IMPROVEMENTS IN DRYING MACHINES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by the said William Alfred Gibbs at
the Office of the Commissioners of Patents on the 24th August 1881.
WILLIAM ALFRED GIBBS, of Gillwell Park, Chingford, in the County of Essex,
Landowner." IMPROVEMENTS IN DRYING MACHINES."
•
For drying hay that is stacked in a comparatively green state I use a shaft of
wood, metal, or other material, which I make telescopic, so that it may be packed
into a small space for transport, and also so that the lengths of which it is formed
may be separated one from the other; this shaft I use in the following manner :—
The stack is formed with a hollow in the middle in the way now sometimes
practised. When the stack has been about half built the telescopic shaft, drawn
out to its full length, is set upright above the top of the central hollow in the
stack, and the tube is when erected held steady by ropes attached to its upper
end.
The building of the stack is then proceeded with, and the hay built up around
the shaft. The chimney is of a height sufficient to create the requisite strength of
upward current through it when filled with warmed air from the hollow in the
middle of the stack, and air is thereby caused to filter inwards through every part
of the stack, and keeps it from getting over heated.
In this way the labor and cost of using suction fans to produce a partial
vacuum in the hollow at the centre of a stack is avoided. Moreover, the chimney
draft will act continuously night and day.
A revolving or other ventilator may be placed at the top of the telescopic
chimney shaft to increase the upward draft through it.
Heaps of corn or other substances that will generate heat when piled together
in masses, may be kept from getting over heated by the use of similar apparatus.
Sometimes in lieu of carrying up the shaft vertically from the centre hole of the
stack, I lay in a branch pipe horizontally from the said centre hole to one side, and
attach this branch pipe to a portable stove, in which fuel is burnt in such a manner
as to draw all the air from the centre through the fuel, and thence up a flue or
stove pipe, the effect of this arrangement being to create a stronger suction of
air, and thus accelerate the drying. Or the same effect may be obtained by

page_text: substituting a steam jet for the stove, so as to create a strong suction draught in
the same manner as commonly used for locomotives.
Another way is to use a revolving fan set on a stand at one side of the stack,
and to form the fan with a long suction pipe capable of swivelling on the fan axis.
When the stack has been partly, or it might be even half built, the suction pipe
is laid into the stack so that its end opens into the hollow chamber in the centre.
The remainder of the stack is then built up, and in so doing the top of the hollow
chamber is closed over.
In this way the mechanism requisite for drawing air through the stack is at all
times ready for use without any previous preparation, and after being used with
one stack can be shifted to another.
For driving the fan a weight might be employed, which could be wound up
during the day and used for driving the fan during the night.
The suction pipe being in one long piece, and being jointed to the fan inlet,
there is no risk of any joints getting leaky, which would endanger the safety of
the stack and risk its firing. A thermometer placed at the mouth of the fan
would be a sufficient indication of the temperature in the middle of the stack.
For drying grain I feed the grain into a hopper at the top of a hollow
rectangular casing or column, and allow it to drop down through this column.
Up through the centre of the column is a rectangular air channel passing across
the column from one end of it to the other. Branching out from the two opposite
sides of this air channel are numerous hollow shelves, one below the other,
projecting downwards and extending to about midway between the central air
shaft and the sides of the column. A coil of pipe, heated by steam or otherwise,
is placed within the air column, and a blast of air is forced into the lower.end
of the column by a revolving fan.
The air heated by the coil of pipe passes from the column through all of the
numerous hollow sloping shelves branching from it, and is thereby. brought into
contact with the grain.
The inner sides of the casing have also shelves standing out from them, and
they come intermediate of the shelves in the central air shaft. The grain fed into
the top of the rectangular column as it descends drops from shelf to shelf, being
first deflected inwards and then outwards over and over again until it reaches the
bottom. Here it drops into a hopper of perforated metal or other reticulate
material enclosed in a rectangular casing, through which a blast of air is passed
continuously by a branch from the fan outlet, the blast being made to enter one
side of the casing, then to pass through the perforated hopper, and to escape from
the opposite side of the casing; the grain which has been heated. whilst dropping
down through the column before mentioned is in this way cooled.
In order that the apparatus may be packed into a small space, the sloping
shelves hereinbefore mentioned may be hinged so that they may be turned down
and lie flat along the sides of the casing.