. The manufacture of pulp and paper : a textbook of modern pulp and paper mill practice. FINE SCREENING 45 pounded and why the compartments become smaller as theyapproach the tailing end of the drum, since each compartmenthas a smaller amount of stock to handle than the preceding accepted stock passes through the plates throughout theentire screen drum and is discharged through the outlet K, seeview (a). Shower pipe L dilutes the unscreened residue whilebeing delivered to each succeeding compartment. Shower pipesM are for the purpose of forcing all unscreened residue out of therotating
. The manufacture of pulp and paper : a textbook of modern pulp and paper mill practice. FINE SCREENING 45 pounded and why the compartments become smaller as theyapproach the tailing end of the drum, since each compartmenthas a smaller amount of stock to handle than the preceding accepted stock passes through the plates throughout theentire screen drum and is discharged through the outlet K, seeview (a). Shower pipe L dilutes the unscreened residue whilebeing delivered to each succeeding compartment. Shower pipesM are for the purpose of forcing all unscreened residue out of therotating drum into the compounding box and keeping plates The drum is the only moving part of the machine; it rotates inbearings outside of the machine; there are no packings, cams, orsprings. The speed is 25 , and about 1 is required tooperate it. The screen-plate area is approximately 70 sq. ft.,and the perforations are holes of .1 in. diameter and 42 holes persq. in. QUESTIONS (1) Name the principal points to be considered in selecting a screen. (2) Explain the effect on the capacity of a rotary screen of (a) increasein consistency, (b) increase in speed of impeller. 46 TREATMENT OF PULP &7 (3) What is the effect of increases as above en the (a) power consump-tion; (b) amount of tailings? (4) Mention some of the difficulties to be met in operating the screenroom. (5) Distinguish between inward flow and outward-flow screens; illustrateyour answer by a sketch. TREATMENT OF PULP AFTER SCREENING SLUSHING OR DECKERING 48. Thickening or Concentrating Stock.—The consistency ofscreened stock is from to ; the process by
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectpaperma, bookyear1921
