JPS6342713A - Method for controlling dust collector performance - Google Patents

Abstract

PURPOSE:To control the performance of a dust collector by detecting the dust concn. in the gas at the inlet of the dust collector, and controlling the moving quantity of a filter medium so that the moving velocity of the filter to a dust load is made constant so as to adjust the dust concn. at the outlet to always be more than a specified value. CONSTITUTION:The dust-contg. gas is supplied to the dust collector main body 1 and passed through a dust collection bed 2, hence the dust in the gas is collected, and the refined gas is supplied to the succeeding stream. Meanwhile, a filter medium is supplied to the dust collector main body 1 through a supply tank 3. The filter medium of the dust collection bed 2 is continuously moved by a roll feeder 4, and the moving quantity of the filter medium can be changed by changing the r.p.m. of the roll feeder. The value of a gas flowmeter 7 provided at the outlet of the dust collector and the value of a dust densitometer 8 furnished at the inlet duct of the dust collector are detected, the dust load is calculated from those values, and the moving quantity of the filter medium is controlled. Besides, the requisite moving quantity to the dust load is obtained, and the r.p.m. of the roll feeder 4 is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling the performance of a dust collector having a moving bed in which a granular filter material is filled between two supports.

The method of the present invention is applied to a dust collector in a gas purification plant for coal gasification combined cycle power generation and other dust collectors that process dust-containing gas.

[Conventional technology]

BACKGROUND ART Conventionally, as a dry filter dust collector, a dust collector having a moving bed in which a granular filter material such as silica sand is filled between supports such as louvers, wire mesh, and punched metal has been used.

[Problem that the invention seeks to solve]

In the above-mentioned conventional dust collectors, the dust collection performance is generally left to chance or manually adjusted in response to fluctuations in the inlet dust load, so there is a problem in that the load followability is poor.

The present invention was made to solve the above problems, and detects the dust load at the inlet of the dust collector, calculates the amount of filter material movement from the level or weight of the lock hopper, and changes the amount of filter material movement. By directly controlling the dust collection performance, the ability to follow the fluctuations in dust load at the entrance of the dust collector is improved, the required performance (exit dust concentration) is always satisfied, and the operating power consumption is reduced. The purpose of this study is to provide a method that can suppress this as much as possible.

[Means and effects for solving the problem] The performance control method of a dust collector of the present invention detects the dust load at the inlet of a dust collector having a moving bed of granular filter material, and adjusts the amount of filter material per dust load. It is characterized in that the amount of movement of the filter medium is controlled so that the movement speed becomes constant and the dust collection efficiency is maintained at a required value.

In addition, when filtration media is intermittently supplied to the filtration media supply tank, the actual amount of filtration media supplied to the dust collector is the moving average of the value calculated from the vertical clearance movement cycle time of the filtration media supply hopper level, Alternatively, control is performed so that it is represented by the moving average value of the value calculated from the vertical gap movement cycle time of the filter medium discharge tank level. Note that detection is performed using a level meter or load cell.

(Example) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.However, the shapes of the components described in this embodiment, their relative positions, etc. are not particularly specific. Unless otherwise specified, they are not intended to limit the scope of the present invention to these examples only (they are merely illustrative examples).

FIG. 1 shows an example of the configuration around a dust collector that implements the method of the present invention.

The gas containing gas is supplied to the dust collector main body 1 and passes through a dust collection layer 2 formed by filling a granular filter material such as silica sand between supports such as louvers, wire mesh, and punched metal. At this time, the dust in the gas is captured by the filter material and is supplied to the downstream stream as purified gas.

On the other hand, the filter material is supplied to the dust collector main body 1 via the supply tank 3. After the dust in the gas has been captured in the dust collection layer 2, the filter material passes through a roll feeder 4, a hopper 5 at the bottom of the dust collector main body, and a filter material discharge tank 6, and is discharged to a filter material regeneration processing section (not shown). be done. The regenerated filter medium is returned to the filter medium supply tank 3 again. Here, supply tank 3
The discharge tank 6 acts as a lock hopper together with the upper and lower valves when the dust collector main body is a high pressure system and the filter material regeneration system is a normal pressure system. Therefore, supply of the filter material to the supply tank 3 and discharge of the filter material from the discharge tank 6 are performed intermittently. On the other hand, the dust collection layer 2 of the dust collector main body 1
The movement of the filter medium is performed continuously by the roll feeder 4, and the amount of movement (supply amount) of the filter medium is adjusted by changing the rotation speed of the roll feeder.

The amount of movement of the filter material is controlled by first detecting the gas flow rate with a gas flow meter 7 installed in the outlet duct of the dust collector, and then with a dust concentration meter 8 installed in the inlet duct of the dust collector.
The dust concentration in the dust-containing gas is detected, and the dust load (total amount of dust supplied) is calculated by the calculator 10 from this flow rate and dust concentration. 11 is a setting device.

As a dust collector characteristic, the dust collection performance (efficiency) has a relationship with (filter moving speed/dust load) as shown in Figure 2, so if you set the dust collection efficiency, the dust load will change. In contrast, the required amount of movement of the filter medium is determined. Therefore, the amount of filter material supplied is detected by the filter material amount detector 12 or 13 consisting of a level meter or a load cell as the vertical clearance movement cycle time of the level of the supply tank 3 or discharge tank 6, and the moving average value is detected by the calculator 14. The calculated value is used as an input signal to the filter medium flow rate controller 15 as the actual supply amount of the filter medium. Based on the output signal of the filter medium flow rate controller 15, the rotation speed of the roll feeder 4 is controlled, and the amount of movement of the filter medium is controlled to a set value.

(Effects of the Invention) Since the present invention is configured as described above, it has the following effects.

(1) Significantly improves load followability by detecting the dust load at the entrance of the dust collector (total amount of dust supplied) and controlling the amount of filter material movement so that the speed of filter material movement of the dust load light is constant. can do.

(2) Since the load followability of performance is improved, the design margin of the dust collector body can be minimized, and costs can be reduced.

(3) Since the amount of movement of the filter media is appropriately controlled, processing of excessive filter media at partial loads can be prevented.
The power required for separation and the consumption of inert gas (N, etc.) required for scavenging such as a lock hopper can be saved.

(4) When the actual supply amount of filter media is calculated from the vertical gap movement time of the hopper level and the moving average value is used as the control amount, it is possible to calculate the actual supply amount of the filter media from the vertical gap movement time of the hopper level and use the moving average value as the control amount. Similarly, this control method can be applied.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of a device implementing the dust collector performance control method of the present invention, and FIG. 2 is a graph showing the relationship between filter medium moving speed and dust collection performance with respect to dust load. 1... Dust collector body, 2... Dust collection layer, 3... Supply tank, 4... Roll feeder, 5... Dust collector main body lower hopper, 6... Discharge tank, 7 ...Gas flow meter, 8...Dust concentration meter, 10...Arithmetic unit, 11
... Setting device, 12.13 ... Filtering material amount detector, 14
... Arithmetic unit, 15... Filter medium flow rate controller

Claims (1)

[Claims] 1. Detect the dust load at the inlet of a dust collector that has a moving bed of granular filter media, and so that the filter media movement speed per dust load is constant and the dust collection efficiency is maintained at the required value.
A method for controlling the performance of a dust collector, characterized by controlling the amount of movement of a filter medium.