JPH09243013A - Steam boiler with drain treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam boiler having a small-sized drain treatment device for performing a neutralization of blow water by feeding combustion discharged gas in blow water in a steam boiler while a proper blowing operation is being carried out. SOLUTION: This is a drain treatment device for a steam boiler in which boiler water condensed by evaporation is discharged regularly and combustion discharged gas after heating boiler water is discharged through a flue 5, an upper part of a drain treatment tank 10 for use in accumulating drain water from the boiler 1 is made to communicate with the flue 5 by an aeration port 3 and then the drain water treatment device is integrally assembled with the flue.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler equipped with a wastewater treatment device for neutralizing alkaline wastewater discharged from the boiler.

[0002]

2. Description of the Related Art Can water of a steam boiler is adjusted to have a high pH in order to suppress corrosion of the boiler. Since the steam boiler supplies water by the amount reduced by evaporation, impurities in water are concentrated each time steam is generated. As the concentration progresses, problems such as carryover will occur, so it is necessary to periodically perform a concentration blow to drain the can water in order to suppress the concentration. Further, when the can water is concentrated, the sludge (sludge) accumulates on the bottom of the can body, so it is necessary to completely blow the sludge from the bottom of the can.

Since the pH of blow water for canned water is about 11 to 12, it is necessary to neutralize the blow water. One of the methods to neutralize wastewater is to store blow water in a wastewater treatment tank and blow the combustion exhaust gas from the boiler into the blow water, so that hydroxide ions in the blow water and carbon dioxide in the combustion exhaust gas are blown. It has been practiced to lower the pH in the tank by reacting a small amount of nitrogen oxide or the like. When the blow water is neutralized by the above method, a neutralizing agent is not required, but a wastewater treatment tank and a neutralizing device are required, and the size of the entire boiler is increased accordingly.

[0004]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to provide a small waste water treatment device for neutralizing blow water by sending combustion exhaust gas into the blow water of a steam boiler while performing proper blow. It is to provide the steam boilers that they have.

[0005]

[Means for solving the problems] Steam is generated by burning in a furnace of a boiler, and can water concentrated by evaporation is drained periodically, and combustion exhaust gas after heating the can water is smoke. A wastewater treatment device for steam boilers exhausting through a road.A wastewater treatment tank that stores alkaline blow water discharged from the boiler, a blowwater pipe that sends boiler boiler water to the wastewater treatment tank, and drainage by opening and closing valves. Blow valve for blow control that sends canned water to the treatment tank, one end is connected to the combustion exhaust gas flow section of the flue, and the other end is connected to the underwater portion of the wastewater treatment tank. Exhaust gas pumping device that sends water into the wastewater treatment tank, treated water drainage pipe that drains water in the wastewater treatment tank connected to the wastewater treatment tank, control device that operates the boiler and opens and closes the blow valve. The provided, communicates the wastewater treatment tank upper flue, provided the water level detector for detecting the water level in the waste water treatment tank in advance by connecting the control device and the water level detector,
When the water level detector detects that the water level in the wastewater treatment tank is higher than a certain level, the blow valve is closed. Also, set the blow time in the control device,
The blow valve opening time when the blow valve is opened is detected, and even after the set blow time has elapsed, the water level detector detects that the water level in the wastewater treatment tank is higher than a certain level. If not, a blow abnormality alarm is output.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. The steam boiler 1 includes a combustion device 2 for generating a flame for heating canned water in the boiler at an upper part, a steam separator 4 for separating steam and canned water at a side, and a combustion exhaust gas after heating the canned water. A flue 5 for passing through is provided, and a water supply pipe 6 for supplying water preheated by an economizer 7 provided in the flue 5 to a boiler, a concentrated blow water pipe 8 for taking out highly concentrated can water, a boiler All blow pipes 11 for discharging canned water from the lower part are connected. A concentrated blow valve 9 is provided in the middle of the concentrated blow water pipe 8, and an all blow valve 12 is provided in the middle of all blow pipes 11. The concentrated blow water pipe 8 and all the blow pipes 11 merge to form a blow water pipe 15. . Opening / closing control of the enrichment blow valve 9 and all the blow valves 12 is performed by a signal from the control device 21 of the boiler.
Alternatively, when all the blow valves 12 are opened, the blow water is sprayed from the upper part of the wastewater treatment tank 10 that stores the blow water. The inside of the wastewater treatment tank 10 is divided into two rooms by a partition plate 13, and the tank connection port 1 at the top and bottom of the tank 1
The room which is communicated with only 4 and is supplied with the blow water by the blow water pipe 15 is the first chamber 16 and the other room is the second chamber 17. On the side surface of the second chamber 17, the treated water drain pipe 18 for draining the water in the second chamber 17 when the water level becomes higher than the set water level L, and the normally open midway of the treated water drain pipe 18. And a water level detector 19 for detecting the presence or absence of water at a set water level H higher than the set water level L. A treated water drainage pipe is also connected to the bottom of the drainage treatment tank 10, and an electrically operated valve 23 for blowing the treated tank, which is normally closed, is provided on the way. At the upper part of the wastewater treatment tank 10, the wastewater treatment tank 1
0 is provided with a ventilation port 3 communicating with the flue 5, and the wastewater treatment tank 10 and the flue 5 are integrated. The flue 5 and the bottoms of the first chamber 16 and the second chamber 17 are connected by an exhaust gas pipe 20, an exhaust gas pumping device (not shown) is provided in the exhaust gas pipe 20, and a heat exchanger is provided in the wastewater treatment tank 10. 22 is provided and the water preheated by the heat exchanger 22 is supplied to the steam boiler 1 through the water supply pipe 6.

The steam boiler 1 is supplied with water through a water supply pipe 6 so that the water level in the can is maintained within a certain range. The combustion device 2 causes a flame to be generated to heat the can water to generate steam. When boiling the canned water, the canned water is lifted together with the steam, but the steam and the canned water are separated by the steam-water separator 4, only steam is taken out, and the steamed water is returned from the steam-water separator 4 into the boiler. . The combustion exhaust gas after heating the canned water is sent to the flue 5, and is preheated by the economizer 7 to be exhausted.

The steam boiler 1 is supplied with water every time the canned water evaporates, and impurities contained in the water are concentrated by repeating evaporation and water supply. A concentration blow is performed in which the valve 9 is opened periodically. In addition, since impurities that have been fixed by concentration are deposited on the bottom and become kettle mud, all blow valves 12 are opened.
Kama mud is discharged by fully blowing the can water from the bottom. The blow water is sent to the wastewater treatment tank 10 through the blow water pipe 15, and the concentration interval of the concentration blow is narrow, and the amount of drainage per time is small. Drainage is done.

A part of the combustion exhaust gas sent to the flue 5 is sucked into the exhaust gas pipe 20 by an exhaust gas pumping device provided in the middle of the exhaust gas pipe 20 connected to the flue 5, and the first chamber 16
And it is sent into the treated water in the second chamber 17. The flue gas discharged into the treated water undergoes a neutralization reaction with carbon dioxide in the flue gas with hydroxide ions in the treated water to lower the pH of the treated water. The combustion exhaust gas reaching the upper part of the wastewater treatment tank is returned to the flue 5 by the ventilation port 3 and exhausted.

The blow water sent to the waste water treatment tank 10 is first subjected to a neutralization treatment by the combustion exhaust gas in the first chamber 16 to lower the pH. First chamber 16 and second chamber 17
Are communicated with each other through the tank communication port 14, the treated water in the wastewater treatment tank 10 gradually moves from the first chamber 16 to the second chamber 17, and the treated water reaching the second chamber 17 is treated in the second chamber 17. The treated water that has been subjected to the neutralization treatment again inside and is treated inside the second chamber is drained through the treated water drain pipe 18 provided at the height of the set water level L. Since the inside of the wastewater treatment tank 10 is divided into a first chamber 16 and a second chamber 17, and the neutralization process is performed again in the second chamber 17 after the neutralization process in the first chamber 16, the wastewater treatment tank 1
The blow water sent to No. 0 is not immediately drained without being neutralized, and the pH of the treated water can be sufficiently lowered.

In the case of the concentrated blow, the fluctuation of the water level in the wastewater treatment tank 10 is small because the amount of blown water per time is small, but in the case of the full blow, a large amount of blown water flows to the wastewater treatment tank 10 at one time. Will be sent. However, since the purpose of full blow is to discharge the mud, it is not necessary to drain all the can water if a certain amount of blow can be reliably performed. 23 is opened to drain the treated water in the wastewater treatment tank, the electric motor 23 for blowing the treatment tank is closed, and then all the blow valves 12 are opened to set by the water level detector 19 provided in the wastewater treatment tank 10. When it is detected that the water level has changed to the water level H, all blow valves 12 are closed to stop all blows. In this case, a certain amount of blow can be reliably performed without increasing the capacity of the wastewater treatment tank 10 more than necessary, so that the capacity of the wastewater treatment tank 10 can be downsized and the water level in the wastewater treatment tank 10 rises. By vent 3
There is no fear that blow water will flow into the flue 5,
Since the water discharged from the waste water treatment tank 10 has been neutralized even in the middle, the blow water from the boiler is not discharged untreated.

Further, the control device 21 is input with a set time period in which the water level in the wastewater treatment tank 10 rises to the set water level H when all the blows are performed, and after all the blow valves 12 are opened. The time is detected. If the water level does not rise to the set water level H even when the opening time of all the blow valves 12 reaches the set time, the blow abnormality is output.

[0013]

By implementing the present invention, since the wastewater treatment tank and the flue are integrated and the capacity of the wastewater treatment tank is reduced, the wastewater treatment apparatus of the steam boiler can be downsized and the proper blow can be performed. It can be performed.

[Brief description of drawings]

FIG. 1 is a flow chart of an embodiment of the present invention.

[Explanation of symbols]

 1 Steam Boiler 2 Combustor 3 Vent 4 Gas / Water Separator 5 Flue 6 Water Supply Pipe 7 Economizer 8 Concentrated Blow Water Pipe 9 Concentrated Blow Valve 10 Waste Water Treatment Tank 11 All Blow Pipe 12 All Blow Valve 13 Partition Plate 14 Tank Connection Port 15 Blow water pipe 16 1st chamber 17 2nd chamber 18 Treated water drainage pipe 19 Water level detector 20 Exhaust gas pipe 21 Control device 22 Heat exchanger 23 Treatment tank blow motor valve 24 Treated water drain motor valve H / L set water level

Claims (5)

[Claims] Claims: 1. Steam is generated by performing combustion in a furnace of a boiler, and can water concentrated by evaporation is periodically discharged, and combustion exhaust gas after heating the can water is exhausted through a flue. Waste water treatment equipment for steam boilers that stores alkaline blow water discharged from the boiler, blow water piping that sends the boiler's can water to the waste water treatment tank, and opens and closes the valve to reach the waste water treatment tank. Blow valve for blow control to send canned water, one end is connected to the flue gas flow section of the flue, and the other end is connected to the underwater section of the waste water treatment tank. Exhaust gas pumping device for sending into the tank, treated water drainage pipe for draining water in the wastewater treatment tank connected to the wastewater treatment tank, control device for operating the boiler and opening and closing the blow valve are installed. A steam boiler with a wastewater treatment device, characterized in that the upper part of the treatment tank is connected to the flue. 2. The steam boiler with a wastewater treatment device according to claim 1, further comprising a water level detector for detecting the water level in the wastewater treatment tank, the water level detector and the control device being connected to each other by the water level detector. A steam boiler with a wastewater treatment device, which performs a closing control of a blow valve when it is detected that the water level in the wastewater treatment tank is higher than a certain level. 3. The steam boiler with wastewater treatment device according to claim 2, wherein when the water level in the wastewater treatment tank does not reach a certain level or more even after a certain time has elapsed since the blow valve was opened, a blow abnormality alarm is issued. Is a steam boiler with a wastewater treatment device. 4. The steam boiler with wastewater treatment device according to claim 1, wherein a heat exchanger is provided in the wastewater treatment tank,
A steam boiler with a wastewater treatment device, characterized in that water supply pipes to the boiler are connected before and after the heat exchanger to supply water preheated in the wastewater treatment tank to the boiler. 5. In the steam boiler with wastewater treatment device according to claim 2, when controlling the opening of the blow valve, the water in the wastewater treatment tank is drained through the wastewater treatment pipe, and then the blow valve is opened. A steam boiler with a wastewater treatment device that is controlled.