JPH1026308A - Washing equipment for economizer of boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To wash an economizer in a flue of a boiler while preventing washing waste water from flowing back into the boiler or from sticking to and being left on the economizer. SOLUTION: In washing equipment of an economizer 7 provided in a flue 6 of a boiler equipped with a combustion device 3 and a blower 4 for sending air to the combustion device, a washing water piping 10 having an on-off control valve V2 in the middle and jetting the water in a body of the boiler onto the surface of the economizer, a pressure detecting means 13 which detects the pressure in the body of the boiler and a control means 14 which receives an output of the pressure detecting means sent therefrom when the pressure in the body of the boiler becomes a washing pressure suited for jetting washing water onto the economizer, and opens the on-off control valve V2 of the washing water piping for a prescribed time to make the piping execute washing of the economizer, while making the aforesaid operations continued, are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device for a boiler economizer provided in a flue of a boiler having a combustion device and a blower for blowing the combustion device.

[0002]

2. Description of the Related Art A boiler economizer is installed in a flue of a boiler, and uses preheating of combustion waste gas flowing out of the boiler into the flue to perform heat exchange of water supplied to a boiler can body for prematuration.
Therefore, the soot of the combustion waste gas adheres to the surface of the portion of the economizer located in the flue, so that the heat exchange rate is reduced and the service life is shortened due to corrosion or the like. For this reason, an injection pipe for injecting washing water onto the surface of the economizer located in the flue is arranged inside the flue, and this jet pipe and the boiler can are connected by a connecting pipe having an on-off valve in the middle. When performing cleaning, the boiler combustion device and the blower are stopped, the operator opens the on-off valve by hand, and the boiler can water is guided to the injection pipe through the connecting pipe by the pressure inside the boiler can, and the can Water was sprayed onto the economizer for a predetermined period of time, and then the bath was closed and the washing was performed.

[0003]

At the bottom of the flue, there is a U-shaped drain pipe that is always open, and during cleaning, the cleaning wastewater is discharged to the outside by the drain pipe.
Since the boiler blower was stopped, a part of the washing wastewater flowed into the boiler from the flue and stayed there, resulting in accelerated corrosion of the boiler can body. Further, water droplets of the cleaning water adhere to the surface of the economizer and remain, which also results in promoting the corrosion of the economizer.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a boiler combustion device and a blower that continue operating a boiler to send combustion waste gas from a boiler to a flue even during cleaning of an economizer. In addition to preventing the inflow into the boiler, the washing water adhering to the economizer is blown off and dried, and the entire washing wastewater is discharged from the drain pipe to eliminate the above-mentioned problem.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Therefore, a boiler economizer cleaning apparatus according to the present invention comprises a combustion device and an economizer cleaning device provided in a flue of a boiler provided with a blower for blowing the combustion device. A washing water pipe having an open / close control valve for injecting water in the boiler can into the surface of the economizer, a timer device for counting the combustion time of the combustion device, and detecting a pressure in the boiler can The pressure detection means and the timer device output that the combustion time of the combustion device has become equal to or longer than the combustion set time for economizer cleaning, and the pressure in the boiler can body is suitable for injecting cleaning water into the economizer. When the pressure detection means outputs that the pressure has been reached, the output is received, and the opening and closing control valve of the washing water pipe is opened for a predetermined time while the operation of the combustion device and the blower is continued to open. Characterized in that a control means for causing the cleaning Konomaiza. In this case, it is preferable to stop the cleaning when the combustion device stops burning during the cleaning, and to perform the cleaning at the next combustion of the combustion device.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Boilers have various structures as is well known, but the point is that water or a special liquid is supplied for about 7 to 8 minutes into a boiler can body which is a sealed pressure vessel. It is a well-known device that extracts the saturated steam by heating it with the heat of combustion of the fuel in the furnace or other heat sources and evaporating it under a pressure higher than the atmospheric pressure, and extracting saturated steam. 1 is a boiler or a casing thereof, 2 is a boiler can body provided therein, 3 is a combustion device as a furnace for heating the boiler can, 4 is a blower for supplying air to the combustion device, and The saturated steam generated in the boiler can 2 by the heating of the device 3 is supplied to a steam outlet pipe 5 having a steam stop valve Vl.
To a predetermined supply point. At this time, the steam stop valve V1 is open.

[0007] A flue 6 communicates with the lower part of the boiler 1, and the combustion waste gas that has heated the boiler can body rises in the flue 6 and is discharged. An economizer 7 is provided in the flue, and water supplied to the boiler can 2 is pressurized by a water supply pump P, and exchanges heat with ascending combustion waste gas in the flue when flowing through the economizer. It is preheated and pushed from the water supply pipe 8 to the bottom of the canister. A normally open U-shaped drain pipe 9 is provided at the bottom of the flue 6.

In the flue 6, above the economizer 7, there is provided an injection pipe 11 for injecting cleaning water onto the surface of the economizer, and this injection pipe and the lower part of the boiler can have an open / close control valve V 2 in the middle. The connection is made by the communication pipe 12. The jet pipe and the connecting pipe constitute the cleaning water pipe 10. When the boiler is operated, the combustion waste gas from the combustion device 3 which has heated the boiler can 2 enters the flue 6 from the boiler and rises in the flue, so that the inner wall surface of the flue and the surface of the economizer 7 have soot. Therefore, it is necessary to use the pressure in the boiler can by the washing water pipe 10 to perform washing as described above.

A pressure gauge 13 for detecting the pressure in the boiler can 2 is provided outside the boiler, and the pressure gauge outputs a pressure value in the boiler can to a control device 14.

In the case of a relatively small boiler installed in, for example, a building that is rotated for 8 hours during a day, the boiler need only be cleaned once a day. The economizer 7 is cleaned under control as shown in the flowchart of FIG. That is, after starting the combustion device 3 and the blower 4 (step ST1), the combustion device 3
Of the combustion time T1 of the fuel cell (step ST
2) It is determined whether or not the combustion time T1 has reached the combustion set time T2 of 8 hours (step ST3). If it is determined in step ST3 that the combustion time T1 is less than the combustion set time T2, the combustion is continued until the combustion time T1 becomes the combustion set time T2, and the combustion time T1 becomes the combustion set time T2.
If above, the steam pressure P based on the output of the pressure gauge 13
It is determined whether 1 is equal to or higher than the cleaning pressure P2, for example, 4 kg / cm2 (step ST4). If it is determined in step ST4 that the steam pressure P1 is lower than the cleaning pressure P2, the process waits until the steam pressure P1 becomes higher than or equal to the cleaning pressure P2. It is determined whether the operation is performed (step ST5). If it is determined in step ST5 that the combustion device is not burning, the cleaning is not performed. If the combustion device is burning, cleaning of the economizer 7 is started (step ST6).

Here, the washing of the economizer 7 will be described. The opening and closing control valve V2 of the washing water pipe 10 is opened.
After the cleaning water is injected from the injection pipe 11 onto the surface of the economizer 7 for a cleaning set time T12, for example, for 10 seconds, the opening / closing control valve V2 is opened to complete the cleaning. At the same time as performing the cleaning in step 6, the cleaning time T11 is counted (step ST7), and it is determined whether the cleaning time T11 has reached the cleaning set time T12 (step ST7).
8). If it is determined in step ST8 that the cleaning time T11 is less than the cleaning setting time T12, the cleaning is continued until the cleaning time T11 becomes the cleaning setting time T12, and the cleaning time T11 is longer than the cleaning setting time T12. If so, the combustion time T1 and the cleaning time T11 are reset (step ST9), and then the process is terminated. When it is determined that the combustion device has stopped burning when the cleaning time T11 is shorter than the cleaning set time T12 (step ST5), the cleaning time T11 is reset (step ST10) and the process ends. In this case, since the combustion time T1 has not been reset, when the next combustion is started, the combustion time T1 is equal to or longer than the set combustion time T3, the steam pressure P1 is equal to or higher than the cleaning pressure P2, and the combustion device performs combustion. If it is, wash it.

As a result, the combustion device 3 and the blower 4 are constantly operated during the cleaning of the economizer. Therefore, during the cleaning process, the combustion waste gas from the boiler enters the flue from the bottom of the boiler and rises in the flue. . Therefore, when the on-off control valve V1 is opened, the water in the boiler can 2 is jetted from the jet pipe 11 to the economizer 7 via the connecting pipe 12 at the washing pressure, and the washing wastewater that has washed the economizer and flowed to the bottom of the flue is The combustion waste gas flowing from the lower part of the boiler into the flue is blocked by the drain pipe 9 without entering the boiler.

[0013] Since the combustion waste gas is sent, the washing water adhering to the surface of the economizer enters the flue from the bottom of the boiler and is blown away from the surface of the economizer by the rising combustion waste gas and falls to the bottom of the flue. Similarly, the exhaust gas is blocked by the combustion waste gas flowing into the flue, does not enter the boiler, and is discharged from the drain pipe 9.

In this manner, the boiler can body and the economizer can be prevented from being corroded by the washing wastewater that has been injected into the economizer and cleaned the economizer.

Further, in the case of a boiler which is operated continuously every day and every night, the combustion is performed even during the washing of the economizer, so that the steam supply can be stably supplied without stopping the steam supply.

Thus, during continuous operation of the boiler, for example, 8
The washing of the economizer is automatically performed every time, and the washing wastewater can be prevented from flowing into the boiler, and the washing wastewater can be prevented from adhering to the surface of the yukonomiser.

[0017]

As is apparent from the above, according to the first aspect of the present invention, when the economizer is washed by injecting the washing water into the economizer, the boiler's combustion device and the blower are operated, so that the flue from the boiler The high-temperature combustion waste gas blown into the boiler prevents washing wastewater that has flowed to the bottom of the flue from flowing into the boiler, and can be drained from the drain pipe. Therefore, since the washing wastewater does not flow into the boiler, the can body of the boiler is not corroded by the washing wastewater. In addition, the washing water that is going to adhere to the economizer is blown off from the economizer by high-temperature combustion waste gas that rises in the flue, falls to the bottom of the flue, and is immediately dried even if it is drained from the drain pipe and remains in the economizer. Therefore, the corrosion of the economizer can be prevented. Further, by burning even during washing, the pressure in the boiler can body can be kept high, the jet of washing water can be stabilized, and the steam supply can be stabilized.

According to the second aspect of the present invention, the above-described effects of the first aspect of the present invention can be reliably obtained because the combustion device and the blower are always operating during economizer cleaning.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of one embodiment of the present invention.

FIG. 2 is a flow sheet of a first example showing an operation state of a boiler according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 boiler 2 boiler can 3 boiler combustion device 4 blower 5 steam extraction pipe V1 steam extraction pipe steam stop valve 6 stack 7 economizer provided in stack 8 water supply pipe 9 drain pipe 10 washing water pipe 11 washing water Injection pipe of pipe 12 Connection pipe of cleaning water pipe V2 Control valve for opening and closing of cleaning water pipe 13 Pressure gauge (pressure detecting means) 14 Control device (control means)

Claims (2)

[Claims] An economizer washing device provided in a flue of a boiler provided with a combustion device and a blower for blowing the combustion device has an opening / closing control valve on the way to remove water in a boiler can. Cleaning water piping that sprays on the surface of the economizer,
A timer device for counting the combustion time of the combustion device, a pressure detecting means for detecting the pressure in the can of the boiler, and that the opening of the combustion device during combustion is equal to or longer than a combustion set time for economizer cleaning. Timer device outputs,
When the pressure detecting means outputs that the pressure in the boiler can has reached a washing pressure suitable for injecting washing water into the economizer, the output is received, and the washing is performed while the operation of the combustion device and the blower is continued. A boiler economizer cleaning apparatus, further comprising: a control unit that opens and closes a water pipe opening / closing control valve for a predetermined time to clean the economizer. 2. The economizer cleaning device according to claim 1, wherein said control means opens and closes a control valve of a cleaning water pipe to clean the economizer, and the combustion device stops burning when the combustion device stops burning. Close the valve to stop cleaning the economizer, and when the pressure detecting means outputs that the pressure in the boiler can body at the next combustion of the combustion device has reached a cleaning pressure suitable for injecting cleaning water into the economizer, An economizer cleaning apparatus for a boiler, which receives the output and opens the on-off control valve of the cleaning water pipe for a predetermined time while the combustion device and the blower continue to operate, thereby performing the economizer cleaning.