U.S. patent application number 11/605084 was filed with the patent office on 2007-06-21 for method for the removal of deposits on the internal walls of industrial furnaces of bunkers.
Invention is credited to Reinhard Effenberger, Anton Neumeir.
Application Number | 20070137539 11/605084 |
Document ID | / |
Family ID | 36001844 |
Filed Date | 2007-06-21 |
United States Patent
Application |
20070137539 |
Kind Code |
A1 |
Neumeir; Anton ; et
al. |
June 21, 2007 |
Method for the removal of deposits on the internal walls of
industrial furnaces of bunkers
Abstract
In a method for the removal of deposits from the inner walls of
industrial furnaces and bunkers or for the destruction of material
accumulations by shelling with an industrial cannon, the shells
include an explosive charge and an impact detonator and are driven
out of the cannon by compressed air with a controllable travel
speed.
Inventors: |
Neumeir; Anton; (Mering,
DE) ; Effenberger; Reinhard; (Affing/Anwalting,
DE) |
Correspondence
Address: |
KLAUS J. BACH & ASSOCIATES
4407 TWIN OAKS DRIVE
MURRYSVILLE
PA
15668
US
|
Family ID: |
36001844 |
Appl. No.: |
11/605084 |
Filed: |
November 27, 2006 |
Current U.S.
Class: |
110/341 |
Current CPC
Class: |
F42B 6/10 20130101; F42B
10/06 20130101; F41B 11/62 20130101; F23J 3/00 20130101; F42B 12/20
20130101; B08B 9/08 20130101; B08B 7/0007 20130101; F41B 11/87
20130101; B08B 7/02 20130101 |
Class at
Publication: |
110/341 |
International
Class: |
F23B 90/00 20060101
F23B090/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 3, 2005 |
EP |
05 026 412.6 |
Claims
1. A method for the removal of deposits from the internal walls of
industrial furnaces and bunkers or for the destruction of material
collections by shelling with ammunition from an industrial cannon,
comprising the steps of loading the cannon with a shell having a
shell body (1) with a charge of explosive or pyrotechnical
material, and shooting the shell onto a target by compressed air
supplied to the cannon.
2. A method according to claim 1, wherein the industrial cannon is
operated by pressurized air of a pressure ranging from 10 to 40
bar.
3. A method according to claim 2, wherein the air pressure is in
the range of 15-25 bar.
4. A method according to claim 1, wherein the shell comprises a
shell body (1, 2, 3) with an impact detonator (4) for detonating
the charge of explosive or pyrotechnical material.
5. A method according to claim 4, wherein the body of the shell
consists of a rear part (1) which narrows down toward its rear end
and is provided with stabilization fins (2) and a front part (3) in
the form of a cover, the rear part (1) and the front part (3)
jointly forming a chamber for receiving the charge.
6. A method according to claim 1, wherein the impact detonator (4)
is arranged at the front end of the shell.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to a method for the removal of
deposits from the internal walls of industrial furnaces or bunkers
such as blast furnaces, cement ovens, waste incineration plants,
coal-burning power plants or other plants such as large silos, bulk
material bunkers, mixing bunkers, etc . . .
[0002] On the inner walls of industrial furnaces or bunkers
increasingly thick layers of slag, encrustations or other deposits
are built up during operation. It is necessary from time to time to
remove these deposits in order to maintain an efficient operation.
Since such deposits may be quite thick and, because of their
strength and hardness, are difficult to remove, it is quite common
to remove these deposits by shelling the interior walls with
industrial cannons whereby the deposits are broken off the
walls.
[0003] With the industrial cannons generally used today, which are
of a design and operated similar to machine guns, a special
ammunition with a drive charge in the cartridge and a drive charge
detonater at the cartridge bottom is used. The shells have a
diameter of 15 to 20 mm. The discharge speed of these shells is in
the supersonic range. They have therefore a high kinetic energy and
a correspondingly large surface pressure when hitting the deposits
on the walls.
[0004] With the common industrial cannons and the ammunition
described above use thereof in the mentioned field of application
is limited. Considering the manufacturers specification for a
common industrial cannon and its ammunition, actually only rotary
cement kilns can be kept clean. The removal of large volume slag
deposits or the formation of annular deposits in cement kilns is
not possible.
[0005] Furthermore, industrial cannons cannot be utilized if,
because of the necessary positioning of the industrial cannon and
because of the dimensions of the furnace or kiln there is an
insufficient distance between the cannon and the furnace wall. In
that case, upon reaching their target, the shells would still have
a large kinetic energy so that they might penetrate the deposits
and damage or destroy the oven lining of fire clay or even the oven
wall. The same possibilities exist also if the industrial cannon is
used at distances in a normal distance range if locally only
relatively thin deposit layers are present and those layers are
penetrated by the shells.
[0006] Current industrial cannons work like a machine gun and use
cartridge ammunition with a drive charge. They are therefore built
sturdily and therefore quite heavy, that is, they weigh about 100
kilograms. As a result, it takes several workers to transport the
cannon and to set it up. In areas for example of power plants which
are difficult to access conventional industrial cannons cannot be
used because of their high weight.
[0007] US 2004/0216698A1 discloses a method for removing deposits
from the walls of ovens and similar apparatus wherein however no
shells are shot at the oven walls covered with deposits. Rather
explosives are detonated adjacent the deposits wherein at the same
time a coolant, particularly water, is admitted via a hose to a
sleeve extending around the explosives. However, this method
requires means for conducting the coolant to the sleeve and also
sources of the coolant and furthermore the control of each
individual explosion. This method is therefore complicated and is
more expensive and relatively slow in comparison with the shooting
method described above. It would appear therefore to be expedient
to pursue a path of improving the shooting method.
[0008] It is therefore the object of the present invention to
provide a method for the removal of deposits on the internal walls
of industrial furnaces, bunkers and other installations by shelling
the wall areas in such a way that, on one hand, industrial cannons
of only relatively small weight are needed and, on the other hand,
the chances of damage to the wall linings or the walls are
reduced.
SUMMARY OF THE INVENTION
[0009] In a method for the removal of deposits from the inner walls
of industrial furnaces and bunkers or for the destruction of
material collections by shelling with an industrial cannon, the
shells include an explosive charge and an impact detonator and are
driven out of the cannon by compressed air so that their impact
speed is controllable.
[0010] For shooting of the ammunition by compressed air, the weight
of the industrial cannon can be substantially reduced and, more
importantly the travel speed of the shells can be easily adjusted
to the particular conditions by adjusting the air pressure used:
For a larger travel distance of the shell or smaller deposit
thickness, it can be reduced, that is, the exposure of the wall to
the shell impact is controllable. Since, furthermore, the shells
include only a percussion detonator and a relatively small
explosive charge, the shell which is lighter than those used by the
conventional industrial cannons still generates on impact a high
energy for the destruction of deposits and their removal from the
wall and those effects are spread over a relatively large area and
not limited just to the cross-section of the shell as it occurs
with the conventional ammunition which generates extremely high
local pressures.
[0011] The invention is first explained on the basis of some
specific application examples:
[0012] In rotating cement kilns during the manufacturing process
often a so-called ring caking is formed on the drum wall which may
have a thickness of up to 0.5 m and extends over several meters of
drum length. With a drum diameter of about 5 m, the weight of such
baked-on ring deposits may be in the area of several tons. Such
enormous deposit volumes cannot economically be removed with a
conventional industrial cannon or rather with the ammunition used
thereby. If at all, it requires a bombardment with several thousand
shells.
[0013] During the bombardment, the rotational speed of the drum
must be reduced whereby the production is slowed resulting in
economic losses. Damage to the kiln wall may also occur. If the
procedure is unsuccessful, the kiln has to be shut down and
permitted to cool down in order to manually remove the baked on
ring deposits. With the method according to the invention, the
baked-on ring deposits can be shot off from a large distance (of
about 50 m) with high targeting accuracy.
[0014] In waste incineration plants, the cleanup requirement for
the industrial cannons are even more complex in that waste
accumulations pushed and baked together in the incineration chamber
must be shot into pieces. Depending on the particular design, also
slug deposits form in the incineration chamber with a thickness of
up to 0.5 m. These slug accumulations then must be bombarded with
cannon shells without damaging the underlying clay lining.
[0015] In the area of exhaust gas purification, there are heat
exchangers on whose walls deposits also form which deposits must be
carefully removed. Such a task is hardly or very difficult to
perform with a conventional industrial cannon, but can be performed
efficiently with a method according to the present invention.
[0016] In some waste incineration plants, the slag generated in the
combustion process is cooled by wetting it with water and the wet
slag is transported to a slag bunker. Depending on the residence
time of the slag in the bunker the slag sticks together or dries
onto the walls while becoming hard like concrete. When the slag is
removed from the bunker by dredging large amounts (tons) remain
attached to the walls which cannot be removed by conventional means
not even with the conventional industrial cannons. Also, in this
case, the method according to the invention, with which the slag
can be accurately targeted for its removal, has been found to be
remarkably effective.
[0017] Also in brown coal and bituminous coal power plants large
area slag deposits must be removed because of the enormous size of
the furnace chambers. However, it must be taken into consideration
that, there, slag deposits may have a thickness of only a few
centimeters and that tube systems covered by the slag deposits
which are used for the transfer of the heat out of the chamber,
must not be damaged. Therefore the method according to the
invention is particularly advantageous as the clean-up effect is
caused by the explosion pressure wave generated by the explosion of
the shells provided with impact detonators, not by the kinetic
energy of the shell.
[0018] In expanded clay factories during the manufacturing
procedure, material deposits occur in the furnace which have the
shape of a glowing ball. This glowing ball is not rigid. It rather
is similar to a wobbling mass such as liquid rock. These deposits
cannot be destroyed by the conventional common shells. Because of
their high kinetic energy, the conventional shells simply penetrate
these balls without really affecting them. With the method
according to the invention however, such glowing balls can be
destroyed very effectively.
[0019] In large silos, in open pit mining operations and in bulk
material handling plants, that is, anywhere, where loose material
is used or stored and deposits are formed by solidification, by
mixing with water, for example exposure to rain, or in blast
furnaces where ores or slag deposits are formed on the walls, these
deposits can be removed with the method according to the invention
using impact detonation ammunition which can be accurately targeted
for the removal of the deposits without damage to the walls
carrying the deposits.
[0020] Preferably, for the method according to the invention, the
air pressure used in the industrial cannon is about 20 bar.
Herewith an impact detonation shell with a weight of 100 g reaches
a discharge speed of about 130 m/s (corresponding to about 130
km/h). However, as mentioned, the pressure can be increased are
reduced depending on a particular application in order to obtain a
greater or smaller discharge speed of the shell or respectively,
impact speed of the shell. When providing different shells with
different sizes or weights, the pressure may be adjusted also in
his respect.
[0021] The impact detonation shell may be equipped with different
pyrotechnical or explosive contents depending on the purpose.
Consequently, there is a widely variable adaptability possible with
respect to the application and intended effect.
[0022] Of course, also by the configuration of the shell and of the
explosive charge the effect of the shelling can be widely varied.
In this way, the shape and effect of the pressure wave generated is
variable. For example, an arrangement can be provided by which a
concentrated pressure wave with a large depth effect in the target
area or a wider reaching, areal effect with lower surface pressure
can be established.
[0023] The air-pressure operated industrial cannon may be compact
and have a weight of only about 15 kg--including the shell. This is
only about a sixth of the weight of a conventional industrial
cannon using normal ammunition. The industrial cannon according to
the invention can therefore easily be transported and be set up in
operating position and operated by one person.
[0024] The ammunition preferably consists of only three parts: a
shell body, a cover and an impact detonator and, upon detonation,
is divided only into these three parts. The ammunition is therefore
relatively safe as no shrapnel or pieces fly around in an
uncontrolled manner upon detonation.
[0025] An embodiment of the industrial cannon used in connection
with the method according to the invention and the impact
ammunition will become more readily apparent from the following
description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a perspective view of a shell with an impact
detonator,
[0027] FIG. 2 shows a compressed air-operated industrial cannon for
shooting shells as shown in FIG. 1, and
[0028] FIG. 3 is an axial cross-sectional view of the area of the
cannon circled by a dash-dotted line in FIG. 2, with a shell as
shown in FIG. 1 disposed in the cannon.
DESCRIPTION OF A PARTICULAR EMBODIMENT
[0029] FIG. 1 shows in a perspective view a shell 1 with an impact
detonator for use in connection with the method according to the
invention. The shell has for example a diameter of 40 mm and a
length of about 130 mm. It comprises a shell body 1 forming a shell
sleeve with flight stabilization fins 2, a cover 3 forming the
front part and an impact detonator 4 disposed at the front end of
the cover 3. The hollow space surrounded by shell body 1 and the
cover 3 is filled with a charge of an explosive material or a
pyrotechnical material.
[0030] FIG. 2 shows, in a side view, an industrial cannon for
shooting shells as shown in FIG. 1. It includes a barrel 11, a
shell chamber 12 at the rear end of the barrel 11, which can be
closed by an axially movable closure sleeve 13, and a cannon body
14 with a rear carrying handle 13 and operating handles 16 as well
as a compressed air connector 17.
[0031] FIG. 3 shows the area of interest of the industrial cannon
which is operated by compressed air from a compressed air bottle
connected to the compressed air connector 17 by a hose. The
compressed air is supplied to the shell chamber 12 at the rear end
of the barrel 11. The shell chamber 12 includes an opening 21 and
an inner tube 22 which is movable forwardly together with the
axially movable closure sleeve 13 in order to expose the opening 21
and to permit the insertion of the shell G. In the position shown
herein, the closure sleeve 13 and the inner tube 22 are in the
retracted closing position and the shell G is in place that is the
cannon is ready for use.
* * * * *