[0001] The present invention concerns improvements in or relating to kiln assemblies, and
especially but not exclusively to kilns for firing ceramic ware.
[0002] According to the present invention there is provided a kiln assembly including a
plurality of cars adapted to carry ware to be fired through the kiln with the cars
arranged such that their dimension transverse to the direction of movement through
the kiln is greater than their dimension parallel to the kiln, receiving and feeding
means, for respectively receiving cars exiting from the kiln and cars to be fed to
the kiln, and conveyor means for moving cars between the receiving and feeding means
said receiving means incorporating a car turning arrangement whereby after leaving
the kiln and prior to re-introduction to the kiln each car is rotated through 90°
such that as it travels from the receiving means to the feeding means its shortest
dimension is transverse to the direction of travel through the kiln.
[0003] Preferably the kiln cars have wheels adapted to run on rails arranged in the kiln
in the longitudinal direction of the kiln. Preferably the receiving and feeding means
each have an elevating device for lifting and lowering kiln cars from and to the rails.
[0004] Preferably the feeding and receiving means are movable transversely to the direction
of travel of cars through the kiln. Preferably the conveyor means is arranged alongside
the kiln to transport cars deposited thereon by the receiving means to the feeding
means, the cars being unloaded and loaded with ware while on the conveyor means.
[0005] Preferably the car comprises a base from the upper surface of which project a plurality
of columns arranged in pairs, a support beam extending between the columns of each
pair and a relatively thin ware supporting bat supported by three or more beams.
[0006] Preferably the columns comprise hollow tubes of refractory material terminating in
enlarged caps having grooves therein to accommodate the beams. Where no caps are provided
the column tops may be grooved to accommodate the beams.
[0007] A method of continuously cycling kiln cars through a kiln assembly comprising passing
a car through a kiln, receiving the car on its discharge from the kiln, rotating it
through 90°, conveying it to the entrance to the kiln and prior to re-introducing
it into the kiln rotating it through 90°.
[0008] Preferably loading and unloading operations are carried out as the car is returned
from the exit to the entrance of the kiln.
[0009] Preferably the car is lifted off a transportation arrangement on exit from the kiln
and deposited on a return conveyor arrangement and is lifted from said conveyor arrangement
and redeposited on the kiln transportation arrangement at the entrance to the kiln.
[0010] An embodiment of the present invention will now be described by way of example only
with reference to the accompanying drawings in which:-
Fig 1 is a partial plan of a kiln assembly: and
Fig 2 is a perspective view of a kiln car suitable for use in the kiln assembly.
[0011] Fig 1 shows only regions at the feed and delivery ends from a tunnel kiln.
[0012] At the entrance 10 to the kiln there is provided a kiln car feed means 12 while at
the exit 14 from the kiln there is provided a kiln car receiving means 16.
[0013] The feed and delivery means are essentially of similar constuction and the description
of one of said means set out below should be regarded as being a description of the
other means.
[0014] A plurality of wheeled kiln cars 18 (only some of which are shown in the drawings)
are provided to carry ware through the kiln. The kiln cars travel through the kiln
on their wheels and are conveyed from the inlet 10 to the outlet 14 of the kiln by
any suitable known means on rails 20 extending through the kiln. The feed means 12
includes a structure 22 adapted to engage the underside of a kiln car 18 and elevate
the car above the level at which its wheels 112 (Fig 2) would engage the rails 20.
The structure 22 is mounted on a turntable 24 which, on operation, rotates the structure
22 with a kiln car thereon through 90°.
[0015] The feeding means 12 is itself mounted on rails whereby it may move from a position
in which the centre of its turntable lies on the longitudinal centre axis of the kiln
to a point laterally spaced from this axis where the structure 22 can engage a kiln
car 18 brought loaded with ware to a pick-up station P by a conveyor 26 arranged alongside
the kiln and running parallel to the rails 20 thereof.
[0016] In operation, a kiln car 18 brought by the conveyor 26 to the pick-up station P is
lifted off the conveyor by the feed means 12 which is then traversed to the position
shown in the drawing at which point the turntable assembly is operated to rotate the
kiln car through 90° such that its shorter dimension lies along the line parallel
to the rails 20. The structure 22 on which the kiln car is supported is then lowered
to engage the kiln car's wheels on the rails 20. The car may then be progressed in
any normal manner through the kiln so that the ware thereon is fired.
[0017] At the outlet from the kiln 14 the receiving means 16 which, as set out above is
similar in construction and operation to the feed means 12, receives on its structure
22 a "fired" kiln car, raises the kiln car 18 clear of the rails 20, rotates this
kiln car through 90° by means of its turntable assembly 24, moves transversely of
the rails 20 and deposits the kiln car at a loading station L on the chain conveyor
26. The chain conveyor then moves the kiln car alongside the kiln from outlet to inlet
and during this movement it can be readily unloaded and loaded manually by operatives
or automatically by machinery, the loading and unloading operations being facilitated
by the fact that the shortest dimension of the car, that is its fore-and-aft dimension
as it passes through the kiln, is normal to the loading and unloading direction so
that the ware when being loaded and unloaded has to be moved over a relatively short
distance.
[0018] Various modifications can be made without departing from the scope of the invention,
for examplealternatively designed feed and receiving means may be employed provided
that they receive a car in one orientation and rotate it through 90° before discharging
it and the feed and receiving means may be arranged to serve more than one kiln whilst
using one or more conveyors for the return transport system.
[0019] The means for transporting cars through the kiln may be amended, for example roller
means may be employed. In another modification two or more cars of the type described
above can be arranged alongside each other and passed side-by-side through the kiln.
In such a situation modified feeding and receiving means would be called for.
[0020] In the embodiments and modifications described above the kiln is a tunnel kiln where
firing is continuous as the cars make from the entrance to the exit of the kiln. The
invention is equally applicable to a shuttle kiln where a batch of cars are fed to
the kiln where they remain stationary while firing takes place. In a shuttle kiln
assembly, according to the invention, cars are fed through the kiln entrance as before
while the exit is closed until sufficient cars are accumulated in the kiln. Firing
then takes place and after firing the kiln exit is opened to allow cars to move to
the receiving means 16.
[0021] The present invention as described above with reference to Fig 1 obviates or mitigates
problems associated with certain kilns.
[0022] Recent developments have been towards kilns which are much shorter in length but
wider than kilns previously employed as it has been found that a design of this nature
gives rise to considerable thermal and other efficiencies.
[0023] As the width of the kiln increases so also does the width of the kiln cars passing
therethrough and this creates problems especially if the cars are loaded by hand or
by certain automatic mechanised loading arrangements as, for example, a manual operator
has only a limited reach and consequently cannot easily set ware to be fired on areas
of the car out of his reach.
[0024] Fig 2 shows one type of kiln car which is suitable for use in a kiln of the type
described with reference to Fig 1.
[0025] The kiln car is adapted to run on rails 20 by means of wheels 112 rotatably mounted
on the underside of the chassis 108 of the car. The car is provided with a layer of
refractory insulating material 114 through which passes a plurality of pairs of refractory
columns in the form of tubes 118 each terminating in an enlarged diameter end cap
120 and being supported by the steel chassis 108 of the kiln car. A horizontal groove
122 is formed in the upper face of each end cap 120 so that a rectangular cross-section
beam 124 may be received therein with the greatest cross-sectional dimension of the
beam being arranged substantially vertically.
[0026] Each edge of the beam 124, at the appropriate location, is provided with notches
126 to mate with the notches 122 in the end caps 120 to firmly locate the beam against
transverse displacement. As notches 126 are formed in each edge of the beam the beams
may be reversed in use.
[0027] A plain or perforated bat 130 of a refractory material is supported on the beam and
the spacing of the beams is so chosen that they take a major proportion of the weight
of the ware on the bat so that the bat need not be particularly rigid and consequently
can be of relatively light weight.
[0028] The bat may be formed from a plurality of rectangular sections.
[0029] Typically a bat thickness of 15mm may be employed as opposed to the thickness of
30 - 40mm now employed with conventional bat supporting means.
[0030] Various modifications can be made to kiln cars of the type illustrated in Fig 2,
for example the construction of the kiln car can take any convenient form and the
beams and the support columns can be arranged in any convenient manner. In a further
modification, depending on the ware used, the bats 130 can be dispensed with and the
ware can be supported directly on the beam tops. Furthermore, under certain circumstances
the columns 118 may be notched to directly receive the beams 124 without the use of
the caps 120.
1. A kiln assembly including a plurality of cars adapted to carry ware to be fired
through the kiln characterized in that the cars (18) are arranged such that their
dimension transverse to the direction of movement through the kiln is greater than
their dimension parallel to the kiln, receiving and feeding means (16,12) for respectively
receiving cars exiting from the kiln and cars to be fed to the kiln, and conveyor
means (26) for moving cars between the receiving and feeding means, said receiving
means (16) incorporating a car turning arrangement (24) whereby after leaving the
kiln and prior to re-introduction to the kiln each car is rotated through 90° such
that as it travels from the receiving means (16) to the feeding means (12) its shortest
dimension is transverse to the direction of travel through the kiln.
2. A kiln assembly as claimed in Claim 1, characterized in that the receiving and
feeding means (16,12) each have an elevating device for lifting and lowering kiln
wheeled cars (18) from and to rails running through the kiln.
3. A kiln assembly as claimed in Claim 1 and Claim 2 characterized in that the feeding
and receiving means (16,12) are movable transversely to the direction of travel of
cars through the kiln.
4. A kiln assembly as claimed in any one of Claims 1 to 3, characterized in that the
conveyor means (26) is arranged alongside the kiln to transport cars (18) deposited
thereon by the receiving means (16) to the feeding means (12), the cars being unloaded
and loaded with ware while on the conveyor means.
5. A kiln assembly as claimed in any one of the preceding Claims, characterized in
that the car comprises a base (108) from the upper surface of which project a plurality
of columns (118) arranged in pairs, a support beam (124) extending between the columns
of each pair and a relatively thin ware supporting bat (130) supported by three or
more beams.
6. A kiln assembly as claimed in Claim 5 characterized in that the columns (118) comprise
hollow tubes of refractory material terminating in enlarged caps (120) having grooves
(122) therein to accommodate the beams (124).
7. A method of continuously cycling kiln cars through a kiln assembly characterized
in that it comprises passing a car (18) through a kiln, receiving the car on its discharge
from the kiln exit (14), rotating it through 90°, conveying it to the entrance (10)
to the kiln and prior to re-introducing it into the kiln rotating it through 90°.
8. A method as claimed in Claim 7, characterized in that loading and unloading operations
are carried out as the car is returned from the exit to the entrance of the kiln.
9. A method as claimed in Claim 7 and Claim 8, characterized in that the car is lifted
off a transportation arrangement on exit from the kiln and deposited on a return conveyor
arrangement and is lifted from said conveyor arrangement and redeposited on the kiln
transportation arrangement at the entrance to the kiln.