SU143410A1 - Installation for dry blast furnace gas cleaning from dust - Google Patents

Description

The conversion of blast furnaces to work with increased gas pressure at the top of the furnace is associated with significant changes in the energy supply of the metallurgical plant, in particular, under the conditions of gas cleaning.

At present, at most metallurgical plants, blast furnace gas is finely cleaned using a throttle device. With this cleaning method, all the potential energy of the blast furnace gas is lost in the throttle device, and the physical heat of the blast furnace gas is lost as its temperature decreases from 250 to 30 °.

The proposed purification scheme is devoid of these drawbacks. Its feature is that it allows the blast furnace gas to be cleaned without decreasing temperature and pressure and to obtain significant power by using its energy in a gas turbine-dilator.

For an example of a 1300 m blast furnace, the power of a gas turbine with a pressure at the top of 2.5 at and a temperature of 250 ° C of blast furnace gas is 9700 kt, i.e. 73% of the power required to compress the blast air.

The use of dry cleaning to maintain pressure and temperature of the blast furnace gas simplifies the installation of the gas turbine expander to the limit.

The proposed plant for dry blast furnace gas cleaning from dust involves the use of metal-ceramic filters made of an anticorrosive metal for fine gas cleaning, which ensures the preservation of pressure and temperature of the blast-furnace gas and long-term operation of filters.

Along with the use of metal-ceramic filters for the fine cleaning of blast furnace gas, it is proposed to replace the existing coarse

5. Buildings are not required for gas cleaning and the installation of a gas turbine-expander is simplified to the limit, since there is no need for a heat exchange and heating device in front of the turbine.

6. Simplification of the gas turbine installation-expander should contribute to its widespread implementation and obtaining significant power without fuel consumption.

The use of centrifugal dust separators and metal-ceramic filters for cleaning blast furnace gas.

Domain oven

by the action of centrifugal force, a path equal to the diameter of the spiral gas pipeline and get through the slit 14 into the diverting annular channel 15.

The dust particles, concentrated in 5-10% of the gas flow, from the exhaust channel / 5 through the gas pipeline 16 are directed to a precipitation device made in the form of a cyclone 17 of the NIIOGAZ design. The main mass of the gas, directed through the pipeline / 5, which contains dust particles not exceeding the value specified by the calculation. The blast furnace gas purified from dust in the cyclone 17 is returned to the main gas pipeline 18 via the gas pipeline 19. The amount of the gas withdrawn to the cyclone is regulated by the throttle valve 20 installed in the gas pipeline 18.

Digital footnotes in FIG. 3 correspond to the description given to FIG. 2

Depending on the specific conditions of the projected gas cleaning, the location of the centrifugal dust separator is allowed both in the vertical and in the horizontal plane.

The filter element 21 (Fig. 4) is made in the form of a hollow box, the height of which is determined by structural considerations.

In the upper part, the filter element is provided with a special flange, with the help of, and which is attached to the partition 22, which separates the purified gas from the dusty gas.

The pre-purge gas through the inlet plug 23 enters the body of collector 3, in which it fits externally to the metlo-ceramic ceramic filter elements 21. The dust containing in the gas is trapped by the metal-ceramic filter elements and is deposited in a thin layer. When the filter is blown back, the dust is discharged into the conical part 24 of the collector 3 and removed through the dust plug 25. The cleaned gas through the openings in the partition 22 and the outlet gas 26 is directed to the clean, gas gas pipeline.

Metal-ceramic filters are known to provide gas cleaning up to 1 mg / m, which is significantly lower than the permissible dust content of pure blast furnace gas (10 mg / m).

Regenerating metal-ceramic filters by back-blowing allows gas to be cleaned on the same equipment indefinitely .time. ....,

During the shutdown period of the blast furnace, it is necessary to maintain a positive temperature of the remaining gas in the body of the collector 3 with metal-ceramic filters above the dew point, in order to avoid condensation of water vapor. Heating of the body of the collector with metal-ceramic filters is easy to implement either with the help of an electric heater or steam heating, since the body of the collector 3 has heat insulation.

The proposed blast furnace gas cleaning system has significant advantages, of which the main ones are:

1. Comparative simplicity of equipment and operation.

2. It does not require water consumption, and therefore, there is no need for a complex and expensive schlamovom household and sewage during wet gas cleaning.

3. The power consumption for gas cleaning service is reduced.

4. The filtering surface is reduced by more than 8 times compared with filters made of glass fiber cloth, which significantly reduces the size of the gas cleaning.

- 3 - № 143410

fu: s.3

Dth

Pus g

Yr

fUd