Improvements in and relating to Kilns for Drying Granular Substances.
Year: 1889

page_text: Improvements in and relating to Kilns for Drying Granular
Substances.
[, WILLIAM DAVIDSON of Mill of Clola, Mintlaw, in the County of Aberdeen, Miller,
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 :-
My Invention which relates to kilns for drying oats and other granular substances
has for its objects improvements in the construction of operating parts of the kiln
whereby more equal distribution of the grain over the floor is ensured and uniform
drying is attained, and of the heating furnace whereby it is adapted for burning husks
or similar light material and consuming smoke.
----
As represented in the accompanying drawings in which figures 1 and 2 are vertical
sections at right angles to each other of the improved kiln and figures 3 and 4
horizontal sections at the lines ✗. X and Y-. Y in figures 1 and 2
respectively the kiln chamber A is provided with the usual floor B and is of circular
form in plan. Situated over the floor is a hopper C which is attached to a shaft D
extending vertically through the centre of the kiln and driven by gearing E from a
shaft F to which rotation is communicated from any suitable prime mover.
The
mouth c of the hopper C is circular in plan to adapt it to receive the oats or other
granular substance which is fed into it and passes down through the body of the
hopper (which is of triangular form and extends from the central shaft to the walls
of the kiln chamber) towards its lower end which is open and through which it is
deposited in a thin layer over the floor B during the rotation of the hopper with
the vertical shaft D. The bottom or lower edge of the hopper is set at any desired
height from the floor and it may be fitted adjustably in order to regulate the
thickness of the layer of grain deposited on the Hoor. Spikes or pins attached to
the bottom of the hopper may also be provided for stirring the grain in drying.
A horizontal blade or bar G of iron or other material and which may be of convex
or similar cross section is attached to the vertical shaft or to the bottom of
the hopper and fitted to rest on and traverse the kilr floor B with the hopper so
as to slacken the grain on the floor and permit hated air to pass freely through
it, at the same time discharging through perforations in the kiln floor sand or grit
and small seeds into the chamber I to be collected and removed through the
shoot J below prior to removal of the dried grain from the kiln. In loading the kiln
the oats or other granular substance is fed into the hopper through a shoot H
whilst the shaft and hopper rotate until a layer is deposited on the floor B completely
filling up the space between the latter and the bottom of the hopper. The supply
of grain is then stopped the shaft D with the hopper C and blade G continuing

page_text: to rotate in order to stir and slacken the grain until it is sufficiently dried when
it is removed through an opening or openings in the walls, or through a trap door
or doors in the kiln floor and then passed through the shoot J below, or the grain
may be continuously discharged by having sufficiently large perforations in the kiln
floor and maintaining a constant supply of grain in the filling hopper to ensure
keeping the space between it and kiln floor quite filled up.
The heating furnace for drying the grain is of novel construction and consists of
a travelling band K composed of narrow iron plates provided with holes for the
admission of air to support combustion said plates being attached to endless pitch
chains passing over sprocket wheels M on rotating shafts N on an iron framing O
and placed one outside and the other within the mouth of a chamber P constituting
the combustion chamber of the furnace. On to this travelling hand K oat husks
or shells or other light combustible materials are fed by a hopper Q situated over
the outer end of the framing O and having an adjustable slide on the side next
the furnace to regulate the supply of fuel which is carried by the band from the
hopper into the furnace mouth the residual ash being dropped over into a chamber
at back of the furnace. Over the band K is an arch R constituting the furnace
crown and serving to direct the heated_products of combustion round a bridge S
whence they pass through an opening T into the chamber under the kiln floor and
pass there through, or are otherwise led off, a fan U being provided to create a
draught and to carry off moisture rising from the grain. The furnace is automatic
in action and the fuel being supplied in a thin layer over the perforated band
complete combustion and absence of smoke are ensured the result being that the
grain is not bleached or discoloured.
When the kiln is made of rectangular form as indicated at figuro 5 the grain is
deposited on to the floor B by means of a hopper C extending across the whole floor
and supported over it by slides or carrying wheels C₁ so that it be traversed in a
direction at right angles to its length by means of wire ropes or chains or other
gearing. A horizontal blade for slackening the grain on the floor and spikes or pins
attached to the hopper aro provided as in the arrangement described with reference to
figures 1 to 4. In operation the hopper C is fully charged and the kiln is loaded at
the first traverse, but the hopper when empty continues to traverse in order to stir up
and slacken the grain. After the grain is thoroughly dried the hopper is drawn to
one side and filled with raw grain for reloading whilst the floor is cleared of the dry
grain.
The under part of the kiln is provided with a hopper shaped chamber and a furnace
constructed as described with reference to the circular form of kiln.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
1. A kiln for drying oats or other granular substances constructed and arranged to
operate substantially as herein before described with reference to the annexed drawings.
2. In a kiln for drying oats or other granular substances the loading hopper C
furnished with means for stirring up and slackening the grain on the kiln floor and
otherwise operating substantially as hereinbefore described.
3. In a kiln for drying oats or other granular substances a heating furnace
constructed and operating substantially as hereinbefore described.
Dated this Fourteenth day of March 1889
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.