Year: 1888

page_text: Date of Application, 13th Jan., 1888
Complete Specification Left, 15th Oct., 1888
Complete Specification Accepted, 23rd Nov., 1888
I, ROBERT FREE of The Elms, Mistley, near Manningtree, in the County of
Essex, Maltster do hereby declare the nature of this invention to be as follows:-
1
The invention relates to improvements upon an invention for which Letters Patent
were granted to me dated February 9th 1876 No. 519 whereby I greatly accelerate
the drying process and improve the quality of the malt or other produce under
treatment.
In carrying my invention into effect I divide the hot air chamber into a number of
separate chambers by means of walls or metal plates placed intermediate of the hori-
zontal air distributing flues and extending from the floor of the hot air chamber to or
near the underside of the drying floor and I may place a deflector over the crown of
the furnace shaft by these means I ensure a more equal distribution of the heated
air passing through the drying floor, and in order to carry off with greater speed the
moist vapours arising from the produce under treatment I form the roof of the kiln
in an air tight manner and connect an exhaust fan thereto whereby as the moisture
rises from the produce on the drying floor it is quickly carried off to the exterior of
the kiln whilst the action of the fan at the same time maintains a strong current
of air through the furnace, vertical shaft and passages, and the produce under
treatment.
The horizontal air distributing flues and the dome or crown to the furnace shaft
may if desired be dispensed with.
The air, or some of the air, is caused to pass through tubes or pipes which are
arranged to enter the shaft above the furnace or to enter the furnance itself and then
rise a short distance up the shaft by which means the air passing through the kiln is
thoroughly heated and dried. Or the air tubes or pipes might pass through or over
Or the air may be
a separate furnace or furnaces, before entering the furnace shaft.
caused to enter the furnace shaft through simple openings or passages in the walls
thereof.

page_text: In all cases suitable dampers would be employed in order to regulate the admission
of air.
I also employ a thermometer placed in the body of the produce under treatment
and from which I conduct an indicator to the stoker's chamber where without ascending
to the drying floor he can read the temperature of the produce thereby enabling
him to regulate the inlets to the furnace and air passages and so to keep the temperature
of the produce at or about the required degree.
By these means I am enabled dry the produce in much less time, at a higher
temperature and more perfectly than heretofore and in consequence of the large
volume of air continuously passing through the bulk of the produce during the drying
operation it is sweetened, purified and otherwise improved."
In order to facilitate the process of kiln drying and reduce the length of time
required for the produce to remain in the kiln I, by preference, submit the grain or
other produce to a preliminary drying process consisting in passing dry heated air
hrough the produce which is supported on a wire work or other permeable floor.
Dated this 13th day of January 1888.
ROBERT FREE.
By Harris & Mills,
23, Southampton Buildings,
Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Kilns for Drying Malt, Hops, Grain, and other
Produce.
L, ROBERT FREE of The Elms, Mistley, near Manningtree in the County of Essex,
Maltster, 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, reference being had to the accompanying drawings and to
the figures and letters marked thereon :-
The invention relates to improvements upon an invention for which Letters Patent
were granted to me dated February 9. 1876, No. 519, whereby I greatly accelerato
the drying process and improve the quality of the malt or other produce under
treatinent.
In the accompanying drawings Figure 1 represents a vertical section and Figure 2
a horizontal section of a kiln constructed with my present improvements applied
thereto.
Figure 3 is a vertical section drawn at right angles to Figure 1 and Figure 4 is. a
horizontal section of the lower portions of the furnace shaft drawn to a larger scale.
Figure 5 is a vertical section drawn at right angles to that shown at Figure 3 and
representing a slight modification and Figures 6 and 7 are two vertical sections,
drawn at right angles to each other, of the lower portions of the furnace shaft
representing another modification.
In all the figures like parts are indicated by similar letters of reference.
a. a. are the walls of the kiln, b is a shaft built in the centre of the kiln, c is the
furnace, which, through the flue & formed in the shaft b, leads into a hot air.
chamber d, above.
The shaft bis domed over at 62 and the heat is distributed therefrom to different
parts by flues e having openings e¹ and provided with dampers to enable the
heat to be regulated and directed to any part of the hot air chamber d.
g is the drying floor.
As thus far described the kiln resembles that hereinbefore referred to.
In carrying my present invention into effect I divide the hot air chamber d into a
number of separate chambers by means of walls or metal plates d' placed inter-
mediate of the horizontal air distributing flues e and extending from the floor of the
hot air chamber d to or near the underside of the drying floor g and I preferably
place a deflector d' over the dome or crown 6 of the furnace shaft b; by these means
ensure a more equal distribution of the heated air passing through the drying
floor g. And in order to carry off with greater speed the moist vapours arising from
the produce under treatment, I form the roof of the kiln in a substantially air tight
manner, which may be done by close boarding the rafters inside and out and covering
them with felt tarred over and slated; and I connect an. exhaust fan i thereto,
preferably using what is known as the Blackman Exhaust Fan, whereby as the moisture
rises from the produce on the drying floor g it is quickly carried off to the exterior of

page_text: the kiln, whilst the action of the fan i at the same time maintains a strong current of
air through the furnace, vertical shaft, and passages, and through the produce under
treatment. The horizontal air distributing flues e and the dome or crown to the
furnace shaft may, if desired, be dispensed with as, by the use of the division walls
or plates d¹ and deflector d the hot air is tolerably well distributed.
The air, or some of the air, passing into the flue is caused to pass through tubes
or pipes arranged in upwardly inclined openings and entering the shaft above
the furnace, or they may be caused to enter the furnace itself, and then rise a short
distance up the flue ', by which means the air passing through the kiln is thoroughly
heated and dried. And in order to ensure the thorough heating of the tubes or
pipes
5f, and consequently the air passing therethrough, I place deflectors 63 in the
Hue so as to prevent the too rapid or direct passage of the products of combustion
up the same.
I also divide the flue into two parts by means of a plate b*, which extends from just
below the pipes or tubes f¹ up to their upper ends and I employ a hinged door or
baffle 6, which, when lowered into the position shown by the full lines in Figure 3,
will cause all the products of combustion to pass up that portion of the flue con-
taining the pipes or tubes f, but, when in the position shown by the dotted lines, will
cause a considerable proportion of the heat and products of combustion to pass direct
up that portion of the flue & which is free from the tubes or pipes f¹. By these
means, combined with dampers or stoppers to the tubes f¹, I am enabled to regulate
the heat acting upon, and the amount of air passing through, the produce under treat-
ment. Or the air tubes or pipes f¹ might be arranged as represented at Figures 6
and 7, in which case the pipes or tubes fare fixed in tube plates and are arranged
in an angular position in a chamber forming an extension of the furnace chamber.
The lower tube plate f carrying the said tubes or pipes f¹ is supported at its lower
end on masonry in such manner as to enable air freely to enter the pipes or tubes f,
they are also supported intermediate of their longth on a bridge or arch 15, at which
point a dividing tube plate or deflector f³ is fixed. The upper tube plate is at its
upper edge connected to the crown of the chamber 6 and a door or baffle 6 is hinged
to the arch or bridge so as to be able to be placed in the position shown by the full
lines or in the position shown by the dotted lines.
Thus, when the door or baffle is in the position shown by the full lines, the
products of combustion from the furnace are all caused to pass under the bridge or
arch and amongst and past that portion of the tubes or pipes which lies between
the tube plate or deflector and the lower tube plate; they then turn over the
upper edge of the deflector and pass amongst and past that portion of the tubes f¹,
which lies between the deflector f and the upper tube plate, and thence into the
flue 6. By these means the air passing through the tubes or pipes 1 becomes highly
heated and dried. When desired however, the door or baile can be placed in the
position shown by the dotted lines, in which position a considerable proportion of the
heat and products of combustion is caused to pass up direct into the flue b¹.
Or the air tubes or pipes f¹ might be arranged to pass through or over a separate
furnace or furnaces before entering the furnace shaft, as will be readily understood.
Or, as shown at Figure 5, the air may be caused to enter the flue b₁ through simple
upwardly inclined openings or passages formed in the walls thereof.
In all cases suitable dampers would be employed to enable the admission of air
through the tubes or pipes for passages to be readily regulated.
I also employ an adjustable electric thermometer, the bulb of which is placed in
the body of the produce under treatment and from which wires are conducted to
different toned bells in the furnace chamber, where, without ascending to the drying
floor, the stoker can hear when the temperature of the produce has reached 'certain
determined limits, high or low, thereby enabling him to regulate the inlets to the
furnace and air tubes and passages and so to keep the temperature of the produce at
or about the required degree.
When commencing to work the air pipes and passages are left fully open and the
fan is driven at a high speed, then, when the moisture is mostly driven off, the air

page_text: passages are partially throttled, the door or baffle 6 is placed in its vertical position
and the number of revolutions of the fan lowered, whereby the heat is increased to
any desired degree.
By the means herein described I am enabled to dry the produce in much less time,
at a higher temperature, and more perfectly than heretofore, and, in consequence of
the large volume of air continuously passing through the bulk of the produce during
the drying operation, it is sweetened, purified and otherwise improved."
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In kilns of the character herein referred to, the combination therewith of walls
or divisions and a deflector 2 in the hot air chamber, air pipes or tubes, an
approximately air tight roof and an exhaust fan substantially as herein shown and
described and for the purpose stated.
2. In kilns of the character herein referred to the employment in the hot air
chamber d of division walls d' and deflector d, either in lieu of, or in combination
with, the horizontal air flues e and dome 12 substantially as herein shown and
described.
3. In kilns of the character herein referred to the combination therewith of walls
or divisions d' deflector d², upwardly inclined openings or air passages ƒ, au
approximately air tight roof and a fan substantially as hercin shown and described.
4. In kilns of the character herein referred to, the combination therewith of an
approximately air tight roof and an exhaust fan substantially as herein shown and
described.
J
11000