3568 



Chapter 28 



WOOD YARD 



71,000 T/YR O.D. 



CHIPS a ROUNDWOOD 



PURCHASED BY 

 CONTRACT OAK < 50% 



PRIMARY PULPING, 



PRESSURE-REFINED 



2,500 HP 



"H 



SECONDARY REFINER 

 2 (® 2,500 HP 



PHENOLIC RESIN 

 WAX EMULSION 

 ALUM 



ADDITION 



STOCK STORAGE 



OVERLAY 



SYSTEM 



20 T/DAY 



FOURDRINIER 

 NOMINAL 4-FOOT 



PROCESS WASTE 



IRRIGATION 



500 M. GAL/DAY 



14,000 LB/DAY BOD. 



200 ACRES 



PURCHASED ELECTRICAL POWErI 



3.06 



10' KWH/YR 



500 KWH/TON 



^ 



t;l 



GRADE a PACK 

 UNIT PACK 



DRY a COOL 



IMPINGING AIR 



TYPE 



* 



FLOOD PAINT 



1.25 MILS, DRY 



WATER BASE 



I I TRIM a SCORE | 4- 



FINISHED 

 GOODS 



IN PROCESS 

 WAREHOUSE 



GRADE AND 



AUTO SORT 



MINIMUM 5 



GRADES 



SINGLE BELT 

 BACK SAND 



HUMIDIFIER 

 MINIMUM 6% 

 6 HRS RETENTION 



r 



HOT PRESS 

 30 OPENING 

 NOMINAL 4-XI8-FT 



i 



3 



POST PRESS 



HEAT TREAT 



3 HR RETENTION 



CAR TYPE 



Figure 28-34. — Flow diagram for manufacture of medium-density hardboard siding by 

 the screenback process. (Drawing after Stewart 1981.) 



Output is projected ot be 200 tons/day or 61,200 tons/year; this amounts to 

 76,500,000 square feet/year, 7/16-inch basis, or 267,000,000 square feet/year, 

 /s-inch basis. 



Annual wood requirement, including bark, is estimated at 71,000 tons, 

 ovendry basis. Water requirement is 500,000 gallons/day (153 million gallons/ 

 year) to be discharged to direct land-irrigation to satisfy requirements for zero 

 discharge. Needed thermal energy is produced in a 600-psi boiler fired with 

 wood residue. 



Plant cost, including land and all facilities, is estimated at $40 million. 

 Annual operating costs, not including depreciation, sales, or administrative 

 overhead above that of the plant manager are estimated at $10,700,000; this 



