Title: Canadian forest industries 1901-1902
Identifier: canadianforest190102donm (find matches)
Year: 1902 (1900s)
Authors:
Subjects: Lumbering; Forests and forestry; Forest products; Wood-pulp industry; Wood-using industries
Publisher: Don Mills, Ont. : Southam Business Publications
Contributing Library: Fisher - University of Toronto
Digitizing Sponsor: University of Toronto

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i6 June, 1900 I WOOD PULP S> * I 0^- DEPARTMENT SODA AND SULPHITE PULP. Dr. Max Muller, who has had a long exper- ience in the manufacture of sulphite and soda wood pulp, states that 108.4 parts of sulphite pulp are obtained by the sulphite process from the same quantity of wood which yields 100 parts of soda pulp by the use of pure caustic soda. As this figure was obtained from many years' the fluid at a high temperature is caused to im- pinge against any cast-iron part. But perhaps the most serious objection to the sulphite wood pulp process is the foul odor es- caping from the digester when the pressure is blown down after the digesting operation has been completed. This smell is so penetrating and offensive as almost to preclude the possibility the sulpho-compounds becomes itself tainted, and its disposal is quite as serious and difficult a j matter as the vapor itself. The best mode of getting rid of the vapor is to first condense' all steam associated with it, and then pass it1 through incandescent fuel in the ordinary fire- place of the recovery furnace. The sulpho-com- pounds are then decomposed and their odor destroyed. Notwithstanding this serious objection the sulphite process is the more frequently used of the two, due to the fact that it yields a larger quantity of pulp from unit weight (or volume) of wood, that the fibre is stronger, has greater bulking properties, and bleaches quite as well as soda pulp, and that the cost for alkali in its prep-
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Spruce Pulp Wood Piled on the Ice.—Thessalon River, Ont. f Fiom the Ontario Forestry Report) manufacturing practice it is particularly interest- ing, and indicates clearly the advantages to be gained by pursuing the sulphite process. The cost for alkali in the process is less than that in the caustic soda method. Salt cake is cheap and is easily decomposed into sulphides, but there is no doubt a larger proportion of al- kaline salts to be dealt with in the sulphite pro- cess, which has a tendency to increase the labor account. Besides the presence of sulphide of sodium in the lyes, as well as the formation of this body in the furnace itself, gives rise to in- ordinate wear and tear. Lyes containing sodi- um sulphide act more severely upon cast or wrought iron than those containing pure caustic soda, so that the plates of the digester and tubes of the evaporator, if a multiple evaporator is used for soda recovery, are more or less acted upon and suffer injury in course of time. This is particularly the case in evaporators in which of the manufacture being carried on in populous districts. In countries such as Norway and Sweden, where pulp works are, as a rule, far re- moved from centres of civilization, the manufac- ture can be carried on with impunity,but in Eng- land it would be practically impossible to do so, unless some special means were adopted to ab- sorb or otherwise render harmless the vapors given off. The odor doubtless arises from the formation inside the digester at high tempera- tures of sulpho-compounds of the turpentines, and other closely allied bodies which exist in the wood, and which being of a highly volatile nature, pass away with the steam as the pressure is blown down. Several schemes have been devised with a view to miminize the evil, such, for example, as passing the vapor through a scrubbing tower through which there flows a plentiful supply of water, but obviously the water which absorbs aration is reduced to a minimum.—James Beve- ridge, in The Paper Trade Review. THE FIRE AT GRANDE MERE. On May 6th fire broke out in the mills of the Laurentide Pulp Company at Grande Mere, Que. The first report of the fire was that the entire buildings of the company had been destroyed. This proved to be incorrect. The loss was con- fined to the pulp mill, chipper mill and pump house. Fortunately the magnificent paper mill and the saw mill of the company were saved by the shifting of the wind. An estimate of the loss places it at $80,000. The fire was caused by a heated shaft on a rope pulley leading to the pulp mill. Six hours after the fire rebuilding operations were com- menced. The pulp mill contained a fine set of grinders made by the New England Machinery Company, of Sandy Hill, N.Y., with 300,000 gallons per hour capacity.

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