CN103111224A - Flash mixer - Google Patents

Abstract

The invention provides a rapid mixer, which is characterized in that: the rapid mixer comprises an outer cylinder, an inner cylinder and a deflector; the outer cylinder is arranged on the periphery of the inner cylinder, and the outer cylinder and the inner cylinder are connected through the deflector. The invention has a reasonable structure, and can ensure that the high-temperature hot air and the clean flue gas are mixed evenly as soon as possible, reduces the use of expensive high-temperature-resistant and anti-corrosion materials, and discharges the clean flue gas at a uniform temperature after heating.

Description

fast mixer

technical field

The present invention is mainly used in the wet desulfurization system of a thermal power plant. In the process of using a high-temperature hot air to heat the low-temperature clean flue gas through direct mixing, it is mainly used to accelerate the rapid mixing of two gaseous substances and ensure that the gas can be mixed in a short period of time. Time, short distance, to achieve rapid mixing of two gaseous substances. the

Background technique

In recent years, with the country's emphasis on environmental protection, thermal power units have adopted a wet limestone-gypsum desulfurization process to remove SO ₂ from boiler exhaust gas. The temperature of the net flue gas at the outlet of the absorption tower of the wet desulfurization system is about 50°C. Currently, there are two ways to discharge the net flue gas with heating and without heating. Heating can increase the temperature of the net flue gas and increase the lifting height of the flue gas, which is conducive to the diffusion of pollutants and avoids the occurrence of smoke and rain. If it is not heated, it will cause corrosion of the tail flue and "gypsum rain" around the chimney, which will affect the surrounding environment and residents' lives.

At present, there are mainly the following methods for reheating the net flue gas:

⑴ Use gas-gas heat exchanger, namely GGH. It is a type of regenerative heating. In the wet desulfurization system, it is used to heat the undesulfurized flue gas (generally 130-150°C) to heat the desulfurized flue gas, usually to 80°C, and then enter the chimney for discharge.

⑵ steam - gas heater. That is to use hot steam to heat the clean flue gas. It is characterized by simple design and operation, small initial investment, but high operating cost, prone to corrosion, and deposits on the pipes that affect the heat transfer effect. Few power plants in China use this type of heater. the

⑶ Bypass reheating. When the flue gas is partially desulfurized, the undesulfurized raw flue gas is mixed with the FGD net flue gas, and the temperature of the mixed flue gas depends on the amount of bypass flue gas and the relative temperature of the flue gas. With the improvement of environmental protection requirements, it is rarely used in China at present. the

⑷ Boiler high temperature air heating. Utilize the hot air margin of the boiler island to draw high-temperature air, pass through the natural pressure difference between the boiler system and the FGD system, without adding any auxiliary power, and send the hot air to the outlet of the absorption tower of the FGD system, where it is directly mixed with the low-temperature clean flue gas after desulfurization, without using Any heat exchange surface eliminates problems such as corrosion and scaling due to the existence of heat exchange surfaces, and has been applied in some thermal power plants. the

In the process of heating with boiler hot air, since the temperature of the hot air is as high as 250°C, the anti-corrosion materials in the clean flue and chimney can withstand a maximum temperature of no more than 170°C, so it is necessary to ensure that the high-temperature hot air and clean flue gas are mixed evenly as soon as possible to reduce the use of expensive The use of high-temperature resistant and anti-corrosion materials, after heating, the net flue gas temperature is evenly discharged. However, the effects of the above methods are not ideal. the

Contents of the invention

Purpose of the invention: The present invention provides a fast mixer, the purpose of which is to solve the problem of uneven mixing of high-temperature hot air and clean flue gas in the conventional wet desulfurization system of thermal power plants. the

Technical solution : the present invention is achieved through the following technical solutions:

A rapid mixer, characterized in that: the rapid mixer comprises an outer cylinder, an inner cylinder and a deflector; the outer cylinder is arranged on the periphery of the inner cylinder, and the outer cylinder and the inner cylinder are connected through the deflector.

The outer cylinder and the inner cylinder are cylindrical structures, and the diameter of the inner cylinder is 1/3 to 1/4 of the diameter of the outer cylinder. the

The axial length of the outer cylinder and the inner cylinder of the rapid mixer is 0.5m to 1m. the

There are 6 to 8 deflectors. the

The deflector is in the shape of a right-angled triangle. One of the slopes of the deflector forms an angle of 60° with the axial direction of the outer cylinder, and the right-angled surface is the same as the axial direction of the outer cylinder. The outer section is on a plane. the

Advantages and effects :

The invention provides a rapid mixer, which is characterized in that: the rapid mixer comprises an outer cylinder, an inner cylinder and a deflector; the outer cylinder is arranged on the periphery of the inner cylinder, and the outer cylinder and the inner cylinder are connected through the deflector.

The invention has a reasonable structure, and can ensure that the high-temperature hot air and the clean flue gas are mixed evenly as soon as possible, reduces the use of expensive high-temperature-resistant and anti-corrosion materials, and discharges the clean flue gas at a uniform temperature after heating. the

Description of drawings:

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a schematic structural diagram of another side of the present invention.

The specific embodiment: the present invention will be further described below in conjunction with accompanying drawing:

The present invention provides a rapid mixer, which is characterized in that: the rapid mixer comprises an outer cylinder 1, an inner cylinder 2 and a deflector 3; the outer cylinder 1 is arranged around the inner cylinder 2, and the outer cylinder 1 and the inner cylinder 2 pass through Deflector 3 is connected.

The outer cylinder 1 and the inner cylinder 2 are cylindrical structures, and the diameter of the inner cylinder is 1/3-1/4 of the diameter of the outer cylinder. the

The axial length of the outer cylinder 1 and the inner cylinder 2 of the rapid mixer is 0.5m-1m. the

Deflector 3 is 6～8 pieces. the

The deflector is in the shape of a right-angled triangle, that is, a triangular prism, and the cross-section of the triangular prism is a right-angled triangle. One of the slopes of the deflector forms an angle of 60° with the axial direction of the outer cylinder, so that the direction of air flow It forms an included angle of 60° with the axial direction of the inner and outer cylinders, and the right-angled side is in the same direction as the axial direction of the outer cylinder, and the other right-angled side of the deflector is on the same plane as the outer section of the inner and outer cylinders. the

In the system that uses high-temperature air to heat the clean flue gas, because there is a certain deviation in the temperature and density of the two gaseous media, if the mixture is uneven, it will cause damage to the anti-corrosion material on the inner wall of the chimney, so this patent is adopted at the port of the hot air duct technology that enhances the mixing of two gaseous media. the

The main function of fast mixer of the present invention is as follows:

⑴ The air flow state in the inner cylinder is a linear flow, while the air flow in the outer cylinder is in a rotational flow due to the action of the deflector. The two airflows leave the mixer in different states and are separated from the clean flue gas. The contact area increases the contact area between the hot air and the clean flue gas, and the heat exchange is more sufficient.

(2) One side of the deflector is arranged in a 60° direction, so that the hot air leaving the mixer has a strong tangential velocity, which strengthens the disturbance and mixing of the clean flue gas. the

⑶ Since the hot air is rotated and jetted out of the fast mixer, a net flue gas recirculation zone is formed at the outlet of the mixer, so that the hot air and the net flue gas are quickly mixed. the

⑷ The temperature of the hot air in the mixer is as high as 300°C, and the temperature of the net flue gas at the outlet of the absorption tower is only 50°C. Through the action of the fast mixer, the temperature deviation of the net flue gas after cross-section mixing of the two gaseous media before entering the chimney The temperature is less than 2°C, and the hot air and the clean flue gas are fully mixed. the

See the following table for the application effect of the quick mixer:

When the boiler load is 70% and 100% of the rated output, the thermal secondary air volume is measured respectively under the condition of maintaining the normal operation of the boiler and the extraction of the hot secondary air adjustment baffle fully opened. The measurement position is at the dust collector On the top horizontal hot air duct, the net flue gas temperature measuring point is located on the chimney inlet flue. The results of the test measurements are shown in Table 1. It can be seen from the test results that the deviation between the net flue gas temperature of the chimney and the design value under the two working conditions is -0.4°C and -0.9°C respectively, which can meet the design requirements of extracting hot air to heat the clean flue gas, and the design effect of the fast mixer is good, realizing Rapid and thorough mixing of hot air and clean flue gas.

Claims (5)

1. flash mixer, it is characterized in that: this flash mixer comprises urceolus (1), inner core (2) and deflector (3); Urceolus (1) is arranged on the periphery of inner core (2), and urceolus (1) is connected by deflector (3) with inner core (2).

2. flash mixer according to claim 1, it is characterized in that: urceolus (1) and inner core (2) are cylinder-like structure, and inner diameter of steel flue is 1/3～1/4 of urceolus diameter.

3. flash mixer according to claim 2, it is characterized in that: the axial length of the urceolus of flash mixer (1) and inner core (2) is 0.5m～1m.

4. flash mixer according to claim 1, it is characterized in that: deflector (3) is 6～8.

5. flash mixer according to claim 1, it is characterized in that: the rectangular triangle build of deflector, one of them inclined-plane of deflector and the axial direction of urceolus are 60 ° of angles, edged surface is identical with the urceolus axial direction always, and another right angle face of deflector and the outer section of inner/outer tube are in one plane.

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