CN114011861A - Steam strengthening-vapor extraction combined soil remediation system and method for circulating tail gas - Google Patents
Steam strengthening-vapor extraction combined soil remediation system and method for circulating tail gas Download PDFInfo
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
- B09C1/005—Extraction of vapours or gases using vacuum or venting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
- B09C1/002—Reclamation of contaminated soil involving in-situ ground water treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C2101/00—In situ
Abstract
The invention provides a system and a method for repairing soil by combining steam strengthening and vapor extraction of circulating tail gas, belonging to the technical field of soil repair. The soil remediation system comprises a steam generator (1), a steam injection well (2), a steam extraction well (3), a gas-liquid separator (4), a heat exchanger (6) and a burner (7). In the invention, the outlet of the steam extraction well (3) is communicated with the heat exchanger (6), so that the heat of the hot gas-liquid mixture extracted by the steam extraction well (3) can be recovered, the heat can be used as a heat source to preheat evaporation water, and when evaporation is carried out, the evaporation energy consumption can be reduced, and the evaporation cost can be saved; meanwhile, after the hot gas-liquid mixture extracted by the steam extraction well (3) is separated by the gas-liquid separator (4) and subjected to heat exchange by the heat exchanger (6), the temperature-reduced mixed gas containing organic pollutants enters the combustor (7) for combustion, so that the combustion heat value can be increased, and the energy consumption is further reduced.
Description
Technical Field
The invention relates to the technical field of soil remediation, in particular to a system and a method for remediating circulating tail gas by combining steam strengthening and vapor extraction.
Background
Soil is the most basic environmental element for human survival and development, and is an indispensable natural resource difficult to regenerate for human beings. However, with the development of human industrialization, soil pollution has become an important global environmental problem. A large amount of waste containing organic matters is generated in industrial and agricultural production and daily life, so that the polluted soil contains a large amount of organic pollutants, such as pollutants of petroleum, pesticides, polycyclic aromatic hydrocarbons and the like. Organic pollutants can enter soil through the actions of atmospheric precipitation, soil gas exchange and the like, and when crops absorb nutrient elements from the soil, part of the organic pollutants can be absorbed by roots, stems and leaves, and then enter animals and human bodies through food chains to cause harm to human bodies.
Common soil remediation techniques include bio-heap treatment, chemical oxidation, thermal desorption, and the like. However, the biological heap treatment has the defects of long period and poor repairing effect of indigenous microorganisms using soil; the chemical oxidation technology is easy to cause secondary pollution to soil due to the use of chemical agents; the thermal desorption technology has the defects of high treatment energy consumption and high operation cost.
Compared with the soil remediation technology, the steam enhanced-gas phase extraction (SEE) method decomposes organic pollutants by using high-temperature steam (the temperature is more than or equal to 100 ℃), has the advantages of high treatment speed, no need of injecting chemical agents into the underground and no secondary pollution, but generates steam, consumes a large amount of energy (such as natural gas) and consumes high energy.
Disclosure of Invention
In view of the above, the present invention aims to provide a system and a method for repairing soil by combining steam enhanced-vapor extraction of cycle tail gas. The steam strengthening-vapor extraction combined soil remediation system for the circulating tail gas provided by the invention has the advantage of low energy consumption.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a steam strengthening-vapor extraction combined soil remediation system for circulating tail gas, which comprises a steam generator 1;
a steam injection well 2 with an inlet communicated with the outlet of the steam generator 1;
a steam extraction well 3;
the gas-liquid separator 4 is communicated with the steam extraction well 3, the gas-liquid separator 4 is provided with a gas-liquid mixture inlet 4-1, an air inlet 4-2, a gas outlet 4-3 and a liquid outlet 4-4, and the gas-liquid mixture inlet 4-1 is communicated with the outlet of the steam extraction well 3;
a sewage treatment system 5 in communication with the liquid outlet 4-4;
the heat exchanger 6 is communicated with the gas-liquid separator 4, and the heat exchanger 6 is provided with a cold water inlet 6-1, a hot gas inlet 6-2, a warm water outlet 6-3 and a cooling gas outlet 6-4; a hot gas inlet 6-2 of the heat exchanger 6 is communicated with a gas outlet 4-3 of the gas-liquid separator 4; a warm water outlet 6-3 of the heat exchanger 6 is communicated with an inlet of the steam generator 1;
the combustor 7 is communicated with the heat exchanger 6, the combustor 7 is provided with a low-temperature gas inlet 7-1, and the low-temperature gas inlet 7-1 of the combustor 7 is communicated with a cooling gas outlet 6-4 of the heat exchanger 6; the burner 7 provides heat to the steam generator 1.
Preferably, the transverse distance between the steam extraction well 3 and the steam injection well 2 is 3.66-6.1 m.
Preferably, a fan 8 is arranged between the pipelines of the heat exchanger 6 communicated with the steam generator 1.
The invention provides a method for performing steam strengthening-vapor extraction combined soil remediation of circulating tail gas based on the soil remediation system, which comprises the following steps:
the burner 7 provides heat for the steam generator 1 to generate steam, and the steam is injected into the steam injection well 2;
carrying out gas phase extraction on the steam extraction well 3 to obtain a hot gas-liquid mixture;
the hot gas-liquid mixture and air enter a gas-liquid separator 4 for gas-liquid separation to obtain hot mixed gas and extract, and the extract enters a sewage treatment system 5 for sewage treatment and then is discharged;
the hot mixed gas enters a heat exchanger 6 to exchange heat with cold water to obtain cooled mixed gas and warm water, and the warm water enters a steam generator 1 to be evaporated to obtain steam; and the cooled mixed gas is mixed with combustible gas and then enters the combustor 7 for combustion.
Preferably, the temperature of the water vapor generated by the steam generator 1 is 140-150 ℃;
the flow rate of the steam injected into the steam injection well 2 is 0.8-1.2 m3/h。
Preferably, the flow rate of the vapor extraction is 7-9 m3H; the absolute pressure of the vapor extraction is 0.6-0.8 bar.
Preferably, the volume ratio of the hot gas-liquid mixture to the air is 1:0 to 0.6.
Preferably, the temperature of the warm water is 30-40 ℃.
Preferably, the combustible gas is natural gas or industrial gas.
Preferably, after the temperature-reduced mixed gas is mixed with the combustible gas, the volume content of the combustible gas in the obtained mixed gas is more than or equal to 30%.
The invention provides a steam strengthening-gas phase extraction combined soil remediation system for circulating tail gas, which comprises a steam generator 1, a steam injection well 2, a steam extraction well 3, a gas-liquid separator 4, a heat exchanger 6 and a combustor 7. Because the hot gas-liquid mixture extracted from the steam extraction well 3 has higher temperature, the invention adopts the way that the outlet of the steam extraction well 3 is communicated with the heat exchanger 6, the heat of the hot gas-liquid mixture extracted from the steam extraction well 3 can be recovered, the heat can be used as a heat source to preheat evaporation water, when the preheated warm water enters the steam generator 1 for evaporation, the evaporation energy consumption can be reduced, the evaporation cost is saved, and water vapor is quickly obtained; meanwhile, the hot gas-liquid mixture extracted from the steam extraction well 3 contains organic pollutants, the temperature-reducing gas outlet 6-4 of the heat exchanger 6 is communicated with the combustor 7, the hot gas-liquid mixture extracted from the steam extraction well 3 is separated by the gas-liquid separator 4 and subjected to heat exchange by the heat exchanger 6, and the temperature-reducing mixed gas containing the organic pollutants enters the combustor 7 to be combusted, so that the combustion heat value can be increased, and the energy consumption is further reduced.
Meanwhile, the soil remediation system provided by the invention has the advantage of no secondary pollution.
Drawings
Fig. 1 is a schematic structural diagram of a steam strengthening-gas phase extraction combined soil remediation system for ring tail gas, in which 1 is a steam generator, 2 is a steam injection well, 3 is a steam extraction well, 4 is a gas-liquid separator, 4-1 is a gas-liquid mixture inlet, 4-2 is an air inlet, 4-3 is a gas outlet, 4-4 is a liquid outlet, 5 is a sewage treatment system, 6 is a heat exchanger, 6-1 is a cold water inlet, 6-2 is a hot gas inlet, 6-3 is a warm water outlet, 6-4 is a cooling gas outlet, 7 is a burner, 7-1 is a low-temperature gas inlet, 8 is a fan, and 9 is a water tank.
Detailed Description
The invention provides a steam strengthening-vapor extraction combined soil remediation system for circulating tail gas, which comprises a steam generator 1;
a steam injection well 2 with an inlet communicated with the outlet of the steam generator 1;
a steam extraction well 3;
the gas-liquid separator 4 is communicated with the steam extraction well 3, the gas-liquid separator 4 is provided with a gas-liquid mixture inlet 4-1, an air inlet 4-2, a gas outlet 4-3 and a liquid outlet 4-4, and the gas-liquid mixture inlet 4-1 is communicated with the outlet of the steam extraction well 3;
a sewage treatment system 5 in communication with the liquid outlet 4-4;
the heat exchanger 6 is communicated with the gas-liquid separator 4, and the heat exchanger 6 is provided with a cold water inlet 6-1, a hot gas inlet 6-2, a warm water outlet 6-3 and a cooling gas outlet 6-4; a hot gas inlet 6-2 of the heat exchanger 6 is communicated with a gas outlet 4-3 of the gas-liquid separator 4; a warm water outlet 6-3 of the heat exchanger 6 is communicated with an inlet of the steam generator 1;
the combustor 7 is communicated with the heat exchanger 6, the combustor 7 is provided with a low-temperature gas inlet 7-1, and the low-temperature gas inlet 7-1 of the combustor 7 is communicated with a cooling gas outlet 6-4 of the heat exchanger 6; the burner 7 provides heat to the steam generator 1.
The invention provides a steam strengthening-gas phase extraction combined soil remediation system for circulating tail gas, which comprises a steam generator 1. The invention has no special requirements on the type and specification of the steam generator 1, and can evaporate water to generate steam.
The steam strengthening-gas phase extraction combined soil remediation system for the circulating tail gas comprises a steam injection well 2, wherein an inlet of the steam injection well is communicated with an outlet of a steam generator 1. The invention has no special requirements on the size and specification of the steam injection well 2, and the steam injection well can be designed correspondingly according to the actual working condition; as an embodiment of the present invention, the steam injection well 2 has a depth of 1 to 20m (adjusted according to the contaminated site) and a diameter of 10 cm.
The steam strengthening-vapor extraction combined soil remediation system for the circulating tail gas comprises a steam extraction well 3, wherein the steam extraction well 3 and a steam injection well 2 are arranged in soil to be remediated and have a certain transverse distance. In the present invention, the soil to be remediated is preferably soil containing organic contaminants, preferably including one or more of polychlorinated biphenyl, dioxin, dichlorvos, hexachloro cyclohexane, C25-below hydrocarbon compounds, nitrobenzene, polybromodiphenyl ether, and furan. In the invention, the content of the organic pollutants in the soil to be repaired is preferably 1000mg/m3～10000mg/m3。
In the invention, the transverse distance between the steam extraction well 3 and the steam injection well 2 is preferably 3.66-6.1 m, and more preferably 4-5 m. The invention has no special requirements on the size and specification of the steam extraction well 3, and the corresponding design is carried out according to the pollution position; as a specific embodiment of the invention, the depth of the steam extraction well 3 is preferably 1-20 m, more preferably 5-15 m, and the diameter is 10 cm.
The steam strengthening-gas phase extraction combined soil remediation system for the circulating tail gas comprises a gas-liquid separator 4, wherein the gas-liquid separator 4 is provided with a gas-liquid mixture inlet 4-1, an air inlet, a gas outlet and a liquid outlet, and the gas-liquid mixture inlet 4-1 of the gas-liquid separator 4 is communicated with an outlet of a steam extraction well 3; and a liquid outlet of the gas-liquid separator 4 is communicated with a sewage treatment system 5. The invention has no special requirements on the type and specification of the gas-liquid separator 4, and can realize the separation of gas and liquid. The present invention does not require any particular sewage treatment system 5, and may be implemented using a sewage treatment system 5 known to those skilled in the art. As a specific embodiment of the present invention, an activated carbon adsorption device is disposed in the sewage treatment system 5.
The steam strengthening-gas phase extraction combined soil remediation system for the circulating tail gas comprises a heat exchanger 6, wherein the heat exchanger 6 is provided with a cold water inlet 6-1, a hot gas inlet 6-2, a warm water outlet 6-3 and a cooling gas outlet 6-4; a hot gas inlet 6-2 of the heat exchanger 6 is communicated with a gas outlet of the gas-liquid separator 4; the warm water outlet 6-3 of the heat exchanger 6 is communicated with the inlet of the steam generator 1. The invention has no special requirements on the type and specification of the heat exchanger 6, and can realize the heat exchange between gas and liquid. As a specific example of the present invention, the heat exchanger 6 is a shell-and-tube heat exchanger. The arrangement positions of the cold water inlet 6-1, the hot gas inlet 6-2, the warm water outlet 6-3 and the cooling gas outlet 6-4 are not required to be special, and corresponding design is carried out according to actual conditions.
In the present invention, the cold water inlet 6-1 of the heat exchanger 6 is preferably in communication with the water sump 9. In the present invention, the cold water in the water bath is preferably plant cooling water.
In the present invention, a blower 8 is preferably provided between the pipes of the heat exchanger 6 communicating with the steam generator 1.
The steam strengthening-gas phase extraction combined soil remediation system for the circulating tail gas comprises a combustor 7, wherein the combustor 7 is provided with a low-temperature gas inlet 7-1, and the low-temperature gas inlet 7-1 of the combustor 7 is communicated with a cooling gas outlet of a heat exchanger 6; the burner 7 provides heat to the steam generator 1. The invention has no special requirements on the type and specification of the combustor 7, and can realize the combustion of cooling gas and combustible gas. In the present invention, the burner 7 is preferably disposed below the steam generator 1.
In the invention, the number of the steam extraction wells 3 and the number of the steam injection wells 2 are independent and preferably 10-15, each group of steam extraction wells 3 are arranged in parallel, and each group of steam injection wells 2 are arranged in parallel.
As a specific embodiment of the invention, a schematic structural diagram of the system for remedying the soil by combining the steam strengthening and the gas phase extraction of the circulating tail gas is shown in FIG. 1. In fig. 1, 1 is a steam generator, 2 is a steam injection well, 3 is a steam extraction well, 4 is a gas-liquid separator, 4-1 is a gas-liquid mixture inlet, 4-2 is an air inlet, 4-3 is a gas outlet, 4-4 is a liquid outlet, 5 is a sewage treatment system, 6 is a heat exchanger, 6-1 is a cold water inlet, 6-2 is a hot gas inlet, 6-3 is a warm water outlet, 6-4 is a cooling gas outlet, 7 is a burner, 8 is a fan, and 9 is a water tank.
The invention provides a method for performing steam strengthening-vapor extraction combined soil remediation of circulating tail gas based on the soil remediation system, which comprises the following steps:
the burner 7 provides heat for the steam generator 1 to generate steam, and the steam is injected into the steam injection well 2;
carrying out gas phase extraction on the steam extraction well 3 to obtain a hot gas-liquid mixture;
the hot gas-liquid mixture is mixed with air and then enters a gas-liquid separator 4 for gas-liquid separation to obtain hot mixed gas and extract, and the extract enters a sewage treatment system 5 for sewage treatment and then is discharged;
the hot mixed gas enters a heat exchanger 6 to exchange heat with cold water to obtain cooled mixed gas and warm water, and the warm water enters a steam generator 1 to be evaporated to obtain steam; and the cooled mixed gas is mixed with combustible gas and then enters the combustor 7 for combustion.
In the present invention, the burner 7 provides heat to the steam generator 1 to generate steam, which is injected into the steam injection well 2. In the invention, the temperature of the water vapor generated by the steam generator 1 is preferably 140-150 ℃, and more preferably 145 ℃; the flow rate of the steam injected into the steam injection well 2 is preferably 0.8-1.2 m3H, more preferably 1m3/h。
In the invention, after the steam generated by the steam generator 1 is injected into the steam injection well 2, the steam enters the soil to be repaired through the steam injection well 2, and the high-temperature steam degrades the organic pollutants in the soil to be repaired. In the present invention, the time for degradation is preferably 10 days to 4 months.
The invention carries out gas phase extraction on the steam extraction well 3 to obtain a hot gas-liquid mixture. In the invention, the flow rate of the vapor extraction is preferably 7-9 m3H, more preferably 8m3H; the absolute pressure of the vapor extraction is preferably 0.6-0.8 bar, and more preferably 0.7 bar. In the invention, the temperature of the hot gas-liquid mixture is preferably 80-90 ℃.
And after the hot gas-liquid mixture is obtained, the hot gas-liquid mixture is mixed with air and then enters a gas-liquid separator 4 for gas-liquid separation to obtain hot mixed gas and extract, and the extract enters a sewage treatment system 5 for sewage treatment and then is discharged. In the invention, the volume ratio of the hot gas-liquid mixture to the air is preferably 1: 0-0.6, and more preferably 1: 0.1-0.5. The present invention has no special requirements for the specific operating parameters of the gas-liquid separation. The invention has no special requirements on the sewage treatment mode, and the sewage treatment mode known by the technicians in the field can be used.
In the invention, the hot mixed gas enters a heat exchanger 6 to exchange heat with cold water to obtain cooling mixed gas and warm water, and the warm water enters a steam generator 1 to be evaporated to obtain steam; and the cooled mixed gas is mixed with combustible gas and then enters the combustor 7 for combustion. In the invention, the temperature of the warm water is preferably 30-40 ℃, and more preferably 35 ℃. In the present invention, the combustible gas is preferably natural gas or industrial gas, the composition of which comprises methane and/or propane; after the cooled mixed gas is mixed with the combustible gas, the volume content of the combustible gas in the obtained mixed gas is preferably not less than 30%, and more preferably 40-50%.
The system and method for repairing soil by combining steam enhanced extraction with gas phase extraction of recycled tail gas provided by the present invention are described in detail with reference to the following examples, which should not be construed as limiting the scope of the present invention.
Example 1
The steam strengthening-gas phase extraction combined soil remediation system for the circulating tail gas shown in the figure 1 is adopted to carry out soil remediation on an oil pollution area, wherein soil texture of the area is distributed by silty clay, clay silty soil, medium and coarse sand, circular gravel and the like. The site stratum structure is approximately from the ground to 2m below the ground and consists of silty clay; the silty clay and the withered silty soil are sandwiched with the thin layer silty clay about 2 to 6 meters below the ground; medium coarse sand and round gravel about 6 to 12 meters below the ground; about 12 to 6 meters below the ground is clay powder with ten sandwiched thin layers of powder clay; medium grit and pebbles were present 16 meters below the surface to the deepest 27 meters of investigation. The total amount of leaked diesel oil is estimated to be about 2000kg according to the pollution thickness, and most of the leaked diesel oil is retained in a ventilation stratum above the underground water level, particularly in a 6-12 m sand gravel layer and a 12-16 m clay dust layer. The contaminated area is an area of 12 meters radius centered on the leakage point. The repairing method comprises the following steps:
the steam generator generates 180 deg.C water vapor at 1m3The flow rate of the steam injection wells is/h, wherein the number of the groups of the steam injection wells is 10, the number of the groups of the steam extraction wells is 15, and the distance between the extraction wells and the injection wells is 5 meters. The temperature of the soil layer is about 20 ℃ before steam injection, and the temperature of the soil layer is increased to 80-90 ℃ after 10 days of injection.
Carrying out gas phase extraction on the steam extraction well to obtain a hot gas-liquid mixture;
after the hot gas-liquid mixture is mixed with air, the mixture enters a gas-liquid separator for gas-liquid separation to obtain hot mixed gas and extract, and the extract enters a sewage treatment system for sewage treatment and then is discharged;
the hot mixed gas enters a heat exchanger to exchange heat with cold water to obtain cooling mixed gas and warm water, and the warm water enters a steam generator to be evaporated to obtain steam; and the cooled mixed gas is mixed with combustible gas and then enters the combustor for combustion.
Extracting for 4 months, extracting about 15kg of non-methane total hydrocarbon every day, and extracting about 1000kg of oil gas in total; about 200L of liquid oil was simultaneously pumped out and about 10L could be collected daily, with the expected total time of 1 year ending.
Example 2
The present application relates to remediation of a 1.6 hectare area of a factory whose activities and leakage of oil result in soil and groundwater contamination with oil and aliphatic hydrocarbons. The main contaminants of the soil are heavy contamination with mineral oil (about 8000mg/kg) and benzene compounds. The maximum depth at which contamination occurs is 5 m. The depth of the underground water level is 4.5-5 m, and the underground water is also polluted by mineral oil and benzene. In some locations, the mineral oil is present in the form of an oil layer having a thickness of about 0.01m at the top of the water table.
The field soil is sandy soil, and 2m of the upper part of the field soil is provided with a large amount of debris. Under the sandy soil layer, the soil is closer to silt until the depth reaches 3.4-7 m, which depends on the exact position of the site. Below the silt layer is a clay layer.
Remediation was carried out as in example 1, with the soil meeting acceptance criteria of less than 230mg/kg of petroleum hydrocarbon and less than 0.64mg/kg of benzene after three months of use.
Example 3
In a certain petroleum-polluted site, the main pollutants are 15mg/kg of benzene, 113mg/kg of toluene and 12mg/kg of chlorobenzene. The main pollution depth is 6-8 m, and the pattern layer at the position is clay and is above the water line. Steam temperature 100 deg.C, flow 0.9m3H, after 2 weeks of heating, the removal rate of various pollutants is already highOver 90 percent, the content of the repaired various pollutants is 1.0mg/kg of benzene, 1.02mg/kg of toluene and 0.87mg.kg of chlorobenzene.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A steam strengthening-gas phase extraction combined soil remediation system for circulating tail gas comprises a steam generator (1);
a steam injection well (2) with an inlet communicated with the outlet of the steam generator (1);
a steam extraction well (3);
the gas-liquid separator (4) is communicated with the steam extraction well (3), the gas-liquid separator (4) is provided with a gas-liquid mixture inlet (4-1), an air inlet (4-2), a gas outlet (4-3) and a liquid outlet (4-4), and the gas-liquid mixture inlet (4-1) is communicated with the outlet of the steam extraction well (3);
a sewage treatment system (5) in communication with the liquid outlet (4-4);
the heat exchanger (6) is communicated with the gas-liquid separator (4), and the heat exchanger (6) is provided with a cold water inlet (6-1), a hot gas inlet (6-2), a warm water outlet (6-3) and a cooling gas outlet (6-4); a hot gas inlet (6-2) of the heat exchanger (6) is communicated with a gas outlet (4-3) of the gas-liquid separator (4); a warm water outlet (6-3) of the heat exchanger (6) is communicated with an inlet of the steam generator (1);
the combustor (7) is communicated with the heat exchanger (6), the combustor (7) is provided with a low-temperature gas inlet (7-1), and the low-temperature gas inlet (7-1) of the combustor (7) is communicated with a cooling gas outlet (6-4) of the heat exchanger (6); the burner (7) provides heat for the steam generator (1).
2. Soil remediation system according to claim 1, wherein the steam extraction well (3) and the steam injection well (2) are laterally spaced from each other by 3.66 to 6.1 m.
3. Soil remediation system according to claim 1, wherein a fan (8) is provided between the pipes communicating the heat exchanger (6) with the steam generator (1).
4. The method for performing steam strengthening-vapor extraction combined soil remediation of the circulating tail gas based on the soil remediation system of any one of claims 1 to 3, comprising the following steps:
the burner (7) provides heat for the steam generator (1) to generate steam, and the steam is injected into the steam injection well (2);
carrying out gas phase extraction on the steam extraction well (3) to obtain a hot gas-liquid mixture;
the hot gas-liquid mixture and air enter a gas-liquid separator (4) for gas-liquid separation to obtain hot mixed gas and extract, and the extract enters a sewage treatment system (5) for sewage treatment and then is discharged;
the hot mixed gas enters a heat exchanger (6) to exchange heat with cold water to obtain cooled mixed gas and warm water, and the warm water enters a steam generator (1) to be evaporated to obtain steam; the cooled mixed gas and the combustible gas are mixed and then enter a combustor (7) for combustion.
5. The method according to claim 4, characterized in that the temperature of the water vapor generated by the steam generator (1) is 140-150 ℃;
the flow rate of the steam injected into the steam injection well (2) is 0.8-1.2 m3/h。
6. The method according to claim 4, wherein the flow rate of the vapor extraction is 7-9 m3H; the absolute pressure of the vapor extraction is 0.6-0.8 bar.
7. The method according to claim 4, wherein the volume ratio of the hot gas-liquid mixture to air is 1:0 to 0.6.
8. The method according to claim 4, wherein the warm water has a temperature of 30 to 40 ℃.
9. The method of claim 4, wherein the combustible gas is natural gas or industrial gas.
10. The method as claimed in claim 4 or 9, wherein the volume content of the combustible gas in the obtained mixed gas is not less than 30% after the temperature-reduced mixed gas is mixed with the combustible gas.
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| US5011329A (en) * | 1990-02-05 | 1991-04-30 | Hrubetz Exploration Company | In situ soil decontamination method and apparatus |
| US5360067A (en) * | 1993-05-17 | 1994-11-01 | Meo Iii Dominic | Vapor-extraction system for removing hydrocarbons from soil |
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