CN206285690U - A kind of device for eliminating white cigarette - Google Patents

Abstract

The utility model discloses a device for eliminating white smoke, which comprises: a water heater arranged on the hot flue gas pipeline; a desulfurization and wet electrostatic precipitator arranged on the hot flue gas pipeline passing through the water heater; the flue gas condensing The device is set on the hot flue gas pipeline after desulfurization and wet electrostatic precipitator; the air heater is connected with the water heater through the circulating hot water pump and the circulating hot water pipeline; the cooling tower is connected with the circulating cooling water pump and the circulating cooling water pipe The road is connected with the flue gas condenser; the hot air pipe is arranged in the chimney, and its inlet end is connected with the hot air outlet end of the air heater. The utility model adopts the circulating cooling water spray condensation process to reduce the water vapor in the wet flue gas by 70-80%, and the hot air added in the chimney is mixed, heated and dried, and discharged to the atmosphere. The heat source of the hot air adopts circulating heat Compared with the self-smoke heat exchange method, the water process has the advantages of small flue gas resistance, low energy consumption, and high reliability.

Description

A device for eliminating white smoke

technical field

The utility model relates to the technical field of flue gas purification, in particular to a purification device for eliminating the flue gas generated after burning coal and petrochemical energy in this field.

Background technique

Due to my country's energy resource endowment rich in coal, poor in oil and little gas, and the price of coal per unit of heat is far lower than the price of oil and gas, resulting in more than 4 billion tons of raw coal per year, most of which are converted into high-temperature heat in metallurgy, electric power, and chemical industries through combustion. Heat sources, power steam, and process steam produce about 30 trillion cubic meters of flue gas every year. In the prior art, wet desulfurization or wet electrostatic precipitation technology is mostly used in the process of flue gas purification and treatment. This technology removes most of SO2, soot, nitrogen oxides, and heavy metals in the flue gas, and has certain positive effects. The flue gas treatment of some enterprises can reach far below the "(GB13223-2011) Thermal Power Plant Air Pollutant Emission Standard": dust ≤ 5mg/m3, sulfur dioxide ≤ 35mg/m3, nitrogen oxides (calculated as NO2) ≤ 50mg /m3, mercury ≤ 0.03mg/m3, and gas turbine exhaust standards with blackness ≤ 1 degree index provide an important guarantee for the clean utilization of coal energy in my country.

However, the wet desulfurization or wet electrostatic precipitator in the process of flue gas purification and treatment has greatly increased the water vapor in the flue gas, reaching a concentration of 10-20%. Under the action of cold air, a large amount of water vapor in the flue gas is rapidly condensed into tiny water droplets, and high-concentration acid gases such as CO2 in the flue gas, along with the formation and growth of tiny water droplets, are continuously dissolved in the water droplets and reduced. The water vapor partial pressure on the surface of the water droplets makes the water droplets grow rapidly and becomes thick acidic white smoke. The acidic white smoke is then absorbed by the PM haze particles in the air, which will further reduce the water vapor partial pressure on the surface and reduce the air humidity. And reach its relatively stable phase equilibrium state, become the smog that pollutes the environment, which is why people regard the white smoke from the chimney as the accomplice of the smog. Therefore, especially in the calm windy weather in winter, reducing the white smoke discharged from the chimney is very helpful to reduce smog, which has become a consensus in the industry.

The current method commonly used to eliminate white smoke is essentially to allow the flue gas and the water vapor in it to diffuse before the temperature drops below the dew point temperature of the water vapor during the process of mixing, cooling and diffusing the flue gas out of the chimney with the air. into the air. Therefore, dehumidifying and heating the flue gas is the physical basis for eliminating the white smoke of the flue gas. The commonly used methods are:

①Condensation heat exchange method, see attached drawing 1, is to lower the temperature of wet flue gas from 50-60°C to about 25°C, condense the water vapor in the flue gas into liquid water and separate the flue gas system, and then use the heat exchanger to After the flue gas is heated, it is discharged to the atmosphere through the chimney. However, this method has the disadvantages of large heat exchanger investment, large flue gas resistance, easy corrosion, poor reliability and stability.

② Self-smoke heat exchange method, see attached figure 2, is to use the temperature of dry flue gas before desulfurization to heat desulfurization or wet flue gas after wet electrostatic precipitator to reach 80°C or above. This technology does not require external heat source, and is generally Applied in the power industry, the heat exchanger has a high heat transfer coefficient at the initial stage of operation, and can raise the wet flue gas to above 80°C. After about 1 to 3 years of operation, the colloids and solid particles in the flue gas adhere to the surface of the heat exchanger, and finally As a result, the heat transfer coefficient is greatly reduced, the temperature of the flue gas cannot be increased, and the chimney still emits white smoke. At the same time, there are also disadvantages that the heat exchanger is easy to block, easy to be damaged, and the resistance of the flue gas is large.

③Electric demisting method, because the water vapor content at the temperature of the flue gas after desulfurization is in a saturated state, most of the water vapor still exists in a gaseous state, and there are no large amounts of fog droplets, so the demisting effect is not good, and there are also large investment in equipment and electricity. High power consumption, poor reliability, etc.;

④The mixed drying method is only to separate the mist water and then mix the hot flue gas to reduce the water vapor content before discharging. This method requires clean hot flue gas, because the dust content of hot flue gas in reality is relatively High, although it can reduce white smoke, it increases smoke and dust. This method can only be used in steel plants where environmental protection requirements are not strict and there is hot smoke.

Utility model content

In view of the existing devices and methods for eliminating white smoke, the heat transfer coefficient of the heat exchanger is fast attenuated, easy to block, easy to corrode, and the resistance of the flue gas is large, so that the white smoke cannot be completely eliminated, or the performance of eliminating white smoke cannot be maintained for a long time, etc., The utility model proposes a condensation dehydration + hot air mixed drying device to solve the problem.

The utility model is realized through the following technical solutions:

A device for eliminating white smoke, comprising:

Water heater, set on the hot flue gas pipeline;

Desulfurization and wet electrostatic precipitators are installed on the hot flue gas pipeline after passing through the water heater;

The flue gas condenser is installed on the hot flue gas pipeline after desulfurization and wet electrostatic precipitator;

The air heater is connected with the water heater through the circulating hot water pump and the circulating hot water pipeline to form a circulating body;

The cooling tower is connected with the flue gas condenser through the circulating cooling water pump and the circulating cooling water pipeline to form a circulating body;

The hot air pipeline is arranged in the chimney, and its inlet end is connected with the hot air outlet end of the air heater.

Further, a fan is also provided at the air inlet of the air heater.

Further, the cooling tower is provided with a flue gas condensed circulating water distribution device and a flue gas condensed circulating water filler, the flue gas condensed circulating water distribution device is arranged at the lower end of the water inlet in the cooling tower, the flue gas The gas condensate circulating water packing is arranged at the lower end of the flue gas condensate circulating water distribution device.

Further, it also includes a water pool partition wall and a filler partition wall, the water pool partition wall is arranged in the water pool formed at the lower part of the cooling tower, and the filler partition wall is arranged in the flue gas condensation circulating water filler

Further, the hot air duct is arranged vertically along the direction of the chimney.

The utility model is provided with a vertically upward hot air pipe in the chimney, a fan and an air heater are arranged outside the chimney, and a water heater is arranged on the dry flue gas channel before desulfurization; between the water heater and the air heater , set up a circulating hot water pump and a circulating hot water pipeline to form a hot water circulation loop structure; use a hot air pipeline to connect the hot air pipeline in the chimney and the air heater; set a cooling tower outside the flue gas condenser, and cool it through circulation The water pump and circulating cooling water pipeline connect the cooling tower and the flue gas condenser to form a cooling water circulation loop structure.

Due to the adoption of the above structure, the concentration of CO ₂ , SO ₂ , NO _X , smoke dust, etc. in the outlet gas of the cooling tower of the utility model is much lower than that of the smoke by hundreds of times, and the partial pressure of water vapor on the surface of the mist is much higher than that of the smoke Therefore, the water vapor droplets entering the atmosphere from the cooling tower will dissipate faster in the atmosphere, which will greatly reduce the formation of haze; in addition, due to the direct contact between the flue gas and the cooling water, the heat Mainly through the mass transfer method of direct dissolution of water vapor, the heat is brought into the cooling water. Not only the heat transfer film coefficient is high, the problem of reducing the heat transfer coefficient K value is avoided, but also the flow resistance of the flue gas is much smaller than that of the heat exchanger, which can Reducing the power consumption of the flue gas fan will help to further reduce the impact of harmful substances such as SO ₂ , NO _X , Hg, and smoke in the flue gas.

Description of drawings

Fig. 1 is the schematic diagram of the existing condensation heat exchange method for removing white smoke;

Fig. 2 is the schematic diagram of the existing white smoke heat exchange method for removing white smoke;

Fig. 3 is a structural principle diagram of the utility model.

detailed description

The utility model will be further described below in conjunction with the accompanying drawings and specific embodiments.

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

The utility model discloses a device for eliminating white smoke, which is an improvement of the existing device for eliminating white smoke, including:

Water heater, set on the hot flue gas pipeline;

Desulfurization and wet electrostatic precipitators are installed on the hot flue gas pipeline after passing through the water heater;

The flue gas condenser is installed on the hot flue gas pipeline after desulfurization and wet electrostatic precipitator;

The air heater is connected with the water heater through the circulating hot water pump and the circulating hot water pipeline to form a circulating body;

The cooling tower is connected with the flue gas condenser through the circulating cooling water pump and the circulating cooling water pipeline to form a circulating body;

The hot air pipeline is arranged in the chimney, and its inlet end is connected with the hot air outlet end of the air heater.

In this embodiment, the structure of the flue gas condenser is an empty tower spray structure, or a packing structure, and a gas-liquid separation structure is provided at the gas outlet.

The using method of the present utility model is as follows:

When the temperature is above 30°C, even if the flue gas with a water vapor concentration of about 13% enters the atmosphere from the chimney, due to the high diffusion rate of water vapor in the atmosphere, white smoke will not appear. At this time, the fan, circulating cooling water pump and circulating cooling water pump can be stopped. Hot water pump to save power consumption;

When the temperature is not too high, such as around 25°C and the humidity is high, the flue gas has a slight white smoke. At this time, only the fan can be turned on, so that the normal temperature air can be mixed with the wet flue gas in the chimney to reduce the humidity in the flue gas. The water vapor concentration can eliminate the white smoke in the flue gas at the chimney outlet;

When the temperature is low, such as around 15°C and the humidity is high, the fan and the circulating hot water pump should be turned on at the same time, so that the heat of the dry flue gas can be transferred to the hot air through the circulating water, thereby reducing the flue gas in the desulfurization or wet process. The amount of water absorbed by the electrostatic precipitator process, the hot air is mixed with the wet flue gas in the chimney, and the relative humidity in the flue gas is further reduced, which can eliminate the white smoke at the chimney outlet;

In winter when the temperature is very low, it is necessary to turn on the flue gas condenser and the circulating cooling water pump, fan and circulating hot water pump at the same time. After mixing and drying, it is discharged into the atmosphere to eliminate white smoke.

The above-described embodiments are only preferred embodiments of the present utility model, and are not limitations to the technical solutions of the present utility model. As long as the technical solutions that can be realized on the basis of the above-mentioned embodiments without creative work, all should be regarded as falling into the scope of this invention. within the protection scope of utility model patents.

Claims (5)

1. A device for eliminating white smoke, characterized in that it comprises: Water heater, set on the hot flue gas pipeline; Desulfurization and wet electrostatic precipitators are installed on the hot flue gas pipeline after passing through the water heater; The flue gas condenser is installed on the hot flue gas pipeline after desulfurization and wet electrostatic precipitator; The air heater is connected with the water heater through the circulating hot water pump and the circulating hot water pipeline to form a circulating body; The cooling tower is connected with the flue gas condenser through the circulating cooling water pump and the circulating cooling water pipeline to form a circulating body; The hot air pipeline is arranged in the chimney, and its inlet end is connected with the hot air outlet end of the air heater. 2. A device for eliminating white smoke according to claim 1, characterized in that a fan is also provided at the air inlet of the air heater. 3. A device for eliminating white smoke according to claim 1, wherein a flue gas condensation circulating water distribution device and a flue gas condensation circulating water filler are arranged in the cooling tower, and the flue gas condensation circulation The water distributing device is arranged at the lower end of the water inlet in the cooling tower, and the flue gas condensed circulating water filler is arranged at the lower end of the flue gas condensed circulating water distributing device. 4. A kind of device for eliminating white smoke according to claim 3, is characterized in that, also comprises pool partition wall and filler partition wall, and described pool partition wall is set in the pool that cooling tower bottom forms, and described filler partition wall The wall is set in the flue gas condensate circulating water fill. 5. A device for eliminating white smoke according to claim 1, wherein the hot air duct is vertically arranged along the direction of the chimney.