RU2462292C2 - Flue gas treatment system - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to heat engineering units with waste gas emissions and may be used in various industries. Proposed system comprises cascade module of taper rings arranged at chimney end. Said module has flutes to accumulate polluted water communicated with discharge pipeline, 1-2 mm. dia-nozzles for uniform distribution of water dispersed to aerosol over tube cross-section, feed and discharge pipelines, pump to force water at 4-6 MPa with 4-5 l flow rate per one cubic metre of flue gases and to ensure preset water particle size complying with flue gas composition and Weber number, water treatment settler with neutraliser communicated with closed cycle of flue gas cleaning system.

EFFECT: higher efficiency of cleaning.

Description

The invention relates to various industries and can be used for cleaning flue gases.

Known methods for dry cleaning of gases [1, - C.39-81], including cyclones, dust collectors, ash collectors and electrostatic precipitators of various types that use gravitational, centrifugal and electrostatic forces to deposit dust and other gases on the stacks and filters of devices with their subsequent unloading .

Known methods for wet cleaning of gases [1, - S.82-136], including ash collectors with a wetted surface, foam scrubbers, high-speed gas scrubbers and wet dust collectors of various types that use gravity, wettability and dissolution of exhaust gases with water to precipitate and hydraulic discharge .

Known scrubbers [2, - S.563] - apparatus for washing with liquid dust and gas mixtures to remove gas or dust components.

The main disadvantage is the low productivity of gas purification due to the low supply of water.

Known electrical processing in the water recycling system of the installation of wet gas cleaning [3, - S.93-97].

The disadvantage of the installation is the high power consumption.

A known system of wet dust collectors with water recirculation [1, - S.137-138].

The main disadvantages of flue gas cleaning systems are the low efficiency of the plants during dry cleaning and the low water consumption during wet cleaning, which does not allow to bind the exhaust flue gases and dust in full, the lack of reliable water purification devices for reuse.

A known flue gas cleaning system [4], in which water is fed into the flue gas at a pressure of 0.7-3 MPa and a flow rate of 1.3-2.6 l / m ³ .

A known method of gas purification [5], adopted as a prototype, in which the deposition of suspended particles of dust and soluble gases is carried out at the end of the exhaust shaft (chimney) by feeding through sprayers (nozzles) in countercurrent to a hollow conical ring located along the axis of the chimney.

The disadvantage of the combined methods [4-5] is the low efficiency of water use and, as a result, low efficiency of flue gas purification and low efficiency.

If the flue gases have a temperature of 90 ° C or higher, then dispersed water, upon meeting the flue gas stream, passes into saturated steam in an amount of 425 g / m ³ and a stable aerosol in an amount of 940 g / m ³ , which is carried into the atmosphere by a stream, and only dispersed water in an amount of more than 1.3 l / m ³ falls with drizzle inside the pipe, which ensures the cleaning of flue gases.

The second disadvantage of the prototypes is the water pressure at the nozzles, at which the beginning of the decay of a thin stream at a distance of more than 80 mm, which creates a window free from aerosols for the passage of untreated flue gases. The experimental dependence of the beginning of the decay of the jet into aerosol for nozzles with a diameter of 1 mm confirms the low efficiency of the prototypes.

The task of the invention is to increase the efficiency of cleaning exhaust flue gases from suspended particles and soluble gases.

The solution to this problem is achieved by the fact that the cascade module of the cone rings is installed at the mouth of the chimney, has gutters for accumulating contaminated water associated with the discharge pipe, nozzles for uniform distribution of water dispersed to the aerosol over the pipe section with a nozzle diameter of 1-2 mm, a pump with by supplying water at a pressure of 4-6 MPa and a flow rate of 4-5 liters per cubic meter of flue gas, providing a given diameter of water particles in accordance with the composition of the exhaust gases and the Weber number, while the sump for cleaning water with a neutralizer is included in the closed cycle of the flue gas treatment system.

Figure 1 presents the flue gas cleaning system, where the following conventions are adopted: 1 - chimney; 2 - gaps between the conical rings, 3 - the exit of the chimney for purified flue gases; 4 - pump with a supply of 4-6 MPa and a flow rate of 4-5 l / m ^{3 of} flue gases; 5 - sump for water purification; 6 - neutralizer of water pollution; 7 - pipeline for supplying water to the nozzle; 8 - nozzles; 9 - ring trough for accumulation and drainage of water; 10 - outlet channel from the gutter; 11 - pipeline drainage of contaminated water; 12 - water recharge pipe.

The operation of the system is as follows. Flue gases rising through the pipe 1 pass through the slots 2 between the cones of the cascade of hollow conical rings with an angle of inclination of 45-55 ° and fall into the aerosol of finely dispersed water, which is created by nozzles 8 with a diameter of 1-2 mm, operating under a pressure of 4-6 MPa from pump 4 with a flow rate of 4-5 liters per cubic meter of flue gas. An aerosol that has absorbed dust and soluble gases from the flue gas drizzles onto the surface of the conical rings, rolls into the annular groove 9 and then through the outlet channel 10 and the pipe 11 enters the water purification system 5, equipped with a water neutralizer 6 and makeup 12. The purified water is pumped 4 is supplied to the nozzle 8, forming a closed cycle of water supply, and the cleaned flue gases through the outlet of the chimney 3 are released into the atmosphere.

Information sources

1. Rusanov A.A., Urbakh I.I., Anastasiadi A.P. Flue gas cleaning in industrial energy. - M .: Energy, 1969, - 456 s.

2. Mountain Encyclopedia, v.4. - M .: Soviet Encyclopedia, 1989. - P.563.

3. Proskuryakov V. A., Smirnov O. V. Purification of petroleum products and oily water by electrical treatment. - St. Petersburg: Chemistry, 1992, - 236 p.

4. Shvidkis B.C. Gas cleaning. - M .: Teploenergetik, 2002, - 442-443, Fig. 13.98.

5. RF patent No. 1473814. A1. Claim 04/23/1989.

Claims (1)

A system for cleaning flue gases, including a cascade module of cone rings, nozzles, inlet, outlet and feed pipelines, a pump, a sump for water purification with a pollution neutralizer, characterized in that the cascade module of cone rings is installed in the mouth of the chimney, has gutters for accumulating contaminated water associated with the discharge pipe, nozzles for uniform distribution of water dispersed to an aerosol over the cross section of a pipe with a nozzle diameter of 1-2 mm, a pump with a water supply at a pressure of 4-6 MPa and Odom 4-5 liters per cubic meter flue gas, providing a predetermined particle diameter of the water according to the composition of exhaust gases and Weber number, the sump for water treatment with neutralizer is included in the closed loop flue gas purification system.