Improvements in the Construction of Kilns for Burning Lime Stone, Cement, and other similar Material.
Year: 1896

page_text: Date of Application, 12th Aug., 1896-Accepted, 24th Oct., 1896
COMPLETE SPECIFICATION.
Improvements in the Construction of Kilns for Burning Lime Stone,
Cement, and other similar Material.
I, JAMES FOSTER of Carnlough in the County of Antrim, Ireland, Lime
Manufacturer, 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 :-
This invention which relates to the construction of kilus for burning lime stone
and other similar material is an improvement of that type of kiln patented by
Peter William Spencer in 1870 dated 15th March and numbered 767, and is
designed to overcome certain serious defects in the manner of fuelling as likewise
in general construction.
According to my present invention as hereafter more fully described I am able
to effect a considerable saving in fuel, also the production of a lime which is
uniformly burnt and of excellent quality in consequence of the equal distribution
of the fuel in the kiln, together with a material reduction in cost of the upkeep of
the kiln.
] propose to describe my improved kiln in the following order:
First. As to nicety of construction.
Secondly. The method of charging with raw material and
Thirdly. The method of charging the fuel through central and annular feed
shoots. These ends are obtained by constructing a kiln composed of four chambers,
the two upper chambers being of such width relatively with the lower conical one
that any jamming of the stones in their descent is entirely obviated. Across the
larger diameter of the conical chamber which for convenience I shall call the
middle chamber an arched bridge is constructed which may be made rectangular,
on its sides, or may be the sectors of a circle. Through the centre of this bridge
the main fuel shoot is led, through which the bulk of the fuel to the kiln is supplied.
The fuel as it thus falls centrally amongst the material to be burut is speedily
converted into flame, and descending through the narrowing chamber mixes freely
with the stones and diverges or spreads with them towards the sides of the lower
chamber.
The escaping heat meanwhile ramifys the masses of raw material in the upper
chambers and partially calcines same in their downward course to seat of greatest
heat.
The neck of the kiln which is formed by blocks carried round the crown of the
dome is of such overhanging contour as not only to leave the requisite space at the
bottom of the circular feed shoot clear, but insures against destruction to the potting
by fuel coming in contact with same.
'he top of the kilu is surmounted with a brick chimney which may be carried
to ny suitable height and is useful for maintaining a suitable draft in kiln, enabling
coa of smallest description to be consumed and also preventing down-draught
whi. so frequently proves troublesome in connection with lime burning.
In order that my said invention may be more readily understood and carried
into practice, I hereunto append explanatory drawings, in the several views of
which corresponding parts are marked with the same letters of reference.

page_text: Fig. 1. is a vertical section of a kiln made in accordance with my said.
invention.
Fig. 2. is a horizontal section taken on line a, b, (Fig. 1).
Fig. 3. is a vertical section taken at an opposite plane c. d. (Fig. 2) and shewing
extended or heightened chamber walls.
Fig. 4 is a part horizonta! section taken on line e. f. (Fig. 3) and
Fig. 5 is a part horizontal section on line g. h, taken from below.
A. B. C, and D, represent the four chambers, the two upper being formed by the
arched bridge E, which may be in the form shewn in Fig. 2., its upper surface may
be formed by parallel. sides and may. consist of a brick wall F, built upon two
arched rows of fireclay blocks G, and H,, as shewn in Fig. 3.
From the side of the kiln to the centre of the said bridge and extending
vertically downward is led the central fuel feed shoot I. Where desirable this
shoot may be carried vertically through the top of the bridge as seen in dot and
pick lines Fig. 1, to, admit of the escape of smoke, and obviate annoyance to the
attendant when charging said central shoot. To afford freer access in the feeding
operation the shoot may he formed with a semi-bell mouth opening J, and the
horizontal part. might be arranged diagonally to facilitate the introduction of fuel.
K shews the several annular shoots through which according to my invention it is
not necessary to feed much fuel, the great bulk being fed through the central shoot.
The feeding through the annular shoots however is regulated by the diameter of
the lower chamber.
The whole of the material to be treated is. passed through the openings L,
and, M, by means of self tipping waggons or trolleys N and O, which run on
rails P, and Qor the material may be charged by manual labour or otherwise as
convenient.
The flames rising from the burning mass R, (Fig. 1) are seen to issue through
the material to be calcined while the dross or coal dust is shewn falling through
the central and annular shoots.
The point in the lower chamber D and downwards where potting of kiln is liable
to suffer from contact with the fuel is indicated by S. By virtue of the projecting
blocks T and by reason of the annular shoots not requiring much fuel this tendency
is obviated. The same observation applies equally, to the neck of dome and
upwards. The downward gradation and faintness of the etching (Fig. 1) represents
the formation of the lime.
It is obvious that according to my system of central feeding the upper chambers
may, be carried to any reasonable height and charged accordingly with material to
be treated, the advantage of this being that an indefinite quantity of material may
be subjected to the heat arising from the lower chamber and thus a considerable
economy in fuel effected.
This arrangement could not possibly be carried out by feeding through the open
top as has hitherto been the practice.
It is also obvious that a series of kilns may be constructed according to my
invention and each provided with a chimney or outlet communicating with one
common shaft whereby the inconvenience arising from smoke may be reduced to a
minimum.
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
olaim is :-
First. In kilns for burning lime and other similar material the arrangement of
feeding fuel by means of a central shoot formed in a superimposed bridge, or arch
substantially in the manner described and shewn in the accompanying drawings.
Second. The general arrangement and combination of parts operating sub-
stantially as set forth whereby kilns may, be charged from the centre in a manner
which permits of the indefinite heightening of the upper chamber without affecting

page_text: the operation of feeding and thereby effecting economy in fuel and producing
results not hitherto obtainable by the process of feeding through the open top and.
annular shoots alone.
Dated this 8th dex of Avmust 1896
J. K. FAHIE & SON,
9 Westland Row, Dublin, Agents for Applicant.