JP2843062B2 - Limestone slurry storage tank - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a limestone slurry storage tank used in a wet flue gas desulfurization apparatus, and particularly to a limestone slurry storage tank suitable for preventing clogging of a limestone input port. It is.

[Conventional technology]

BACKGROUND ART In a wet flue gas desulfurization device (hereinafter, may be simply referred to as a desulfurization device), a limestone slurry prepared by mixing water and limestone powder as an absorbent is used as an absorbing solution, and the limestone slurry is prepared. The storage tanks are generally called limestone slurry storage tanks.

FIGS. 3, 4 and 5 are explanatory diagrams of a conventional limestone slurry storage tank, respectively.

In FIG. 5, the limestone powder carried in by the limestone supply conveyor 2 is introduced into the limestone slurry tank 1 through the limestone input port 5 together with the purge air supplied from the conduit 3, and the limestone slurry is stirred in the limestone slurry tank 1. By 6, the limestone slurry is stirred and mixed with the water introduced from the conduit 8 to form a limestone slurry, and then taken out of the tank via a limestone slurry pump 9.

The water mixed with the limestone powder is usually industrial water or filtered water generated in the system of a wet flue gas desulfurization device, and has a certain temperature, so that when introduced into the limestone slurry storage tank 1, Steam rises from the surface. The steam flows into the limestone charging port 5 and the limestone supply conveyor 2 and condenses. In the limestone charging port 5 or the limestone supply conveyor 2, the limestone powder absorbs moisture and adheres. Air is introduced to prevent steam from flowing in.

By the way, recent thermal power plants operate only during periods of high electricity usage in accordance with trends in power demand,
The so-called DSS that stops driving at night and on holidays
Since the operation is dominant, the wet flue gas desulfurization device is also operated intermittently. So the fifth
In the limestone slurry storage tank shown in the figure, even when the desulfurization device is stopped, it is necessary to continuously supply purge air from the conduit 3 in order to prevent steam from flowing into the limestone input port 5 and the limestone supply conveyor 2. However, it was not an economic operation to reduce utility consumption, and a solution was desired.

The limestone slurry storage tank shown in FIGS. 3 and 4 has been improved to satisfy such demands. FIG. 3 shows the operation of the desulfurization device by providing an on-off valve 4 downstream of the limestone supply conveyor 2. When stopped, the on-off valve 4 is closed and the conduit 3
The purpose of this is to stop the supply of air for purging from, and to reduce utility consumption. The limestone slurry storage tank shown in FIG. 4 is provided with an on-off valve 4 and a purging air conduit 10 connected to the downstream of the on-off valve 4 in order to prevent steam from flowing into the downstream side thereof. .

[Problems to be solved by the invention]

However, steam flows into the limestone slurry storage tank of FIG. 3 from the limestone input port 5 to the on-off valve 4 when the operation is stopped,
Since the water condenses into water, there is a problem that limestone powder adheres to the water when the operation is restarted, solidifies, gradually grows, and finally blocks the inlet. Also, in the limestone slurry storage tank of FIG. 4, even when the operation is stopped, purging air must be kept flowing in order to prevent steam from flowing downstream of the on-off valve 4 even when the operation is stopped. Therefore, there is a problem that the utility consumption is not reduced.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a limestone slurry storage tank which prevents limestone powder from sticking and growing to a limestone supply conveyor and a limestone input port, and has low utility consumption. is there.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a limestone slurry storage tank provided with opening / closing means at a limestone charging port for charging limestone powder, wherein the flexible means expands or contracts by supplying compressed air or partial pressing as the opening / closing means. The limestone bag is provided inside the limestone inlet.

[Action]

By disposing a flexible bag that expands or contracts due to the supply of compressed air or partial pressing inside the limestone inlet, when the flexible bag is expanded, the limestone inlet closes, When the bag is contracted, the limestone inlet is opened. Also, the limestone powder once adhered to the flexible bag and solidified is blown off each time the bag is expanded and contracted to open and close the limestone input port, and a state in which there is no deposit is always reproduced. Therefore, the blocking of the input port due to the adhesion of limestone is prevented.

In the present invention, when the desulfurization apparatus is operated, the flexible bag is contracted to open the limestone charging port, and the limestone powder is introduced into the limestone slurry tank together with the purge air.
On the other hand, when the operation of the desulfurization device is stopped, the flexible bag body is inflated to close the limestone charging port and the flow of steam to the upstream side is prevented, so that the limestone powder does not adhere. In addition, moisture adhering to the closed portion of the bag while the flexible bag is closed causes limestone powder to be introduced when the desulfurization apparatus starts operation, that is, when the bag is opened, to absorb moisture and adhere. Even if it does, the growth is prevented by the air for purge introduced together with the limestone powder, and when the flexible bag is expanded again to close the limestone inlet, the expansion and contraction operations of the bag are performed. Repeat several times, if the bag is moved in a wavy manner, the deposits are washed off,
The condition without deposits is regenerated.

In the present invention, the flexible bag body is a flexible bag-like material, which is disposed inside the limestone charging port to introduce compressed air,
The limestone inlet is opened or closed by expansion or contraction by discharging or partial pressing.

The flexible bag may be provided annularly inside the limestone input port, or several bags may be provided along the inside of the input port. The bag is provided with a means for introducing compressed air and a valve. When the bag expands and contracts by pressing, it is sufficient to seal the air.

The flexible bag may be used as a part of the limestone inlet pipe, and the bag may be tied from the outside or the tie may be released to open and close the limestone inlet.

In the present invention, as the material of the flexible bag, for example, a film of polyamide, polyethylene, polyvinyl chloride, polypropylene, or the like, woven fabric, non-woven fabric, or the like is used. There is no particular limitation as long as it exists.

〔Example〕

 Next, the present invention will be described in more detail with reference to examples.

FIG. 1 is a sectional view of a limestone slurry storage tank showing one embodiment of the present invention, and FIG. 2 is a partially enlarged view of FIG.

In FIG. 1, the limestone slurry storage tank includes a limestone slurry tank 1 and a limestone supply conveyor 2 for carrying limestone powder into the limestone slurry tank 1 through a limestone inlet 5.
A conduit 3 for purging air connected to the limestone supply conveyor 2, a flexible annular bag body 12 (13) provided inside the limestone inlet 5, and a water inlet for the limestone slurry tank 1. , A stirrer 6 attached to the limestone slurry tank 1 for mixing limestone powder and water to prepare limestone slurry, an exhaust port 7, and a tank for supplying the prepared limestone slurry. It mainly comprises a limestone slurry pump 9 to be transported outside.

The limestone powder carried in by the limestone supply conveyor 2 is introduced into the limestone slurry tank 1 through the limestone inlet 5 together with the purge air introduced from the conduit 3, and the conduit 8
The limestone slurry is stirred and mixed with water supplied from the reactor to form a limestone slurry, which is then taken out of the tank via a limestone slurry pump 9.

In FIG. 2, the on-off valve casing of the limestone inlet 5
The flexible annular bag body provided on the inner wall surface of the device 15 contracts and hangs down when the desulfurization device is operating, and opens the charging port 5 while the operation of the desulfurization device is stopped. Compressed air is introduced from a compressed air introducing means (not shown) into the space between the bag 15 and the bag body, and expands, so that the space 13 at the center of the annular bag body is closed and the limestone inlet 5 is closed. To close.

The limestone powder at the start of charging may be adhered to moisture condensed and condensed when the annular bag is closed in the annular bag 12 opened during the operation of the desulfurization device. Since the purge air is supplied from the inlet, the growth air does not grow any more and the inlet 5 is not blocked. When the desulfurization device is stopped, compressed air is introduced into the annular bag, the annular bag is expanded, and the charging port 5 is closed.
At this time, by repeatedly performing the operation of introducing and discharging the compressed air, that is, the operation of expanding and contracting the annular bag, the deposit 16 of the limestone powder once deposited is removed. Next, compressed air is again introduced into the annular bag from which the deposits 16 have been removed, and the bag is kept in an expanded state 13, and the charging port 5 is closed until the operation is started again. The introduction and the introduction of the purge air are stopped. When restarting the operation, the compressed air between the openable casing and the annular bag is discharged, the expanded bag is contracted to open the space in the center of the annular bag, and the inlet 5 is opened, Limestone powder is injected with the purging air.

According to the present embodiment, a flexible annular bag that opens and closes the limestone inlet by expanding or contracting by supplying or discharging compressed air is arranged inside the limestone inlet 5.
Since the limestone powder once adhered and solidified can be wiped off by expansion or contraction of the annular bag body, a state without any adhered substance can always be regenerated, and blockage of the charging port 5 can be prevented. Further, it is not necessary to introduce air for purging while the limestone charging port 5 is closed due to the expansion of the annular bag, so that utility consumption can be reduced.

〔The invention's effect〕

Advantageous Effects of Invention According to the present invention, it is possible to prevent the limestone charging port from being blocked due to moisture absorption and adhesion of limestone powder, and to save the consumption of purge air even when the wet flue gas desulfurization device is frequently started and stopped. .

[Brief description of the drawings]

FIG. 1 is a sectional view of a limestone slurry storage tank showing an embodiment of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, and FIGS. 3, 4 and 5 show a conventional slurry storage tank. FIG. 1 limestone slurry tank 2 limestone supply conveyor 3
... conduit, 5 ... limestone inlet, 6 ... stirrer, 7 ...
Exhaust port, 8 ... conduit, 9 ... limestone slurry pump, 12
(13) ... A bag.

Claims (1)

(57) [Claims] In a limestone slurry storage tank provided with an opening / closing means at a limestone charging port for charging limestone powder, a flexible bag which expands or contracts by supply of compressed air or partial pressing is used as the opening / closing means. A limestone slurry storage tank provided inside the limestone charging port.