JPH0473509A - Method of operating soot blower - Google Patents

Abstract

PURPOSE:To suppress the generation of drain by supplying steam to an inner tube at the position to which an outer tube retreats and, then, moving forwards the outer tube and, after jetting out the steam from the jet nozzle at its tip end section, moving backwards the outer tube and at the same time supplying air to the outer tube. CONSTITUTION:In the stage before operating a soot blower a solenoid valve 2 is open and the steam flows from a steam piping 7 through the solenoid valve 2 and a needle valve 4 to the inside of the body of a soot blower 8. Next, an outer tube 10 is moved forward and the soot blower is operated, and the steam is jetted out from a nozzle 12. At this time a base valve 1 is open and the solenoid valve 2 is closed. The steam does not flow to the side of a three- way valve by a check valve 5. After the steam jetting is finished, the base valve 1 and solenoid valve 2 are closed, and the three-way valve is switched to the side of NC, and the air from the air piping 6 is sent to an air jet port 13 in an inner tube 9 to discharge and remove by a jet nozzle 12 the steam that is staying in the gap 15 between the outer tube 10 and inner tube 9. The soot blower stands by until the next operation.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of operating a soot blower, and in particular, the residual steam after steam injection is turned into a drain, and when the soot blower is restarted, the steam is injected with This invention relates to a method of operating a soot blower that prevents damage to objects.

[Conventional technology]

In a boiler device, a soot blower (soot blowing device) is installed in order to remove soot adhering to a tube group of internal heat exchanger tubes. Generally, steam is mainly used as the medium for soot blowing, but after the soot blowing process is finished, condensate generated in the pipe through which the injection medium passes is not completely removed and accumulates, so when reusing the soot blower, it is necessary to Drain that has accumulated in the tube is injected with steam and collides with the tube group, causing so-called erosion and drain cant. In order to solve this problem, conventionally, when installing a soot blower, the tip of the medium injection nozzle is tilted downward so that the drain slopes downward.
A method is used to remove the drain that has accumulated inside the pipe.

FIG. 3 shows a method according to the prior art, in which the soot blower device is installed with a slope so that the nozzle tip side faces downward. In Fig. 3, 8 is a valve body of a valve for controlling supplied steam, 9 is an inner tube, 10 is an outer tube, 12 is an injection nozzle provided at the tip of the outer tube, 14 is a boiler tube, and the outer tube IO is It is installed at an angle so that it goes downward towards the tip.

However, the long outer tube, which is the injection medium communication pipe, curves under its own weight, so even if the tip is installed at a downward slope, the internal drain may not be removed sufficiently, and the slope may not be sufficient. If the soot blower is installed separately, there are problems such as the need to increase the installation space required to insert and remove the soot blower. In addition, the drain in the pipe leaked from the ground banking when the medium was injected, and the ground 1
'It also shortens the life of the backing.

Conventional technology not only has the problems mentioned above, but also
There was also no circuitry or control system in place to prevent condensate formation.

[Problem to be solved by the invention]

The above-mentioned conventional technology merely expects that the drain in the outer tube or inner tube of the soot blower will disappear naturally, but does not take into consideration how to forcefully remove the drain under appropriate conditions. However, the problems of erosion and L-len cutting of objects to be cleaned have not been solved.

An object of the present invention is to provide a method of operating a soot blower using a circuit and a control system for operating the circuit, which solves the problems of the prior art described above, forcibly removes the condensate accumulated in the pipe, and prevents the generation of condensate. It is about providing.

[Means for solving the problem] The problem with the above conventional technology is that the steam supplied from the inner tube is sprayed from the injection nozzle at the tip of the outer tube that moves forward and backward in contact with the inner tube to clean the object. The soot blower operating method includes a step of warming up the soot blower by supplying an appropriate amount of steam to the inner tube at the retracted position of the outer tube before operating the soot blower, and then moving the outer tube forward to warm up the soot blower. Operation of a soot blower characterized by comprising the steps of injecting from a tip injection nozzle, and retracting the outer tube after the injection step and supplying cleaning air to the outer tube to expel residual steam. In a method for operating a soot blower in which steam supplied from an inner tube is sprayed from an injection nozzle at the tip of an outer tube that moves forward and backward in contact with the inner tube to clean an object, the inner tube is There is a step of supplying this steam to warm it up, a step of injecting the steam supplied from the inner tube from the injection nozzle at the tip of the advanced Arata Tana 1-b, and a step of injecting air into the outer tube and the inner tube after the end of the injection step. The present invention is solved by a method of operating a soot blower characterized by comprising a step of supplying steam and expelling residual steam.

[Effect]

By flowing a small amount of steam into the inner tube to warm up the inside of the tube before operating the soot blower, it is possible to suppress the generation of condensate during steam injection. Furthermore, after the soot blower is operated, by blowing dry air into the gap between the outer tube and the inner tube, steam stagnant in the gap can be pushed out and the generation of condensate can be suppressed. Furthermore, by continuing to flow air into the inner tube even while the soot blower is on standby, it is possible to prevent the formation of -layer drain and drain accumulation.

As described above, by generating drain and eliminating drain accumulation, erosion and drain cut during medium injection can be prevented.

Furthermore, leakage of drain from the ground backing can be prevented, and the life of the backing can be extended.

〔Example] Embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a time chart diagram showing the movements of the soot blower main valve 1, solenoid valve 2, and three-way valve 3 when one cycle is defined as one cycle from the start of injection to the end of injection when operating the soot blower. The operations (processes) at each time will be explained with reference to FIGS. 1A to 1D. This control circuit includes a soot blower control system having a structure for injecting air into a solenoid valve 2, a three-way valve 3, a check valve 5, a needle valve 4, and a gap 15 between an inner tube 9 and an outer tube 10.

In addition, in FIG. 1, a to d are the warm-up process,
The injection process, residual vapor expulsion process and standby process are shown.

In the warm-up process (FIG. 1A), the solenoid valve 2 is opened before the soot blower is operated.

At this time, steam flows from the steam pipe 7 through the solenoid valve 2 and the needle valve 4 into the soot blower body 8.

Note that steam does not flow to the three-way valve 3 side due to the check valve 5.

By changing the opening degree of the needle valve 4, an appropriate amount of steam can flow into the inner tube 9.

In the injection step (FIG. 1B), the outer tube 10 is advanced, the soot blower is operated, and steam is injected from the nozzle 12. At this time, the main valve 1 is open and the solenoid valve 2 is closed. Further, steam does not flow to the three-way valve 3 side due to the check valve 5.

The residual steam expulsion step (FIG. 1C) shows the operation after the end of steam injection. At this time, the main valve 1 and the solenoid valve 2 are closed, and the three-way valve 3 is electrically switched to the NC side. The air from the air pipe 6 reaches the air outlet 13 in the inner tube 9 from the NC side of the three-way valve 3, is injected from here into the gap 15 between the outer tube 10 and the inner tube 9, flows there, and accumulates in the gap. The steam is discharged and removed by the injection nozzle 12.

The standby step (FIG. 1D) shows a standby state until the condensate soot blower is operated. Main valve 1 and solenoid valve 2 are closed, and three-way valve 3 is open to the NC side, so
Air from the air pipe 6 passes through the check valve 5 and flows into the soot blower body 8.

The air that has flowed into the body 8 flows through the inner tube 9 and is discharged to the outside from the injection nozzle 12 at the tip of the outer tube 10.

By continuing these series of actions,
No condensate is generated because the humid gas that causes condensate does not stagnate in the soot blower tube.

In addition, in the above embodiment, an example was shown in which the residual steam in the inner tube is removed after the residual steam in the outer tube is discharged, but both steps can also be performed at the same time.

From warming up the soot blower before operation, to discharging the steam that is the source of condensate stagnant in the gap between the outer tube and inner tube after steam injection, and furthermore, the steam that is the source of condensate generation while waiting until the next soot blower operation. By controlling the discharge of water and the prevention of gas stagnation inside the tubes as a series of systems, it is possible to prevent condensate generation, thereby preventing erosion of the boiler tubes into the group due to condensate accumulated in the tubes during steam injection, and condensate cut. I can do it.

〔Effect of the invention〕

According to the present invention, in a soot blower, the generation of condensate can be suppressed by eliminating the stagnation of steam after steam injection and the stagnation of gas in the soot blower tubes (outer tube and inner tube), which are the causes of condensate generation. Since the condensate does not accumulate in the tube, no condensate is spouted out during steam injection, which has the effect of preventing erosion and drain cut.

It also has the effect of extending the life of the ground backing.

[Brief explanation of the drawing]

FIG. 1 and FIGS. 1A to 1D are detailed explanatory diagrams of the present invention, FIG. 2 is a structural diagram of main parts of a soot blower device used in an embodiment of the present invention, and FIG. 3 is a diagram of the prior art. It is an explanatory diagram. 1... Soot blower main valve, 2... Solenoid valve, 3...
Three-way valve, 4... Needle valve, 5... Check valve, 6...
・Air piping, 7...Steam piping, 8...Valve body 9...Inner tube, 10...Outer tube, 11...Gland packing, 12...Injection nozzle, 13...Air Injection port, 14...boiler tube,
15...Gap between inner tube and outer tube. time-eleven

Claims (3)

[Claims] (1) In a soot blower operating method in which steam supplied from an inner tube is sprayed from an injection nozzle at the tip of an outer tube that moves forward and backward in contact with the inner tube to clean an object, the outer tube before soot blower operation is A step of warming up the soot blower by supplying an appropriate amount of steam to the inner tube in the retreated position, a step of moving the outer tube forward and injecting the steam supplied from the inner tube from its tip injection nozzle, and the injection 1. A method of operating a soot blower, comprising the step of retracting the outer tube after the process is completed and supplying cleaning air to the outer tube to expel residual steam. (2) In claim (1), the feature further comprises a step of blowing out cleaning air to the inner tube between the step of removing the residual steam and the warming-up step to drive out the residual steam in the inner tube. How to operate a soot blower. (3) In a soot blower operating method in which the steam supplied from the inner tube is sprayed from the injection nozzle at the tip of the outer tube that moves forward and backward in contact with the inner tube to clean the object, the inner tube is cleaned before the soot blower is operated. a step of supplying steam to warm up the tube, then a step of injecting the steam supplied from the inner tube from the injection nozzle at the tip of the advanced outer tube, and supplying air to the outer tube and the inner tube after the injection step is completed. and expelling residual steam.