AN IMPROVED KILN OR COMBINATION OF KILNS
Year: 1873

page_text: LETTERS PATENT to Robert Pickwell, of High Street, Hull, in the
County of York, Engineer, for the Invention of "AN IMPROVED
KILN OR COMBINATION OF KILNS."
Sealed the 14th April 1874, and dated the 17th October 1873.
PROVISIONAL SPECIFICATION left by the said Robert Pickwell at the
Office of the Commissioners of Patents, with his Petition, on the
17th October 1873.
I, ROBERT PICKWELL, of High Street, Hull, in the County of York,
Engineer, do hereby declare the nature of the said Invention for
"AN IMPROVED KILN OR COMBINATION OF KILNS," to be as follows:-
The structure contemplated is a series of kiln chambers in juxta-
position and may be considered as stated in the title either as a
combination of separate kilns or together as a kiln. ·

page_text: And the Invention consists in disposing, erecting, or constructing a
scries of kilns in combination with all necessary hot air and steam
passages, flues, and chambers, and regulating valves and dampers, so as
to obtain in working a regenerative effect or action and advantageous
employment of the fuel, and heating of external air for supply to the
kilns, and means of regulating the heat of any particular kiln, and of
discharge as desired of steam or watery or waste therefrom.
vapors
The accompanying Drawing shews two sketches or Diagram plan
views in illustration of the means of performing the Invention. In
cach of these the cight kilns A₁, A², A³, A', &c., are indicated as a
convenient number, are or some of them are of a generally rectangular
shape (on plan), and are arranged in a rectangular combination.
A shaft or chimney is contemplated, and also the passages, flues,
chambers, and valves or dampers above mentioned to direct the hot or
heated currents from one to another in succession, or otherwise to 1
the chimney, or if desired by a shorter route to the chimney and to
direct external cold air from one to another in succession or otherwise,
so as to heat the said air for and as a supply to the kiln or kilns which
are being fired or require the admission of air for combustion of the fuel.
Thus supposing A¹ is being fired A³ is receiving the waste heat and
harmless gases in a highly heated state, producing a red heat, A³ is being
dried by same air at a lower temperature, A' is steaming and discharging
steam directly or indirectly into the chimney, A" is being set, A6 is
being drawn, A' and A³ are themselves cooling by air passing through
them which becomes heated for supply to the fire in A¹.
The several kilns are supposed to be fired in succession and the varied
action or purpose of each to follow or be accomplished in succession in
the order described. Any convenient number of kilns instead of eight
may be used in the combination.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of October, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Robert Pickwell, Her special
licence that I, the said Robert Pickwell, my executors, administrators,
and assigns, or such others as I, the said Robert Pickwell, 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 "AN IMPROVED
KILN OR COMBINATION OF KILNS," upon the condition (amongst others) that
I, the said Robert Pickwell, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, 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 immediately after the date of the said Letters

page_text: In the accompanying Drawing Figures 1 and 2 are two sketches or
diagram plan views in general illustration of the means of performing
the Invention. In each of these the eight kilns A³, A³, A³, A*, &c., are
indicated as a convenient number and arc or some of them are of a
generally rectangular shape (on plan) and are arranged in a rectangular
combination.
A shaft or chimney is contemplated and also the passages, flues,
chambers and valves or dampers above mentioned to direct the hot or
heated currents from one to another in succession or otherwise to the
chimney, or if desired by a shorter route to the chimney and to direct
external cold air from one to another in succession or otherwise so as to
heat the said air for and as a supply to the kiln or kilns which are being
fired or require the admission of air for combustion of the fuel.
Thus supposing A¹ is being fired or burning, A³ is receiving the waste
heat and harmless gases in a highly heated state, producing a dull read
heat, A³ is being dried by same air or gas at a lower temperature, A* is:
steaming caused by same air or gas at a still lower temperature and
discharging steam directly or indirectly into the chimney, A³ is being.
set, A is being drawn, A' and A³ are themselves cooling by air passing
through them which becomes heated for supply to the fire in A².
The several kilns are supposed to be fired in succession and the varied
action or purpose of each to follow or be accomplished in succession in
the order described. Thus by the time A¹ is burnt sufficiently A² has
been raised to red heat and is being fed with fuel from the feed holes,
A³ is at red heat, A' is being dried, A³ is steaming, A' is being set, A' is
being drawn, A³ (and A¹) are cooling. This round of operation goes on
continually, the arrangement permitting one kiln to be drawn and one
to be set each day.
Having thus by reference to the Figures 1 and 2 explained the
general principle or character of the Invention I will now proceed to
describe the Figures 3, 4, and 5, which illustrate in some degree of
detail the actual construction of a kiln or combination of kilns in
accordance with such character or principle.
-
Figure 3 is a vertical and longitudinal section taken through the
line X, X*, in Figure 4. Figure 4 is a plan view, one half taken at top
and the other half through the line Y, Y*, in Figure 3; and Figure 5 is
a transverse and vertical section taken through the line Z, Z*, in
Figure 4.

page_text: It will be seen that a number of separate arched kilns A², A³, &c., are
built side by side in two rows, each row containing 4 (or there may
be 6, 8, or any desired number), the division walls are built solid and are
provided with small fire-holes B, B¹, B³, &c., placed a little below the
floor line, as shewn, which arrangement by the assistance of the
moveable dampers secures the most perfect bottom draught and ensures
burning the bricks, &c., at bottom of kiln practically without waste.
The waste heat flues C³, 0, 0, in these kilns are built each between
one pair of kilns and at the top in the spandril of main arches the air
passages to which are shewn at a, a, a, a. Each of these flues is fitted
with a pair of valves c and d, so that the most perfect control over the
draught and fire is obtained. The fire is made to travel along the
outside cold walls of kiln with perfect ease, and an equal and regular
temperature is maintained in every part of the kiln operated upon. The
advantage of this position for the flues is very great since the waste
heat which is still at a considerable temperature is permitted to rise into
them and out at the chimney and is not compelled against its nature to
descend into subterranean flues on its way to the chimney. This
alone reduces the necessary capacity and height of chimney to a
minnimum.
The arrangement of valves to these flues is such that they can with
the greatest possible ease be examined periodically and adjusted without
the necessity of the fireman entering any of the flues to do so. E is a.
hot air flue provided with valves so that a current of hot air can at will
be drawn from the fire and passed through any isolated kiln quite
independently of the main draught. This will be found of great use in
drying material before burning when needed.
Provision is made for drawing off steam generated from the damp
material by a steam flue D built at the crown of each kiln and including
one row of fuel feed holes G which thus do double duty. The steam
from cach kiln by this means is allowed to rise naturally into these flues,
and is drawn off to the chimney instead of being allowed to throw
undue duty on the chimney, seriously interfereing with the draught
by being driven on before the fire from kiln to kiln along with the
ordinary hot air draught. I apprehend that the chimney shaft F in
consequence of the easy and natural flow of waste heat is only needed a
height of 50 to 65 feet. The kiln is fed with slack from the top through
the feed. holes G, G, G, these being provided with removeable caps or

page_text: allowed to escape in the ordinary system of burning bricks, tiles, pipes,
lime, cement, and such like articles as to produce in the consumption of
fuel an economy equivalent or approximating to from 50 to 75 per
cent.
Having now described the nature of the said Invention and the
manner in which the same is to be and may be performed, I claim
the constructing kilns or combination of kilns, substantially as herein
set forth and as represented in the Drawing.
In witness whereof, I, the said Robert Pickwell, have hereunto
set my hand and scal, this Fifteenth day of April, in the
year of our Lord One thousand eight hundred and seventy-
four.
ROBERT PICKWELL. (L.S.)