Steam white smoke eliminating system

Abstract

The utility model belongs to the field of steam treatment, and particularly relates to a steam white elimination system which is characterized in that a steam incoming pipe is connected with a steam inlet of a spraying tank, a steam outlet in the top of the spraying tank is connected to a first air inlet of a condensation tank, an air outlet of the condensation tank is connected to an air inlet of an induced draft fan, and a second air inlet of the condensation tank is communicated with outside air; an air outlet of the induced draft fan is connected with a heat return pipeline for emptying, the heat return pipeline is arranged adjacent to the steam incoming pipe, and a water outlet is formed in the bottom of the spraying tank. By the adoption of the scheme, steam is subjected to heat exchange through low-temperature gas in the heat return pipeline and then enters the spraying tank to be rapidly cooled, most of the steam and spraying water are gathered at the bottom of the spraying tank in the spraying tank, and a small part of the cooled steam enters the condensation tank and is mixed with cold air entering the condensation tank to be cooled; and then the steam enters the heat return pipeline to be heated after passing through the induced draft fan and is discharged into the air, so that the problem of white steam pollution is solved, and the steam is effectively recycled.

Description

Technical Field

[0001] The utility model belongs to the field of steam treatment, and in particular relates to a steam dewhitening system. Background Art

[0002] With the continuous improvement of environmental awareness, people have questioned the phenomenon of a large amount of white water mist formed by the emission of steam from some factories in industrial areas (such as coal-fired power plants, smelters, etc.). The boilers or heating furnace systems of metallurgical and power plants will produce a certain amount of steam, which will be incorporated into the steam pipe network and basically used. However, due to insufficient subsequent users and low pressure, some of them will be released, and the waste heat energy will not be fully recycled. During the release of low-pressure steam, a large amount of "white smoke" is visually formed, accompanied by a certain degree of noise pollution. In fact, some factories will recycle the excess low-pressure steam, flash steam, and steam drains they emit. At the end of the recovery device, non-condensable gases will still be entrained with a small amount of escaped steam and discharged into the atmosphere. Although it has reached the national emission standards, its composition is basically water vapor. The reason why it appears visually as white fog is that when the saturated wet steam is discharged in contact with the low-temperature ambient air, the water vapor contained in the air is supersaturated and condensed, and the condensed water droplets refract and scatter the light, making the fog plume appear white or gray, which is called wet fog plume (commonly known as big white fog). Although these mists no longer contain toxic and harmful gases, they still cause certain visual pollution to surrounding residents.

[0003] Eliminate the "white smoke" produced by low-pressure steam release and improve the environmental protection image of the factory. Therefore, how to solve the visual pollution of white steam (referred to as white steam pollution or simply white pollution in the industry) is a further environmental protection demand put forward by enterprises and technicians.

[0004] Theoretically speaking, the key to the white color of fog lies in the humidity and temperature of the water vapor. Therefore, as long as the absolute water content in the fog is reduced, the fog emission temperature is increased, and the relative humidity of the fog is reduced, the fog will diffuse at the emission port before it cools down to the dew point (i.e. the dew point temperature, the temperature at which the air is cooled to saturation when the water vapor content in the air remains unchanged and the air pressure is kept constant), thereby eliminating the visual fog.

[0005] There are studies on flue gas de-whitening in the prior art, such as the document entitled "Causes of white smoke formation in coal-fired power plants and principles of flue gas de-whitening" (Hangzhou Xinlan Energy Engineering Co., Ltd.), which designs a MGGH flue gas de-whitening system. After the high-temperature flue gas (above 190°C) is desulfurized, denitrated and dusted, it is cooled and condensed with circulating cooling water, and the high-temperature mist at the front end is used to heat the low-temperature mist at the rear end, thereby achieving de-whitening of the mist. However, this method uses circulating cooling water to cool the high-temperature flue gas, which is slow and inefficient. It is obvious that a large amount of low-temperature cooling water is required to reduce the high-temperature flue gas above 190°C to about 50°C, and the processing capacity is extremely low, which is not suitable for enterprises with large emissions.

[0006] Therefore, how to quickly achieve steam dewhitening and solve the problem of white steam pollution is a technical problem that technicians urgently need to solve. Utility Model Content

[0007] The utility model aims to provide a steam dewhitening system, which can not only quickly realize steam dewhitening, but also consumes little water and energy.

[0008] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a steam descaling system, characterized in that: a steam inlet pipe is connected to the steam inlet of a spray tank, the steam outlet on the top of the spray tank is connected to the first air inlet of a condensing tank, the air outlet of the condensing tank is connected to the air inlet of an induced draft fan, the second air inlet of the condensing tank is connected to the outside air, the air outlet of the induced draft fan is connected to a heat recovery pipeline and is emptied, the heat recovery pipeline is arranged closely to the steam inlet pipe, and a drain outlet is provided at the bottom of the spray tank.

[0009] With the above scheme, steam (about 100°C) first passes through the low-temperature gas in the heat recovery pipeline for heat exchange to achieve the first cooling and condensation (about 90°C), and then enters the spray tank to be sprayed with water for the second rapid cooling. Most (more than 95%) of the steam gathers at the bottom of the spray tank together with the spray water in the spray tank, and a small part of the cooled steam (about 50°C) enters the condensation tank, mixes with the cold air (outside air, about 10°C) entering the condensation tank for the third cooling (down to about 30°C), and then enters the heat recovery pipeline after the induced draft fan, exchanges heat with the upstream steam pipe and heats up (about 60-70°C). After three cooling and condensation, the air flow humidity is lower than 50%, and after heating again, the humidity is low and the temperature is high when discharged into the air, and there is no white fog phenomenon, which solves the generation of white steam pollution and effectively recovers water vapor. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the steam descaling system of the utility model DETAILED DESCRIPTION

[0011] The scheme of the utility model is further described in detail below in conjunction with the accompanying drawings.

[0012] A steam de-whitening system, characterized in that: a steam inlet pipe is connected to the steam inlet 11 of a spray tank 10, a steam outlet 12 at the top of the spray tank 10 is connected to the first air inlet 21 of a condensing tank 20, an air outlet 23 of the condensing tank 20 is connected to the air inlet 31 of an induced draft fan 30, a second air inlet 22 of the condensing tank 20 is connected to the outside air, an air outlet 32 ​​of the induced draft fan 30 is connected to a heat recovery pipe 40 and emptied, the heat recovery pipe 40 is arranged adjacent to the steam inlet pipe, and a drain is provided at the bottom of the spray tank 10. Generally, the condensed water produced in the steam condensation process will produce secondary steam due to its high temperature, but the treatment of secondary steam is not considered in the prior art, because the secondary steam is not discharged from a large chimney and will not be seen by outsiders, so there will not be a large amount of white mist visible to non-operating personnel visually, but the generation of secondary steam often affects the working environment of the operating personnel, but it has not been taken seriously by technical personnel. In the solution of the present application, the secondary steam generated by the condensed water will be directly transferred downstream along with the primary steam under the negative pressure state of the entire system, so there will be no secondary steam discharge that affects the working environment.

[0013] The second air inlet 22 of the condenser 20 is connected to an air inlet pipeline 50 with a valve, and the air inlet end of the air inlet pipeline 50 is connected to the outside air. The steam entering the condenser 30 is cooled by the outside air with a lower temperature, and the humidity of the outside air is relatively lower, which also reduces the humidity of the mixed gas entering the condenser 20 after mixing.

[0014] In order to ensure the negative pressure state in the entire steam descaling system, the diameter of the air inlet pipeline 50 is smaller than the diameter of the air outlet 23 of the condensing tank 20.

[0015] The outlet end of the heat recovery pipe 40 is spaced apart from the inlet end of the inlet pipe 50 connected to the second inlet port 22 of the condenser 20. There are two pipe ends connected to the air in the steam de-whitening system. One is the inlet pipe 50 connected to the second inlet port 22 of the condenser 20, which uses air with lower outside temperature and humidity to cool and dilute the steam entering the condenser; the other is the outlet end of the heat recovery pipe 40, which discharges the mist processed by the entire steam de-whitening system into the air. The mist discharged here is heated by the upstream high-temperature steam, and the temperature is about 60-70°C. Therefore, it should be separated from the former (the inlet pipe 50 of the second inlet port 22 of the condenser 20) to prevent the high temperature of the latter from affecting the cooling effect required by the former.

Claims

1. A steam descaling system, characterized in that: The steam inlet pipe is connected to the steam inlet (11) of the spray tank (10), the steam outlet (12) at the top of the spray tank (10) is connected to the first air inlet (21) of the condensing tank (20), the air outlet (23) of the condensing tank (20) is connected to the air inlet (31) of the induced draft fan (30), the second air inlet (22) of the condensing tank (20) is in communication with the outside air, the air outlet (32) of the induced draft fan (30) is connected to the heat recovery pipeline (40) and emptied, the heat recovery pipeline (40) is arranged closely to the steam inlet pipe, and a drain outlet is provided at the bottom of the spray tank (10).

2. The steam descaling system according to claim 1, characterized in that: The second air inlet (22) of the condensation tank (20) is connected to an air inlet pipeline (50) with a valve, and the air inlet end of the air inlet pipeline (50) is in communication with the outside air.

3. The steam descaling system according to claim 2, characterized in that: The diameter of the air inlet pipeline (50) is smaller than the diameter of the air outlet (23) of the condensation tank (20).

4. The steam descaling system according to claim 1, characterized in that: The air outlet end of the heat recovery pipeline (40) and the air inlet end of the air inlet pipeline (50) connected to the second air inlet (22) of the condensation tank (20) are arranged at intervals.

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