A device and process for the regeneration of activated carbon by direct overheat steam coupled pressure release

Abstract

The present application relates to a kind of active carbon regeneration device and process of direct current overheating steam coupling pressure release, active carbon regeneration device includes steam boiler, mixed delivery equipment, direct current pressure heating system and pressure release system, the steam boiler is connected to mixed delivery equipment with pressure steam, the mixed delivery equipment is also connected active carbon storehouse, the outlet of mixed delivery equipment is connected with the inlet of direct current pressure heating system, the outlet of direct current pressure heating system is connected with pressure release system, and the pressure release system is equipped with steam condensing device and active carbon collection device.The present application is combined with overheating steam, fast pressure release by rotating pressure vessel, realizes the one-step completion of pollutant removal and active carbon activation, and improves regeneration efficiency and active carbon regeneration quality.

Description

Technical Field

[0001] This invention belongs to the field of activated carbon regeneration technology, specifically relating to an activated carbon regeneration device and process using DC superheated steam coupled with pressure release. It is suitable for the efficient regeneration of saturated activated carbon, especially for the regeneration of activated carbon that treats adsorbates such as organic pollutants and heavy metal ions. Background Technology

[0002] Activated carbon, as a highly efficient adsorption material, is widely used in water treatment, waste gas treatment, food processing, and other fields. However, activated carbon loses its adsorption capacity after becoming saturated. Direct disposal not only wastes resources but may also cause secondary pollution due to adsorbate leakage. Therefore, activated carbon regeneration technology is key to achieving its recycling and reducing application costs.

[0003] Currently, mainstream activated carbon regeneration methods include thermal regeneration, chemical regeneration, and biological regeneration. Among them, thermal regeneration is widely used due to its high regeneration efficiency and wide applicability. Its principle is to desorb and decompose the pollutants adsorbed by the activated carbon through heating, and then restore the pore structure of the activated carbon through activation. Traditional thermal regeneration processes typically consist of three stages: drying, carbonization, and activation. These stages need to be carried out step-by-step under different equipment or operating conditions, resulting in problems such as complex process flow, high energy consumption, and long regeneration cycles.

[0004] While existing superheated steam regeneration technologies can accelerate pollutant desorption by utilizing the high temperature and pressure characteristics of steam, they mostly employ fixed-bed reactors, resulting in uneven contact between activated carbon and steam and a tendency for incomplete regeneration in certain areas. Furthermore, pollutant removal and activated carbon pore activation typically require separate control of temperature and pressure parameters, making it difficult to achieve a one-step process and thus limiting regeneration efficiency. In addition, the pressure release process in traditional processes is relatively gradual, failing to utilize the "detonation" effect generated by a sudden pressure drop to further strip away stubborn adsorbates and expand pores, thus requiring improvement in activation effectiveness.

[0005] Therefore, developing a regeneration process and device that can achieve one-step removal of pollutants and activation of pores in activated carbon, with high regeneration efficiency and low energy consumption, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to provide an activated carbon regeneration device and process using DC superheated steam coupled with pressure release. By combining a rotating pressure vessel with the introduction of superheated steam and rapid pressure release, pollutant removal and activated carbon activation can be completed in one step, thereby improving regeneration efficiency and activated carbon regeneration quality.

[0007] To achieve the above objectives, the present invention employs the following technical solution: An activated carbon regeneration device with DC superheated steam coupled to pressure release includes a steam boiler, a mixing and conveying device, a DC pressure heating system, and a pressure release system. The steam boiler supplies pressurized steam to the mixing and conveying device, which is also connected to an activated carbon silo. The outlet of the mixing and conveying device is connected to the inlet of the DC pressure heating system, and the outlet of the DC pressure heating system is connected to the pressure release system. The pressure release system is equipped with a steam condensation device and an activated carbon collection device.

[0008] The DC pressure heating system includes a spiral coil and a burner. The spiral coil has a membrane spiral cylindrical wall structure with an insulation shell on the outside and a hollow combustion chamber on the inside. The spiral coil inlet is connected to the outlet of the mixing and conveying equipment, and the spiral coil outlet is connected to the pressure relief system. The burner is used to ignite the combustion chamber.

[0009] Temperature and pressure sensors are installed in both the combustion chamber and the spiral coil.

[0010] The spiral coil is a vertical spiral coil.

[0011] The spiral coil is made of seamless steel pipe, and the outlet is a hyperbolic tapered nozzle with an outlet diameter greater than 25 times the diameter of the activated carbon particles.

[0012] The activated carbon collecting device is located above the steam condensing device. The activated carbon collecting device is an inclined plate with an inclination angle of 60 degrees or more and has multiple holes.

[0013] The bottom of the steam condensing device is connected to a condensate collector via a non-condensable steam pipeline.

[0014] It also includes a non-condensable gas recycling system, which includes a vacuum pump and pipelines. The vacuum pump is connected to a pressure relief system and the secondary air section of the boiler burner via pipelines.

[0015] A process for regenerating activated carbon using a DC superheated steam coupled with pressure release device specifically includes: 1) Steam boilers are used to generate superheated steam at a temperature of 350-400℃ and a pressure of 0.3-0.5MPa.

[0016] 2) In the mixing and conveying equipment, superheated steam is used as the conveying medium to mix with activated carbon and carry the activated carbon into the spiral coil of the DC pressure heating system.

[0017] 3) A mixture of hot steam and activated carbon passes through the inside of the spiral coil, and the fuel is used to ignite and heat the spiral coil in the combustion chamber.

[0018] 4) The activated carbon collection device is under a slight positive pressure of 0 to 20 Pa above it and under a negative pressure of -50 kPa to -10 kPa below it. The negative pressure is achieved by a steam condensation device. The mixture of hot steam and activated carbon is injected into the pressure release system from the spiral coil. The activated carbon falls into the activated carbon collection device, and the superheated steam enters the steam condensation device below and is condensed into liquid.

[0019] 5) Non-condensable steam in the steam condensing unit is extracted by a vacuum pump and transported to the secondary air section of the steam boiler burner for combustion treatment.

[0020] The activated carbon has a particle size of 0.5–5 mm.

[0021] Compared with the prior art, the beneficial effects of the present invention are: 1) The present invention has a short process flow, fewer equipment, low failure rate, and stable finished product quality. By coupling the high-temperature desorption of superheated steam with the "detonation" activation of sudden pressure drop, the drying, carbonization, and activation steps are eliminated, simplifying the process flow and shortening the regeneration cycle by 30% to 50%.

[0022] 2) The present invention has high and uniform regeneration efficiency: the rotary pressure vessel combined with the spiral guide allows the activated carbon to fully contact the superheated steam, avoiding the problem of incomplete local regeneration of the fixed bed. The adsorption capacity recovery rate of the activated carbon after regeneration can reach 85% to 95%.

[0023] 3) This invention has good sealing performance, no mechanical open or semi-open equipment, and all transportation is done through pipelines, which eliminates the possibility of pollutant spillage and has a small environmental impact.

[0024] 4) This invention has low energy consumption and is environmentally friendly: superheated steam is used as the regeneration medium, which has high heat transfer efficiency and the condensate can be recycled; the pollutants generated during the pressure release process are discharged in compliance with standards after being incinerated at high temperature in the boiler, which is a thorough treatment and has no secondary pollution.

[0025] 5) The device of the present invention has a compact structure: it integrates feeding, regeneration, activation and discharging functions, occupies a small area, is easy to operate and can be easily automated.

[0026] 6) The two-stage pressure vessel of this invention avoids air leakage into the system, which would increase the amount of non-condensable vapor in the system; it also makes it easy to judge the goodness of the discharge sealing system.

[0027] 7) The present invention can control the pressure release intensity by controlling the condensation intensity of the steam condensation device and in conjunction with a two-stage pressure vessel.

[0028] 8) This invention does not involve the combustion process of activated carbon. The heat source is external heating, so the activated carbon is not burned off. The regeneration economy of activated carbon is superior to that of existing technologies. Attached Figure Description

[0029] Figure 1 This is a process flow diagram of the present invention.

[0030] In the diagram: 1. Steam boiler; 2. Mixing and conveying equipment; 2-1. Activated carbon silo; 3. DC pressure heating system; 3-1. Seamless steel pipe; 3-2. Combustion chamber; 3-3. Insulated outer shell; 3-4. Burner; 4. Pressure relief system; 4-1. Pressure relief container; 4-2. Activated carbon collection device; 4-3. Activated carbon sealed outlet; 4-4. Steam condensation device; 4-5. Condensate collector; 5. Vacuum pump; 6. Water treatment device. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings: like Figure 1 As shown, an activated carbon regeneration device with DC superheated steam coupled to pressure release includes a steam boiler 1, a mixing and conveying device 2, a DC pressure heating system 3, and a pressure release system 4. The steam boiler 1 supplies pressurized steam to the mixing and conveying device 2. The mixing and conveying device 2 is also connected to an activated carbon chamber 2-1. The outlet of the mixing and conveying device 2 is connected to the inlet of the DC pressure heating system 3. The outlet of the DC pressure heating system 3 is connected to the pressure release system 4. The pressure release system 4 is equipped with a steam condensation device 4-4 and an activated carbon collection device 4-2.

[0032] The DC pressure heating system 3 includes a spiral coil and a burner 3-4. The spiral coil has a membrane spiral cylindrical wall structure, with an insulation shell 3-3 on the outer side of the cylinder and a hollow combustion chamber 3-2 on the inner side of the cylinder. The spiral coil inlet is connected to the outlet of the mixing and conveying equipment 2, and the spiral coil outlet is connected to the pressure relief system 4. The burner 3-4 is used to ignite and heat the combustion chamber 3-2.

[0033] The spiral coil is a vertical spiral coil. The DC pressure heating system 3 is a pressure vessel made by rotating and winding seamless steel pipe 3-1. It has a membrane wall structure and is generally vertical, meaning that the mixture spirals upward from bottom to top.

[0034] The spiral coil is made of seamless steel pipe 3-1, and a mixture of superheated steam and activated carbon flows inside the seamless steel pipe 3-1. The outlet of the seamless steel pipe 3-1 is a hyperbolic tapered nozzle with an outlet diameter greater than 25 times the diameter of the activated carbon particles.

[0035] The pressure vessel, constructed using seamless steel pipe 3-1, features a membrane-type water spiral cylindrical wall structure. An insulated outer shell 3-2 surrounds the cylinder, while the inner side houses a hollow combustion chamber 3-3. A mixture of hot steam and activated carbon flows through the inner side of the seamless steel pipe 3-1. The bottom of the combustion chamber 3-2 is heated by a burner 3-4 burning fuels such as natural gas. The inlet of the seamless steel pipe 3-1 receives the superheated steam and activated carbon mixture, while the outlet connects to a pressure relief system 4. Temperature and pressure sensors are installed within both the combustion chamber 3-2 and the seamless steel pipe 3-1.

[0036] The pressure relief system 4 includes a pressure relief container 4-1, an activated carbon collection device 4-2, a steam condensation device 4-4, a condensate collector 4-5, and an activated carbon sealed outlet 4-3. The pressure relief container 4-1 is installed at the pressure relief port of the DC pressure heating system 3. The bottom of the pressure relief container 4-1 is connected to the steam condensation device 4-4 and the condensate collector 4-5 to collect the steam discharged during the pressure relief process and provide a negative pressure environment. The activated carbon collection device 4-2 is used to collect the activated carbon particles released from the pressure relief container 4-1 and allow steam to pass through.

[0037] The activated carbon collecting device 4-2 is positioned above the steam condensing device 4-4. Above the activated carbon collecting device 4-1 is a slight positive pressure of 0–20 Pa, and below it is a negative pressure of -50 kPa to -10 kPa. The activated carbon collecting device 4-2 is generally an inclined plate with an inclination angle greater than or equal to 60 degrees. The inclined plate has multiple small holes for steam to pass through. The inclined plate and the activated carbon layer form a material layer resistance, achieving pressure gradient control.

[0038] The bottom of the steam condensing device 4-4 is connected to the condensate collector 4-5 via a non-condensable steam pipeline.

[0039] The mixing and conveying system includes a mixing and conveying device 2 and an activated carbon bin 2-1. The activated carbon in the activated carbon bin 2-1 enters the conveying pipeline through the mixing and conveying device 2. The conveying medium for the activated carbon in the mixing and conveying device 2 is steam, and the steam and activated carbon are mixed in this device.

[0040] It also includes a non-condensable gas recycling system, which includes a vacuum pump 5 and pipelines. The vacuum pump 5 is connected to the pressure relief system 4 and the secondary air section of the burner of the steam boiler 1 via pipelines. Non-condensable steam is extracted from the steam condensing device 4-4 of the pressure relief system 4 by the vacuum pump 5 and transported to the secondary air section of the burner of the steam boiler 1 for combustion treatment.

[0041] A process for regenerating activated carbon using a DC superheated steam coupled with pressure release device, specifically including: 1) Steam boiler 1 is used to generate superheated steam at a temperature of 350-400℃ and a pressure of 0.3-0.5MPa.

[0042] 2) In the mixing and conveying device 2, superheated steam is used as the conveying medium to mix with activated carbon and carry the activated carbon into the spiral coil of the DC pressure heating system 3.

[0043] 3) A mixture of hot steam and activated carbon passes through the inside of the spiral coil, and the spiral coil is ignited and heated in the combustion chamber 3-2 using fuels such as natural gas.

[0044] 4) The activated carbon collecting device 4-2 is under a slight positive pressure of 0 to 20 Pa above it and under a negative pressure of -50 kPa to -10 kPa below it. The negative pressure is achieved by the steam condensing device 4-4. The mixture of hot steam and activated carbon is injected into the pressure release system 4 from the spiral coil. The activated carbon falls into the activated carbon collecting device 4-2 and the superheated steam enters the steam condensing device 4-4 below and condenses into liquid. 5) The non-condensable steam in the steam condensing device 4-4 is extracted by the vacuum pump 5 and transported to the secondary air section of the burner of the steam boiler 1 for combustion treatment.

[0045] Specifically, the process of this invention is achieved through the following five stages: 1. Pressure establishment stage: Start steam boiler 1 to generate superheated steam at a temperature of 350-400℃ and a pressure of 0.3-0.5MPa. The superheated steam enters the conveying system to preheat the pipelines of the conveying system and establish pressure.

[0046] 2. Feeding stage: The adsorption-saturated activated carbon (particle size of 0.5-5mm) inside the activated carbon bin 2-1 is added to the conveying pipeline through the mixing and conveying equipment 2 and steam.

[0047] 3. Steam Heating Stage: Start the burner 3-4 of the DC pressure heating system 3 to heat the activated carbon and steam two-phase flow medium that enters the seamless steel pipe 3-1 of the DC pressure heating system 3. The high-temperature steam desorbs and decomposes the organic pollutants adsorbed by the activated carbon, and the pollutants flow with the steam.

[0048] 4. Pressure Release and Activation Stage: Activated carbon arrives at the outlet of the DC pressure heating system 3 with steam and randomly enters the pressure relief container 4-1. The pressure release system 4 is a negative pressure device, and the negative pressure is achieved through the steam condensation device 4-4 and the non-condensable steam recycling system. During the rapid pressure drop, the steam adsorbed inside the activated carbon expands rapidly, producing a "detonation" effect, which not only further strips away stubborn adsorbates but also expands the pore structure of the activated carbon, thus activating it. The water-insoluble pollutants generated during the pressure release process are sent to the non-condensable gas recycling system via vacuum pump 5 and then to the combustion chamber of the steam boiler 1 for combustion treatment. Water-soluble pollutants are discharged to the water treatment system 6 with the condensate.

[0049] 5. Discharge stage: The activated carbon is rapidly dried under negative pressure and high temperature conditions and discharged from the activated carbon sealed discharge port 4-3 of the pressure release system 4.

[0050] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An activated carbon regeneration device with DC superheated steam coupling and pressure release, characterized in that, The system includes a steam boiler, a mixing and conveying device, a DC pressure heating system, and a pressure relief system. The steam boiler supplies pressurized steam to the mixing and conveying device, which is also connected to an activated carbon chamber. The outlet of the mixing and conveying device is connected to the inlet of the DC pressure heating system, and the outlet of the DC pressure heating system is connected to the pressure relief system. The pressure relief system is equipped with a steam condensation device and an activated carbon collection device.

2. The activated carbon regeneration device with DC superheated steam coupling and pressure release according to claim 1, characterized in that, The DC pressure heating system includes a spiral coil and a burner. The spiral coil has a membrane spiral cylindrical wall structure with an insulation shell on the outside and a hollow combustion chamber on the inside. The spiral coil inlet is connected to the outlet of the mixing and conveying equipment, and the spiral coil outlet is connected to the pressure relief system. The burner is used for ignition and combustion in the combustion chamber.

3. The activated carbon regeneration device with DC superheated steam coupling and pressure release according to claim 2, characterized in that, Temperature and pressure sensors are installed in both the combustion chamber and the spiral coil.

4. The activated carbon regeneration device with DC superheated steam coupling and pressure release according to claim 2, characterized in that, The spiral coil is a vertical spiral coil.

5. The activated carbon regeneration device with DC superheated steam coupling and pressure release according to claim 2, characterized in that, The spiral coil is made of seamless steel pipe, and the outlet is a hyperbolic tapered nozzle with an outlet diameter greater than 25 times the diameter of the activated carbon particles.

6. The activated carbon regeneration device with DC superheated steam coupling and pressure release according to claim 1, characterized in that, The activated carbon collecting device is located above the steam condensing device. The activated carbon collecting device is an inclined plate with an inclination angle of 60 degrees or more and has multiple holes.

7. The activated carbon regeneration device with DC superheated steam coupling and pressure release according to claim 1, characterized in that, The bottom of the steam condensing device is connected to a condensate collector via a non-condensable steam pipeline.

8. The activated carbon regeneration device with DC superheated steam coupling and pressure release according to claim 1, characterized in that, It also includes a non-condensable gas recycling system, which includes a vacuum pump and pipelines. The vacuum pump is connected to a pressure relief system and the secondary air section of the boiler burner via pipelines.

9. A process for regenerating activated carbon using a DC superheated steam coupled with pressure release activated carbon regeneration device as described in any one of claims 1-8, characterized in that, Specifically, it includes: 1) Steam boilers are used to generate superheated steam at a temperature of 350–400℃ and a pressure of 0.3–0.5MPa; 2) In the mixing and conveying equipment, superheated steam is used as the conveying medium to mix with activated carbon and carry the activated carbon into the spiral coil of the DC pressure heating system; 3) A mixture of hot steam and activated carbon passes through the inside of the spiral coil, and the fuel is used to ignite and heat the spiral coil in the combustion chamber; 4) In the pressure release system: the upper part of the activated carbon collection device is a slight positive pressure of 0 to 20 Pa, and the lower part of the activated carbon collection device is a negative pressure of -50 kPa to -10 kPa. The negative pressure is achieved by the steam condensation device. The mixture of hot steam and activated carbon is injected into the pressure release system from the spiral coil. The activated carbon falls into the activated carbon collection device, and the superheated steam enters the steam condensation device below and condenses into liquid. 5) Non-condensable steam in the steam condensing unit is extracted by a vacuum pump and transported to the secondary air section of the steam boiler burner for combustion treatment.

10. The process for activated carbon regeneration using a DC superheated steam coupled with pressure release activated carbon regeneration device according to claim 9, characterized in that, The activated carbon has a particle size of 0.5–5 mm.

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