A dual-fluid injection integrated system for soil and groundwater remediation

Abstract

The present invention discloses a dual-fluid injection integrated system for soil and groundwater remediation, comprising an injection unit, a dispensing unit and an auxiliary unit; the injection unit comprises an injection pump, an air compressor, an injection rod, an injection ejector rod, a connecting chamber, an injection head, a nozzle housing and an injection control mechanism; the dispensing unit comprises a medicine configuration slot and a medicine storage slot; the auxiliary unit comprises an electric control cabinet, a rod box, a downward pressure device and a skid-mounted platform; the injection unit, the dispensing unit and the auxiliary unit are all integrated on the skid-mounted platform. The integrated system provided by the present invention can complete the in-situ injection remediation of soil and groundwater, achieve the dual-fluid injection of liquid medicine and gas at the same time, enhance the dispersion, diffusion, penetration ability of the medicine and the mixing ability with underground pollutants, thereby improving the remediation efficiency and enhancing the remediation effect.

Description

Technical Field

[0001] The invention relates to an in-situ injection technology system used in the field of environmental remediation technology, and in particular to a mobile dual-fluid injection integrated system used for remediating soil and groundwater pollution in low-permeability formations. Background Art

[0002] my country has long regarded the petrochemical industry as an important pillar industry. The characteristics of petrochemical enterprises, such as large water consumption, large drainage volume, and transportation requirements for raw materials and products, have created their layout characteristics of being close to the sea, rivers, and lakes. There are hundreds of thousands of chemical companies along the Yangtze River alone. The Yangtze River Economic Belt carries 30% of the country's petrochemical industry with 21% of the land. Possible pipeline and tank leakage or wastewater discharge in the chemical industry will cause serious pollution to the soil and groundwater. The main pollutants involved include petroleum hydrocarbons, benzene series, polycyclic aromatic hydrocarbons, phenols, chlorinated hydrocarbons, etc. These substances will cause serious harm to health after entering the human body.

[0003] At present, the commonly used remediation method for this type of pollution in petrochemical sites is in-situ remediation. Compared with ex-situ remediation, in-situ remediation does not involve the excavation / extraction, transportation and storage of soil or groundwater, which can not only reduce the cost of remediation but also effectively prevent secondary pollution. It is also suitable for sites that are not suitable for large-scale excavation. The in-situ injection remediation technology included in in-situ remediation refers to the injection of specific remediation agents into the soil or groundwater to react with underground pollutants, converting them into non-toxic or low-toxic substances to achieve the purpose of remediation. Compared with other in-situ remediation technologies, in-situ injection has outstanding advantages such as high efficiency and wide application range.

[0004] Conventional in-situ injection technologies used in soil and groundwater remediation projects mainly include direct pressure high-pressure injection and injection well injection, which are mainly suitable for pollution remediation of saturated soil and groundwater. Direct pressure high-pressure injection is to inject the configured liquid agent into the contaminated soil layer through an injection pump by directly pressing the injection rod into the ground for remediation. Injection well injection is to set up an injection well in the remediation area, and the liquid remediation agent enters the contaminated soil layer through the injection well under the pressure of the injection pump to achieve pollution remediation. The disadvantages of these conventional injection technologies are that they mainly rely on pores and cracks in the soil layer as channels to disperse the remediation agent and use groundwater flow to help the further diffusion of the agent, so they are mainly suitable for uniform and medium-to-high permeability saturated zone formations.

[0005] The Yangtze River Economic Belt in my country, where petrochemical enterprises are concentrated, has the characteristics of low soil permeability, many clay / interlayers, shallow groundwater level and poor permeability. If conventional injection technology is used, the function of the remediation agent will mainly act on the high hydraulic conductivity area due to the existence of preferential flow pathways, and the remediation effect will be mainly limited to the high permeability strata. Pollutants remaining in the low permeability soil layer will slowly diffuse into the high permeability soil layer due to the concentration gradient, becoming a long-term secondary source of pollutants, inhibiting the remediation effect and causing the remediation work to "tail" or even rebound. The diffusion of pollutants in low permeability areas can last for years to decades, and the inclusion of low permeability and high permeability strata in the plot makes this defect more significant, which also greatly increases the difficulty of overall remediation.

[0006] The Chinese invention patent for "In-situ injection of soil and groundwater - high-pressure rotary jet injection in-situ remediation system and method" with application number 201610464626.7 mentions a technology for in-situ injection using the high-pressure rotary jet method for foundation treatment in the geotechnical field to solve the in-situ injection problem in low-permeability areas. The problems are that the required injection pressure is high (25-30Mpa), the equipment requirements are high, and there is a certain degree of danger during on-site operation; it will cause damage to the soil structure, which will greatly reduce the bearing capacity of the soil, and the effect is limited in some shallow soil layers; the injection flow is large, which is easy to cause slurry backflow, resulting in waste of reagents and secondary pollution; the system components need to be frequently disassembled and assembled when the equipment is moved, etc. Summary of the invention

[0007] The purpose of the present invention is to provide a mobile dual-fluid injection integrated system for in-situ remediation of soil and groundwater pollution in low-permeability formations, to solve the defects and shortcomings of existing in-situ injection technology, to complete the gas-liquid dual-fluid injection of the formation, thereby improving the remediation efficiency and reducing the remediation time and cost.

[0008] In order to achieve the above-mentioned objectives, the present invention provides a dual-fluid injection integrated system for soil and groundwater remediation, wherein the integrated system comprises an injection unit, a dispensing unit and an auxiliary unit; the injection unit comprises an injection pump, an air compressor, an injection rod, an injection ejector rod, a connecting chamber, an injection head, a nozzle housing and an injection control mechanism; the dispensing unit comprises a medicine configuration slot and a medicine storage slot; the auxiliary unit comprises an electric control cabinet, a rod box, a downward pressure device and a skid-mounted platform; the injection unit, the dispensing unit and the auxiliary unit are all integrated on the skid-mounted platform; the electric control cabinet, the rod box, the downward pressure device, the injection ejector rod, the air compressor, the injection pump, the medicine storage slot and the medicine configuration slot are arranged in sequence above the skid-mounted platform in a horizontal direction; the injection rod is arranged vertically downward from the skid-mounted platform, and the connecting chamber, the injection head and the nozzle housing are arranged vertically below the skid-mounted platform and connected to the injection rod.

[0009] The above-mentioned dual-fluid injection integrated system for soil and groundwater remediation, wherein the injection push rod is vertically connected to and penetrates the injection rod downward, the connecting cavity is arranged at the bottom end of the injection rod, the bottom of the connecting cavity is connected to the injection head, and the nozzle housing is sleeved outside the injection head; the downward pressure device is fixed on the skid-mounted platform for installing the injection rod.

[0010] The above-mentioned dual-fluid injection integrated system for soil and groundwater remediation, wherein the auxiliary unit also includes cables and pipelines; the pipeline includes a drug delivery hose and a compressed air hose; the cable is arranged between the electric control cabinet and the injection unit, the dispensing unit, and the downward pressure device; the downward pressure device, the injection control mechanism, the injection pump, and the air compressor are respectively connected to the electric control cabinet through cables; the drug delivery hose and the compressed air hose are arranged between the injection unit and the dispensing unit; the drug preparation tank, the drug storage tank, and the injection pump are connected in sequence through the drug delivery hose, the outlet of the injection pump is connected to the injection ejector rod through the drug delivery hose, and the outlet of the air compressor is connected to the injection ejector rod through the compressed air hose.

[0011] The above-mentioned dual-fluid injection integrated system for soil and groundwater remediation, wherein, in the auxiliary unit, the skid-mounted platform integrates and carries the entire system, and is equipped with universal wheels with a self-locking structure at the bottom of both sides; the downward pressure device includes a hydraulic cylinder, an electromagnetic regulating valve, an electromagnetic reversing valve, a hydraulic check valve, and a gear pump to complete the downward pressure on the injection rod; the rod box stores rods including the injection rod; the electric control cabinet completes the overall power access and distribution of the system.

[0012] The above-mentioned dual-fluid injection integrated system for soil and groundwater remediation, wherein the system adopts 380V three-phase power input.

[0013] The above-mentioned dual-fluid injection integrated system for soil and groundwater remediation, wherein in the dispensing unit, a mixer is provided in the reagent preparation tank with a liquid level scale, and a dosing metering mechanism is also provided on the top.

[0014] In the above-mentioned dual-fluid injection integrated system for soil and groundwater remediation, the dosing metering mechanism is a cumulative flow meter.

[0015] The above-mentioned dual-fluid injection integrated system for soil and groundwater remediation, wherein, in the injection unit, the injection control mechanism includes a pressure gauge, a flow meter, and a regulating valve, and the injection control mechanism is connected to the injection pump and the air compressor, and adjusts their flow rates respectively for control.

[0016] The above-mentioned dual-fluid injection integrated system for soil and groundwater remediation, wherein, in the injection unit, the injection push rod is a double-tube structure, an outer cavity is formed between the outer tube and the inner tube, an inner cavity is provided in the inner tube, and two inlet channels are provided on the injection push rod, which are respectively connected to the air compressor and the injection pump, and the lower part of the injection push rod is connected to the injection rod by a thread; the injection rod is composed of a plurality of connections, each of which is a double-tube structure, an outer cavity is also formed between the outer tube and the inner tube, and an inner cavity is provided in the inner tube, which are respectively communicated with the outer cavity and inner cavity of the injection push rod, and the inner cavity is connected to the injection pump through the injection push rod, and the outer cavity is connected to the air compressor; the two injection rods are fixed by threaded connection, and the injection rod at the lower end is connected to the connecting cavity; the injection rod is connected to the top of the connecting cavity, and the injection head is connected to the bottom.

[0017] The above-mentioned dual-fluid injection integrated system for soil and groundwater remediation, wherein the injection head is a dual-fluid rotary nozzle driven by compressed air, which is connected to the connecting cavity by a thread; the injection head is covered and protected by the nozzle shell when pressed into the soil layer, the top of the nozzle shell is conical, the rear is cylindrical, and is connected to the connecting cavity by a sliding strip.

[0018] The dual-fluid injection integrated system for soil and groundwater remediation provided by the present invention has the following advantages:

[0019] (1) The entire system is integrated on a skid-mounted platform, which is convenient for lifting and transportation, saving the time required for disassembly, assembly, and debugging, reducing the labor intensity of construction personnel, and improving the efficiency of repair construction. Universal wheels with a self-locking structure are installed under the skid-mounted platform to facilitate the movement of the system between injection points. The skid-mounted platform and the system it carries as a reaction force overcoming mechanism when the injection rod is pressed down, making the downward pressure more stable.

[0020] (2) During the injection process, the injection rod is pressed down using static hydraulics, which avoids lateral disturbances caused by operations such as hammering and reducing the impact on the soil layer. It can effectively avoid problems such as slurry bubbling during the injection process, and compared with high-pressure injection, the system consumes less energy.

[0021] (3) The shearing and impacting effects of dual-fluid injection on the soil can help open some of the originally closed pores in the soil, increase the effective porosity of the soil, and enable the remediation agent to have more complete contact with the contaminated soil and groundwater, thereby reducing the bubbling phenomenon. At the same time, the pollutants originally enclosed in the non-connected pores will also increase the mixing contact with the agent and be removed through reaction due to the increase in effective porosity and the opening of microchannels.

[0022] (4) The dual-fluid injection head is a rotary nozzle that is driven by compressed air to rotate. The rotary spraying makes the injection of the agent more uniform. After entering the soil pores, part of the compressed gas will escape upward, which helps to open the soil pores vertically and further helps to disperse the repair agent in the vertical direction.

[0023] (5) The simultaneous injection of gas and liquid dual fluids will form effective turbulence, which will accelerate the diffusion rate of the agent in the soil cracks; the irregular movement of the turbulent flow causes the gas and liquid to mix strongly, making the distribution of the agent more uniform; and the turbulent flow increases friction, which is conducive to the full contact between the agent and the pollutant, thereby strengthening the reaction between the agent and the pollutant.

[0024] (6) Through the combination of rotary injection of a dual-fluid rotary injection head and compressed gas dual fluid, the agent can be effectively atomized so that the droplets can be dispersed along with the gas in the aeration zone. The droplet size can be reduced and the number of droplets can be increased, thereby increasing the surface area of ​​the agent and realizing the application of injection technology in direct aeration zone pollution remediation. The atomized small droplets can allow the agent to enter and spread more evenly in the soil pores and microchannels, thereby improving the dispersion and diffusion effect of the remediation agent in the aeration zone and low permeability formations, reducing or eliminating the long-term reverse diffusion caused by the slow release of residual pollutants in low permeability formations, and solving the "tailing" and rebound problems of the remediation project. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the dual-fluid injection integrated system for soil and groundwater remediation of the present invention.

[0026] Figure 2 It is a schematic diagram of the connection chamber and the nozzle housing in the integrated system of the present invention in a closed state.

[0027] Figure 3 It is a schematic cross-sectional view of the dual-fluid rotating nozzle of the injection head in the integrated system of the present invention.

[0028] Figure 4 It is a schematic structural diagram of the injection component in the integrated system of the present invention in the injection state.

[0029] Among them: 1. Electric control cabinet; 2. Injection pump; 3. Air compressor; 4. Injection rod; 5. Injection ejector rod; 5-1. External cavity entrance; 5-2. Internal cavity entrance; 6. Connecting cavity; 7. Injection head; 7-1. Rotating nozzle; 8. Nozzle housing; 9. Drug preparation tank; 10. Drug storage tank; 11. Rod box; 12. Pressing device; 13. Skid-mounted platform; 14. Slide bar; 15. Injection control mechanism. DETAILED DESCRIPTION

[0030] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0031] The dual-fluid injection integrated system for soil and groundwater remediation provided by the present invention comprises an injection unit, a dispensing unit and an auxiliary unit; the injection unit comprises an injection pump 2, an air compressor 3, an injection rod 4, an injection ejector rod 5, a connecting chamber 6, an injection head 7, a nozzle housing 8 and an injection control mechanism 15; the dispensing unit comprises a medicine configuration slot 9 and a medicine storage slot 10; the auxiliary unit comprises an electric control cabinet 1, a rod box 11, a downward pressure device 12 and a skid-mounted platform 13; the injection unit, the dispensing unit and the auxiliary unit are all integrated on the skid-mounted platform 13; the electric control cabinet 1, the rod box 11, the downward pressure device 12, the injection ejector rod 5, the air compressor 3, the injection pump 2, the medicine storage slot 10, and the medicine configuration slot 9 are sequentially arranged above the skid-mounted platform 13 in a horizontal direction; the injection rod 4 is arranged vertically downward from the skid-mounted platform 13, and the connecting chamber 6, the injection head 7, and the nozzle housing 8 are arranged below the skid-mounted platform 13 in a vertical direction and connected to the injection rod 4.

[0032] Preferably, the injection ejector rod 5 is vertically connected to and penetrates the injection rod 4 downward, the connecting cavity 6 is arranged at the bottom end of the injection rod 4, the bottom of the connecting cavity 6 is connected to the injection head 7, and the nozzle housing 8 is sleeved outside the injection head 7; the downward pressing device 12 is fixed on the skid-mounted platform 13, which is used to install the injection rod 4.

[0033] The auxiliary unit also includes cables and pipelines; the pipelines include drug delivery hoses and compressed air hoses; the cables are arranged between the electric control cabinet 1 and the injection unit, the dispensing unit, and the pressing device 12; the pressing device 12, the injection control mechanism 15, the injection pump 2, and the air compressor 3 are respectively connected to the electric control cabinet 1 through cables; the drug delivery hose and the compressed air hose are arranged between the injection unit and the dispensing unit; the drug preparation slot 9, the drug storage slot 10, and the injection pump 2 are connected in sequence through the drug delivery hose, the outlet of the injection pump 2 is connected to the injection ejector rod 5 through the drug delivery hose, and the outlet of the air compressor 3 is connected to the injection ejector rod 5 through the compressed air hose.

[0034] The skid-mounted platform 13 in the auxiliary unit integrates the whole system and is equipped with universal wheels with self-locking structure at the bottom of both sides for easy movement. The skid-mounted platform 13 as a whole serves as a reaction force overcoming mechanism when pressed down; the pressing device 12 includes a hydraulic cylinder, an electromagnetic regulating valve, an electromagnetic reversing valve, a hydraulic check valve, and a gear pump to complete the pressing of the injection rod 4; the rod box 11 stores the rods including the injection rod 4; the electric control cabinet 1 completes the power access and distribution of the whole system.

[0035] The system uses 380V three-phase power input.

[0036] The medicine dispensing tank 9 in the dispensing unit is provided with a stirrer, a liquid level scale, and a dosing metering mechanism on the top. The medicine storage tank 10 is connected to the medicine dispensing tank 9 to store the prepared medicine liquid, and is connected to the injection unit through a medicine delivery hose.

[0037] The dosing metering mechanism is a cumulative flow meter.

[0038] The injection control mechanism 15 in the injection unit includes a pressure gauge, a flow meter, and a regulating valve. The injection control mechanism 15 is connected to the injection pump 2 and the air compressor 3, and adjusts their flow rates for control. The outlets of the injection pump 2 and the air compressor 3 are both connected to the injection ejector 5 through pipelines. The injection control mechanism 15 is used to adjust the flow rates of the injection pump 2 and the air compressor 3.

[0039] The injection ejector rod 5 in the injection unit is a double-tube structure, with an outer cavity formed between the outer tube and the inner tube, and an inner cavity provided in the inner tube. Two inlet channels are provided on the injection ejector rod 5, which are respectively connected to the air compressor 3 and the injection pump 2, and the lower part of the injection ejector rod 5 is connected to the injection rod 4 through a thread; the injection rod 4 is composed of a number of connections, each of which is a double-tube structure, that is, a double tube; an outer cavity is also formed between the outer tube and the inner tube, and an inner cavity is provided in the inner tube, which is respectively communicated with the outer cavity and the inner cavity of the injection ejector rod 5, and the inner cavity is connected to the injection pump 2 through the injection ejector rod 5, and the outer cavity is connected to the air compressor; the two injection rods 4 are fixed by threaded connection, and the injection rod 4 at the lower end is connected to the connecting cavity 6; the top end of the connecting cavity 6 is connected to the injection rod 4, and the bottom end is connected to the injection head 7.

[0040] The injection head 7 is a two-fluid rotary nozzle driven by compressed air, provided with a rotary nozzle 7-1, and is connected to the connecting cavity 6 by a thread; when the injection head 7 is pressed into the soil layer, it is covered and protected by the nozzle shell 8. The top of the nozzle shell 8 is conical and the rear is cylindrical, and is connected to the connecting cavity 6 by a sliding strip 14.

[0041] The dual-fluid injection integrated system for soil and groundwater remediation provided by the present invention is further described below in conjunction with embodiments.

[0042] Example 1

[0043] A dual-fluid injection integrated system for soil and groundwater remediation is particularly suitable for in-situ remediation of low-permeability strata contamination in petrochemical sites, which includes an injection unit consisting of an injection pump 2, an air compressor 3, an injection rod 4, an injection ejector 5, a connecting chamber 6, a dual-fluid rotary injection head 7, and a nozzle housing 8; a dispensing unit consisting of a drug dispensing tank 9 and a drug storage tank 10; and an auxiliary unit consisting of an electric control cabinet 1, a rod box 11, a downward pressure device 12, and a skid-mounted platform 13. All systems are integrated on the skid-mounted platform 13.

[0044] When the dual-fluid injection integrated system is in the injection working state, the injection ejector 5, the injection rod 4, the connecting chamber 6, and the dual-fluid rotary injection head 7 are connected in sequence through threads. The nozzle housing 8 protects the dual-fluid rotary injection head 7 when pressed in, and slides down to expose the dual-fluid rotary injection head 7 before injection. The above components are all pressed down to the planned repair depth by the pressing device 12. The injection pump 2 and the air compressor 3 are connected to the injection ejector 5 through a hose. The drug storage tank 10 is connected to the injection pump 2 through a drug delivery hose. Prepare the drug in the drug preparation tank 9 according to actual needs. See Figure 1 As shown, the direction indicated by the arrow in the figure is the direction of fluid transmission.

[0045] The formation data obtained in the preliminary exploration and the calculated parameters such as injection volume, flow rate, pressure, etc. are input by the injection control mechanism 15, and the parameter adjustment is realized through the actuators on the injection pump 2 and the air compressor 3 to achieve precise injection for each formation and depth, effectively improve the many in-situ injection problems caused by formation heterogeneity, and avoid the waste of reagents and potential secondary pollution caused by slurry.

[0046] When the injection unit rod is pressed down, the connecting cavity 6 and the nozzle housing 8 are in a closed state. Figure 2 As shown. A gas-liquid outlet tapered end is provided in the connecting chamber 6, which is connected to the dual-fluid rotary injection head 7, so that the diameter of the gas and liquid pipes is reduced to the same size as the inlet of the dual-fluid rotary injection head 7. The lower end of the nozzle shell 8 is a cone, and the outer diameter is the same as the connecting chamber 6, which is conducive to pressing down to drill into the soil layer. When pressed down, the nozzle shell 8 is subjected to the vertical upward force of the soil layer below, and slides upward through the slide bar 14, and contacts and closes with the connecting chamber 6, so that the dual-fluid rotary injection head 7 is hidden in the nozzle shell 8 when drilling, preventing the soil from being squeezed and contacting the dual-fluid rotary injection head 7 during drilling, and avoiding possible blockage, damage or uneven rotation of the rotating nozzle 7-1.

[0047] The cross section of the dual fluid rotary injection head 7 is shown in Figure 3 As shown, the rotating nozzle 7-1 is oriented in the tangential direction of the center. Compressed gas is ejected through the rotating nozzle 7-1, and its reaction force drives the nozzle to rotate, helping the repair agent to be ejected through the nozzle, realizing the mechanical atomization and uniform dispersion of the agent, and further forming smaller droplets under the influence of the compressed gas, realizing the diffusion of the repair agent in the low permeability area and the air-encapsulating zone.

[0048] The overall structure of the injection unit rod during injection is shown in Figure 4As shown. Through the overall lifting of the rod, the nozzle housing 8 slides down along the slide bar 14 due to gravity and separates from the connecting cavity 6, and is suspended below the connecting cavity 6 through the slide bars 14 on both sides, so that the double-fluid rotating injection head 7 originally hidden in the nozzle housing 8 is exposed, allowing the injection repair work to be carried out, and a small cavity is formed between the connecting cavity 6 and the nozzle housing 8 to prevent the injection head 7 from contacting the soil and causing rotation problems. The outer cavity inlet 5-1 and the inner cavity inlet 5-2 on the injection ejector 5 are respectively connected to the air compressor 3 and the injection pump 2 through a hose, so that the compressed air and the repair agent enter the outer and inner tubes of the injection ejector 5 and the injection rod 4 respectively and flow down along the injection rod 4, and enter the double-fluid rotating injection head 7 with a smaller diameter through the tapered end in the connecting cavity 6, driving the rotation of the rotating nozzle 7-1 and spraying through it. The number of injection rods 4 will be determined by the injection depth. The rotation direction of the rotating nozzle 7-1 is perpendicular to the interface direction, and it rotates horizontally when the injection rod 4 is vertically pressed in.

[0049] The electric control cabinet 1 is an outdoor expandable electric control cabinet, which includes the system power supply access and control module; the flow range of the injection pump 2 is 0-2m 3 / h, the pressure range is 0-2.5MPa; the flow rate of air compressor 3 is 1-5m 3 / min, pressure is 0.4-0.7MPa; the injection rate of the agent is generally controlled at 10-35L / min; the diameter of the agent configuration tank 9 is 1m, and the height is 1m; the diameter of the agent storage tank 10 is 1m, and the height is 1m; the size of the skid-mounted platform 13 is 6m×2.4m. For petrochemical site pollution, the typical remediation method is in-situ chemical oxidation technology, so the remediation agent is preferably Fenton reagent or activated persulfate solution, and the injection rod 4, injection ejector 5, connecting cavity 6, dual-fluid rotary injection head 7, nozzle housing 8 and other systems in contact with the oxidative remediation agent need to use corrosion-resistant materials, preferably 316L stainless steel.

[0050] Example 2

[0051] A dual-fluid injection integrated system for soil and groundwater remediation, the working process of which includes:

[0052] Step 1: Use a lifting device to lift and place the skid-mounted platform 13 to the repair site.

[0053] Step 2, move the skid-mounted platform 13 to the injection point, align the pressing device 12 with the injection point, and lock the self-locking structure on the universal wheel; turn on the power, start the mixer in the medicine preparation tank 9 to start preparing the medicine;

[0054] Step 3, assemble the dual-fluid rotary injection head 7, connect the cavity 6 and the nozzle housing 8, and the injection rod 4 and fix them to the pressing device 12; start the pressing device 12 to start pressing; when the first injection rod 4 is pressed down, release the fixation, connect and fix the second injection rod 4 under the pressing device 12, and press again;

[0055] Step 4, repeat step 3 until the actual pressing depth exceeds the designed maximum injection depth by about 0.5m, fix the injection rod 4, and assemble the injection ejector rod 5 on the uppermost injection rod 4;

[0056] Step 5, slightly lift the entire injection rod so that the dual-fluid rotary injection head 7 reaches the designed injection depth, and the nozzle housing 8 slides down along the slide bar 14 to expose the injection head 7;

[0057] Step 6, connecting the injection pump 2, the air compressor 3 and the injection ejector 5; the air compressor 3 is connected to the outer cavity of the injection ejector 5, and the injection pump 2 is connected to the inner cavity of the injection ejector 5;

[0058] Step 7, start the injection unit; the injection pump 2 and the air compressor 3 inject the medicine and compressed air into the inner and outer cavities of the injection ejector 5 and the injection rod 4 respectively, and enter the connecting cavity 6 along the injection rod 4; the medicine and compressed air enter the dual-fluid rotary injection head 7 from the connecting cavity 6, and the compressed air drives the rotary nozzle 7-1 to rotate, and the medicine is atomized and then sprayed out;

[0059] Step 8, lift the injection rod 4 to the next injection depth, repeat steps 6, 7, and 8 until the injection of the medicine is completed at all designed injection depths of the injection point;

[0060] Step 9, repeat steps 2 to 8 until all designed injection points have completed the injection of the drug.

[0061] The dual-fluid injection integrated system for soil and groundwater remediation provided by the present invention can use a set of integrated systems to complete the in-situ injection remediation of soil and groundwater, achieve the dual-fluid injection of liquid agents and gases at the same time, enhance the dispersion, diffusion, penetration ability of the agents and the mixing ability with underground pollutants, thereby improving the remediation efficiency and enhancing the remediation effect. When in use, the integrated skid-mounted system is transferred to the vicinity of the injection point, and the injection rod is directly pressed to the underground remediation depth using a downward pressure device; the gas and liquid dual-fluid injection uses a double tube rotation injection connected to the injection rod by an air compressor and an injection pump, and the compressed air drives the nozzle to rotate. At the same time, the gas is used to cut the soil to achieve liquid agent atomization, which helps the liquid agent to be smoothly dispersed in the low-permeability formation and fully mixed and contacted with the pollutants. It can be applied to the pollution remediation of the aeration zone soil and the saturated zone soil and groundwater at the same time.

[0062] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A dual-fluid injection integrated system for soil and groundwater remediation, characterized in that: The integrated system comprises an injection unit, a dispensing unit and an auxiliary unit; The injection unit comprises an injection pump, an air compressor, an injection rod, an injection ejector rod, a connecting cavity, an injection head, a nozzle housing and an injection control mechanism; The medicine dispensing unit comprises a medicine dispensing tank and a medicine storage tank; The auxiliary unit includes an electric control cabinet, a rod box, a pressing device and a skid-mounted platform; The injection unit, dispensing unit and auxiliary unit are all integrated on the skid-mounted platform; The electric control cabinet, rod box, downward pressure device, injection ejector, air compressor, injection pump, medicine storage tank, and medicine configuration tank are arranged in sequence above the skid-mounted platform in the horizontal direction; the injection rod is arranged vertically downward from the skid-mounted platform, and the connecting cavity, injection head, and nozzle housing are arranged vertically below the skid-mounted platform and connected to the injection rod; The injection ejector rod is vertically connected to and penetrates the injection rod downward, the connection cavity is arranged at the bottom end of the injection rod, the bottom of the connection cavity is connected to the injection head, and the nozzle housing is sleeved outside the injection head; In the injection unit, the injection ejector rod is a double-tube structure, an outer cavity is formed between the outer tube and the inner tube, an inner cavity is provided in the inner tube, two inlet channels are provided on the injection ejector rod, which are respectively connected to the air compressor and the injection pump, and the lower part of the injection ejector rod is connected to the injection rod through a thread; the injection rod is composed of a plurality of connections, each of which is a double-tube structure, an outer cavity is also formed between the outer tube and the inner tube, an inner cavity is provided in the inner tube, which are respectively communicated with the outer cavity and the inner cavity of the injection ejector rod, and the inner cavity is connected to the injection pump through the injection ejector rod, and the outer cavity is connected to the air compressor; the two injection rods are fixed by threaded connection, and the injection rod at the lower end is connected to the connecting cavity; a gas-liquid outlet tapered end is provided in the connecting cavity, which is communicated with the injection head; The injection head is a dual-fluid rotary nozzle driven by compressed air, which is connected to the connecting cavity through threads; when the injection head is pressed into the soil layer, it is covered and protected by the nozzle shell. The top of the nozzle shell is conical and the rear is cylindrical, and is connected to the connecting cavity through a sliding strip.

2. The dual fluid injection integrated system for soil and groundwater remediation according to claim 1 is characterized in that: The pressing device is fixed on the skid-mounted platform and is used for installing the injection rod.

3. The dual fluid injection integrated system for soil and groundwater remediation according to claim 1 is characterized in that: The auxiliary unit also includes cables and pipelines; the pipelines include drug delivery hoses and compressed air hoses; the cables are arranged between the electric control cabinet and the injection unit, the dispensing unit, and the pressing device; the pressing device, the injection control mechanism, the injection pump, and the air compressor are respectively connected to the electric control cabinet through cables; the drug delivery hose and the compressed air hose are arranged between the injection unit and the dispensing unit; the medicine preparation tank, the medicine storage tank, and the injection pump are connected in sequence through the drug delivery hose, the outlet of the injection pump is connected to the injection ejector rod through the drug delivery hose, and the outlet of the air compressor is connected to the injection ejector rod through the compressed air hose.

4. The dual fluid injection integrated system for soil and groundwater remediation according to claim 3 is characterized in that: In the auxiliary unit, the skid-mounted platform integrates the entire system and is equipped with universal wheels with self-locking structures at the bottom of both sides; the downward pressure device includes a hydraulic cylinder, an electromagnetic regulating valve, an electromagnetic reversing valve, a hydraulic check valve, and a gear pump to complete the downward pressure on the injection rod; the rod box stores the rods including the injection rod; the electric control cabinet completes the overall power access and distribution of the system.

5. The dual fluid injection integrated system for soil and groundwater remediation according to claim 4 is characterized in that: The system adopts 380V three-phase power input.

6. The dual fluid injection integrated system for soil and groundwater remediation according to claim 3 is characterized in that: In the medicine dispensing unit, a stirrer is arranged in the medicine dispensing tank, and a liquid level scale is provided, and a medicine adding metering mechanism is also arranged on the top.

7. The dual-fluid injection integrated system for soil and groundwater remediation according to claim 6, characterized in that: The dosing metering mechanism is a cumulative flow meter.

8. The dual fluid injection integrated system for soil and groundwater remediation according to claim 3 is characterized in that: In the injection unit, the injection control mechanism includes a pressure gauge, a flow meter, and a regulating valve. The injection control mechanism is connected to the injection pump and the air compressor, and adjusts their flow rates respectively for control.

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