JPS6354913A - Dust collector - Google Patents

Abstract

PURPOSE:To carry out stabilized continuous operation for a long time by pretreating a dust-contg. gas in a louver dust collector to mostly remove dust, then sending the gas into a filter cylinder, and passing the gas through the partition wall of the filter cylinder to further purify the gas. CONSTITUTION:When a dust-contg. gas is introduced from an inlet 1, the main gas stream changes its course and passes through the gap between the respective vanes of the louver dust collector 7, and the gas flows into a dust-contg. gas chamber 9. Coarse dust is passed through a duct 8 as it is by inertial force, and introduced into the dust-contg. gas inlet 17 of an auxiliary dust collector E. The gas with the dust concn. reduced by the louver dust collector 7 is introduced into each filter cylinder 6 from the dust-contg. gas chamber 9, and purified. The purified gas is introduced to a purified gas outlet 3. Meanwhile, the dust collected by the filter cylinder 6 flows down through the inside of the filter cylinder 6, and is collected in a dust hopper 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a compact dust collector capable of efficiently removing dust from high-temperature dust-containing gas such as blast furnace exhaust gas.

"Prior Art and its Problems" Fluids such as exhaust gas in industrial plants such as iron and ceramics contain a lot of dust, and releasing these into the atmosphere or outside the system is problematic. Also,
In the case of high-temperature exhaust gas such as blast furnace exhaust gas, the thermal energy of the exhaust gas is usually recovered through a heat exchanger, etc., but as mentioned above, such exhaust gas contains a lot of dust. This causes significant wear on heat transfer members such as heat exchangers, requiring replacement every few years, resulting in considerable costs and labor. From this point of view, there is a need for a technology for removing dust from dust-containing gas.

Incidentally, as dust collectors for removing dust from dust-containing gas, devices using filter cloth such as bag filters have been used conventionally, but in the case of these devices, the filter cloth has poor heat resistance. When the temperature of the dust-containing gas exceeds, for example, 250°C, it can no longer be used.

In recent years, dust collectors that use air-permeable ceramic walls such as ceramic foam and ceramic honeycomb as filter materials have been provided as devices that can be applied to purify such high-temperature dust-containing gases. Examples of such dust collectors include the dust collectors disclosed in Japanese Patent Application Laid-open No. 59-206028 and Japanese Patent Application Laid-open No. 59-225721, which were previously proposed by others. All of these devices introduce dust-containing gas into the inside of a porous ceramic tube that has air permeability. The clean gas is extracted by passing through the wall of the cylinder.

On the other hand, part of the dust that is blocked from passing by the wall of the chamfer adheres to the inner wall of the chimney, and most of it falls inside the chimney and is collected in a dust hopper provided below the chimney.

In such a dust collector, if the dust collection operation is performed continuously, a layer of dust will gradually accumulate on the inner surface of the inner surface, which increases the ventilation resistance of the inner surface and increases the differential pressure required for filtration. Therefore, a so-called backwash operation is required to remove accumulated dust by flowing fluid from the clean gas flow path side to the dust-containing gas flow path side every time the dust collection operation is performed for a predetermined period of time. becomes.

By the way, even if the dust concentration of the dust-containing gas is as high as 40 g/Nm or more, in a dust collector that introduces the dust-containing gas from above the dust-containing gas into the dust-containing gas, the dust-containing gas at the dust-containing gas inlet is If the speed is set to a high speed of approximately 5 m/s or more, the dust falling inside the 1!I cylinder has a self-cleaning effect that scrapes off the dust accumulated on the inner wall of the cylinder, so the rate of increase in differential pressure will be However, the need to perform backwash operations frequently still exists even in this state, and further measures to prevent a decrease in filtration performance are desired.

In this respect, it is useful to perform preliminary dust removal before applying the dust-containing gas to the dust collector to reduce the dust concentration of the dust-containing gas introduced into the dust collector. However, with the preliminary dust removal methods conventionally used in the steel industry, such as the cyclone method and dust catcher method, these devices require a volume equal to or larger than that of the main dust collector, and A disadvantage has arisen that it is difficult to form an integrated structure with a dust collector. A preliminary dust removal method may also be considered in which a buckle plate is installed in the dust collection device of the main body, but this method has the problem that the dust removal efficiency is not high.

Therefore, the present inventors previously proposed in Japanese Patent Application No. 81-122388 that a porous body having air permeability was used in a can body having an inlet header having a dust-containing gas inlet, a clean gas outlet, and a dust hopper. A dust-containing gas flow path from the dust-containing gas inlet to the dust hopper passing through the inside of the gas chamber, and a clean gas flow path extending from the outer periphery of the gas chamber to the clean gas outlet are formed. In the dust device, a louver dust remover for processing the dust-containing gas from the dust-containing gas inlet is disposed in the inlet header, and a gas outlet of the louver dust remover is communicated with the inlet of the filter cylinder;
The present invention has proposed a dust collector characterized in that a dust outlet of the louver dust remover communicates with the dust hopper through a conduit.

In this dust collector, the dust outlet of the louver dust remover opens into the dust hopper through a conduit.

Therefore, if the open end of the conduit is inserted into the powder layer at the bottom of the dust hopper, this powder layer will block the gas flow.
The gas flow velocity at the dust outlet of the louver dust remover becomes zero.

Therefore, only relatively coarse dust can be separated by the louver dust remover. In addition, when the flow rate of the dust-containing gas introduced into the louver dust remover decreases, the dust collection efficiency of the louver dust remover also decreases.
It was affected by this decrease in flow rate, resulting in a significant decrease.

On the other hand, if the open end of the conduit is above the powder layer mentioned above, or if there is no powder layer, the dust-containing gas from the dust outlet of the louver dust remover will pass through the conduit and pass through the dust hopper. There was a problem that the water would flow backwards upwards.

``Object of the Invention'' The present invention aims to solve the problems of the prior art as described above, namely, it is possible to efficiently remove dust from dust-containing gas, and it is possible to remove dust from dust-containing gas with high dust concentration for a long time. To provide a compact dust collecting device in which the filtration efficiency is not reduced even when applied continuously over time, the dust collecting efficiency in a louver dust remover is maintained at a high level, and moreover, the dust collecting device is compact.

"Summary of the Invention" The present invention provides a structure in which a porous material having air permeability is disposed in a can body having an inlet header having a dust-containing gas inlet, a clean gas outlet, and a dust hopper. In the dust collector in which a dust-containing gas flow path is formed from a dust gas inlet to the dust hopper through the inside of the gas chamber, and a clean gas flow path from the outer periphery of the gas chamber to the clean gas outlet, A louver dust remover is disposed in which the dust-containing gas from the dust-containing gas inlet is processed, and a low dust-containing gas outlet of the louver dust remover is communicated with the inlet of the device, and the louver dust remover is The dust-containing gas outlet is characterized in that it communicates with a dust-containing gas inlet of a separate dust collector.

Therefore, the dust-containing gas is first introduced into the louver dust remover through the dust-containing gas inlet. In the louver dust remover, not only most of the coarse dust in the dust-containing gas but also a considerable part of the medium to fine dust are separated from the main stream of the gas, and together with a small amount of gas, a high dust-containing gas is introduced. This forms a gas with a higher dust concentration than the dust-containing gas. This highly dust-containing gas is led to the dust-containing gas inlet of a separate dust collector through the high-dust gas outlet of the louver dust remover, and is converted into clean gas or low-dust gas by this separate dust collector. Separated into dust.

Further, the main stream of gas mainly contains some amount of medium to fine dust, forming a low dust-containing gas, that is, a gas having a lower dust concentration than the introduced dust-containing gas. This low-dust gas exits the low-dust gas outlet of the louver dust remover, is guided to the gas inlet communicating with it, roughly enters the gas chamber, is purified through the gas barrier, and is passed through the clean gas flow path. The clean gas is taken out through the clean gas outlet. Then, the separated dust passes through the interior of the chamber and is collected in the dust hopper.

In this way, after removing the main dust in the dust-containing gas using the louver dust remover, dust removal is carried out through the interior wall of the interior, which reduces the amount of dust that accumulates on the inner wall of the interior and prevents clogging of the interior. This enables stable continuous operation for a long period of time without increasing gas pressure loss. Further, by employing a louver dust remover as the preliminary dust removal means and incorporating this louver dust remover into the integrated can body, the apparatus can be made compact.

The high dust-containing gas outlet of the louver dust remover is connected to the dust-containing gas inlet of a separate dust collector.

By operating this different dust collector, gas always flows at a certain speed at this high dust-containing gas outlet. Therefore, the dust collection efficiency of the louver dust remover is improved compared to the case where there is no gas flow at this highly dust-containing gas outlet, and the dust collection efficiency of the louver dust remover is improved, and it can collect not only relatively coarse dust but also a considerable part of medium to fine dust. It will be separated from the main stream of gas. In addition, by having a certain gas flow rate at the high dust-containing gas outlet like this,
Even if the dust-containing gas flow rate decreases significantly, the dust collection efficiency of the louver dust remover does not decrease significantly. Contributes to more efficient operation.

"Embodiment of the Invention" FIG. 1 shows an embodiment of the dust collector of the present invention.

This dust collector is composed of a main dust collector and a sub dust collector E as a whole.

The main dust collector has an inlet header 15 with a dust-containing gas inlet 1 at its upper end, and a dust header at its lower end which is closed during operation and opened when removing accumulated dust. It has a dust hopper 2 with a discharge port 18, and a can body 4 having a plurality of clean gas outlet ports 3 on its side surface.

Inside the can body 4, a plurality of tube sheets 5 are disposed vertically in multiple stages, and a plurality of tube sheets 6 are vertically erected and supported in parallel to each other via these tube sheets 5. Each sex 6 may be composed of one vertically continuous thread, or may be composed of a plurality of threads connected vertically on the middle tube plate 5. The outer periphery of each sex 6 may be , and a clean gas chamber 11, and according to these characteristics 6, a dust-containing gas flow path A and a clean gas flow path B are divided.

A louver dust remover 7 is disposed within the inlet header 15, and the dust-containing gas from the dust-containing gas inlet 1 is first treated by the louver dust remover 7. The lower end of the louver dust remover 7 is connected to a conduit 8, and this conduit 8 is isolated from the clean gas flow path B and extends to a sub-dust collector E, which is a separate dust collector. Together with the vessel 7, it constitutes a conduit C.

The sub-dust collector E is a filtration type dust collector of the same type as the main dust collector, and is considerably smaller than the main dust collector. The sub-dust collector E includes a dust-containing gas inlet 17, a filter 18, a clean gas outlet 19, and a dust hopper 20, and a pipe C is connected to the dust-containing gas inlet 17. Clean gas outlet 19
may be connected to the clean gas flow path B or may be independent, and the dust hopper 20 may also be connected to the dust hopper 2 of the main dust collector or may be independent, Furthermore, it is also possible to take the same configuration as the main dust collector and include a louver dust remover.

The outer periphery of the louver dust remover 7 is a dust-containing gas chamber 9, and the gas treated by the louver dust remover 7 is sent into each filter tube 6 from this dust-containing gas chamber 9.

Various materials such as metals and ceramics can be used for the louver dust remover 7, but ceramics with excellent heat resistance are preferable in order to be applied to high-temperature exhaust gas. In addition, various materials such as sintered metal, woven ceramic fabric, non-woven ceramic fabric, and porous ceramics can be used for material 6, but in order to apply it to high-temperature exhaust gas, porous ceramics with excellent heat resistance are used. preferable.

In this dust collector, the dust-containing gas is supplied to the dust-containing gas inlet 1
When the gas is introduced further, the main flow of gas changes its flow direction and passes through the gaps between the blades of the louver dust remover 7 to enter the dust-containing gas chamber 9.
On the other hand, many dust particles, including coarse dust in the dust-containing gas, cannot change their direction of movement and fall downward due to inertia, so they cannot pass through the gap in the louver dust remover 7. Instead, it passes through the conduit 8 as it is, becomes a highly dust-containing gas together with some gas, and is guided to the dust-containing gas inlet 17 of the sub-dust collector E. This highly dust-containing gas is separated into dust and clean gas by the filter 18 of the sub-dust collector E, the clean gas is led out from the clean gas outlet 19, and the dust is transferred to the dust hopper 2.
collected to 0.

The gas whose dust concentration has been reduced by the louver dust remover 7 is
It is introduced into each filter tube 6 from the dust-containing gas chamber 9, passes through the wall surface of each filter tube 6, and is cleaned. The thus purified gas is led out from the clean gas chamber 11 to the clean gas outlet 3. On the other hand, the dust captured by the filter tube 6 is
The dust descends inside and is collected in the dust hopper 2.

In this way, the dust-containing gas is treated in advance with the louver dust remover 7 to remove the main dust, and then introduced into the filter tube 6 to roughly remove dust. ! The amount of dust that accumulates on the inner wall of the cylinder 6 is relatively small, making it difficult for clogging to occur even after long-term operation.

Of course, after a long period of operation, if dust adheres to the wall surface of the gas flow path 6 and the ventilation resistance exceeds the predetermined value, the fluid is introduced from the clean gas outlet 3 and the air is removed from the clean gas flow path B side. It is also possible to perform a backwashing operation by venting to the dust-containing gas flow path A side.

FIG. 2 shows another embodiment of the dust collector of the present invention. This embodiment is a suitable example when the scale of the dust collector increases. That is, in the inlet header 15, a plurality of louver dust removers 7 are arranged in parallel for processing the dust-containing gas from the dust-containing gas inlet 1, and each louver dust remover 7
are respectively connected to individual conduits 8, forming a plurality of conduits C. Each conduit 8 is extended to a sub-dust collector E. The outer periphery of the louver dust remover 7 is a dust-containing gas chamber 9, and the gas treated by the louver dust remover 7 is guided from this dust-containing gas chamber 9 to the corresponding cancer cylinders 6. In this embodiment, a partition wall 12 is provided that partitions each louver dust remover 7 and its corresponding group of cancer tubes 6 into one compartment, but this partition wall 12 is not necessarily essential.

Therefore, in this embodiment, the dust-containing gas introduced from the dust-containing gas inlet 1 is processed by the plurality of louver dust removers 7, major dust is removed, and after flowing into the dust-containing gas chamber 9, It is introduced into each corresponding cancer tube 6. The gas then passes through the partition walls of each tube 6 to remove any remaining dust, and is led out from the clean gas chamber 11 to the clean gas outlet 3. In this way, since the dust-containing gas is processed by the plurality of louver dust removers 7, even when the flow rate of the dust-containing gas is large, it is possible to process the dust-containing gas at once without increasing the pressure drop of the gas.

FIG. 3 shows an example of the louver dust remover 7 employed in these embodiments. This louver dust remover 7 has a plurality of blades 1 on both sides of a pipe C into which dust-containing gas flows.
3 are inclined and arranged parallel to each other to form a gap 14 that opens diagonally rearward with respect to the direction in which the dust-containing gas flows into the pipe C. In this case, the conduit C as a whole is configured to gradually narrow toward the downstream, and its V-shaped angle θ1 is approximately 4''.
The angle of inclination θ2 of the blade 13 relative to the blade 13 is approximately 2O4.

Furthermore, the thickness t of the blade 13 is lhm, @W is 40■,
The interval G is 80 mm, and the number of blades 13 is about 18 on one side.

The louver dust remover 7 configured under these conditions can separate about 95% of the dust with a particle size of 60 L or more by directing about 10% of the introduced dust-containing gas flow rate from the conduit 8. As a result, the dust captured by the cancer tube 6 is
This can be reduced by approximately 0%. Accordingly, the utilities used for backwashing operations can be reduced by about 70 to 80%. The conditions for the louver dust remover 7 are as follows:
The design is changed as appropriate depending on the flow rate and processing amount of dust-containing gas.

From the standpoint of space saving, the dust collector of the present invention is much smaller than a case where a cyclone or dust catcher is installed as a preliminary dust removal device (volume,
(Installation area: 172 or less), the volume can be reduced by approximately 15% compared to when the louver dust remover and main dust collector are installed separately, and pressure loss due to piping etc. in the middle can be eliminated. Pressure loss can be reduced by about 20% compared to a separate system. The sub dust collector E is 6 to 8 of the main dust collector.
In many cases, a scale of about % is sufficient.

In the dust collector of the present invention, the louver dust remover 7 can also be placed horizontally as shown in FIGS. 4 and 5. That is, an inlet header 15 having a dust-containing gas inlet 1 opening laterally is provided at the top of the can body 4, and a louver dust remover 7 is disposed horizontally in succession to the dust-containing gas inlet 1. ing. A conduit 8 connected to the high dust-containing gas outlet of the louver dust remover 7 is separated from the can body 4, drawn out to the outside, and communicated with the sub-dust collector E. After the main dust is removed by the louver dust remover 7, the dust-containing gas flows out into the dust-containing gas chamber 9, passes through the device 6 and flows out from its partition into the clean gas chamber 11, where it is purified and becomes clean gas. It is taken out from the takeout port 3. The main dust separated by the louver dust remover 7 is accompanied by a small amount of gas, passes through the conduit 8, is processed by the sub-dust collector E, and is collected in the dust hopper 20, and the dust separated by the device 6 is left as is. It passes through the pole part 6 and is collected in the dust hopper 2.

By placing the louver dust remover 7 horizontally in this way,
It is possible to save more space. However, in the case of a dust-containing gas with a high dust specific gravity, there is a risk of dust accumulating on the louver floor unless the gas flow rate is high. is preferred.

Further, in the dust collector of the present invention, the conduit 8 connected to the louver dust remover 7 may be constructed to be inserted into the inside of the louver dust collector 6. A typical example of such a structure is shown in FIG. In this case, there is no need to seal the conduit 8 with the tube plate 5 in order to isolate the conduit C and the clean gas flow path B, and there is no need to consider thermal expansion of the conduit 8 when sealing with the tube plate 5. . Therefore, there is an advantage that the seal structure is simplified.

"Effects of the Invention" As explained above, according to the present invention, the dust-containing gas is treated in advance with a louver dust remover to remove the main dust, and then it is sent into the gas chamber and further purified through the gas barrier wall. This reduces the amount of dust that accumulates on the inner walls of the body.
This prevents clogging and enables stable continuous operation over a long period of time. In addition, since the rate of increase in pressure loss due to dust adhesion is also reduced, the filter differential pressure can be reduced, and as a result, the power of the fan required for the system's gas pressure feeding etc. can be reduced. 1 more
Combined with the recycling of collected dust, the possibility of direct dust removal from high-temperature gas, which has a large heat recovery effect in the wake, and the ease of maintenance in the wake, the energy saving effect can be achieved. is recognized to be large. Furthermore, a louver dust remover is used as a preliminary dust removal means, and the high dust-containing gas outlet of this louver dust remover is connected to the dust-containing gas inlet of a separate dust collector, so that the louver dust remover has a blowdown function. This improves dust removal efficiency.

Furthermore, by integrating the louver dust remover into the can body, the device can be made more compact.

[Brief explanation of drawings]

1 and 2 are longitudinal cross-sectional views showing different embodiments of the dust collector of the present invention, and FIG. 3 is a cross-sectional view showing an example of a louver dust remover that can be used in the dust collector of the present invention. Fourth
The figure is a longitudinal sectional view showing still another embodiment of the dust collector of the present invention, FIG. 5 is a sectional view taken along the v-v line in FIG. 4,
FIG. 6 is a longitudinal sectional view showing yet another embodiment of the dust collector of the present invention. 1: dust-containing gas inlet, 2: dust hopper, 3: clean gas outlet, 4: can body, 5: tube plate, 6: nature, 7: louver dust remover, 8: conduit. 9: Dust-containing gas chamber, 11: Clean gas chamber, 15: Inlet header, A: Dust-containing gas flow path, B: Clean gas flow path, C: Pipeline, D: Main dust collector, E: Sub-dust collector Device. 1 @ 2nd figure leopard 31st figure ta

Claims (1)

[Scope of Claims] 1. A filter tube made of a porous material having air permeability is arranged in a can body having an inlet header having a dust-containing gas inlet, a clean gas outlet, and a dust hopper, and In the dust collector in which a dust-containing gas flow path from the dust gas inlet through the inside of the filter cylinder to the dust hopper and a clean gas flow path from the outer periphery of the filter cylinder to the clean gas outlet are formed, the inlet A louver dust remover is disposed in the header to process the dust-containing gas from the dust-containing gas inlet, and a low dust-containing gas outlet of the louver dust remover is communicated with the inlet of the filter cylinder, and the louver dust remover is connected to the inlet of the filter cylinder. A dust collector characterized in that a high dust-containing gas outlet of the container communicates with a dust-containing gas inlet of a separate dust collector. 2. In claim 1, a plurality of louver dust removers for processing the dust-containing gas from the dust-containing gas inlet are arranged in the inlet header, and the louver dust removers have low dust content. A dust collector in which a gas outlet is communicated with the inlet of the filter cylinder, and a high dust-containing gas outlet of these louver dust removers is communicated with a dust-containing gas inlet of another dust collector. 3. The dust collector according to claim 1 or 2, wherein the filter cylinder is made of ceramics. 4. In any one of claims 1 to 3, the high dust-containing gas outlet of the louver dust remover communicates with the dust-containing gas inlet of another dust collector through a conduit. , a dust collector in which the conduit is inserted into the filter tube;