JPH0356119A - Limestone slurry storage tank - Google Patents

Abstract

PURPOSE:To prevent powders of limestone from adhering to a charging port for limestone and from building-up by using, as an opening and closing means of the charging port, a flexible bag which is inflated or deflated by feeding compressed air thereinto or partially pressing it. CONSTITUTION:An opening an closing means is provided in a charging port 5 for limestone, through which powders of limestone are fed into a limestone slurry storage tank 1, wherein flexible bag bodies 12, 13, which are inflated or deflated by feeding compressed air thereinto or by partially pressing them, are provided in the charging port 5. As a result, blocking of the charging port due to moisture absorption and adhesion of powders of limestone can be avoided and also consumption quantity of air for purging can be reduced in the case of frequent start-up and shut-down of a wet type flue gas desulfurization device.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a limestone slurry storage tank used in a wet flue gas desulfurization device, and particularly to a limestone slurry storage tank suitable for preventing clogging of a limestone input port. It is. (Prior art) In a wet flue gas desulfurization device (hereinafter sometimes abbreviated as a desulfurization device), a limestone slurry prepared by mixing water and limestone powder as an absorbent is used as an absorption liquid.
The storage tank in which the limestone slurry is prepared is generally called a limestone slurry storage tank.

FIG. 3, FIG. 4, and FIG. 5 are explanatory diagrams of conventional limestone slurry storage tanks, respectively.

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

The water to be mixed with the limestone powder is usually industrial water or filtered water generated within the system of a wet flue gas desulfurization equipment, and has a certain temperature, so when it is introduced into the limestone slurry storage tank, the liquid Steam rises from the surface. This steam flows into the limestone inlet 5 and the limestone supply conveyor 2 and condenses, and within the limestone inlet 5 or the limestone supply conveyor 2,
Conduit 3 may cause limestone powder to absorb moisture and stick.
Purge air is introduced from the tank to prevent steam from entering.

By the way, recent thermal power plants have adopted the so-called DSS system, which operates only during periods of high electricity usage and shuts down at night and on holidays, in line with trends in electricity demand.
Since this is the mainstream operation, the wet flue gas desulfurization equipment will also be operated intermittently. Therefore, the fifth
In the limestone slurry storage tank shown in the figure, even when the desulfurization equipment is stopped, it is necessary to continue supplying purge air from the conduit 3 in order to prevent steam from flowing into the limestone inlet 5 and the limestone supply conveyor 2. , it was not an economical operation to reduce utility consumption, and a solution was desired. The limestone slurry storage tank shown in Fig. 3 and Fig. 4 has been improved to meet such requirements. When the system is stopped, the on-off valve 4 is closed and the supply of purge air from the conduit 3 is stopped to reduce utility consumption. The limestone slurry storage tank shown in FIG. 4 is provided with an on-off valve 4, and a purge air conduit 10 is connected to the downstream part of the on-off valve 4 in order to prevent steam from flowing into the downstream part of the on-off valve 4. .

[Problem to be solved by the invention]

However, in the limestone slurry storage tank shown in Fig. 3, when the operation is stopped, steam flows from the limestone inlet 5 to the on-off valve 4 and condenses to become moisture, so when the operation is restarted, limestone powder adheres to this moisture and solidifies. However, there is a problem that it gradually grows stronger and eventually blocks the input port. Furthermore, in the limestone slurry storage tank shown in FIG. 4, even when the operation is stopped as in FIG. 5, in order to prevent steam from flowing into the wake of the on-off valve 4,
There is a problem in that the purge air must continue to flow in, and utility consumption is not reduced.

It is an object of the present invention to solve the problems of the prior art described above, to provide a limestone slurry storage tank that prevents limestone powder from sticking to a limestone supply conveyor and a limestone input port, and prevents its retention, and which consumes less utility. It is in.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a limestone slurry storage tank in which an opening/closing means is provided at the limestone inlet into which limestone powder is input, and the opening/closing means is capable of expanding or contracting by supplying compressed air or by partial pressure. The present invention is characterized in that a flexible bag body is provided inside the limestone inlet.

[Effect]

By arranging a flexible bag that expands or deflates by supplying compressed air or partial pressure inside the limestone inlet, when the flexible bag is inflated, the limestone inlet closes; When the bag is deflated, the limestone inlet opens.

Furthermore, the limestone powder that has once adhered to the flexible bag and solidified is dislodged every time the bag is expanded and contracted to open and close the limestone inlet, thereby constantly regenerating a state free of any adhesion. Therefore, clogging of the input port due to adhesion of limestone is prevented. In the present invention, when the desulfurization apparatus is operated, the flexible bag is contracted to open the limestone inlet, and limestone powder is introduced into the limestone slurry tank together with purge air.

On the other hand, when the desulfurization equipment is stopped, the flexible bag is inflated and the limestone inlet is closed, and steam is prevented from flowing into the upstream side, so that limestone powder does not adhere to the desulfurizer. In addition, due to moisture adhering to the closed part of the flexible bag while the flexible bag is closed, the limestone powder that is introduced when the desulfurization equipment starts operating, that is, when the bag is opened, absorbs moisture and adheres to it. Even if it does, the purge air introduced together with the limestone powder prevents it from clogging, and when the flexible bag is inflated again and the limestone inlet is closed, the bag cannot be inflated or deflated. By repeating this several times and moving the bag in a waving motion, the deposits will be brushed off.
The deposit-free condition is regenerated.

In the present invention, a flexible bag is a flexible bag-like object,
It is placed inside the limestone inlet and expands or contracts to open and close the limestone inlet by introducing, discharging, or partially pressing compressed air.

The flexible bag may be provided in a ring shape inside the limestone inlet, or several bags may be provided along the inside of the inlet. The bag is provided with compressed air introduction means and a valve, but when inflating and deflating by pressure, it is sufficient to simply seal the air.

The flexible bag may be used as a part of the limestone inlet piping, and the limestone inlet may be opened and closed by tying or untying the bag from the outside. In the present invention, as the material of the flexible bag, for example, polyamide, polyethylene, polyvinyl chloride, polypropylene film, woven fabric, non-woven fabric, etc. are used, but the material must have flexibility and a certain strength. If so, there are no particular limitations.

〔Example〕

Next, the present invention will be explained 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. 1.

In FIG. 1, this limestone slurry storage tank is connected to a limestone slurry tank 1, a limestone supply conveyor 2 that carries limestone powder into the limestone slurry tank 1 through a limestone inlet 5, and the limestone supply conveyor 2. a purge air conduit 3, a flexible annular bag 12 (l3) provided inside the limestone inlet 5, and a conduit 8 for introducing water into the limestone slurry tank 1 through the water inlet. , an agitator 6 attached to the limestone slurry tank 1 that mixes limestone powder and water to prepare limestone slurry, an exhaust port 7, and a limestone slurry ribbon 9 that transports the prepared limestone slurry to the outside of the tank. It is mainly structured.

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 purge air introduced from the conduit 3, and is stirred and mixed with water introduced from the conduit 8. It becomes a limestone slurry and is then taken out of the tank via a limestone slurry pump 9. In FIG. 2, the flexible annular bag provided on the inner wall surface of the on-off valve casing 15 of the limestone inlet 5 contracts during operation of the desulfurization equipment and becomes a hanging shape 1l12, opening the inlet 5. On the other hand, when the desulfurization equipment is stopped, compressed air is introduced from a compressed air introducing means (not shown) into the space between the on-off valve casing l5 and the bag body and expands, filling the space in the center of the annular bag body. becomes a closed state fll3 and closes the limestone inlet 5. When the desulfurization equipment is in operation, the limestone powder at the start of charging may stick to the moisture that adhered and condensed when the annular bag was closed, but during operation, the conduit 3 Since purge air is supplied from the inlet, the inlet 5 will not grow any further and the inlet 5 will not be clogged. In addition, when stopping the desulfurization device, compressed air is introduced into the annular bag to inflate the annular bag and close the inlet 5.
At this time, by repeating the operation of introducing and discharging compressed air, that is, the operation of expanding and deflating the annular bag, the deposits 16 of limestone powder that have once adhered are 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 the inflated state 13. The inlet 5 is closed until the operation is restarted, and the limestone powder is The introduction of input and purge air is stopped. When restarting the operation, the compressed air between the opening/closing casing and the annular bag is discharged, the inflated bag is contracted, a space in the center of the annular bag is opened, and the input port 5 is opened. Limestone powder is introduced along with purge air.

According to this embodiment, a flexible annular bag is disposed inside the limestone inlet 5 to open and close the limestone inlet by expanding or contracting by supplying or discharging compressed air. Since the limestone powder can be brushed off by the expansion or contraction of the annular bag, a state free of stuck substances can be constantly reproduced, and the clogging of the input port 5 can be prevented. Moreover, since there is no need to introduce air for purging while the limestone input port 5 is closed due to the expansion of the annular bag, utility consumption can be reduced.

[Effects of the Invention] According to the present invention, it is possible to prevent the limestone inlet from being blocked due to moisture absorption and adhesion of limestone powder, and to reduce the consumption of purge air even when the wet flue gas desulfurization equipment is frequently started and stopped. You can save money.

[Brief explanation of 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. This is an explanatory diagram showing the DESCRIPTION OF SYMBOLS 1... Limestone slurry tank, 2... Limestone supply conveyor, 3... Conduit, 5... Limestone input port, 6... Stirrer, 7... Exhaust port, 8... Conduit, 9 ...Limestone slurry pump, 12(13).・Bag body.

Claims (1)

[Claims] (1) In a limestone slurry storage tank in which a limestone inlet into which limestone powder is introduced is provided with an opening/closing means, the opening/closing means is a flexible bag that expands or contracts by supplying compressed air or by partial pressure. A limestone slurry storage tank characterized by being installed inside an input port.