Document 65pgrOq9V0EZeYj09w4Bj0YM9

sideration be given to the VVRS of all lined, the new boiler plant was de necessitate building a new pump- .j i! rotating equipment, to see that it is signed to house two 207,000-tb-per- - house at Victoria Lake, some 270 ft in line with the intensity and dura hr, 600-psig, 725-F total temperature above the mill and approximately tion of peak loads so that desired boilers. The existing turbine room two miles distant from it. By install regulation can be maintained. was utilized by raising the operating ing the most efficient pumps and Process steam for pulp mills is floor level 5 ft 3 in. The existing prime movers at the lake and taking normally required at more than one switchboard and mill electrical dis advantage of the maximum siphon pressure. With by-product power tribution system, being no longer head at the high point in the pipe turbines, steam demands should be adequate, were replaced by a new line, it is possible, by reducing hy supplied direct from the turbine ex metalclad totally-enclosed board, in draulic losses to an economic mini traction or exhaust nozzles for a new switchboard bay. Two Elliott mum, to pass the water supplv maximum power generation. It is 3500-kw back-pressure turbine-gen through a hydraulic turbine, installed essential that the operating char erators were installed at the new in place of the existing 3000-kw con acteristics of turbine governors be operating floor level, one turbine ex densing turbine-generator, and gen specified so as to conform to the plant hausting at 150 psig and the other erate enough power in the recently load conditions if maximum by at 50 psig. purchased 2000-kw Elliott generator, i product power is to be developed. A new deaerator and utility tower to operate the pumps at the lake with i With two back-pressure turbines, the was appended to the boiler-house a slight power excess. The system is i unit with the tower exhaust pressure structure to enclose a deaerating designed so that the water supply should be loaded to the full extent of heater, chemical lab, toilet, and will be self-sustaining, even if a dis the low-pressure steam demand be locker rooms. To reduce the capital turbance on the main switchboard fore the second turbine takes its share expenditure, it was decided to install shuts down the steam-driven gen of load surges. initially one boiler large enough to erators. Pulp mill steam requirements in provide the plant steam demand A new screen structure is being excess of that required to satisfy the burning fuel oil. The old low-pres built between the digester building power demand must be furnished by sure boilers were maintained for and the powerhouse to screen solid by-passing the turbine-generator stand-by service and to dispose of the matter from the mill water supply. through suitable pressure-reducing wood fuel produced in the break The screen structure is located at stations. Turbine governor action, down plant. sufficient height to permit water dis power frequency, and steam pressure Design of the new powerhouse was tribution by gravity throughout the regulation are affected by the size complicated by the fact that con mill. and sensitivity of the pressure reduc struction work was carried out so as Space is available in the turbine ing stations, the size and design of not to interfere with mill production. room to install a third high-pressure piping, and the position at which the In 1951, when the Port Alice mill turbine-generator exhausting at 150 t pressure clement for the reducing was acquired by Alaska Pine & Cellu psig, should mill expansion exceed t valve is located, in respect to boilers, lose Ltd., it was decided to build a the power generating capacity of the turbines, piping, and steam load new bleach plant, woodroom, and existing units. connections. water supply system. Boiler No. 15 is Prior to 1950, the Port Alice mill now being installed and dutch ovens operated on steam produced in are being added to boiler No. 14 to thirteen 150-psig boilers. Process burn the refuse from the woodroom. steam was piped direct from the When boiler No. 15 is in operation, boilers to the mill and to the three boilers one to thirteen inclusive, will condensing turbine-generators, rated be dismantled. If more steam than 3000 kw, 3200 kw, and 2000 kw, re can be produced with boiler No. 14 spectively, any two of which de or 15 is required in the future, a veloped the peak power demand. third high-pressure unit will be in In 1950 it was decided to provide stalled in the space now occupied by the Port Alice mill with a high- low-pressure boilers three to six. The pressure by-product power plant to third high-pressure boiler will be of realize the savings enjoyed by the sufficient size so that any two units company's recently constructed will provide the mill's total steam Woodfibre high-pressure generating demand. station. The new bleach plant will double Predicated on the principles out the fresh-water requirements and PAGE 18 rowEiiKw. swung mss