CN217549414U

CN217549414U - Coking wastewater loss VOCs treatment system

Info

Publication number: CN217549414U
Application number: CN202221045200.5U
Authority: CN
Inventors: 陈瑶姬; 朱廷钰; 邓丽萍; 谢军; 黄坚; 徐文青
Original assignee: Institute of Process Engineering of CAS; Zhejiang Tiandi Environmental Protection Technology Co Ltd
Current assignee: Institute of Process Engineering of CAS; Zhejiang Tiandi Environmental Protection Technology Co Ltd
Priority date: 2022-04-29
Filing date: 2022-04-29
Publication date: 2022-10-11
Anticipated expiration: 2032-04-29

Abstract

The utility model relates to a coking wastewater loss VOCs processing system, include: VOCs waste gas collection device, preprocessing device, filter equipment, absorption desorption device, mixing arrangement, heat accumulation burner, sweep device, fan, pipeline valve and discharge port. The utility model has the advantages that: the utility model discloses utilize VOCs waste gas collection device, preprocessing device, filter equipment and absorption desorption device to carry out the concentrated enrichment with the VOCs of the big amount of wind, low concentration, improve VOCs concentration, reduce the tolerance, reduced the fuel quantity of follow-up heat accumulation burning, reduce the cost of VOCs burning operation.

Description

Coking wastewater loss VOCs treatment system

Technical Field

The utility model relates to an exhaust-gas treatment field, more precisely, it relates to coking wastewater loss VOCs processing system.

Background

VOCs (Volatile Organic Compounds) have the chemical name of Volatile Organic Compounds, have photochemical reaction characteristics, are important precursors of photochemical smog, can perform photochemical reaction with nitrogen oxides under the irradiation of light to generate harmful photochemical oxidants such as ozone and the like, and simultaneously form secondary Organic aerosol to participate in the formation of secondary particles in the atmosphere to induce haze. Meanwhile, VOCs have a destructive effect on the ozone layer, strongly absorb infrared rays, cause global warming, and have great harm to the atmospheric environment and human health. In recent years, with the rapid development of industry and economy in China, the situation of regional composite pollution, such as fine particulate matters (PM 2.5) and ozone (O3), is becoming more severe and gradually the most important problem of air pollution in China. VOCs are also important precursors of PM2.5 and O3, are one of main pollutants influencing the atmospheric environment, and gradually become the key point of national control in recent years.

Chemical products, coke ovens, waste water and other processes in coking production are important VOCs emission sources except for electric arc furnaces and steel rolling processes in the steel industry, and are the most typical complex sources for VOCs emission. Coking wastewater dissipation VOCs belongs to wastewater unorganized discharge VOCs, VOCs discharged by the wastewater are derived from wastewater generated in each process of nearly covering coking production (including coking, gas purification, fine processing of chemical products and the like), the wastewater is used for dissipating VOCs waste gas in an unorganized mode in the collection treatment process, and the generated VOCs waste gas has the following typical characteristics: (1) Each process of wastewater treatment can dissipate VOCs in an unorganized way, and the wastewater treatment has various types and complex components. The main VOCs are benzene series, esters, alcohols and the like, and simultaneously contain a certain amount of inorganic matters such as H2S, NH and the like and malodorous gases such as mercaptan, thioether and the like; (2) The inorganically dissipated waste gas generally has large gas volume and high moisture content, and meanwhile, the concentration of VOCs (volatile organic compounds) in the waste water of most industries is low, generally dozens of hundreds of mg/m < 3 >.

Due to the particularity of the steel industry, the treatment of the VOCs is a starting stage, the existing VOCs control technology is few, the coverage is low, and more VOCs control technologies which are urgently needed are still in a research and development stage. Coking wastewater dissipation VOCs treatment adopts four technologies at present: active carbon adsorption, photocatalysis, plasma and biological methods. The activated carbon adsorption method is a high-efficiency VOCs control technology, but has the defects of poor adsorption selectivity, flammability, low quality of VOCs adsorbed in unit time, large equipment volume and the like, the photocatalysis technology and the plasma technology are relatively low-efficiency VOCs control technologies, the VOCs treatment efficiency is usually lower than 40%, and the plasma technology has explosive risks and the like. The biological method is a mature deodorization technology, can realize the cooperative control of multiple pollutants such as H2S, NH, VOCs and the like, and has the defect of low VOCs treatment efficiency (similar to a photocatalysis/plasma method, the VOCs treatment efficiency is low, and the high-efficiency treatment retention time is long). At present, methods such as heat storage combustion or catalytic combustion are often adopted to treat VOCs in coking wastewater. However, the single technologies are difficult to realize the efficient and low-cost treatment of the volatile VOCs of the coking wastewater at present.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the not enough among the prior art, provide a coking wastewater loss VOCs processing system, include: the system comprises a VOCs waste gas collecting device, a pretreatment device, a filtering device, an adsorption and desorption tank, a mixing device, a heat storage combustion device, a purging device, a fan, a pipeline valve and an exhaust port;

the VOCs waste gas collecting device comprises a gas inlet end and a gas outlet end, the gas inlet end is connected with the coking wastewater pool, and the gas outlet end, the pretreatment device, the filtering device, the pipeline valve and the adsorption and desorption device are sequentially connected; the adsorption and desorption device comprises an adsorption device and a desorption device, and the adsorption device, the desorption device, the pipeline valve, the fan and the heat storage combustion device are sequentially connected; the filtering device and the heat storage combustion device are respectively connected to the mixing device, and the mixing device is connected with the adsorption and desorption device through a pipeline valve; the adsorption and desorption device is connected to the discharge port through a pipeline valve and a fan; the purging device is connected with the heat storage combustion device; the heat storage combustion device is connected with the pretreatment device through a fan.

Preferably, the coking wastewater dissipation VOCs treatment system comprises at least two adsorption and desorption devices which are connected in parallel.

Preferably, the adsorption and desorption device is internally provided with an adsorbent, and the adsorbent is a molecular sieve.

Preferably, the VOCs waste gas collecting device comprises a waste water pool cover and a collecting air pipe, the waste water pool cover is provided with the air inlet end, and the collecting air pipe is provided with the air outlet end.

Preferably, the regenerative combustion device has a two-chamber structure or a three-chamber structure.

Preferably, the system further comprises a purification device connected to the regenerative combustion device.

The utility model has the advantages that:

the utility model discloses fully considered the lower characteristic of coking wastewater VOCs concentration, low to coking wastewater workshop section VOCs waste gas concentration, the component is complicated, the moisture content is great, utilize VOCs waste gas collection device, preprocessing device, filter equipment and absorption desorption device to carry out the enrichment of concentrating with the VOCs of the big amount of wind, low concentration, improve VOCs concentration, reduce tolerance, reduced the fuel quantity of follow-up heat accumulation burning (RTO), reduce the cost of VOCs burning operation. In addition, aiming at the complex components of VOCs waste gas in the coking industry, a catalysis or absorption unit is arranged for purifying benzopyrene, polycyclic aromatic hydrocarbon or other byproducts formed by combustion. The utility model discloses can solve low concentration, the high-efficient difficult problem of administering of complicated component VOCs waste gas, and avoid the accessory substance pollution problem that the combustion technology exists.

Drawings

FIG. 1 is a schematic diagram of a coking wastewater VOCs dissipation treatment system provided herein;

description of reference numerals: VOCs waste gas collection device 1, preprocessing device 2, filter equipment 3, adsorb desorption apparatus 4, mixing arrangement 5, heat accumulation burner 6, sweep device 7, fan 8, pipeline valve 9, discharge port 10.

Detailed Description

The present invention will be further described with reference to the following examples. The following description of the embodiments is merely provided to aid in understanding the invention. It should be noted that, for those skilled in the art, the present invention can be modified in several ways without departing from the principle of the present invention, and these modifications and modifications also fall into the protection scope of the claims of the present invention.

Example 1:

as shown in fig. 1, a system for treating VOCs by dissipating coking wastewater comprises: the system comprises a VOCs waste gas collecting device 1, a pretreatment device 2, a filtering device 3, an adsorption and desorption tank 4, a mixing device 5, a heat storage combustion (RTO) device 6, a purging device 7, a fan 8, a pipeline valve 9 and a discharge port 10;

the VOCs waste gas collecting device 1 comprises a gas inlet end and a gas outlet end, the gas inlet end is connected with the coking wastewater pool, and the gas outlet end, the pretreatment device 2, the filtering device 3, the pipeline valve 9 and the adsorption and desorption device 4 are sequentially connected; the adsorption and desorption device comprises an adsorption device and a desorption device, and the adsorption device, the desorption device, the pipeline valve 9, the fan 8 and the heat storage combustion device 6 are sequentially connected; the filtering device 3 and the heat storage combustion device 6 are respectively connected to the mixing device 5, and the mixing device 5 is connected with the adsorption and desorption device 4 through a pipeline valve 9; the adsorption and desorption device 4 is connected to a discharge port 10 through a pipeline valve 9 and a fan 8; the purging device 7 is connected with the heat storage combustion device 6; the regenerative combustion device 6 is connected to the pretreatment device 2 via a fan 8.

In the coking wastewater dissipation VOCs treatment system, the VOCs waste gas collecting device 1 comprises a wastewater pool cover and a collecting air pipe, wherein the wastewater pool cover is provided with an air inlet end, and the collecting air pipe is provided with an air outlet end; the wastewater pool is covered by a stainless steel SUS304 arch cover plate, the periphery of the pool body is provided with a fence and a handrail, and an observation port can be designed on the cover plate according to the field condition; the collection air pipe is made of stainless steel SUS304 and has good corrosion resistance.

In addition, the pretreatment device 2 adopts two towers of acid washing and alkali washing, a single-layer spray is arranged, and the washing tower is in a packing tower form and comprises alkali washing, oxidation washing and the like of waste gas. The alkaline washing mainly removes gases such as H2S contained in coking wastewater dissipated VOCs, and the oxidation washing removed part mainly contains sulfur-containing malodorous substances.

The adsorption and desorption device 4 adopts single-tank adsorption and single-tank desorption, and the adsorption tank is designed according to 10000m < 3 >/h air quantity, 50mg/m < 3 > concentration of VOCs and 50mg/g penetrating adsorption quantity of an adsorbent. The desorption gas leads high-temperature gas out of the combustion chamber of the heat accumulation combustion device 6 to be mixed with part of gas of the adsorption gas, and the flow of the lead-out gas is controlled by a regulating valve, so that the temperature of the desorption gas can be regulated within the range of 100-350 ℃. The adsorption stage can realize 90.5% of VOCs removal efficiency on VOCs waste gas, and then regeneration gas (the gas amount is 1/10 of the initial VOCs waste gas) is used for regenerating the adsorbent to desorb the adsorbed VOCs. It should be noted that, this application does not restrict the quantity of adsorption and desorption device 4, and coking wastewater dissipates VOCs processing system can only adsorb desorption device 4, also can have two or more than two adsorption and desorption device 4. When coking wastewater dissipation VOCs processing system includes two at least absorption desorption device 4, these two at least absorption desorption device 4 are parallelly connected. Wherein, the adsorption and desorption device 4 is internally provided with an adsorbent which is a molecular sieve, including but not limited to one or a combination of more than two of high-silicon USY, ZSM-5 and other molecular sieves.

The heat accumulation combustion device 6 adopts a two-chamber structure or a three-chamber structure, the amount of the waste gas treated by the reactor is 1000-2000m < 3 >/h, the residence time is more than 1.2s, the reaction temperature is more than 800 ℃, and a filtering box body is arranged at the inlet section. The heat accumulation catalysis double-function material is placed in a heat accumulation type temperature floating change area of 350-450 ℃, and the volume space velocity is about 2000h < -1 >. The desorbed high-concentration VOCs waste gas enters the RTO reactor to decompose the VOCs at high temperature, the released heat maintains the operation of the RTO reactor without additional fuel, and the VOCs degradation efficiency can reach 99.6 percent.

Coking wastewater loss VOCs processing system still includes purifier, and this purifier is connected with heat accumulation burner 6.

Claims

1. The utility model provides a coking wastewater loss VOCs processing system which characterized in that includes: the system comprises a VOCs waste gas collecting device (1), a pretreatment device (2), a filtering device (3), an adsorption and desorption device (4), a mixing device (5), a heat storage combustion device (6), a purging device (7), a fan (8), a pipeline valve (9) and a discharge port (10);

the VOCs waste gas collecting device (1) comprises a gas inlet end and a gas outlet end, the gas inlet end is connected with the coking wastewater pool, and the gas outlet end, the pretreatment device (2), the filtering device (3), the pipeline valve (9) and the adsorption and desorption device (4) are sequentially connected; the adsorption and desorption device comprises an adsorption device and a desorption device, and the adsorption device, the desorption device, the pipeline valve (9), the fan (8) and the heat storage combustion device (6) are sequentially connected; the filtering device (3) and the heat storage combustion device (6) are respectively connected to the mixing device (5), and the mixing device (5) is connected with the adsorption and desorption device (4) through a pipeline valve (9); the adsorption and desorption device (4) is connected to a discharge port (10) through a pipeline valve (9) and a fan (8); the purging device (7) is connected with the heat storage combustion device (6); the heat accumulation combustion device (6) is connected with the pretreatment device (2) through a fan (8).

2. The coking wastewater escaping VOCs treatment system according to claim 1, characterized in that the coking wastewater escaping VOCs treatment system comprises at least two adsorption-desorption devices (4), and the at least two adsorption-desorption devices (4) are connected in parallel.

3. The coking wastewater escaping VOCs treatment system according to claim 1, characterized in that the adsorption and desorption device (4) has an adsorbent inside, and the adsorbent is a molecular sieve.

4. The coking wastewater fugitive VOCs treatment system of claim 1, wherein the VOCs waste gas collection device (1) comprises a lagoon lid having the inlet end thereon and a collection plenum having the outlet end thereon.

5. The coking wastewater dissipation VOCs treatment system of claim 1, wherein the regenerative burner (6) is of a two-chamber or three-chamber configuration.

6. The coking wastewater dissipation VOCs treatment system of claim 1 further comprising a purification unit connected to the regenerative burner unit (6).