Direct thermal desorption tail gas deodorization device

Abstract

The utility model relates to a direct thermal desorption tail gas deodorization device, and belongs to the field of organic matter contaminated soil remediation equipment. The device comprises a circulating water tank, a high-pressure spraying device, a pressure pump and a return pipeline, the circulating water tank is used for storing a natural plant extracting solution with the concentration of 0.1%-0.3%, the high-pressure spraying device is installed at the top end of a spraying tower, and a deodorant is sprayed into tail gas through the pressure pump and makes full contact with reverse airflow to achieve odor removal. And the sprayed liquid is returned to the circulating pool through the return pipeline. The tail gas treatment device is compact in structure, convenient to install, free of secondary pollution and suitable for tail gas treatment of complex contaminated soil remediation scenes, and the odor removal efficiency reaches 90% or above due to the adoption of natural environment-friendly deodorants.

Description

Technical Field

[0001] This utility model relates to the technical field of contaminated soil remediation equipment, specifically a direct thermal desorption tail gas deodorization device for odor control of tail gas during the thermal desorption remediation process of organic contaminated soil. Background Technology

[0002] Due to the complex composition of polluted soil, a large amount of sulfur compounds, nitrogen compounds, halogens and their derivatives, hydrocarbons and aromatic hydrocarbons, oxygen-containing organic matter, etc. are generated during the direct thermal desorption process, which often leads to excessive odor concentrations in the exhaust gas.

[0003] For waste gas generated at remediation sites, the current mainstream approach is to treat it using secondary combustion and desulfurization / deacidification processes, with the treated waste gas then discharged through an exhaust stack. Direct thermal desorption processes are effective for treating contaminated soil with low pollution concentrations and simple compositions, achieving a high odor removal rate in the waste gas; however, for contaminated soil with high pollution concentrations and complex compositions, it is difficult to remove odors from the exhaust gas. Utility Model Content

[0004] The purpose of this invention is to provide a simple, efficient and environmentally friendly exhaust gas deodorization device. By optimizing the spray tower structure and deodorant circulation system, it solves the problems of low deodorization efficiency and high risk of secondary pollution in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A direct thermal desorption tail gas deodorization device includes:

[0007] The circulating water tank, made of corrosion-resistant material, is used for storing and preparing biological deodorizing agents;

[0008] The spray tower is connected to the rear end of the desulfurization and deacidification equipment and is used for the contact reaction between the exhaust gas and the deodorizing agent.

[0009] A high-pressure spray device is fixedly installed 50cm from the top of the spray tower, with the nozzle facing downwards, covering the cross-section of the exhaust gas flow.

[0010] A pressure pump, connected to a circulating water tank and a high-pressure spray device via pipeline, is used to deliver deodorant;

[0011] The return pipeline is located at the bottom of the spray tower and connected to the circulating water tank to recover the liquid after spraying.

[0012] Furthermore, the spray pressure range of the high-pressure spray device is 0.5 to 1.2 MPa, and the spray atomization particle size is 50 to 200 μm.

[0013] Furthermore, the volume of the circulating water tank is adjusted according to the amount of exhaust gas treated, and a concentration monitoring instrument is installed in the tank to control the concentration of the deodorant in real time.

[0014] Furthermore, a filter screen is provided between the return pipeline and the bottom of the spray tower to intercept solid impurities.

[0015] Beneficial Effects: This invention addresses the issue of excessive odor concentration in the exhaust gas of direct thermal desorption equipment. After the exhaust gas has undergone baghouse dust collection, desulfurization, and deacidification treatment, a high-pressure spray biological deodorization process is added. A natural plant extract solution with a concentration of 1‰ to 3‰ is prepared in a circulating water tank and then pumped into a high-pressure spray device at the top of the spray tower. The solution is sprayed from top to bottom, ensuring full contact with the reverse airflow. The biological deodorizer undergoes a thorough physicochemical reaction (polymerization, substitution, displacement, adsorption, etc.) with the waste gas molecules without generating secondary pollution. This achieves the goal of reducing odor concentration. The deodorization efficiency can reach over 90%.

[0016] The high-pressure spray device in this invention is located at the tail end of the desulfurization tower, allowing for quick installation and removal, and facilitating maintenance. The spray device is low-cost, space-saving, and does not alter the original equipment structure.

[0017] The biological deodorizer used is extracted from natural plants and is readily available on the market. It is natural, environmentally friendly, neutral, non-toxic, and non-corrosive. Before the gas is released into the atmosphere, the biological deodorizer, sprayed using a high-pressure spray device, undergoes a full physicochemical reaction with the waste gas molecules. The odor emission concentration meets the "Odor Pollutant Emission Standard (GB14554-1993)" and no secondary pollution is generated. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the direct thermal desorption device;

[0019] Figure 2 This is a schematic diagram of the structure of the present invention, including: a circulating water tank (A), a high-pressure spray device (including a spray pipe (E), a high-pressure atomizing nozzle (F)), a pressure pump (C), a return pipe (K), a spray tower (I), a concentration monitor (B), a flow meter (D), a process waste gas inlet (G), a system main exhaust fan (H), and an exhaust stack (J). Detailed Implementation

[0020] The present invention will be further explained below with reference to the accompanying drawings.

[0021] like Figure 1 As shown, the direct thermal desorption tail gas deodorization device of this utility model is installed at the tail end of the desulfurization tower.

[0022] like Figure 2The present invention includes a device comprising the following core components, which are connected by pipes, flanges, or fixed supports to form a complete exhaust gas deodorization system:

[0023] Circulating water tank A: Used for storing and preparing biological deodorizing agents. It is made of corrosion-resistant materials (such as anti-corrosion concrete or fiberglass). The tank is equipped with a concentration monitor B and a flow meter D to monitor the concentration and flow rate of the deodorizing agent in real time.

[0024] Spray Tower I: Vertically installed at the rear end of the desulfurization and deacidification equipment, with a gas distribution plate inside the tower body, a high-pressure spray device connected to the top, and the bottom connected to the circulating water tank A through the return pipeline K.

[0025] High-pressure spray device: The integrated spray pipeline E and high-pressure atomizing nozzle F are fixed to the top of the spray tower I at 50cm via flange. The nozzle faces downward to cover the cross-section of the exhaust gas flow. The spray pressure range is 0.5 to 1.2 MPa, and the atomized particle size is 50 to 200 μm.

[0026] Pressure pump C: Located between circulating water tank A and spray tower I, connected by corrosion-resistant pipes, it is used to deliver deodorant to the high-pressure spray device.

[0027] Return line K: Connects the bottom of spray tower I to circulating water tank A. A filter screen is installed in the line to intercept solid impurities and ensure clean liquid circulation.

[0028] Exhaust stack J: Installed at the top outlet of spray tower I, used to discharge treated exhaust gas that meets standards.

[0029] The workflow of this utility model includes:

[0030] Exhaust gas input: Process waste gas is introduced into the bottom of the spray tower by a fan and flows upward.

[0031] Deodorant spraying: The biological deodorant (concentration 1‰~3‰) in the circulating water tank is boosted to the high-pressure spray device by the pressure pump and sprayed downward to form atomized droplets, which fully contact the reverse exhaust gas.

[0032] Gas-liquid reaction: Atomized droplets adsorb and decompose sulfides, nitrogen compounds and organic matter in the exhaust gas, and odor is removed through polymerization, substitution and other reactions.

[0033] Liquid recovery: The liquid after spraying is collected at the bottom of the spray tower and returned to the circulating water tank through the return pipeline, thus completing the recycling.

[0034] Exhaust gas emissions: The purified gas is discharged through the exhaust pipe, and the odor concentration meets the "Odor Pollutant Emission Standard" (GB14554-1993).

Claims

1. A direct thermal desorption tail gas deodorization device, characterized in that, include: The circulating water tank (A), made of corrosion-resistant material, is used for storing and preparing biological deodorizing agents; The spray tower (I) is connected to the rear end of the desulfurization and deacidification equipment and is used for the contact reaction between the exhaust gas and the deodorizing agent. A high-pressure spray device is fixedly installed 50cm from the top of the spray tower, with the nozzle facing downwards, covering the cross-section of the exhaust gas flow. A pressure pump (C) is connected to a circulating water tank and a high-pressure spray device via a pipeline to deliver deodorant; The return pipe (K) is located at the bottom of the spray tower and is connected to the circulating water tank. It is used to recover the liquid after spraying.

2. The apparatus according to claim 1, characterized in that, The spray pressure range of the high-pressure spray device is 0.5 to 1.2 MPa, and the spray atomization particle size is 50 to 200 μm.

3. The apparatus according to claim 1, characterized in that, The volume of the circulating water tank (A) is adjusted according to the amount of exhaust gas treated, and a concentration monitoring instrument is installed in the tank to control the concentration of deodorant in real time.

4. The apparatus according to claim 1, characterized in that, A filter screen is installed between the return pipe (K) and the bottom of the spray tower (I) to intercept solid impurities.

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