PURPOSE
[0001] This descriptive report refers to a longitudinal continuous furnace applicable to
construction material, the obvious use of which lies on its configuration as a mechanism
that causes the drying and baking of the clay with which the construction ceramic
material is manufactured so that it acquires its own characteristics.
[0002] The invention permits the drying and baking of clay by means of providing heat that
uses pressurized air as the conductor element. This characteristic gives it good performance
and effectiveness for the work entrusted, at the same time as the configuration as
a longitudinal and continuous furnace provides the invention with a high degree of
automation of the drying and baking process and avoids time losses associated to the
intermittency that characterize conventional discontinuous furnaces.
SCOPE
[0003] The invention has its application scope within the industry dedicated to the manufacture
of industrial furnaces, more specifically within the industry dedicated to the manufacture
of industrial furnaces applicable to construction ceramic materials.
HISTORY
[0004] Manufacture of construction ceramic material is based on two fundamental activities,
molding and baking, the first of which is normally carried out by introducing the
unworked clay under pressure into molds in the negative shape of the brick section
it is desired to manufacture, obtaining a continuous form of plastic clay that is
subsequently cut into the desired lengths by means of a wire or similar.
[0005] So that the clay has homogeneous properties and does not present air bubbles, it
is made to pass through rollers located before being molded under pressure. This is
usually carried out by means of an endless screw that places the clay in the above
described molds.
[0006] Once the plastic and humid clay bricks are obtained in the length and section desired,
they are grouped together and placed in a furnace which first dries them at moderate
temperature and then bakes them at an appreciably higher temperature.
[0007] The furnaces normally used are of the discontinuous and very large type which must
be heated before placing the load of bricks to be dried and baked inside them so that,
after approximately thirty hours, the supply is cut off and the furnace slowly cooled
in order to extract the product.
[0008] The process is slow and the size of the furnaces, although directly dependent on
the capacity of the plant, is usually very large.
[0009] It would be advisable to have furnaces applicable to the manufacture of construction
ceramic material that decreased the time the product is inside them and reduced their
general size. These improvements would give rise to a proportional decrease in the
investment, proportional to the size, and in the operating costs, proportional to
the time the bricks are inside the furnace.
[0010] The applicant, on the other hand, has no record of the existence of longitudinal
continuous furnaces specifically applicable to the drying and baking of construction
ceramic material.
DESCRIPTION OF THE INVENTION
[0011] The longitudinal continuous furnace applicable to construction ceramic material,
purpose of this descriptive report, constitutes an obvious novelty within its field
of application, as it allows the drying and baking of construction ceramic material
in a substantially shorter time than the conventional discontinuous furnaces applicable
to this field, and with a smaller-sized furnace the characteristics indicated as desirable
for a device of this type are thus obtained.
[0012] More specifically, the invention is constituted of a main body of the furnace in
the shape of a very long and squared section tunnel, coated inside with refractory
bricks and provided with rails on the floor along which low speed wagons that transport
groups of bricks through it circulate.
[0013] There are two types of devices on the lateral walls of the main body of the furnace
that inject air inside, nozzles located on one of the interior lateral faces that
blow hot air coming from gas burners located outside and, on the opposite internal
face, fans that blow outside air at ambient temperature which, together with the previous
ones, obtain spiral currents the axis of which is parallel to the large size of the
main body of the tunnel.
[0014] In this way it is obtained that the hot air in movement reaches all the points of
the bricks conveyed on the wagons, accelerating the drying and baking processes as
regards the conventional furnaces, in other words, whilst the transmittal of heat
in traditional furnaces is basically made by radiation, in this invention it is made
by convection.
[0015] The calories provided inside the invention by the nozzles can be regulated by varying
the gas flow burnt per unit of time in same, thus the temperature throughout the main
body of the furnace can be varied at will, creating a drying area with a suitable
temperature in the initial area of the main body of the furnace, followed by a second
high temperature area suitable for the baking of the bricks and a third area, in the
final section of the mentioned main body of the furnace, with progressive temperature
reduction in order to reach slow cooling of the bricks so that stresses in same are
not created.
[0016] The speed of the wagons must be studied so that, due to the length of the main body
of the furnace, the time the bricks are inside said furnace is suitable.
DESCRIPTION OF THE DRAWINGS
[0017] In order to better understand the terms in which this descriptive report is written,
two sheets of drawings are attached in which the following has been represented in
an illustrative but not limiting way:
Figure 1 shows a section view of the invention where the wagons that contain the bricks,
nozzles and, by means of a spiral curve, the shape of the hot air current created
along the inside of the main body of the furnace can be seen.
Figure 2 shoes a perspective view of the invention from the inlet mouth where a wagon
loaded with bricks and, by means of a line with arrows, the hot air flow lines can
be seen.
Figure 3 shows the same object that represents the above figure but without the brick
wagon, observing the hot air nozzles and blowers in depth.
PREFERRED PERFORMANCE OF THE INVENTION
[0018] In view of the figures it can be seen how the proposed longitudinal continuous furnace
applicable to construction ceramic material is made up of a main body of the furnace
(1), constituted by a rectangular base prismatic body where one of the sizes parallel
to the horizontal is comparatively much larger that the other two, that are appreciably
the same, constituting a body in the shape of a squared section tunnel which is covered
on the inside by refractory bricks and the upper area of which has a line of hot air
nozzles (2) on one of its inside lateral faces that diffuse the hot air provided by
gas burners (4), located coaxially on the outside area of the main body of the furnace
(1).
[0019] The diffused air temperature may vary by means of modifying the gas flow with which
the mentioned gas burners (4) are supplied.
[0020] It can also be noticed that on the opposite inside face there are a number of blowers
(3) which are supplied by means of compressed air at ambient temperature and the mission
of which is to create convection currents inside the main body of the furnace (1)
to permit rapid drying and baking of the bricks (5) that go through the inside of
the invention a low speed on wagons (6) that circulate on rails (7).
[0021] The bricks (5) must be placed on the wagons so that their holes are aligned according
to the normal direction of the larger size of the main body of the furnace (1) to
facilitate the formation of the convection currents and so that these easily penetrate
inside said bricks (5).
[0022] On the inside area of the main body of the furnace (1), in the region where the horizontal
surface of the wagons (6) passes by, there is a projection (8) on each lateral wall
in order to prevent that the air currents flow through the inferior area of the wagons
(6), creating longitudinal flows that come into contact with the bricks (5) placed
inside the invention. In the same way, the brick load (5) must be placed near the
ceiling and walls of the main body of the furnace (1)
[0023] In the preferred performance of the invention, the main body of the furnace (1) is
manufactured in brickwork, although it can be perfectly made in teal provided with
suitable insulating components.
1. Longitudinal continuous furnace applicable to construction material, characterized
by the fact that it is made up of a main body of the furnace (1), manufactured in
brickwork and covered inside by refractory bricks, that has one on or its inside lateral
walls a line of nozzles (2) that spread hot air generated in gas burners (4) located
coaxially, that the opposite interior wall has a number of blowers (3) that inject
pressurized air at ambient temperature from the outside and that is has some rails
(7) on the floor along which wagons (6) transporting the bricks (5) to be baked can
circulate.
2. Longitudinal continuous furnace applicable to construction ceramic material, according
to the first claim, characterized by the fact that inside the main body of the furnace
(1) there is a projection (8) located in the region through which the horizontal surface
of the wagons (6) circulates.