JP6299334B2 - Coke oven electric dust collector operation management method - Google Patents

Description

  The present invention relates to an operation management method for an electrostatic precipitator that removes tar mist from a by-product gas discharged from a coke oven (hereinafter referred to as “coke oven gas”).

  Coke oven gas is purified by removing tar mist, sludge, naphthalene, hydrogen sulfide, ammonia and the like, and is used as, for example, fuel. Sludge is removed in a sludge settling tank, and compounds such as naphthalene, hydrogen sulfide, and ammonia are removed by operations such as cooling and absorption. Tar mist is usually removed by a rotary saddle type tar remover or an electric dust collector.

  FIG. 1 schematically shows a cross section of the electrostatic precipitator. While the coke oven gas G flows in from the bottom inlet 10a of the electrostatic precipitator 1, passes through the perforated plate 8 between the discharge wire 4a and the dust collector 4b, and flows out of the top outlet 10b, the DC power source 11 is supplied. A high voltage is applied to the coke oven gas G from the discharge wire 4a connected via the high voltage cable 12, and the tar mist is charged and collected on the dust collecting plate 4b.

  However, when the electrostatic precipitator 1 is used for a long time, the inside is naturally contaminated with tar mist. However, the insulator tower 3 accommodating the supporting insulator 3a and the penetrating insulator 3b for insulating and supporting the high voltage cable 12 is used. When the inside of the container becomes dirty, the insulation resistance decreases, or the discharge wire 4a and the dust collecting plate 4b are short-circuited. In FIG. 1, reference numeral 9 denotes a manhole for taking out the collected dust (tar mist).

  Patent Document 1 proposes an electrostatic precipitator that suppresses intrusion of tar mist into the inside of an insulator tower and ensures insulation of a high-voltage cable. However, the operation management of the electrostatic precipitator is the same as before, and even if the contamination inside the insulator tower can be suppressed, the removal efficiency of tar mist is not improved.

  In order to efficiently remove tar mist in coke oven gas with an electric dust collector, the electric dust collector needs to be operated and managed at a relatively high level. However, at present, operation management is performed by current monitoring in the instrument room or measurement work and patrol monitoring depending on the experience and intuition of the operator, and removal of tar mist is not efficient.

JP 2004-043534 A

  Normally, coke oven gas is flowed through an electrostatic precipitator system equipped with several electrostatic precipitators to remove tar mist, but the flow rate of coke oven gas becomes uneven and the amount of tar mist that accumulates in the electrostatic precipitator (removal) Amount) becomes uneven. Eventually, a difference occurs in the dust collection capacity of the electrostatic precipitator, and the overall dust collection efficiency of the electrostatic precipitator system is reduced.

  The present invention aims to improve the overall dust collection efficiency of the electric dust collection system when flowing coke oven gas through an electric dust collection system equipped with several electric dust collectors and removing tar mist. An object of the present invention is to provide a method for managing an electrostatic precipitator that solves this problem.

  The present inventors diligently studied a method for solving the above problems. As a result, when removing tar mist from coke oven gas with a dust collection system equipped with a plurality of electrostatic precipitators, (x) the amount of coke oven gas flowing into the electrostatic precipitator system, It has been found that adjusting the amount to be equal improves the overall dust collection efficiency of the electric dust collection system.

  In addition, (y) the voltage of the electrostatic precipitator is monitored over time, the voltage application to the electrostatic precipitator in which irregular voltage fluctuation has occurred is stopped, and the amount of coke oven gas flowing into the electrostatic precipitator system remains. It has been found that the overall dust collection efficiency of the electric dust collection system is improved by adjusting the dust collection amounts of the individual electric dust collectors to be equal.

  This invention was made | formed based on the said knowledge, and the summary is as follows.

In operation management method for an electro-precipitator coke furnace to remove tar mist from by-product gas to be discharged,
(I) (i-1) While adjusting the amount of coke oven gas flowing into an electric dust collector system having a plurality of electric dust collectors so that the individual dust collectors have the same dust collection amount, (i-2) Monitor the voltage applied to the electrostatic precipitator over time,
(Ii) (ii-1) Stops the application of voltage to the electrostatic precipitator in which irregular voltage fluctuation has occurred in the above voltage to shut off the inflow of coke oven gas, and (ii-2) the remaining multiple electrostatic precipitators An operation management method for an electric dust collector of a coke oven, wherein the amount of coke oven gas flowing into the electric dust collector system is adjusted again so that the amount of dust collected in each electric dust collector becomes equal.

  According to the present invention, when the coke oven gas is allowed to flow through an electric dust collection system equipped with several electric dust collectors and tar mist is removed, the overall dust collection efficiency of the electric dust collection system is improved.

It is a figure which shows typically the cross section of an electric dust collector. It is a figure which shows two electric dust collection systems. It is a figure which shows the time-dependent change of the voltage characteristic of an electrostatic precipitator.

The operation management method of the electric dust collector of the coke oven of the present invention (hereinafter sometimes referred to as “the method of the present invention”) is an operation management method of the electric dust collector that removes tar mist from the by-product gas discharged from the coke oven .
(I) (i-1) While adjusting the amount of coke oven gas flowing into an electric dust collector system having a plurality of electric dust collectors so that the individual dust collectors have the same dust collection amount, (i-2) Monitor the voltage applied to the electrostatic precipitator over time,
(Ii) (ii-1) Stops the application of voltage to the electrostatic precipitator in which irregular voltage fluctuation has occurred in the above voltage to shut off the inflow of coke oven gas, and (ii-2) the remaining multiple electrostatic precipitators The amount of coke oven gas flowing into the electric dust collection system provided is adjusted again so that the amount of dust collection in each electric dust collector becomes equal.

  Hereinafter, the method of the present invention will be described with reference to the drawings.

  FIG. 2 shows two electric dust collection systems. An inflow pipe 2a and an inflow pipe 2b are branched from the gas flow main pipe 2, and three electrostatic precipitators 1a, 1b, 1c are connected in parallel to the inflow pipe 2a. The electric dust collectors 1d, 1e, and 1f of the machine are connected in parallel to form two electric dust collection systems.

  The gas flow main pipe 2 includes a coke oven between an adjustment valve 7a for adjusting the flow rate of the coke oven gas flowing into the inflow pipe 2a and an adjustment valve 7b for adjusting the flow rate of the coke oven gas flowing into the inflow pipe 2b. A flow meter 5 for measuring the gas flow rate and a damper 6 for adjusting the flow rate are arranged (in the drawing, arranged on the upstream side and the downstream side of the flow meter). Based on the measured value (flow value) measured by the flow meter 5, the opening degree of the damper 6 is adjusted by a control arithmetic device (not shown).

  The coke oven gas flows into the electrostatic precipitators 1a, 1b, 1c and the electrostatic precipitators 1d, 1e, 1f connected to the inflow pipe 2a and the inflow pipe 2b, respectively, from the bottom inlet, and after tar mist is removed, Outflow from the outlet at the top of the electric dust collector to the outflow pipe 2a 'and the outflow pipe 2b', respectively.

  In the inflow pipe 2a, a flow meter 5a for measuring the flow rate of the coke oven gas flowing into the electric dust collector and a damper 6a for adjusting the flow rate are arranged. Based on the measured value (flow rate value) measured by the flow meter 5a, the opening degree of the damper 6a is adjusted by a control calculator (not shown), and the flow rate of the coke oven gas flowing into the electrostatic precipitators 1a, 1b, 1c is determined. Be controlled.

  The inflow pipe 2b is provided with a flow meter 5b for measuring the flow rate of the coke oven gas flowing into the electric dust collector and a damper 6b for adjusting the flow rate. Based on the measured value (flow value) measured by the flow meter 5b, the opening of the damper 6b is adjusted by a control calculator (not shown), and the flow rate of the coke oven gas flowing into the electrostatic precipitators 1d, 1e, 1f is determined. Be controlled.

  The coke oven gas after the tar mist is removed by the electric dust collector flows out from the outlet at the top of the electric dust collector to the outflow pipe 2a 'and the outflow pipe 2b', respectively. In the method of the present invention, the amount of coke oven gas flowing into the electric dust collection system is adjusted by a flow meter and a damper so that the dust collection amount of each electric dust collector becomes equal.

  In order to remove tar dust in coke oven gas, high voltage is applied to each electrostatic precipitator. During operation, the voltage characteristics of each electrostatic precipitator are measured, and the operating state is constantly monitored.

  In FIG. 3, the time-dependent change of the voltage characteristic of an electrostatic precipitator is shown. While the electrostatic precipitator is operating normally, the voltage changes at a substantially constant V0, but when an abnormal sign appears in the electrostatic precipitator, the voltage starts to rise.

  In FIG. 3, the voltage starts to increase from time t0. That is, it means that the electrostatic precipitator has started to be in an abnormal operating state from time t0. When the rising trend of voltage continues for time T1 (t1-t0) and the electrostatic precipitator reaches an abnormal state (tar mist accumulates to the limit amount and short-circuits with the discharge electrode), the voltage fluctuates randomly Start (interval of T2 (= t2-t1) in the figure). After the voltage fluctuation continues for a predetermined time T2, the voltage drops to zero.

  Therefore, in the method of the present invention, when irregular voltage fluctuation occurs in the voltage of a specific electrostatic precipitator, the voltage application is stopped and the inflow of coke oven gas is shut off without waiting for the voltage to drop to zero. Continue to remove tar mist with the remaining electrostatic precipitator. At this time, the amount of coke oven gas flowing into the electrostatic precipitator system is again adjusted so that the amount of dust collected by each electrostatic precipitator becomes equal, within a range where the excessive load is not applied to the remaining electrostatic precipitator. Adjust with.

  As mentioned above, although this invention was demonstrated based on the two electric dust collection systems shown in FIG. 2, this invention method is not restricted to two electric dust collection systems. The electric dust collection system may be one system or three or more systems. In the method of the present invention, the overall dust collection rate is remarkably improved regardless of the number of electric dust collection systems.

  Next, examples of the present invention will be described. The conditions in the examples are one example of conditions used for confirming the feasibility and effects of the present invention, and the present invention is based on this one example of conditions. It is not limited. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

(Example)
In the electric dust collection system shown in FIG. 2, coke oven gas is supplied to the inflow pipe 2a at 100,000 Nm ³ / hr and to the inflow pipe 2b at 100,000 Nm ³ / hr. Inside tar mist was removed. The voltage characteristics of each electrostatic precipitator were measured to monitor the operating state, and the amount of dust collected was measured at regular intervals. The voltage characteristics were almost constant and good, and the amount of dust collected was almost equal.

Since irregular fluctuations appeared in the voltage characteristics of the electrostatic precipitator 1c, the voltage load was immediately stopped and the inflow of coke oven gas was shut off. At the same time, the damper is adjusted to change the flow rate of the inflow pipe 2a from 100,000 Nm ³ / hr to 80,000 Nm ³ / hr, and the flow rate of the inflow pipe 2b from 100,000 Nm ³ / hr to 120,000 Nm ³ / hr. changed.

  Even after the flow rate was changed, the voltage characteristics of each electrostatic precipitator were measured to monitor the operating state, and the dust collection amount was measured at regular intervals. The voltage characteristics were almost constant and good, and the amount of dust collected was almost equal.

After repairing the electrostatic precipitator 1c, it is restarted, the damper is adjusted, the flow rate of the inflow pipe 2a is changed from 80,000 Nm ³ / hr to 100,000 Nm ³ / hr, and the flow rate of the inflow pipe 2b is 120,000 Nm ^3. / Hr was changed to 100,000 Nm ³ / hr.

  Even after the flow rate was changed, the voltage characteristics of each electrostatic precipitator were measured to monitor the operating state, and the dust collection amount was measured at regular intervals. The voltage characteristics were almost constant and good, and the amount of dust collected was almost equal.

  As described above, according to the present invention, when the coke oven gas is allowed to flow through an electric dust collection system equipped with several electric dust collectors and tar mist is removed, the overall dust collection efficiency of the electric dust collection system is improved. improves. Therefore, the present invention has high applicability in the coke manufacturing industry.

DESCRIPTION OF SYMBOLS 1 Electric dust collector 1a, 1b, 1c Electric dust collector 1d, 1e, 1f Electric dust collector 2 Gas flow main pipe 2a, 2b Inflow pipe 2a ', 2b' Outflow pipe 3 Insulator tower 3a Support insulator 3b Through insulator 4a Discharge wire 4b Dust collector plate 5, 5a, 5b Flow meter 6, 6a, 6b Damper 7a, 7b Regulating valve 8 Perforated plate 9 Manhole 10a Bottom inlet 10b Top outlet 11 DC power supply 12 High voltage cable E Earth G Coke oven gas

Claims (1)

In the operation management method of the electric dust collector that removes tar mist from the by-product gas discharged from the coke oven,
(I) (i-1) While adjusting the amount of coke oven gas flowing into an electric dust collector system having a plurality of electric dust collectors so that the individual dust collectors have the same dust collection amount, (i-2) Monitor the voltage applied to the electrostatic precipitator over time,
(Ii) (ii-1) Stops the application of voltage to the electrostatic precipitator in which irregular voltage fluctuation has occurred in the above voltage to shut off the inflow of coke oven gas, and (ii-2) the remaining multiple electrostatic precipitators An operation management method for an electric dust collector of a coke oven, wherein the amount of coke oven gas flowing into the electric dust collector system is adjusted again so that the amount of dust collected in each electric dust collector becomes equal.

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