JPH0823414B2 - Dust removal method of sludge incinerator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust removal method for a sludge incinerator, which collects dust contained in exhaust gas from an incinerator for sewage sludge, cleans it, and discharges it into the atmosphere.

[0002]

Conventionally, the figure as filtration apparatus of sludge incinerator
As shown in FIG. 2 , a cyclone 11, a dry electrostatic precipitator 12, a scrubber 13, and a wet electrostatic precipitator 14 connected in series were used. However, recently, from the environmental point of view, it has been desired to further reduce the dust concentration in the exhaust gas.

However, in order to improve the dust removing performance of the electrostatic precipitator, the size of the device itself must be increased. For example, if the device size of the electrostatic precipitator having a dust removing performance of 90% is 100,
99% requires 200, 99, and 9% requires 300, which is exponentially large, and there is a problem that the size of the electrostatic precipitator is significantly larger than the dust removal performance. Therefore, in order to solve this, the present inventors are studying the use of a small bag filter with high dust removal performance in a dust removal device of a sludge incinerator. However, since the exhaust gas from the sludge incinerator contains 30 to 50% of water, the dust has a strong adhesive force, and the dust does not uniformly drop from the surface of the filter cloth at the time of removing it and becomes an avatar shape. There was a problem that stable operation could not be performed because dust suddenly adhered and pressure loss increased in a short time.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems, and can remove dust in the exhaust gas of a sludge incinerator economically and stably, and a dust removing method for a sludge incinerator. Has been completed in order to provide.

[0005]

[Means for Solving the Problems ] To solve the above problems
The present invention, which has been made possible, can be installed in a dust removal line of a sludge incinerator.
A cron and a bag filter are installed to remove sludge incinerator
The gas is passed through a cyclone to remove coarse particles and bugs.
While sending it to the filter, a part of the exhaust gas is cyclone
By sending it directly to the bug filter without passing it,
10 μm contained in the exhaust gas supplied to the bag filter of
It is characterized by adjusting the ratio of the above coarse particles to 10% or more.
Is what you do.

[0006]

EXAMPLES will be described in detail based on the illustrated embodiment of the present invention. FIG. 1 shows an embodiment of the present invention , 1 is a fluidized sludge incinerator, 2 is a heat exchanger, 3 is a bag filter for collecting dust in exhaust gas, and the bag filter 3 and the sludge incinerator are shown. A cyclone 4 for separating and collecting coarse particles is provided between the furnace 1 and the furnace 1. In this embodiment, a bypass 5 is provided in parallel with the cyclone 4 so that a part of the exhaust gas containing coarse particles is guided to the bag filter 3 as it is, so that the exhaust gas supplied to the bag filter 3 has a roughness of 10 μm or more. The proportion of particles is adjusted to 10% or more, more preferably 20% or more.

The reason for setting the ratio of coarse particles of 10 μm or more to 10% or more is to facilitate the removal by mixing coarse particles in the dust adhering to the filter cloth of the bag filter 3. The reason is that if the ratio is less than 10%, the pay-off property is poor as in the conventional case. The ratio of the coarse particles can be adjusted by adjusting the exhaust gas flow rate of the bypass 5. In addition, 6 is a scrubber for removing acidic gas such as HCl and SO _X in the exhaust gas and washing away residual dust, 7 is an exhaust gas fan, and 8 is a chimney.

This dedusting line passes exhaust gas discharged from the sludge incinerator 1 through a cyclone 4 to remove coarse particle dust, and then sends it to the bag filter 3, and also part of the exhaust gas directly through the bypass duct 5. 10μ in the exhaust gas supplied to the bag filter 3 by sending it to the bag filter 3
When the proportion of coarse particles of m or more is set to 10% or more, coarse particles are mixed in the dust layer adhering to the filter cloth surface of the bag filter 3, so the pressure loss is low without clogging. In addition to being able to keep it, the dust is evenly removed when the dust layer is removed.

Exhaust gas discharged from the sludge incinerator 1
If the amount of coarse particles inside is insufficient, use the coarse particle injection device.
It is also possible to inject coarse particles into the bag filter 3. this
Separation by cyclone as coarse particles if injected
It goes without saying that you can use the
It

[0010]

As is apparent from the above description, the present invention provides a cyclone and a bag filter in the dust removal line of a sludge incinerator, so that the dust concentration in exhaust gas can be reduced without increasing the size of the device. You can do it
Particle size in the exhaust gas flowing into the bag filter due to
Since 10% or more of coarse particles of 10 μm or more are mixed, the pressure loss can be kept low, the discharging performance can be improved, and stable operation can be performed.

[Brief description of drawings]

FIG. 1 is a flow sheet showing an embodiment of the present invention.

FIG. 2 is a flow sheet showing a conventional example.

[Explanation of symbols]

 1 Sludge incinerator 3 Bag filter 4 Cyclone 5 Bypass

Claims (1)

[Claims] 1. A cyclone in a dust removal line of a sludge incinerator.
And may be provided and a bag filter, the exhaust gas of sludge incinerator
After passing through a cyclone to remove coarse particles, bag fill
Not only send it to the computer but also pass some exhaust gas through a cyclone.
A dust removal method for a sludge incinerator, characterized in that the proportion of coarse particles of 10 μm or more contained in the exhaust gas supplied to the bag filter is adjusted to 10% or more by directly sending it to the bag filter.