Improvements in the Manufacture of Briquettes from Wood-refuse, Wood-shavings, Sawdust and the like.
Year: 1897

page_text: Date of Application, 27th Nov., 1897--Accepted, 15th Jan., 1898
Improvements in the Manufacture of Briquettes from Wood-refuse,
Wood-shavings, Sawdust and the like.
I, ROBERT MEYER, of 9, Lohestrasse, Breslau, Silesia, in the Empire of Germany,
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
The disintegrated wood and wood refuse such as sawdust, shavings and the like
hitherto employed for making briquettes were made as dry as possible before being
compressed, and an artificial agglutinant was added in order to bind the wood
substances together or an increased adhesiveness in the resin contained in the
wood was produced by dry heating and this adhesive resin used as agglutinant.
In both cases the pressing of the wood masses is attended with some difficulties
as the dry wood is hard and brittle. The compressed briquettes also set or adhere
very firmly in the mould in consequence of the added agglutinant or the great
adhesiveness of the softened resin, and it requires a considerable expenditure of
power to expel the briquettes from the press. The greatest drawback of briquettes
thus obtained consists however in the circumstance that they very freely absorb
moisture from the air, and when stored in the open air or in damp roms, they
consequently first swell and finally fall to pieces.
Such briquettes when heated also do not retain their form so that it is impossible
to obtain solid briquette shaped wood charcoal therefrom by dry distillation, and
on the contrary wood briquettes produced by the methods hitherto employed dis-
integrate under dry distillation in a retort to a groats-like charcoal dust.
By the present invention wood blocks are obtained which are entirely unaffectedl
by moisture or even by the direct action of cold water and which on being con-
verted into wood charcoal by means of dry distillation fully retain their form and
even then still possess sufficient solidity to allow of their being transported.
This result is attained by the disintegrated wood, wood shavings, sawdust, or
the like being first treated with hot steam by which means the elasticity of the
wood fibres is destroyed. The wood fibres obtain a certain plasticity by this
destruction of the elasticity and are reduced to a condition which may be described
as non-hygroscopic. The treatment of the wood substances with hot steam may
he carried out in the following manner.
The sawdust, wood shavings or the like are fed into a receptacle which may be
closed. After the receptacle has been closed hot steam of about 120° to 180°
Centigrade is passed in and the sawdust or the like exposed to the action of said
steam for a suitable time. Of course at the commencement of the introduction
of the steam a greater or lesser quantity of condensed water will be formed. The
receptacle is also provided with a steam discharge pipe capable of being closed or
shut off. Certain ethereal oils and more particularly turpentine oil is evaporated
by the steaming. These evaporated oils are let off at intervals by opening the tap
or valve of the steam discharge pipe and preferably caught in a suitable receive;
and condon sed

page_text: The most important point however is that wood fibre thus treated with steam
loses both its elasticity and its hygroscopic property and obtains a certain degree
of plasticity, and if the sawdust or the like treated in the manner described be
compressed into briquettes in presses which allow the water to escape from the
press mould, such briquettes entirely maintain their form even under the direct
action of moisture. The briquettes are also firm, do not adhere, or only slightly so
to the mould, and do not disintegrate even when carbonised by dry distillation,
whilst the wood charcoal obtained has the form of briquettes and the retorts may
be entirely filled as the briquettes made by this process do not increase in volume
even under the action of heat as was the case with the briquettes produced by the
processes previously employed, the volume of which briquettes when heated
frequently more than doubled.
The process herein before described may of course he carried out by pouring
water into the receptacle containing the sawdust or the like, and heating the said
receptacle to cause the water to boil and then by suitably loading a safety valve
causing the steam pressure to be raised to such an extent that the steam contained
in the receptacle undergoes a superheating to 120° or 130° C.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
-
The improvement in the manufacture of briquettes from wood-refuse, wood-
shavings, sawdust, disintegrated wood and the like, which consists in exposing the
wood substances to the action of hot steam until the elasticity of the wood fibre is
destroyed whilst the ethereal constituents are at the same time evaporated,
substantially as hereinbefore set forth.
·וו מ
1
1005
WM. P. THOMPSON & Co.,
of 6, Lord Street, Liverpool, Agents for the Applicant.