WO2003011485A2

WO2003011485A2 - Method of cleaning steam and water pipes inside combustion ovens

Info

Publication number: WO2003011485A2
Application number: PCT/EP2002/008277
Authority: WO
Inventors: Mario Martinez
Original assignee: Technisches Büro Steur Gmbh
Priority date: 2001-07-25
Filing date: 2002-07-25
Publication date: 2003-02-13
Also published as: WO2003011485A3; AU2002325365A1; ITRM20010448A0; ITRM20010448A1

Abstract

As it is known, ovens burning coal, garbage and other materials for the production of electrical energy or for other purposes, have the problem with the accumulation of combusting residues on water and steam tubes. Such residues cause large problems with respect to the effectiveness of steam/hot water and to the production of electrical power. The subject of this invention is a method for the removal of slag from inside water/steam pipes (4) which makes it possible to clean the oven (5) while it is operating at high temperature conditions of 300 °C or more, in particular 1000 °C. Said method is characterized by the fact that while the oven (5) is in a condition at temperatures above 800 °C, in particular 1000 °C, small balls or other bodies (2) are shot into the oven (5), in particular against pipes (4) carrying slag (3), which has to be removed, whereby the balls (2) are made preferably of compressed coal, wood or iced liquids.

Description

Technisches Bϋro Steur GmbH Hansestraβe 18, 27419 Sittensen

Method of cleaning steam and water pipes inside ovens burning coal, garbade and other materials for the production of electrical energy, disposal of garbage and other materials

As it is known, ovens burning coal, garbage and other materials for the production of electrical energy or for other purposes, have the problem with the accumulation of combusting residues on water and steam tubes. Such residues cause large prob- lems with respect to the effectiveness of steam/hot water and to the production of electrical power.

Current methods of removing slag are generally based upon the cooling down of the oven temperature to 20°C to 30°C, and removing such residues basically by means of sandblasting tools or other similarities.

Such methods cause significantly economic disadvantages owed both to the loss of power production due to the considerable period of time needed for cooling down the oven, removing the slag and bringing the oven temperature again to its opera- tional standards, and to the cost for the fuel needed for bringing the temperature level to its operational standard after that - as said above - such temperature was lowered to 20/30°C. ^■

The subject of this invention is a method for the removal of slag from inside wa- ter/steam pipes which makes it possible to avoid the aforementioned disadvantages by cleaning the oven while it is operating at high temperature conditions of 300°C or more, in particular 1000°C.

The subject is solved by the invention according to claim 1.

According to the invention, the method is to discharge bodies or balls, consisting of burnable material like coal or wood with different shapes and dimensions or iced liquids (like water) by means of compressed air or water or any other useful means. It is also possible to discharge the afore-mentioned materials in a compressed status such that compressed coal or compressed wood is forming the body or the ball and is shot against the pipes containing the slag to be removed.

The balls with chosen components will move at high velocity, for example a velocity in a range between 50 m/sec to 200 m/sec, in particular 100 m/sec, to clean the slag covered pipes and to remove the slag as a function of the overall impact and the rapid cooling of the slag, which will rapidly change its tension and crack and thus thereafter may fall down to the ground of the inner side of the oven.

This method will be highly effective when the oven is in full operation at temperatures above 1000°C.

In addition to the above, the following description will help to better understand the method through referenced numbers as indicated in the attached drawing:

Figure 1 shows the scheme of method procedures,

Figure 2 shows different structures of the balls in cross section and outer shapes. According to this invention, the method of cleaning steam and water pipes inside ovens 5 which burn coal, garbage and other materials for the production of electrical and/or thermal energy is basically an operating unit 1 , for example a pressurised gas operated unit which releases compressed air/gas into the barrel where the small balls, - as mentioned above - can be composed of compressed coal or wood having different shapes or iced liquids 2.

The removal mechanisms can also be different than those herein described such as spring, hydraulic, electric detonating mechanisms and so forth.

The small balls made of compressed coal or wood or iced liquids (or other material) can but does not have to be fully filled, that is up to 100 %. The small balls can also have an internal air/gas pocket. The variation of filling ratio can be done without any significant changes to the efficiency.

The discharging water velocity is important to the efficiency of this method.

The shot device 1 of small balls 2 targets the steam/water pipes 4 and hits the slag 3 to be removed.

Experiments have shown that the use of a velocity in a range of 50 m/sec to 200 m/sec, in particular of 100 m/sec is effective for good results.

When the small balls hit the target (a pipe with the slag thereon), it will rupture and remove the slag from inside the pipes of the oven while the oven is still in full opera- tion.

Aiming and shooting are executed from the inspection hatches on the oven sides 5.

Insofar as described and illustrated, it is clear that many different variations can be made both to the composition of the external part containing the compound of water, dust, solids, etc, and to the composition itself without going beyond the characteris- tics of the patent and the following claims. The balls as mentioned in this application may have a skin, made of artificial material like plastic, whereby the thickness of the skin is in a range between 0,1 mm to 2 mm. It is also possible that such a ball is filled with a liquid like water, whereby the filling grade is less than 100 %, such that the ball contains also air.

The shot device for shooting the balls can be a shot device, which is known as a fire extinguishing device from the company IFEX Impuls Fire Extinguishing System GmbH and having a structure as disclosed in EP 0 402 425 B1 and in EP 0 689 857 B1. Such devices provide the possibility to discharge high pressured gas, for example air, onto a ball, which as a result of the discharge is shot out of the gun of the shot device.

The diameter of the balls is less than the inner diameter of the shot device, whereby single balls may be shot out or several balls inside of the shot device.

For shooting the balls into the inner room of the oven 5 an opening 6 of the oven is opened and the shot device is arranged in such a manner that the balls can be shot into the inner room of the oven. After shooting the opening 6 is again closed.

It is possible with the shot device that the balls are shot in a distance of more than 5 m, also 15 m to 30 m are possible shot distance.

The balls may also consist of plastic material, also compressed plastic material is possible. It is also possible to use balls made of compressed plastic granulates.

In Figure 2 there are shown typical structures - in cross section 2a) to 2c) - and forms - 2d) to 2f) - of balls, whereby there are many other possible variants not shown in figure 2.

Claims

1. Method of cleaning steam and water pipes inside ovens, for example burning coal, garbage and other materials for production of electrical and/or thermal power or for disposal of garbage or other materials, said method is characterized by the fact that while the oven is in. a condition at temperatures above 800°C, in particular 1000°C, small balls or other bodies are shot into the oven, in particular against pipes carrying slag, which has to be removed, whereby the balls are made preferably of compressed coal, wood or iced liquids.

2. Method according to claim 1 , characterized by the fact that this balls can be of any possible configuration and are capable of removing the slag from the pipes as a function of both the velocity impact of the shot balls and the rapid cooling of the slag, which will rapidly change its tension and crack.

3. Method according to claim 1 or 2, characterized by the fact that the preferred velocity of the shot is in a range between 50 m/sec to 200 m/sec, in particular 100 m/sec.

4. Method according to one of the afore-mentioned claims, characterized by the fact that the small balls are shot by a pressurized gas operating unit.

5. Method according to one of the afore-mentioned claims, characterized by the fact that the balls can, but do not have to be fully filled, that is up to 100 %, and can also have an internal small air/gas pocket.