AN IMPROVE- MENT IN THE CONSTRUCTION OF MALT KILNS, SO AS TO PREVENT DAMAGE BY FIRE AND TO SAVE FUEL IN THE DRYING MALT
Year: 1805

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
BARRETT, of Saffron Walden, in the County of Essex, Smith and Ironmonger,
do send greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Twenty-ninth day of January, in the forty-fifth year of His reign,
did give and grant unto me, the said James Barrett, my executors, adminis-
trators, and assigns, His special licence, full power, sole privilege and authority,
that I, the said James Barrett, my executors, administrators, and assigns,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "AN IMPROVE-
MENT IN THE CONSTRUCTION OF MALT KILNS, SO AS TO PREVENT DAMAGE BY FIRE
AND TO SAVE FUEL IN THE DRYING MALT;" in which Letters Patent there is con-
tained a proviso, obliging me, the said James Barrett, under my hand and seal,
to cause a particular description of the nature of my said Invention, and the
manner in which the same is to be performed, to be inrolled in His Majesty's
High Court of Chancery within one calendar month next and immediately
after the date of the said in part recited Letters Patent, as in and by the same,
relation being thereunto had, may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso in the said
Letters Patent contained, I, the said James Barrett, do hereby declare that
my said Invention is described and ascertained in manner and form following,
reference being made to the Drawings hereunto annexed, that is to say:-

page_text: My improvement consists in building kilns agreeably to the Drawings
varying their shape, height, and size, as circumstances may dictate, so as to
increase the draught, which I introduce sometimes under and sometimes over
the neck or furnace of the kiln, as well as by the sides, and I generally build
the kilns at least ten feet higher than is shewn in the Drawing. I introduce
into the barrel or chimney of the kiln an apparatus, made of iron or other fit
material, which I denominate an extinguisher, as, by its being closed, it will
totally stop the draught of the kiln, and thereby prevent fire from communi-
cating to the cowl, if made of wood, as at present, but which I construct of
iron, or other fit metal, and of a peculiar construction, without ribs or any
wood-work whatever; and, when circumstances permit, I recommend that the
internal windows and doors in the kiln over the wire aud their frames be made
of iron instead of wood, as it is not subject, as wood, to shrink, swell, nor warp,
by which means the cold external air will be kept out and the draft of the
kiln improved. I construct or build the walls of the kiln hollow or double, so
as to leave a space between them; I also apply, according to circumstances,
as afterwards is fully explained, apertures, channels, flues, dampers, valves,
expellers, dischargers, registers, &c. For the drying of pale malt, I make use
of a moveable furnace or stove of a peculiar construction, which may be used
with but little alteration of the kiln, either for drying pale or brown malt; and
by means of an additional contrivance, also herein-after described, it will burn
with advantage Newcastle or pit coal without the previous preparation of being
burnt into coke, under circumstances where Welch coal or cinders cannot
be procured. I also conduct the flame and heat from the furnace through
the malt kiln, wherever required, without impediment from the wind blowing
hard from either quarter, which I accomplish by means of what I term direc-
tors, also herein-after explained.
Having ascertained generally the nature of my improvement in the con-
struction of malt kilns, so as to prevent damage by fire and to save fuel in the
drying of malt, I shall proceed to describe particularly the manner in which
the same is to be performed with reference to the Drawings hereunto
annexed.
A, Fig. 1, is an elevation of one side of a malt kiln next to the kiln house,
constructed. according to my improvement; B, B, B, B, B, iron plate and
frame, with grooves in the same for the iron doors C, C, to slide up and down
in; C, C, iron doors, which slide over the apertures F to admit more or less
atmospheric air to circulate round the furnace neck or receiver of the kiln D,
by means of which the air becomes rarified, and afterwards enters the channels
on the right and left, (shewn on one side by the letters K and L.) which

page_text: conduct it to and discharge it at the apertures a, b, and c. shewn in Fig. 3,
which is a geometrical view and section; and also in Fig. 4, which is a
section of the end of the kiln next the furnace. It is discharged either under
or over the wire tile, hair cloth, or other floor on which the malt is dried, in
5 order to disperse and carry off the vast quantity of steam which always arises
in the process of drying malt, and it then may be conducted, by means of the
registers E, shewn in Figs. 1 and 3, which move on a pivot, either entirely over
or under, or partly in either channel, as the process may require, which will
be found particularly advantageous in the process of drying palé malt. G shews
half of the iron slide door at the mouth of the furnace, which door is for the
purpose of regulating the admission of cold air to the fire, and prevent its
rushing forcibly in, as is the case in kilns now in common use, which mate-
rially increases the consumption of feel. This door is connected to the before-
mentioned doors C, C, by means of the chains I, I, I, and pullies H, H, so that
by a single and easy motion of the balance handle M, shown in Figs. 2 and 8,
the three slide doors C, C, and G, act conjunctively to admit air into the aper-
ture F, and exclude the air from the mouth of the kiln D, they being so
contrived and adjusted that no more air is excluded at the furnace than is
admitted at the apertures and channels round the kiln and sides thereof, that
is to say, as much air is excluded from one place as is at the same time
admitted at the other, which tends very materially to the saving of fuel and
carrying off the steam arising from the malt; it also affords the advantage of
increasing or decreasing the draught at pleasure to the greatest nicety, and
consequently permits the workman to continue his drying in all weathers with
case and safety, which cannot be done in kilns on the old construction, on
account of danger from fire. N, the iron horse on which the fuel is consumed
while drying brown malt. For the purpose of ventilating the kiln, and, ren-
dering it healthful and comfortable for the workmen while they are turning,
taking off, or putting on the malt, I make doors, to be opened occasionally
in hot weather, into the channels K and L; but in the Drawing, one door
is only shown, as at O, the other side exhibiting the channels K, L, before
mentioned. By this means the rarified air is kept in reserve in the air
box under, in the air chamber over, and in the flues round the furnace,
and again makes its progress on shutting the said door. P, P, are two-
entrances by double wooden doors, leading round the under side of the
benches Q, in Fig. 2, by which means the neutral air contained therein repels
he damps, which, otherwise, in the kilns now in common use with solid
benchings, is imperceptibly absorbed by the heat of the fire, and which con-
sequently occasions a much greater waste of fuel than is absolutely necessary

page_text: I, therefore, in cases where new kilns are to be erected, recommend an
arch or arches to be constructed under the ash-pit floor. R, a step-ladder or
staircase, and landing, leading to the entrance S, which opens into the kiln.
In Fig. 2 is shewn a sight hole, to view the progress of the drying without
opening the door. T, the barrel or chimney over the kiln; V, the cross
bearing beam, on which the cowl X, which is made of iron or other fit metal,
without ribs or any wood-work whatsoever, turns, with its spindle W, which is
also made of iron, or other proper material; Y is the apparatus which I deno-
minate the extinguisher, to prevent damage by fire; it may be made of wood,
but more properly of iron or other metal; it is so constructed, that by pulling
the wire or chain pending therefrom down to the side of the kiln and attached
to the handle Z, it will either partially or completely close, at the option
of the workman, the barrel or chimney of the kiln, and effectually stop or
regulate the draught; and if the wire or chain be continued from the said
handle Z down to the fire side, the workman may, in windy weather, be
enabled to regulate the draught and currency of air at his pleasure, with
the greatest case, and extinguish the malt if on fire, without the necessity of
ascending the step-ladder or staircase for that purpose, as he can by that means
close the extinguisher, which will immediately stop the draught of air that
feeds the flames, and of course the fire is suffocated and extinguished by the
smoke arising therefrom, and cannot do any further damage. The workman
may, therefore, by means of the handle Z and the balance handle M, before
mentioned, regulate the extinguisher and iron slide door, so as to dry the malt,
either exceedingly slow or exceedingly fierce, as may best suit his purpose, with
the same ease that a miller regulates his brake when grinding corn. Fig. 2
shows the elevation of the front of the kiln, with the moveable furnace in the
neck, as used in drying pale malt. The letters refer to similar parts as
described under the same letters in Figure 1. Figure 3, geometrical view and
section of the kiln, drying floor, benchings, hurdle, spark plate or defender, and
a section of the neck of the kiln, shewing the flucs and channels which convey
the external air, after being rarified, either under or over the kiln, by means of
pipes, flues, or hollow walls, as expressed in Figure 1. a, &c. are apertures
from the walls, which are double or hollow, for conveying the rarified air over
the malt, in order to dispell or carry off the steam arising therefrom while
drying. These apertures are closed next the kiln with open kiln wires, in
order to keep out vermin. b, &c. are apertures for the same purpose, but con-
veying rarified air under and through the malt while drying; c shews one of
the apertures or pipes under, and over, and by the sides of the neck of the
kiln, for equalizing the flame under the spark plate; d, &c., cylindrical iron

page_text: pipes, to which is fixed the spiral tube, Fig. 12, when it is intended to dry pale
malt; E, the handle of the register, described before in Fig. 1; e, brick
partition between the flues adjoining the neck; f, the top of the neck,
over the furnace, round which the atmospheric air revolves and becomes
rarified; B, section of the iron frame and sliding doors, described in Figs. 1
and 2, which are moved up or down by the balance handle M, with its chain
or metallic rope placed immediately over the workman's head, or at any other
part where most convenient, by which.he may regulate the fire to the greatest
possible nicety; Q, neutral air under the benches, explained in Fig. 1, P, P;
g.g, the top side of the said benchings; h, h, side walls of the ash-pit; i, the
wire tile or hair cloth on which the malt is dried; k, iron hurdle under the said
wire tile or hair cloth, which was originally invented by my father, who, in the
year One thousand seven hundred and seventy-three, fixed one up in a kiln
belonging to the late Mr. Jabez Wyatt, Common Brewer, in Saffron Walden,
where it now remains unaltered, universally acknowledged by every malster
to be a great improvement in the economy of fuel, and in expediting the
process, particularly in high-dried, or commonly called brown or porter malt.
7, the spark plate or defender; m, m, m, the walls of the kiln. F. 4, section
of the farther end of the kiln opposite the furnace. d, d, d, air pipes; m, m,
section of the walls of the kiln; h, h, walls of the ash-pit; g,g, the benching;
K, K, L, L, channels for air, explained in Fig. 1; 0, 0, floor of the ash-pit.
Fig. 5, ground plan of the kiln, here supposed to be about sixteen by eighteen
feet withinside the walls. d, d, d, air pipes; m, m, m, m, m, plan of the walls
of the kiln; 9,9, 9, plan of the walls of the benching; n, &c., plan of the walls
of the air box; P, P, plan of the opening of the double doors, described in
Fig. 1; Q, Q, Q, the space for neutral air, sec Fig. 3 and 4; o, plan of the
ash-pit; r,r, two doors, which I call directors, placed on each side at the
farther end of the neck, to be made of cast iron, or other fit metal, or of earth
made into the consistency of brick or fire-stone. They are moveable at
pleasure for equalizing the flame arising from wood in drying brown malt. In
kilns on the old construction this object cannot be attained by any skill or
labour of the workman.
Figs. 6, 7, 8, 9, 10, exhibit the apparatus of which I have before spoken,
called the extinguisher, separated from the barrel or chimney of the kiln, that
it may be more clearly understood. Fig. 6 shews the top of the extinguisher
when closed, made with two semicircular plates of iron, but I have found by
experience that it is best to construct them in quadrants, as in Fig. 7, also in
Fig. 9, which is shewn open. Fig. 8, 9, and 10 shew the extinguisher open
when the kiln is at work, to permit the steam and smoke to pass through.

page_text: a in all these Figures denote the circular iron frame in which the iron plates 6
hang
Note. I do not mean to confine myself to the precise forms here described,
as the extinguisher may be constructed of various shapes, and fixed in other
situations above the malt, according as circumstances may suggest, my Inven-
tion consisting in the application of the apparatus. If the extinguisher be
closed when the kiln is not in use, it will protect the kiln wire or hair cloth
from damage by the weather, or soil from birds. When the kiln is loaded with
pale malt, if the extinguisher be constructed in quadrants, it should at the
commencement of the operation be nearly closed by the handle Z, and it will
then resemble the flyers of a smoke jack, and will not only exclude the vast
quantity of cold atmospheric air which otherwise unavoidably enters the kiln
at the top of the barrel or chimney, and condenses the vapour which arises
from the nialt, and thereby keeps the surface thereof in a chilled state, even to
the injury of the malt, as the heat which should be gentle cannot immediately
penetrate to the surface, particularly if loaded thick, but assists greatly to the
generation of heat, so that a very small fire in my newly invented furnace,
herein-after to be described, will in a very little time render the malt as hot at
top as at the bottom; the whole of the malt will therefore be in a complete
state of vegetation, which contributes very much to its tenderness and flavor.
The steam or vapour also become lighter, and consequently passes off quicker
than in kilns without this apparatus. As the steam increases, the extinguisher
is to be gradually opened, and closed in the same way as the steam or vapour
subsides, so that no heat escapes without doing its office.
Fig. 11 exhibits, in perspective and geometrically, my newly invented
moveable stove or furnace for drying pale malt or amber where Welch coal or
cinders are used. It runs on four wheels or rollers, and may be set in a kiln
either for drying brown or pale malt with but little alteration, as herein-after
described. It may be regulated by the ash-pit register A, so that in all
weathers a due sufficiency of air may be admitted to keep the process of drying
in the most regular manner, which in the present constructed kilns cannot
be accomplished, from the various changes of weather, as a high wind often
consumes the fire rapidly in the absence of the workmen, who on their return
frequently find the fire extinct, and the process of drying ceased, which tends
to injure the malt both in bulk and flavor. By means of the double door to
the furnace B, B, the heat is so confined as that considerably less fuel will be
required than is consumed in furnaces now in use, which I have ascertained
by experience to be a saving of one-third. I am indebted to his Excellency
Count Rumford for this Invention, which he has described in his essays, from

page_text: which I have acquired much information. Contiguous to the double door B, B,
I have added another door E above the furnace, which completely closes
the whole of the furnace, so that no heat can possibly escape; and as I
am confident that the process of drying to be carried on with advantage
depends on a judicious arrangement of the air and heat, it will be found
that this door E, in conjunction with the slides C, C, described in Fig. 1,
and the apertures F, F, thro' which the atmospheric air passes, will become
rarified, conducted, and discharged, as before described, with the same motion
that the doors C, C, Fig. 1, are opened or slid up; the door G in the same
Figure will slide down upon the frame of the double doors in Fig. 11, and by
this means will form a double door with E alternately, and entirely prevent
the escape of the radiant heat.
It sometimes happens that there is a failure in the supply of Welch coals
and cinders, on which account I have added a contrivance to this moveable
furnace, in order that Newcastle or other pit coal may be used without the
previous preparation of being burnt into coke. This I effect by means of
the register F, which closes the farther end of the neck of the kiln, and
prevents the smoke arising from pit coals passing into the kiln, which is
accomplished by the screw and roller G, with its winch H, at the front
of the furnace, so that in this case both ends of the neck are effectually
stopped, and the smoke passes thro' the top of the neck by means of the
iron pipe I, Fig. 12, round which is a spiral tube to receive the air,
which enters the aperture F, in Fig. 1, and its air chambers, and by its
revolving round the said pipe so immediately in contact, it becomes sufficiently
heated to effect the operation, and the smoke becomes so chilled, that what
heat remains in the pipe exhausts itself in its passage thro' a pipe for that
purpose under the wire, and empties itself into the communication pipe,
Fig. 13, placed withinside the barrel of the kiln, with a conjunctive movement
of the valve a, a, or damper b, to the ash-pit register A.
Note. I apprehend that this last-described Invention will be found of great
utility as an addition to the cooking apparatus, on the economical principles
recommended by Count Rumford, and may also be applied with advantage in
manufactories, or other places where boilers or stoves are used. I think proper
also to observe, that altho' I have in this Specification spoken only of the
drying of malt, it must be evident to every one that various other commodities
may be dried with advantage in kilns erected according to my improvement.
In drying of brown malt, it is the particular interest of the malster and
the merit of the workman to obtain as much increase in bulk as possible,
which is principally accomplished by the process of drying, and it is the

page_text: common observation among workmen, that they could dry the malt higher and
larger if it could be protected from the risk of taking fire, and the danger
which the workman himself encounters in his endeavors to extinguish the fire
whenever it happens, which is very frequent. In this trying situation he is in
imminent danger of being burnt or suffocated to death, and his endeavors
are often frustrated. Thus it is in all malting towns that fires are so frequent,
to the terror of the inhabitants, and it is presumed that all these dangers and
inconveniences are most effectually done away by my improvement. The
workman may now raise or force the malt to any extreme of heat short of
actual flame, which is the grand desideratum in the process of drying brown
malt. The extinguisher, slide doors, channels, furnace, &c. may easily be
added to kilns already constructed.
In witness whereof, I, the said James Barrett, have hereunto set my
hand and seal, this Twenty-sixth day of February, in the year of our
Lord One thousand eight hundred and five.
Inrolled the Twenty-eighth day of February, in the year of our Lord One
thousand cight hundred and five.