cool to about 60°, and the colorless crystalline product is filtered, washed with 100 ml. of xylene, and dried in a vacuum oven at about 20 mm. pressure and 60° to constant weight. The yield is 99-101 g. (91-93%), m.p. 224-226° (Note 3). [Pg.36]

Of this material 1.0 g is dissolved in 150 ml of warm 95% ethyl alcohol. To the solution is added 1.0 g of 5% palladium on carbon catalyst, and the mixture is hydrogenated at room temperature and atmospheric pressure by bubbling hydrogen into it for 3 hours with stirring. The hydrogenation product is filtered. The solid phase, comprising the catalyst and the desired product, is suspended in ethyl acetate and water and adjusted to pH 2 with hydrochloric acid. The suspension is filtered to remove the catalyst. The aqueous phase is separated from the filtrate, and is evaporated under vacuum to recover the desired product, 7-(D-a-aminophenylacetamido)cephalosporanic acid. [Pg.283]

A mixture of 9.6 parts of 4-amino-3-nitrobenzophenone, 160 parts of methanol, 8 parts of concentrated hydrochloric acid and 1 part of palladium-on-charcoal catalyst 10% is hydrogenated at normal pressure and at room temperature. After the calculated amount of hydrogen is taken up, hydrogenation is stopped. The catalyst is filtered off and the solvent is evaporated. The solid residue is triturated in 2-propanol. The latter is partly evaporated and the solid product is filtered off, washed with 2-propanol and dried, yielding 3,4-diaminobenzophenone hydrochloride MP 207 C. [Pg.900]

A solution of 1.7 g of 2-hydroxymethyl-3-benzyloxy-(1-hydroxy-2-tert-butyl-aminoethyl)py-ridine in 30 ml of methanol containing 1.2 ml of water is shaken with 700 mg of 5% palladium-onatmospheric pressure. In 17 minutes the theoretical amount of hydrogen has been consumed and the catalyst is filtered. Concentration of the filtrate under reduced pressure provides 1.4 g of the crude product as an oil. Ethanol (5 ml) Is added to the residual oil followed by 6 ml of 1.75N ethanolic hydrogen chloride solution and, finally, by 5 ml of Isopropyl ether. The precipitated product is filtered and washed with isopropyl ether containing 20% ethanol, 1.35 g, melting point 182 (dec.). [Pg.1252]

The reaction product is filtered and the filtrate is evaporated in vacuo to remove the alcohol. There remains an oily product from which the excess formyl-ethylenedlamine is removed by distillation under 1 mm Hg pressure up to 125°C. The dark yellow, residual product is treated with 10% hydrochloric acid at 100°C for 12 hours to eliminate the formyl group it is evaporated to a syrupy consistency and taken up with ethyl alcohol at the boiling point until complete miscibility is attained it is then discolored over carbon, filtered and stored at low temperature. [Pg.1545]

This three-dimensional cutaway drawing illustrates the filtering operation of the QAF9 filter-bag pressure filter system, showing the flow patterns of unflltered liquid through a preselected micronrated felt filter bag which renders the desired quality of filtered product. [Pg.277]

Sodium hydrosulfite is produced through the Formate process where sodium formate solution, sodium hydroxide, and liquid sulfur dioxide reacted in the presence of a recycled stream of methanol solvent. Other products are sodium sulfite, sodium bicarbonate, and carbon monoxide. In the reactor, sodium hydrosulfite is precipitated to form a slurry of sodium hydrosulfite in the solution of methanol, methyl formate, and other coproducts. The mixture is sent to a pressurized filter system to recover sodium hydrosulfite crystals that are dried in a steam-heated rotary drier before being packaged. Heat supply in this process is highly monitored in order not to decompose sodium hydrosulfite to sulfite. Purging is periodically carried out on the recycle stream, particularly those involving methanol, to avoid excessive buildup of impurities. Also, vaporized methanol from the drying process and liquors from the filtration process are recycled to the solvent recovery system to improve the efficiency of the plant. [Pg.944]

After the reaction mixture has been cooled, the excess phosphorus oxychloride is distilled under reduced pressure (80-100 mm.) (0.5-1.0 hour). Near the end of the distillation the product begins to sublime into the still head. The residual dark-brown oil is poured with stirring into an 800-ml. beaker containing 280-300 g. of crushed ice (Notes 3 and 4). The volume of the ice-water mixture is brought to 600 ml. and allowed to stand at 5° overnight. The crude light-brown product is filtered by suction and washed with water. [Pg.65]

Polymerizations were carried out in a jacketed, 1-gal, stirred, pressure tank reactor. Typical reactions were run by adding water, alcohol, or chain transfer agent, phosphate buffer, and persulfate to the reactor. The reactor was pressurized with CTFE monomer. Sulfite solution was fed at a rate to maintain reaction. Copper and iron ions were used at times as catalysts by adding cupric sulfate or ferrous sulfate.3 The product was filtered, washed with 90 10 water methanol followed with deionized water. The product was dried at 110°C. [Pg.82]

Bezold—Br eke effect, 7 308 B-form oligonucleotides, 17 606 BHK cell based products, 5 35 It Bhopal disaster, 21 829, 830 BHS-Fest pressure filter, 11 378-379 Bi2223 magnets, refrigerator-cooled,... [Pg.98]

The crude benzotriazole is placed in a 200-cc. modified Claisen flask (Org. Syn. Coll. Vol. 1, 125) and distilled under reduced pressure (Note 2). The yield of white solid (yellow cast) boiling at 201-204° at J5 mm. or 156-159° at 2 mm. is 92-99 g. The product in the receiver is melted over a luminous flame and poured into 250 cc, of benzene. The clear solution is stirred until crystallization sets in after being chilled for two hours, the product is filtered on a Buchner funnel. The colorless benzotriazole weighs 90-97 g. (75-81 per cent of the theoretical amount) (Note 3) and melts at 96-97°. [Pg.68]

The solution is allowed to stand for three days at room temperature, and is then concentrated on the steam bath under reduced pressure (water pump) until spattering makes further evaporation impossible. Two hundred cubic centimeters of water is added to the residue, and the contents of the flask are washed into a small beaker where they are stirred to a smooth slurry. The product is filtered, washed thoroughly on the funnel with cold water, and dried in an oven at 80 90°. The crude material melts at 204-206° and weighs 47-57 g. (80-96 per cent of the theoretical amount). It is purified by recrystallization from 650 cc. of boiling methyl alcohol using 5 g. of decolorizing charcoal. The recrystallized, pale yellow needles of 5-nitroinda-zole melt at 208-209°. The yield is 42-47 g. (72-80 per cent of... [Pg.96]

To a solution of 0.25 mmol (58 mg) of f-)-(S )-l-amino-2-(/e/- -butyIdimelhylsilyloxymcthyi)pyrrolidinc (SASP) and 0.2 g of MgS04 in 2.5 mL of cyclohexane, 0.20 mmol of the aldehyde is added and stirred at r.t. for 20 min. The solution is filtered from the MgS04, the solvent is evaporated under reduced pressure, and the crude product is filtered through a Pasteur pipette filled with silica gel using petroleum ether/elhyl acetate (98 2). The diastereomeric excess (de, which is the ee of the aldehyde) is then determined by analytical HPLC using hexane/elhyl acetate/ isopropyl alcohol (99 1 0.2). [Pg.1012]

To 10 gm (0.021 mole) of (I) and 5.0 gm (0.077 mole) of sodium azide is added 200 ml of dioxane and 50 ml of water. The solution is refluxed under a nitrogen atmosphere for 5 days, cooled, treated with Darco G50 (2 mg), and diluted to 500 ml with water. The solid product is filtered, washed with water, and dried at 60°C under reduced pressure to afford 9.19 gm (83 % crude), m.p. 164°-230°C. This material is adsorbed onto 275 gm of Fluorsil in methylene chloride and eluted with twenty-one 375 ml fractions of Skellysolve B over the range 5-20% acetone. On combination, fractions 4-10 are concentrated and then recrystallized from acetone to afford 3.44 gm (32%) of (II), m.p. 184.5°-185.5°C, vmax 3510, 2100, 1723, and 1250 cm"1. [Pg.148]

A solution of 2.45 gm (0.019 mole) of A-heptyl-4-hydroxylamine is prepared in 2 AT hydrochloric acid. To this solution is added, with vigorous stirring, bromine water until the bromine color just persists. During this addition a colorless precipitate of the product begins to form. After the addition has been completed, stirring is continued for a short time. Then the product is filtered off, washed with a small quantity of ice-cold water, and dried on an unglazed clay plate yield 1.93 gm (80%), m.p. 46°-48°C. The product may be recrystallized from acetone or distilled under reduced pressure (b.p. 90°-93°C, 0.4 mm Hg). The final melting point is reported as 49°-50°C. [Pg.214]

Gulf Research and Development Co. Two of the coals were processed in the Gulf continuous flow reactor, fed at the rate of about 1.5 kg coal/hr for 15-18 hrs. The third coal was processed in a conventional batch autoclave run. In all three runs, the coal was processed at about 400 °C and 3000 psi pressure of hydrogen using a proprietary catalyst. In the continuous runs, distillate from previous experiments was used as vehicle while in the autoclave experiment, partly hydrogenated phenanthrene was used. The vehicle-to-coal ratio was 2 1. In each case the reaction products were filtered on a steam-heated Buchner funnel. [Pg.197]


See other pages where Productivity pressure filters is mentioned: [Pg.830]    [Pg.412]    [Pg.134]    [Pg.25]    [Pg.212]    [Pg.193]    [Pg.201]    [Pg.472]    [Pg.773]    [Pg.78]    [Pg.830]    [Pg.69]    [Pg.136]    [Pg.114]    [Pg.406]    [Pg.94]    [Pg.33]    [Pg.99]    [Pg.146]    [Pg.478]    [Pg.222]    [Pg.85]    [Pg.199]    [Pg.269]    [Pg.830]    [Pg.60]    [Pg.188]    [Pg.812]   
See also in sourсe #XX -- [ Pg.441 , Pg.460 ]




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Pressure filtering

Pressure filters

Pressurized products

Product filtering

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