JPS6333885B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas cleaning device that dry-cleans blast furnace top gas and other high-temperature, high-pressure gases containing a large amount of dust.

Conventionally, methods for cleaning dust-containing gas include a gas cleaning method using wet dust collection and a gas cleaning method using dry dust collection.

In the case of wet dust collection, the dust-containing gas is brought into contact with gas cleaning water, so moisture is contained in the gas, which reduces the calorific value per unit capacity. There is a problem that the sensible heat cannot be recovered because the temperature is cooled down to a certain temperature.

On the other hand, in the case of dry dust collection, the dust collection section is made up of a layer of abrasion-resistant filter material such as sand, and when the dust-containing gas passes through this dust collection section, the dust in the gas is removed. The dry dust collection method has recently replaced the wet dust collection method because it removes dust with high performance and low pressure loss and provides clean gas in a high temperature and dry state. It has come to be attracting attention.

In the conventional gas cleaning method using dry dust collection, as mentioned above, there is little drop in gas temperature, heat amount, or pressure, so it is possible to clean the clean gas in a dry state at high temperature and high pressure after removing dust from high temperature and high pressure dust-containing gas. In order to recover the large amount of energy it possesses, it is led to an energy recovery section and then stored.

To give an example of the conventional method, a wear-resistant filter material such as sand or gravel is continuously or intermittently filled in a layered manner between vertically arranged wire meshes or perforated metal plates, so that the material can move freely. Some filters collect dust by allowing gas to pass through the filter material. However, in this method, the filter material in the packed bed is movable, so the dust collected in the dust collection section moves not only downward but also to the downstream side of the gas as it moves from above to below the packed bed. Therefore, the collection efficiency decreases. In order to increase this collection efficiency, it is necessary to have multiple packed layers. Furthermore, in the conventional method described above, since the filled filter material is mobile, a means for circulating it is required.

In addition, conventionally, a packed bed of abrasion-resistant filter material such as sand is formed in a horizontal state inside the cylindrical body, and dust is collected when gas passes through this fixed packed bed.
In addition, air is blown upward from below the packed bed from an air pipe led from outside to the bottom of the packed bed, and the dust collected in the packed bed is made to float by the head wind that blows up the packed bed. There were also some configurations. However, with this method, the suspended dust is discharged by settling downward from the spaces between the filled layers arranged in the circumferential direction, so the suspended dust cannot be discharged quickly. At the same time, a blower pipe is required to introduce air from the outside to fluidize the packed bed, and the presence of spaces between the packed beds makes it impossible to continuously collect dust-containing gas.

The present invention was made in an attempt to collect all dust by fluidizing a packed bed without blowing in outside air, and to enable continuous collection of dust. A filling layer is provided in which a filter material such as sand is filled, and the filling layer is filled by sucking gas in the direction opposite to the gas flow while covering a part of the filling layer on the upstream side of the gas flow of the filling layer. It is characterized in that a cleaning hood that partially fluidizes the bed is positioned, and the cleaning hood and the packed bed move relative to each other.

Embodiments of the present invention will be described below with reference to the drawings.

The drawing shows, as an example of the present invention, two dry filling layers arranged in a container, each filling layer being partitioned into a plurality of parts, and a plurality of sets of dust suction cleaners installed above each filling layer. A hood is positioned and the cleaning hood is rotated to sequentially fluidize the packed bed.

To be more specific, a dust collection container 1 having a gas inlet 2 at the top and a clean gas outlet 3 at the bottom has a bottom plate made of wire mesh, metal perforated plate, etc., and particles of sand or the like are used to form a substantially uniform particle size. Filled layers 5 and 6 are arranged in upper and lower two stages, and each filled layer 5 and 6 is divided into a plurality of layers by a partition plate 7 in the radial direction. At the same time, a large number of radially extending partition plates 8 are used to divide the packed layers 5 and 6 into a large number of adjacent small chambers. Make it pass through 5 and 6.

A rotary cylinder 9 is arranged vertically in the center of the packed beds 5 and 6 of each stage, and a box girder 10 of each stage is arranged vertically.
The rotary cylinder 9 is airtightly supported by a gas seal 11 on the lower surface of the container 1, and the upper part of the rotary cylinder 9 is guided by a guide roller 12 attached to an upper box girder 10, and the lower end of the rotary cylinder 9 is A rail/gear 13 attached to the outer periphery of the container 1 is received by a guide roller 14 attached to the container 1, and the rotary cylinder 9 is rotated by a drive device 15 via a power transmission device 16. In this rotary cylinder 9, fine particle ducts 17, 18 corresponding to the upper and lower two stages of packed beds 5, 6 are fixed at a plurality of locations on the circumference. Washing hoods 19 and 20 of a number and size corresponding to the number and size of the partitions in the radial direction are arranged on the upper surface, and each washing hood (in the radial direction in FIG. 19 (corresponding to the outer packed layer is shown) are respectively connected to the fine particle duct 17 fixed on the upper stage, and similarly each cleaning hood (shown in FIG. 2 shows what corresponds to the radially inner packed layer)
0 is also connected to a particulate duct 18 fixed to the lower stage of the rotary cylinder 9, so that the upper and lower cleaning hoods 19, 20 are rotated by the rotation of the rotary cylinder 9.

In this embodiment, the cleaning hoods 19 and 20 have a size that almost corresponds to the size of the packed bed portion of each partitioned small chamber in the circumferential direction, and are arranged on the front and rear sides in the direction of high rotational movement as shown in FIG. As shown, it has a skirt 21 so that it can perform a suction action even if it straddles the filling layer of each circumferentially adjacent chamber during movement.
Further, each of the fine particle ducts 17 and 18 is connected to various dust collectors outside the container 1 through the inside of the rotary cylinder 9, and the insides of the hoods 19 and 20 are made to have negative pressure by a blower or the like. 22 is a telescopic tube, and 23 is a leg.

The particle size of the filter material 4 in the packed beds 5 and 6 is appropriately large enough to not be scattered by suction by the cleaning hoods 19 and 20, for example, about 3 mm, but depending on the size of the dust. It is natural to change the ratio accordingly.

Since the gas purifying device of the present invention has the above-described configuration, when dry gas containing dust enters at high temperature and high pressure from the gas inlet 2 of the container 1, this gas first flows into the upper packed bed. Pass 5.
At this time, most of the dust is collected and deposited on the filling layer 5. The gas that has passed through the packed bed 5 further passes through the packed bed 6, and at this time, dust in the gas is collected and deposited on the packed bed 6. The gas that has passed through the lower packed bed 6 is removed from dust and is discharged from the gas outlet 3 of the container 1 as clean gas.

The cleaning hoods 19 and 20 on the upstream side of the packed beds 5 and 6 in each stage are slowly rotating together with the rotary cylinder 9 rotated by the drive device 15, and the cleaning hoods 19 and 20, which are located on the upstream side of the packed beds 5 and 6 in each stage, rotate slowly together with the rotary cylinder 9 rotated by the drive device 15. Each of the small chambers in the layers 5 and 6 is caused to flow by causing a portion of the gas that has passed through the packed beds 5 and 6 to flow back from the bottom to the top in each packed bed due to the negative pressure in the hoods 19 and 20. Layered. As a result, the dust deposited on the packed bed 5 is suspended and scattered by the gas flowing back, and is sucked and collected by the cleaning hood 19.
Similarly, dust accumulated on the packed bed 6 is sucked and collected by the hood 20. At this time, the filter material 4 of the packed bed
Since the particles have a certain size, they are not scattered by the backflow of the gas and are washed into clean particles. Note that the gas on the upstream side is difficult to enter into the hoods 19 and 20 because of the skirt 21.

The gas containing the scattered dust sucked by the cleaning hoods 19 and 20 is led to the dust collector outside the container 1 through the fine particle ducts 17 and 18.

When the packed beds 5 and 6 are partitioned in the radial direction in this way, the cleaning hoods 19 and 20, which are different on the outside and inside in the radial direction, are used to fluidize and scatter dust, and the dust is also partitioned in the circumferential direction. By sequentially bringing the packed bed parts into a fluid state and scattering dust, all the dust accumulated in the entire area of the packed bed can be continuously scattered and actively sucked and removed.

The gas purifying device of the present invention has been described above, and the device of the present invention is particularly suitable for cleaning large amounts of dry gas containing dust at high temperatures (100 to 200 degrees Celsius or higher) and high pressures (1 to 3 atmospheres or higher). It is valid.
Note that the apparatus of the present invention is not limited to the illustrated and described embodiments; for example, the packed bed is partitioned into a plurality of parts with respect to the gas flow cross section, but the packed bed is partially partitioned into a fluidized bed using a cleaning hood. There is no need to divide the packed bed into multiple parts as long as the packed bed can be divided into multiple stages, the packed bed may be in one or more stages, and an example in which the packed bed is fixed and each cleaning hood 19, 20 is movable. However, it is sufficient that the packed bed and the cleaning hood are relatively movable, and either one of them may be fixed or both may be movable, and within the scope of the present invention. Of course, various changes can be made.

As described above, according to the gas cleaning device of the present invention, (i) the packed bed is fluidized by suction by the cleaning hood, so there is no need to separately blow in cleaning gas from the outside.

(ii) The cleaning hood actively sucks and removes the fluidized and scattered dust-containing gas.
There is no need to provide a space for dust to descend in the circumferential direction as in the past, and dust can be collected continuously and efficiently, and the dust collection efficiency is very high.

It can produce excellent effects such as

[Brief explanation of the drawing]

FIG. 1 is a partial explanatory diagram showing an example of the gas purifying device of the present invention, FIG. 2 is an enlarged view in the direction of the arrow in FIG. 1, and FIG.
The figure is an enlarged view of FIG. 1 in the direction of the arrows. 1...dust collection container, 4...wear-resistant filter material, 5,
6... Filled bed, 7, 8... Partition plate, 9... Rotating tube, 19, 20... Cleaning hood.

Claims (1)

[Claims] 1. A container having a gas inlet and an outlet is provided with a packed bed filled with a filter material such as sand, and a part of the packed bed is placed on the upstream side of the packed bed in the direction of the gas flow, covering a part of the packed bed and opposite to the gas flow. A gas cleaning device characterized in that a cleaning hood is positioned to partially fluidize the packed bed by sucking gas in the direction of the cleaning hood, and the cleaning hood and the packed bed are moved relative to each other.