CN111604368A - A device for continuous remediation of contaminated soil by supercritical carbon dioxide extraction - Google Patents

Abstract

The invention discloses a device for continuously repairing polluted soil by supercritical carbon dioxide extraction. The lower part is provided with an extraction agent inlet, the lower right end of the extraction chamber is provided with a soil outlet, and the upper left end is provided with an extraction agent outlet; the soil inlet is provided with a feed gate valve, feed cavity, vacuum gate valve, vacuum cavity, transition from top to bottom in sequence. Gate valve, transition cavity and inlet gate valve; the soil outlet is provided with outlet gate valve, discharge cavity, discharge gate valve, recovery cavity, recovery gate valve, discharge cavity and discharge gate valve in sequence from top to bottom; when feeding, the feeding gate valve , vacuum gate valve, transition gate valve and inlet gate valve are opened and closed alternately in sequence; when discharging, the outlet gate valve, discharge gate valve, recovery gate valve and discharge gate valve are opened and closed alternately in sequence. The invention utilizes the supercritical state of carbon dioxide to extract and separate pollutants, thereby effectively improving the pollutant extraction capacity.

Description

A device for continuous remediation of contaminated soil by supercritical carbon dioxide extraction

technical field

The invention relates to a polluted soil remediation device, in particular to a device for continuously remediating polluted soil by extraction of supercritical carbon dioxide.

Background technique

With the rapid development of the industry, a series of pollution problems have become more and more serious at the same time. Many industrial lands are seriously polluted after use and cannot be used for secondary use, so soil remediation has to be carried out.

In the existing soil remediation technologies, in-situ remediation and ex-situ remediation are mostly used. Among them, in-situ remediation means that the contaminated soil is not moved, but the pollutants are removed by direct in-situ treatment; Purpose. Most of the commonly used disposal methods for ex situ restoration are physical pyrolysis, chemical leaching and landfill, but these methods often result in waste of energy and materials, or cause problems such as residual chemical residues and secondary pollution after pollution treatment.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a device for continuously remediating contaminated soil by extraction of supercritical carbon dioxide, which utilizes the inertness of easy-to-produce and recyclable carbon dioxide to make the soil in There is no harmful solvent residue after treatment, which is safe, non-toxic and non-polluting; the use of carbon dioxide supercritical state to extract and separate pollutants effectively improves the pollutant extraction capacity.

In order to solve the above-mentioned technical problems, the technical scheme adopted by the present invention is:

A device for continuously repairing polluted soil by supercritical carbon dioxide extraction, comprising an extraction cavity inclined upward from left to right and provided with a screw conveying blade inside; the upper left end of the extraction cavity is provided with a soil inlet and the lower left end is provided with There is an extraction agent inlet, a soil outlet is arranged at the lower part of the right end of the extraction cavity and an extraction agent outlet is arranged at the upper part of the left end; a feed pipe is arranged on the soil inlet, and a feed gate valve, an inlet Material cavity, vacuum gate valve, vacuum cavity, transition gate valve, transition cavity and inlet gate valve; the soil outlet is provided with a discharge pipeline, and the discharge pipeline is sequentially provided with an outlet gate valve, a discharge cavity, and a discharge gate valve from top to bottom , recovery cavity, recovery gate valve, discharge cavity and discharge gate valve; when feeding, the feeding gate valve, vacuum gate valve, transition gate valve and inlet gate valve are alternately opened and closed in sequence; when discharging, the outlet gate valve, discharge gate valve , the recovery gate valve and the discharge gate valve are alternately opened and closed.

Further, an evacuation pipeline is installed on one side of the vacuum chamber, and a vacuum pump is installed on the evacuation pipeline.

Further, an extraction agent discharge pipe is installed on the extraction agent outlet, and an extraction liquid cooler is arranged at the end of the extraction agent discharge pipe; and an extraction liquid cooler is installed on the extraction agent discharge pipe in sequence from the extraction agent outlet to the extraction liquid cooler. an extraction pressure reducing valve, a gas-liquid separator, an activated carbon adsorption tank and a pressurizing pump; the outlet of the extraction liquid cooler is connected to the extraction agent inlet through an extraction agent adding pipeline.

Further, one side of the recovery cavity is installed with an extraction agent recovery pipeline that communicates with the extraction agent discharge pipeline between the extraction pressure relief valve and the gas-liquid separator, and a recovery pump is installed on the extraction agent recovery pipeline.

Further, one side of the unloading cavity is installed with a discharge pressurization pipeline that communicates with the extraction agent adding pipeline, and a discharge pressure relief valve and a discharge solenoid valve are installed on the discharge pressurization pipeline.

Further, a feed decompression pipeline communicated with the extraction agent addition pipeline is installed on one side of the feed cavity, and a feed decompression valve is installed on the feed decompression pipeline.

The beneficial effects produced by the above technical solutions are:

The invention utilizes the inertness of easily-produced and recyclable carbon dioxide, so that there is no harmful solvent residue in the soil after treatment, which is safe, non-toxic and non-polluting; the supercritical state of carbon dioxide is used to extract and separate pollutants, which effectively improves the Contaminant extraction capacity.

The main structure of the present invention is an extraction cavity conveyed by paddles, and the extraction agent for repairing the contaminated soil is carbon dioxide in a supercritical state. The extraction cavity is a closed heating cavity, and the appropriate temperature and pressure are set in the cavity to maintain the supercritical state of the carbon dioxide extractant; the supercritical carbon dioxide extractant is introduced into the extraction cavity, and the material is stirred evenly by the paddle; the soil inlet of the extraction cavity and the Multiple sets of gate valves and cavities are installed at the soil outlet, and the internal environment of the extraction cavity is guaranteed to be stable through the alternate sequence opening and closing of multiple sets of gate valves and the filling of carbon dioxide extractant; after the extraction is completed, the supercritical carbon dioxide extractant is decompressed and vaporized through the extraction pressure reducing valve Then use the gas-liquid separator to separate the extracted pollutants, avoid the secondary pollution of the soil by the extractant, improve the separation efficiency, and treat the carbon dioxide produced by the vaporization to participate in the next extraction process again to realize the recycling of the extractant and save costs. .

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly and implement it according to the content of the description, the following describes the embodiments of the present invention and the accompanying drawings in detail.

Description of drawings

Fig. 1 is the structural principle diagram of the present invention;

In the picture: 1. Feeding gate valve, 2. Feeding chamber, 3. Vacuum gate valve, 4. Vacuum chamber, 5. Vacuum pump, 6. Transition gate valve, 7. Transition chamber, 8. Inlet gate valve, 9. Extraction chamber, 10 , outlet gate valve, 11, discharge chamber, 12, discharge gate valve, 13, recovery chamber, 14, recovery pump, 15, recovery gate valve, 16, discharge chamber, 17, discharge gate valve, 18, extraction pressure reducing valve, 19. Gas-liquid separator, 20, Activated carbon adsorption tank, 21, Booster pump, 22, Extract liquid cooler, 23, Discharge pressure relief valve, 24, Discharge solenoid valve, 25, Feed pressure relief valve.

Detailed ways

The above description is only an overview of the technical solutions of the present invention. In order to understand the technical means of the present invention more clearly, the present invention will be further described below through the accompanying drawings and implementation examples.

As shown in FIG. 1, the present invention discloses a device for continuously remediating contaminated soil by supercritical carbon dioxide extraction, including an extraction cavity 9 inclined upward from left to right and provided with a screw conveying blade inside; The upper left end is provided with a soil inlet and the lower left end is provided with an extraction agent inlet, the lower right end of the extraction cavity 9 is provided with a soil outlet and the upper left end is provided with an extraction agent outlet; A feed gate valve 1, a feed cavity 2, a vacuum gate valve 3, a vacuum cavity 4, a transition gate valve 6, a transition cavity 7 and an inlet gate valve 8 are arranged in sequence at the bottom. The bottom is provided with outlet gate valve 10, discharge chamber 11, discharge gate valve 12, recovery chamber 13, recovery gate valve 15, discharge chamber 16 and discharge gate valve 17; when feeding, feed gate valve 1, vacuum gate valve 3, transition The gate valve 6 and the inlet gate valve 8 are opened and closed alternately in sequence; when discharging, the outlet gate valve 10, the discharge gate valve 12, the recovery gate valve 15 and the discharge gate valve 17 are opened and closed alternately in sequence. The sequential opening and closing of the gate valves can isolate the external environment and ensure that the internal environment of the extraction chamber 9 is stable.

One side of the vacuum chamber 4 is provided with an evacuation pipeline, and a vacuum pump 5 is installed on the evacuation pipeline to discharge the air that enters with the material.

An extraction agent discharge pipe is installed on the extraction agent outlet, and an extraction liquid cooler 22 is arranged at the end of the extraction agent discharge pipe; an extraction pressure reducing valve 18 is installed on the extraction agent discharge pipe and from the extraction agent outlet to the extraction liquid cooler 22 in sequence. , a gas-liquid separator 19, an activated carbon adsorption tank 20 and a pressurizing pump 21; the outlet of the extractant cooler 22 is connected to the extractant inlet through an extractant adding pipeline.

One side of the recovery chamber 13 is installed with an extraction agent recovery pipeline that communicates with the extraction agent discharge pipeline between the extraction pressure reducing valve 18 and the gas-liquid separator 19, and a recovery pump 14 is installed on the extraction agent recovery pipeline for recovering the The extractant from the material discharge.

One side of the unloading cavity 16 is installed with a discharge pressurization pipeline that communicates with the extraction agent adding pipeline, and a discharge pressure relief valve 23 and a discharge solenoid valve 24 are installed on the discharge pressure pipeline. The discharge chamber 16 controls the discharge solenoid valve 24 to pass carbon dioxide gas according to the valve opening and closing cycle to prevent air from entering the extraction chamber.

One side of the feed chamber 2 is installed with a feed decompression pipeline that communicates with the extraction agent adding pipeline, and a feed decompression valve 25 is installed on the feed decompression pipeline.

The main structure of the present invention is an extraction cavity 9 conveyed by paddles, and the extraction agent for repairing the contaminated soil is carbon dioxide in a supercritical state. The extraction cavity 9 is a closed and heated cavity, and the appropriate temperature and pressure are set in the cavity to maintain the supercritical state of the carbon dioxide extraction agent; the supercritical carbon dioxide extraction agent is introduced into the extraction cavity 9, and the material is stirred evenly by the paddle; The soil inlet and soil outlet of cavity 9 are installed with multiple groups of gate valves and cavities. Through the alternate sequence opening and closing of multiple sets of gate valves and the filling of carbon dioxide extractant, the internal environment of extraction cavity 9 is guaranteed to be stable; after the extraction is completed, the supercritical carbon dioxide extractant passes through. After the extraction pressure reducing valve 18 is decompressed and vaporized, the extracted pollutants are separated by the gas-liquid separator 19, and the carbon dioxide produced by the vaporization is treated and then re-participated in the next extraction process.

Contaminated soil is continuously fed into the upper port of the feed gate valve 1, carbon dioxide gas is introduced into the feed chamber 2 to prevent air from entering the extraction chamber, and the vacuum chamber 4 is evacuated by the vacuum pump 5 to discharge the air that enters with the material. , vacuum gate valve 3, transition gate valve 6 and inlet gate valve 8 are opened and closed alternately in sequence to complete the process of material discharging air and entering extraction chamber 9, while maintaining the pressure in extraction chamber 9 and the purity of extraction agent.

In the extraction chamber 9, the contaminated soil and supercritical carbon dioxide are mixed for extraction, and the extraction pressure reducing valve 18 is connected to the top of the soil outlet of the extraction chamber 9 through a pipeline, and the supercritical carbon dioxide dissolved in the pollutants is evaporated after being decompressed through the extraction pressure reducing valve 18, Enter the gas-liquid separator 19 to separate out the pollutants and discharge them to the outside of the device. The gaseous carbon dioxide is purified by the activated carbon adsorption tank 20 and then pressurized by the pressurizing pump 21 to a supercritical state, and cooled to an appropriate temperature by the extraction liquid cooler 22, and then again The extraction chamber 9 enters the extraction chamber 9 through the nozzle near the soil inlet of the extraction chamber 9, and the contaminated soil is mixed, stirred and transported by the paddles in the extraction chamber 9, and supercritical extraction is performed at the same time.

The soil after extraction is discharged from the extraction chamber 9 through the soil outlet, and is alternately opened and closed by the outlet gate valve 10 , the discharge gate valve 12 , the recovery gate valve 15 and the discharge gate valve 17 , and passes through the discharge chamber 11 , the recovery chamber 13 and the discharge chamber 16 , and finally discharged from the system.

Obviously, the above-mentioned embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Claims (6)

1. A device for continuously repairing polluted soil by supercritical carbon dioxide extraction is characterized in that: comprises an extraction cavity (9) which is obliquely arranged from left to right and is internally provided with a screw conveying blade; a soil inlet is formed in the upper portion of the left end of the extraction cavity (9), an extracting agent inlet is formed in the lower portion of the left end of the extraction cavity, a soil outlet is formed in the lower portion of the right end of the extraction cavity (9), and an extracting agent outlet is formed in the upper portion of the left end of the extraction cavity; a feeding pipeline is arranged on the soil inlet, and a feeding gate valve (1), a feeding cavity (2), a vacuum gate valve (3), a vacuum cavity (4), a transition gate valve (6), a transition cavity (7) and an inlet gate valve (8) are sequentially arranged on the feeding pipeline from top to bottom; a discharge pipeline is arranged on the soil outlet, and an outlet gate valve (10), a discharge cavity (11), a discharge gate valve (12), a recovery cavity (13), a recovery gate valve (15), a discharge cavity (16) and a discharge gate valve (17) are sequentially arranged on the discharge pipeline from top to bottom; during feeding, the feeding gate valve (1), the vacuum gate valve (3), the transition gate valve (6) and the inlet gate valve (8) are opened and closed alternately in sequence; during discharging, the outlet gate valve (10), the discharge gate valve (12), the recovery gate valve (15) and the discharge gate valve (17) are opened and closed alternately in sequence.

2. The apparatus for supercritical carbon dioxide extraction continuous remediation of contaminated soil as claimed in claim 1, wherein: and a vacuum pumping pipeline is arranged on one side of the vacuum cavity (4), and a vacuum pump (5) is arranged on the vacuum pumping pipeline.

3. The apparatus for supercritical carbon dioxide extraction continuous remediation of contaminated soil as claimed in claim 1, wherein: an extractant discharge pipeline is arranged on the extractant outlet, and an extraction liquid cooler (22) is arranged at the tail end of the extractant discharge pipeline; an extraction pressure reducing valve (18), a gas-liquid separator (19), an activated carbon adsorption tank (20) and a pressure pump (21) are sequentially arranged on the extraction agent discharge pipeline from an extraction agent outlet to an extraction liquid cooler (22); the outlet of the extract liquid cooler (22) is connected with the extractant inlet through an extractant feeding pipeline.

4. The apparatus for supercritical carbon dioxide extraction continuous remediation of contaminated soil as claimed in claim 3, wherein: and an extractant recovery pipeline communicated with an extractant discharge pipeline between the extraction pressure reducing valve (18) and the gas-liquid separator (19) is arranged on one side of the recovery cavity (13), and a recovery pump (14) is arranged on the extractant recovery pipeline.

5. The apparatus for supercritical carbon dioxide extraction continuous remediation of contaminated soil as claimed in claim 3, wherein: and a discharge pressurizing pipeline communicated with the extractant adding pipeline is arranged on one side of the discharge cavity (16), and a discharge pressure reducing valve (23) and a discharge electromagnetic valve (24) are arranged on the discharge pressurizing pipeline.

6. The apparatus for supercritical carbon dioxide extraction continuous remediation of contaminated soil as claimed in claim 3, wherein: and a feeding pressure reducing pipeline communicated with the extractant adding pipeline is installed on one side of the feeding cavity (2), and a feeding pressure reducing valve (25) is installed on the feeding pressure reducing pipeline.

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