JP2001009236A - Method and device for washing gypsum dehydrator in wet flue gas desulfurization equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drastically reduce the consumption of the washing water of a belt filter and to reduce the operation cost of a plant. SOLUTION: In this washing method, a washing water line 18 is formed so that the washing water 17 may be sprayed to only a prescribed place on downstream side of the belt filter 14, and also low chlorine washing water (recovered water 21) after being sprayed at the prescribed place on the downstream side of the belt filter 14 from the washing water line 18 is recovered at a low chlorine vacuum receiver 16, and the low chlorine washing water (recovered water 21) recovered at the vacuum receiver 16 is sprayed to a prescribed place on the upstream side of the belt filter 14 from a low chlorine washing water line 27 by the actuation of a washing pump 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cleaning a gypsum dewatering machine in a wet flue gas desulfurization apparatus.

[0002]

2. Description of the Related Art In general, coal-fired
SO from exhaust gas discharged from irrigation _Two(Sulfur oxides)
To absorb and remove calcium carbonate as absorbent
(CaCO_Three) Will be installed
However, the wet-type flue gas desulfurization apparatus is generally configured as shown in FIG.
In the lower part, a liquid reservoir 1a of the absorbing liquid 1 is formed and the upper part is formed.
An absorption tower 3 provided with a number of spray nozzles 2;
The absorption liquid 1 in the liquid reservoir 1a of the collecting tower 3 is pumped up and sprayed.
Multiple circulation pumps for spraying and circulating from nozzle 2
And oxidizing air is supplied to the liquid reservoir 1a of the absorption tower 3.
An oxidizing air blower 5 is provided.

Further, the above-mentioned wet flue gas desulfurization apparatus is provided with an absorption tower 3
Gypsum dewatering machine supply tank 7 for adding a neutralizing agent such as caustic soda (NaOH) to absorbing liquid 1 withdrawn from liquid reservoir 1a through extraction line 6 and neutralization in gypsum dewatering machine supply tank 7 The absorbed liquid 8 is introduced through the neutralizing absorbent line 9,
A gypsum dewatering machine 11 of a belt filter type for separating gypsum 10 by dewatering a slurry containing a solid content (gypsum) in the absorbing liquid 8 by operating a vacuum pump 12 is provided.

The gypsum dewatering machine 11 wraps an endless belt filter 14 between guide rolls 13 rotatably arranged at a required interval, and rotates the belt filter 14 in a required direction by rotating the guide rolls 13. To the vacuum receiver 1 and the operation of the vacuum pump 12
In a state where the lower surface of the belt filter 14 is maintained at a negative pressure via the belt filters 5 and 16, an absorbent 8 containing gypsum after desulfurization from the gypsum dewatering machine supply tank 7 is provided at an upstream end on the belt filter 14.
Is allowed to flow down to perform dehydration and separate into gypsum 10 and filtrate.

At a required upstream position and a required downstream position on the belt filter 14 of the gypsum dewatering machine 11, a washing water 17 such as industrial water is sprayed from a washing water line 18 so that the belt filter 14 is sprayed. The washing water 17 sprayed to a required position on the belt filter 14 on the upstream side is washed with the filtrate separated from the gypsum 10 by the operation of the vacuum pump 12.
While being collected by the vacuum receiver 15 via the collection line 20, the washing water 17 sprayed at a required downstream position on the belt filter 14 is turned into the collection line 22 as the collection water 21 by the operation of the vacuum pump 12. Through the vacuum receiver 16. Here, the recovered water 19 collected in the vacuum receiver 15
Since the chlorine concentration is high, the vacuum receiver 15 in which the recovered water 19 is collected is called a high chlorine-based vacuum receiver,
Further, the recovered water 21 collected in the vacuum receiver 16 is:
Since the chlorine concentration is low, the vacuum receiver 16 in which the recovered water 21 is collected is called a low-chlorine vacuum receiver.

The recovered water 19 collected in the high-chlorine vacuum receiver 15 is drained by the operation of a drain pump 24 through a drain line 23, and is collected in the low-chlorine vacuum receiver 16. The water 21 is supplied to the drain pump 2 through a drain line 25 and the drain line 23.
The water is discharged by the operation of 4.

[0007]

However, as described above, the washing water 17 such as industrial water or the like is provided at the required upstream and downstream positions on the belt filter 14 of the gypsum dewatering machine 11.
Spraying to wash the belt filter 14,
A large amount of washing water 17 is required, which increases the operating cost of the plant, but has a problem that it is difficult to secure the washing water 17 such as industrial water depending on the location of the plant.

In view of the above circumstances, the present invention provides a method for cleaning a gypsum dewatering machine in a wet flue gas desulfurization apparatus which can significantly reduce the amount of cleaning water used for a belt filter and reduce plant operation costs. It is intended to provide a device.

[0009]

SUMMARY OF THE INVENTION According to the present invention, an endless belt filter is wrapped around a guide roller rotatably disposed at a required interval, and the belt filter is rotated in a required direction by rotating the guide roll. By moving the absorption liquid containing gypsum after desulfurization to the upstream end on the belt filter while holding the lower surface side of the belt filter at a negative pressure via the vacuum receiver by moving the vacuum pump and operating the vacuum pump. A method of washing a gypsum dewatering machine in a wet flue gas desulfurization apparatus that performs dewatering and separates into gypsum and a filtrate, by spraying washing water at a required position downstream of a belt filter, and downstream of the belt filter. The low-chlorine-based washing water after spraying at a required position is collected, and the collected low-chlorine-based washing water is sprayed at a required position upstream of the belt filter. In which according to the cleaning method of the gypsum dewatering in the wet flue gas desulfurization apparatus that.

Further, according to the present invention, an endless belt filter is wrapped between guide rollers rotatably arranged at a required interval, and the belt filter is moved in a required direction by driving the guide rolls to rotate. In a state where the lower surface side of the belt filter is maintained at a negative pressure via the vacuum receiver by the operation of the vacuum pump, dehydration is performed by flowing an absorbent containing gypsum after desulfurization to the upstream end on the belt filter. A washing device for a gypsum dewatering device in a wet flue gas desulfurization device configured to separate gypsum and a filtrate, a washing water line for spraying washing water at a required position downstream of a belt filter, and a belt from the washing water line. A low-chlorine-based vacuum receiver for collecting low-chlorine-based cleaning water after spraying to a required position downstream of the filter, and a low-chlorine-based cleaning water collected by the vacuum receiver. In which according to the cleaning apparatus of the gypsum dewatering in the wet flue gas desulfurization apparatus is characterized in that a low-chlorine-based cleaning water line spraying the upstream predetermined position bets filter.

According to the above means, the following effects can be obtained.

In the method for cleaning a gypsum dewatering machine in a wet flue gas desulfurization apparatus according to the present invention, washing water is sprayed at a required position downstream of the belt filter and low chlorine after spraying at a required position downstream of the belt filter. System wash water is collected,
The collected low-chlorine-based washing water is sprayed at a required position upstream of the belt filter.

Further, in the washing apparatus for the gypsum dewatering machine in the wet flue gas desulfurization apparatus of the present invention, the washing water is sprayed from the washing water line to a required position on the downstream side of the belt filter, and from the washing water line to the downstream side of the belt filter. Cleaning water after spraying to the required position on the side is collected by a low-chlorine-based vacuum receiver, and the low-chlorine-based cleaning water collected by the vacuum receiver is passed from the low-chlorine-based cleaning water line to the belt filter. It is sprayed to the required upstream position.

As a result, in the method and the apparatus for cleaning the gypsum dewatering machine in the wet flue gas desulfurization apparatus of the present invention, both the required upstream position and the required downstream position on the belt filter of the gypsum dewatering machine are different from the prior art. It is not necessary to spray cleaning water such as industrial water, and it is sufficient to spray cleaning water only at a required position on the downstream side of the belt filter.Therefore, a large amount of cleaning water is not required, and the operation cost of the plant is reduced, and industrial water is reduced. It is easy to secure the washing water.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of an embodiment of the present invention. In the figure, portions denoted by the same reference numerals as those in FIG. 2 represent the same components. This is the same as the above, but the feature of the illustrated example is that, as shown in FIG. 1, a washing water line 18 is formed so that the washing water 17 is sprayed only at a required position on the downstream side of the belt filter 14. The low chlorine-based cleaning water (recovered water 21) after spraying from the cleaning water line 18 to a required position on the downstream side of the belt filter 14 is collected by the low chlorine-based vacuum receiver 16, and the low chlorine-based cleaning water collected by the vacuum receiver 16 is collected. Chlorine-based washing water (recovered water 2
1) is sprayed from the low chlorine-based washing water line 27 to a required position on the upstream side of the belt filter 14 by the operation of the washing pump 26.

Next, the operation of the above illustrated example will be described.

The washing water 17 is sprayed from a washing water line 18 to a required position on the downstream side of the belt filter 14, and the low chlorine type washing water (A) is sprayed from the washing water line 18 to a required position on the downstream side of the belt filter 14. The recovered water 21) is collected by the low-chlorine-based vacuum receiver 16, and the vacuum receiver 16
The low-chlorine-based cleaning water (recovered water 21) collected in the above step is sprayed from a low-chlorine-based cleaning water line 27 to a required position on the upstream side of the belt filter 14 by the operation of the cleaning pump 26.

The low chlorine-based washing water (recovered water 21) sprayed to a required position on the belt filter 14 on the upstream side is recovered by the operation of the vacuum pump 12 together with the filtrate separated from the gypsum 10. The collected water 19 collected by the high-chlorine-based vacuum receiver 15 via the collection line 20 as the reference numeral 19 and collected by the high-chlorine-based vacuum receiver 15 is drained by the operation of the drain pump 24 via the drain line 23. .

Since cleaning water of low chlorine type (recovered water 21) is sprayed to a required position on the upstream side of the belt filter 14 for cleaning, there is no concern that the cleaning effect is reduced.
Since low-chlorine-based cleaning water (recovered water 21) can be directly supplied from the low-chlorine-based vacuum receiver 16 by operating the cleaning pump 26, there is no need to provide a buffer device such as a pit or a tank.

As a result, it is not necessary to spray the cleaning water 17 such as industrial water on both the required position on the upstream side and the required position on the downstream side of the belt filter 14 of the gypsum dewatering machine 11 as in the prior art. It is sufficient to spray the washing water 17 only at a required position on the downstream side, so that a large amount of washing water 17 is not required, the operating cost of the plant is reduced, and the washing water 17 such as industrial water is easily secured.

Thus, the cleaning water 1 for the belt filter 14 is
7 can be significantly reduced, and plant operating costs can be reduced.

The method and the apparatus for cleaning the gypsum dewatering machine in the wet flue gas desulfurization apparatus of the present invention are not limited to the illustrated examples described above, and various changes can be made without departing from the gist of the present invention. Of course, it can be added.

[0024]

As described above, according to the method and apparatus for cleaning a gypsum dewatering machine in a wet flue gas desulfurization apparatus according to the present invention, the amount of cleaning water used for a belt filter can be greatly reduced, and plant operation can be reduced. An excellent effect of reducing costs can be achieved.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram of an example of an embodiment of the present invention.

FIG. 2 is an overall schematic configuration diagram of a conventional example.

[Explanation of symbols]

 3 Absorption Tower 8 Absorbent 10 Gypsum 11 Gypsum Dehydrator 12 Vacuum Pump 13 Guide Roll 14 Belt Filter 15 Vacuum Receiver 16 Vacuum Receiver 17 Washing Water 18 Washing Water Line 21 Collected Water (Low Chlorine Washing Water) 26 Washing Pump 27 Low Chlorine cleaning water line

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) B01D 33/58 (72) Inventor Yasuto Nara 3-2-16-1 Toyosu, Koto-ku, Tokyo Ishikawajima-Harima Heavy Industries, Ltd. Tokyo Engineering Center F term (reference) 4D002 AA02 BA02 CA01 DA05 DA16 EA09 EA12 EA13 EA20 FA03 HA10 4D026 BA03 BB03 BC11 BE05 BF20

Claims (2)

[Claims] 1. An endless belt filter is wrapped between guide rolls rotatably arranged at a required interval,
The belt filter is moved in the required direction by the rotation of the guide roll, and the lower end of the belt filter is maintained at a negative pressure via the vacuum receiver by the operation of the vacuum pump. A method for cleaning a gypsum dewatering machine in a wet flue gas desulfurization apparatus in which dewatering is performed by flowing down an absorbent containing gypsum after desulfurization to separate the gypsum and a filtrate, a required position downstream of a belt filter. The low-chlorine-based washing water after spraying to a required position on the downstream side of the belt filter is collected, and the collected low-chlorine-based washing water is sprayed to a required position on the upstream side of the belt filter. A method for cleaning a gypsum dewatering machine in a wet flue gas desulfurization apparatus, characterized in that: 2. An endless belt filter is wrapped between guide rolls rotatably arranged at a required interval,
The belt filter is moved in the required direction by the rotation of the guide roll, and the lower end of the belt filter is maintained at a negative pressure via the vacuum receiver by the operation of the vacuum pump. A washing device for a gypsum dewatering device in a wet flue gas desulfurization device that is designed to perform dehydration by flowing down an absorbent containing gypsum after desulfurization and separate the gypsum and a filtrate, and a required position downstream of a belt filter. A washing water line for spraying washing water onto the cleaning water line, a low-chlorine-based vacuum receiver for collecting low-chlorine-based washing water after being sprayed from the washing water line to a required position downstream of the belt filter, and a recovery by the vacuum receiver A low-chlorine-based cleaning water line for spraying the low-chlorine-based cleaning water to a required position on the upstream side of the belt filter. Dehydrator of the cleaning apparatus.