Utilising Sawdust. 



The iises of sawdust was the sub- 

 ject of an interesting article in the 

 Amencan Lumhennan recently from 

 the pen of C. W. R. Eichoff!' M.E. 

 The writer, in his introduction, al- 

 ludes to the immense piles of sawdust 

 and other mill refuse to be found 

 near many large mills, and discusses, 

 first, the use of this waste for fuel. 



'The inconvenient process of burn- 

 ing this valuable waste,' he writes, 

 * taking into consideration the fact 

 that this sawdust, when moderately 

 dry, has the same heat value as the 

 wood from which it originates, has led 

 to the design and construction of 

 many different styles of furnace, 

 which in some cases have brought a 

 betterment and in others failure. 

 Furnaces of the ''Dutch oven" style 

 are mostly used in this connection, 

 and especially with boilers. But there 

 are other convenient constructions 

 now in existence. In all these fur- 

 naces the main effort was directed to 

 a better distribution of the air neces- 

 sary for a successful combustion of 

 the material. 



'Abroad, where conservation of the 

 natural resources has been practised 

 to a greater extent than on this con- 

 tinent, experiments have been made 

 to form this dust into briquettes. At 

 present a number of briquetting 

 plants are in successful operation 

 across the Atlantic, and of later 

 years lumbermen and other mill- 

 owners on this side of the Atlantic 

 have become interested in the briquet- 

 ting of such sawdust. But the Ameri- 

 can has not looked favorably on this 

 utilization. The large lumber con- 

 cerns considered it more profitable 

 not to bother with such a process, 

 claiming that these briquettes can be 

 used only to a small extent and could 

 not compete with other fuels in which 

 this continent is so rich. More inter- 

 est in the matter was shown by the 

 smaller concerns, where the loss of 



such valuable wood wastes demands 

 serious consideration. Many owuers 

 took up the proposal, but dropped it 

 when they learned the cost of such 

 sawdust-briquetting plants. Consid- 

 ering that a product has to be manu- 

 factured which requires for its fabri- 

 cation either a suitable binder or great 

 pressure not using a binder, it is es- 

 sential that every part of such a plant 

 be designed and constructed with the 

 utmost care and skill in all its de- 

 tails. 



'Suitable binders are water-gas, 

 pitch, tar, rosin, flour, water-glass 

 and others of the same nature as 

 used in the briquetting of coal. As 

 these binders materially increase the 

 cost of manufacture, their use was 

 found prohibitive, and machines are 

 now used that deliver the goods with- 

 out the application of a binding ma- 

 terial. 



'The sawdust in this process has to 

 be perfectly dry before being put in- 

 to the press. From the press the bri- 

 quettes are transported automatically 

 into a cooling room, and when cool 

 they are hard and ready for trans- 

 portation. Such briquettes are an 

 excellent fuel for residence use in 

 fire-places and stoves, do not corrode 

 and leave very little ashes and soot. 

 The cleanliness, rapid ignition, in- 

 tense heat and odorless combustion 

 make them a fuel preferable to the 

 best wood. They are also the most 

 convenient fuel for power-house use 

 in saw-mills and in logging locomo- 

 tives, replacing coal or sawdust, which 

 latter would take considerable space. 

 They are also very convenient as a 

 kindling material. The briquettes 

 are of oval form, to facilitate ventila- 

 tion when piled up. 



' Presses are built with a capacity of 

 24 bri(juettes a minute, giving 14,400 

 briquettes in ten hours, each briquette 

 weighing about half a pound, which 

 would be equivalent to a daily output 



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