CERTAIN IMPROVE- MENTS IN THE APPLICATION OF HEAT TO DRYING PURPOSES
Year: 1854

page_text: LETTERS PATENT to William Watt, of Glasgow, in the County of
Lanark, North Britain, Chemist, for the Invention of "CERTAIN IMPROVE-
MENTS IN THE APPLICATION OF HEAT TO DRYING PURPOSES."
Scaled the 30th June 1854, and dated the 11th January 1854.
PROVISIONAL SPECIFICATION left by the said William Watt at the Office
of the Commissioners of Patents, with his Petition, on the 11th January
1854.
I, WILLIAM WATT, do hereby declare the nature of the said Invention for
"CERTAIN IMPROVEMENTS IN THE APPLICATION OF HEAT TO DRYING PURPOSES"
to be as follows:-
The nature of my Invention consists in the peculiar configuration and
arrangement of stove hereafter described, so as to combine economy in fuel
with safe and effective results in the process of drying.
In the accompanying Drawings Figure 1 is a longitudinal section of the
apparatus, with chimney attached; Figure 2 is a plan shewing smoke flue,
damp air shaft, and chimney; Figure 3 is a plan shewing pipes, cold and hot
air drains, and floor; Figure 4, cross section; Figure 5, end clevation; Figures
6 and 7, section and plan of chimney, with small furnace. A, a common
furnace front and bars; B, cast iron pipes of oval shape, about 7 inches by
3 inches; C, plates on each side of furnace with faucet joints, into which the

page_text: pipes Bare fitted and made tight by any suitable material; I prefer for this pur-
pose lime putty mixed with common salt; D, an arch of fire brick, which acts as
a reverberatory furnace in heating the pipes B; E, upright binders; F, the rods
connecting these, so as to bind the whole together; G, a drain for the supply
of cold air, and communicating with the outside of the building; H, a hot air
drain situated at the other end of the pipes B; I, dampers for. regulating the
supply of hot air, and opening to the inside of the house; K, a damper for
transferring the supply of hot air into a separate drying house, if required;
L, continuation of smoke flue; M, damp air shaft or drain communicating
with chimney, having openings into the stove room, for the purpose of drawing
off the damp air; N, damp air shaft communicating with lower part of drying
house and connected with chimney 0; P, small furnace for increasing the
draft when desired. This is particularly useful when a chimney other than
the smoke chimney is used for drawing off the damp air, as it produces a
a stronger current, and so renews more frequently the atmosphere in the stove
room. Q, shews the chimney used both as smoke and damp air chimney; it
is double for a part of its height; into the centre chimney the smoke flue is
led, and the damp air into the outer space. In carrying out effectively these
arrangements, the stove room requires to be made as air tight as possible, the
only ingress for air being by cold air drain, and only egress by damp air shaft
and chimney.
By the above arrangements I am enabled to abstract a large proportion of
the heat of the fire, and distribute it through the stove room in the form of
heated air, and by drawing off the damp air as described, and thus constantly
supplying the stove room with a fresh current of heated air, I am enabled to
abstract the moisture from what may be exposed to be dried at a moderate
temperature, and in a simple and economical manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Watt in the Great Seal Patent Office on the
11th July 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
WATT, of Glasgow, in the County of Lanark, North Britain, Chemist, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of January, in the year of our Lord One
thousand eight hundred and fifty-four, in the seventeenth year of Her reign,

page_text: did, for Herself, Her heirs and successors, give and grant unto me, the said
William Watt, Her special licenco that I, the said William Watt, my execu-
tors, administrators, and assigns, or such others as I, the said William Watt,
my executors, administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend, within
the United Kingdom of Great Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for "CERTAIN IMPROVEMENTS IN THE APPLICATION OF
HEAT TO DRYING PURPOSES," upon the condition (amongst others) that I, the said
William Watt, by an instrument in writing under my hand and seal, should
particularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office, within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Watt, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement
thereof, reference being had to the accompanying Drawing, and to the figures
and letters marked thereon, that is to say:-
The Invention relates to the construction and application of a peculiar
arrangement and combination of apparatus for drying by means of heated air,
as herein-after described, whereby economy in fuel is combined with safe and
effective results in the process of drying.
Figure 1 of the accompanying Drawing is a longitudinal section of the
apparatus which I employ; Figure 2 is a sectional plan of the same, taken
below the grate of the furnace; Figure 3 is a plan partly in section; Figure 4
is a transverse section; and Figure 5 is an end elevation. The same letters
refer to similar parts in each Figure. A, is an ordinary furnace front, with fire
door and fire bars; B, B, are a number of cast iron pipes of oval shape fitted
into cast iron plates C, C. The flames and products of combustion from this
furnace pass along a brick flue or gallery containing the series of cast iron pipes
B, B, which are fitted into faucet joints on cast iron plates C, C, placed on
the outside of the side walls of the flue. The flue is covered by an arch D,
which, together with the side walls and plates C, C, is sustained by the upright
binders E, E, which are connected by tie rods F. The faucet joints of the
pipes are made sufficiently air-tight with lime putty mixed with common salt,
or any other suitable cement. By arranging the pipes in this manner their
expansion and contraction can take place without cracking or straining the
pipes, or endangering the stability of the furnace. R, is a riddled or perforated

page_text: arch extending some distance under the pipes where the heat is greatest, to
protect them and diffuse the heat more uniformly. The products of com-
bustion, after leaving this arched or reverberatory flue, descend and return by
the flue L, to the chimney Q. G is a flue or cold air drain which is built over
the flue L, and conveys the cold air to the pipes B, B, through which it passes,
and becoming heated in its passage, enters the hot air flue II, whence it escapes
through the passages I, I, into a large room or drying chamber, in which are
placed the articles to be dried; or the hot air may be conveyed from the end
of the flue at K, into the drying chamber, or into another separate drying
chamber, as may be desired. The passages I and K are furnished with
dampers or valves for regulating the entrance of the air. M is another flue
or drain, which communicates with the drying chamber by one or more
apertures, and serves to convey the damp air from the drying chamber to the
chimney Q. An inner chimney or lining is carried up a short distance within
the outer chimney, and the damp air is conducted into the space between the
lining and the outer chimney, while the products of combustion ascend in
the lining or inner chimney. The drying chamber is made as air-tight as
possible.
The draught of the chimney Q, draws a constant current of air through
the cold air drain G, pipes B, B, hot air drain H, and openings I or K, into the
drying chamber, and from the drying chamber through the damp air flue M,
into the chimney Q. At the same time the draught of the chimney keeps up
the combustion of the fuel in the furnace, and draws the products of com-
bustion through the reverberatory gallery or flue and the return flue L, into
the chimney Q. The products of combustion in their passage through the
reverberatory flue give out a large portion of their heat to the pipes B, B, and
the heat which still remains in the products of combustion serves to create the
draught up the chimney Q. The furnace and flues may be surrounded with
good non-conducting materials, to prevent the escape of heat, and they may be
built within the drying chamber, so that the heat which does escape from them
may not be lost or wasted.
In lieu of employing the chimney of the furnace A, to produce the current
of air through the drying chamber, a separate chimney may be employed for
that purpose. Figure 6 is a vertical section, and Figure 7 is a plan of such
an arrangement. N, is the damp air flue leading from the drying chamber
into the chimney 0; P, is a small furnace constructed within the chimney O,
and furnished with a short piece of pipe ascending within the chimney O.
This furnace is provided with a fire door for the introduction of fuel, and a
door to its ashpit also. When both these doors are closed, a portion of the

page_text: damp air passes through the furnace, while the remainder ascends round it, as
shewn by the arrows; the whole finally escapes up the chimney O.
Having now described the nature of my said Invention, and in what manner
the same is to be performed, I wish it to be understood that I do not claim
generally the application to drying purposes of air heated by passing through
hot pipes; but what I claim is,---
The construction and application of a long reverberatory furnace, with
transverse pipes fitted into faucet joints, in manner herein-before described, in
connection with a drying chamber, through which passes a current of air
heated by passing through the aforesaid pipes.
In witness whereof, I, the said William Watt, have hereunto set my
hand and seal, this Tenth day of July, One thousand eight hundred
and fifty-four.
5 Witness,
ROB. N. LEADBETTER,
77, Queen St.,
Glasgow.
WILLIAM WATT. (L.S.)