Internal heat regeneration system and regeneration method for waste powdered activated carbon

Abstract

The present application provides an internal heat regeneration system for waste powdered activated carbon, comprising a feeding system, an internal heat rotary regeneration furnace, a burner, a flue gas cooler, a bag-type trap, a choke fan, a choke device, a secondary combustion chamber, a waste heat boiler, and an exhaust gas treatment system; a gas cooler is provided at the tail section of the internal heat rotary regeneration furnace, and the heat from the powdered regenerated carbon and the flue gas in the gas cooler is transferred to the circulating cooling water for cooling; the top air outlet of the gas cooler is connected to the air inlet of the flue gas cooler, and the heat from the flue gas in the flue gas cooler is transferred to the circulating cooling water for cooling; the air outlet of the flue gas cooler is connected to the air inlet of the bag-type trap, and the bottom outlet of the bag-type trap is used to discharge the powdered regenerated carbon. A method for regenerating waste powdered activated carbon is also provided, using the above-mentioned internal heat regeneration system. The method solves the problem that powdered activated carbon is difficult to regenerate, and has high thermal efficiency, high regeneration yield, high safety factor, long equipment service life, and low regeneration cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of activated carbon regeneration equipment and methods, and in particular relates to an internal heat regeneration system and a regeneration method for waste powdered activated carbon. Background Art

[0002] Currently, the regeneration cost of spent activated carbon is high. The regeneration of powdered activated carbon has not yet been mass-produced. In other words, the regeneration of powdered activated carbon is difficult. The main difficulties in regenerating powdered activated carbon are:

[0003] (1) The physical state of powdered activated carbon is powder. Generally, the powder on the market is 350 mesh fine powder. During the regeneration process, if the oxygen content is not well controlled, it is easy to burn out. Powdered activated carbon is a fine powder. If the oxygen content in the regeneration furnace is greater than 10%, the powdered activated carbon will be easily burned out. The control of oxygen content in the regeneration furnace is an extremely complicated process.

[0004] (2) The regeneration rate of powdered activated carbon after high-temperature regeneration is low, and the product quality is difficult to control. This is because the current process makes it difficult to control the regeneration temperature during operation. For example, a regeneration temperature of 850°C is required during the regeneration process. However, in the actual process, after the temperature in the regeneration furnace reaches 850°C, this temperature is uncontrollable. As the powdered activated carbon is continuously added, the temperature will continue to rise, and the carbon loss will increase, resulting in a low regeneration rate. At the same time, the ash content of the product continues to increase, and the product quality is difficult to control.

[0005] (3) At present, the regeneration equipment for waste powdered activated carbon is very simple and cannot be scaled up and industrialized. The temperature is difficult to control during the regeneration process, which makes it easy to burn out the regeneration equipment and shorten the life of the regeneration equipment. Summary of the Invention

[0006] The purpose of the present invention is to provide an internal heat regeneration system and a regeneration method for waste powdered activated carbon.

[0007] In order to achieve the above object, the technical solution of the present invention is as follows:

[0008] An internal heat regeneration system for waste powdered activated carbon, comprising a feeding system, an internal heat rotary regeneration furnace, a burner, a flue gas cooler, a bag filter, a choke fan, a secondary combustion chamber, a waste heat boiler, and an exhaust gas treatment system;

[0009] The discharge port of the feeding system is communicated with the feeding port of the furnace head of the internal heat rotary regeneration furnace, so that the feeding system supplies the waste powdered activated carbon to the feeding port of the furnace head of the internal heat rotary regeneration furnace;

[0010] The internal heat rotary regeneration furnace is a horizontal furnace and is inclined downward by 2-4 degrees from the furnace head to the furnace tail;

[0011] The internal heat rotary regeneration furnace is provided with a burner at the furnace head;

[0012] The tail section of the internal heat rotary regeneration furnace is provided with a gas cooler, which is a shell and tube heat exchanger structure. The tail end of the furnace body of the internal heat rotary regeneration furnace is sealed and welded with the head end of the gas cooler so that the furnace of the furnace body of the internal heat rotary regeneration furnace and the tube side of the gas cooler are interconnected. The high-temperature powdered regenerated carbon and flue gas move in the tube side of the gas cooler, and circulating cooling water flows in the shell side of the gas cooler. The heat on the powdered regenerated carbon and the flue gas in the gas cooler is transferred to the circulating cooling water so that the powdered regenerated carbon and the flue gas are cooled and lowered in temperature.

[0013] The internal heat rotary regeneration furnace is divided into 4 sections, namely the drying section, the carbonization and pyrolysis section, the activation section, and the non-oxidation cooling section in the gas cooler;

[0014] The top air outlet at the tail end of the gas cooler is connected to the air inlet of the flue gas cooler, and the bottom discharge port at the tail end of the gas cooler is connected to the top feed port of the water-cooled converter;

[0015] The flue gas cooler is a shell and tube heat exchanger structure. The high-temperature flue gas moves in the tube side of the flue gas cooler, and the circulating cooling water flows in the shell side of the flue gas cooler. The heat of the flue gas in the flue gas cooler is transferred to the circulating cooling water, so that the flue gas is cooled down.

[0016] The air outlet of the flue gas cooler is connected to the air inlet of the bag-type catcher, the air outlet of the bag-type catcher is connected to the air inlet of the choke fan, the bottom discharge port of the bag-type catcher is used to discharge powdered regenerated carbon, the air outlet of the choke fan is connected to the air inlet of the secondary combustion chamber, the air outlet of the secondary combustion chamber is connected to the air inlet of the waste heat boiler, and the air outlet of the waste heat boiler is connected to the air inlet of the exhaust gas treatment system.

[0017] Preferably, the feeding system includes a feeding bin, a closed conveyor, a buffer bin and a screw feeder;

[0018] The bottom discharge port of the feeding bin is connected to the bottom feed port of the closed conveyor, the top discharge port of the closed conveyor is connected to the top feed port of the buffer bin, the bottom discharge port of the buffer bin is connected to the right feed port of the screw feeder, and the left discharge port of the screw feeder is connected to the furnace of the furnace head of the internal heat rotary regeneration furnace.

[0019] Preferably, the tail gas treatment system includes a quenching tower, a dry deacidification tower, a bag filter, a spray tower, a main fan and an exhaust chimney;

[0020] The air outlet of the waste heat boiler is connected to the air inlet of the quenching tower, the air outlet of the quenching tower is connected to the air inlet of the dry deacidification tower, the air outlet of the dry deacidification tower is connected to the air inlet of the bag-type dust collector, the air outlet of the bag-type dust collector is connected to the bottom air inlet of the spray tower, the top air outlet of the spray tower is connected to the air inlet of the main fan, the air outlet of the main fan is connected to the bottom air inlet of the exhaust chimney, and the top air outlet of the exhaust chimney is used for exhausting.

[0021] A method for regenerating waste powdered activated carbon, using any one of the above-mentioned internal heat regeneration systems for waste powdered activated carbon;

[0022] During the regeneration process, the temperature of the drying section is 300-500°C, which thermally decomposes and evaporates the water and low-boiling-point organic matter in the waste powdered activated carbon.

[0023] The temperature of the carbonization and pyrolysis section is 500-700°C, which decomposes the organic matter adsorbed in the waste powdered activated carbon at high temperature. The combustible gas generated by the pyrolysis reacts with oxygen in the internal heat rotary regeneration furnace to release heat, carbonizing the adsorbed volatile substances and high-boiling-point organic matter remaining in the pores of the activated carbon. The high-boiling-point organic matter is decomposed and carbonized in the adsorbed state and remains in the form of fixed carbon.

[0024] The temperature of the activation section is 700°C-850°C. In this section, the powdered activated carbon is fully in contact with water vapor. In the presence of oxygen, fuel gas and water vapor, the residual carbon generated during the carbonization process undergoes an activation reaction, wherein the water vapor comes from the pyrolysis of the powdered activated carbon. The powdered activated carbon is gradually opened by water vapor activation under the action of high temperature, and the organic elements and halogens undergo oxidation reactions to generate stable oxides. The occurrence of chemical reactions causes the carbon atoms on the capillary surface of the activated carbon to gasify, expand the capillary pores, and form new active surfaces. In addition, a large amount of combustible gas is released in the process. The combustible gas reacts with the introduced oxygen to release a large amount of heat energy, which serves as a heat source for maintaining the furnace temperature. The adsorbed substances are carbonized, activated or burned at high temperature to complete the regeneration process. If the heat energy is insufficient during the regeneration process, the heat energy is supplemented by the burner at the burner head.

[0025] The high-temperature powdered activated carbon in the tube side of the non-oxidative cooling section directly exchanges heat with the circulating cooling water in the shell side. After the non-oxidative cooling, the temperature of the powdered regenerated carbon drops to 300° C. or below, and the cooled powdered activated carbon is not easily burned.

[0026] Preferably, the particle size of the waste powdered activated carbon is 300-350 mesh, the feed rate is 0.2-1 t / h, and the water content is 40wt%-50wt%.

[0027] Preferably, the flue gas cooler cools high-temperature flue gas and powdered activated carbon mixed in the flue gas, the inlet flue gas temperature of the flue gas cooler is 280°C-350°C, and the outlet flue gas temperature of the flue gas cooler is 100°C-120°C.

[0028] Preferably, the filter mesh number of the bag of the bag catcher is 500-600 mesh, it is equipped with water vapor fire protection, and the bag is temperature-resistant at 200°C.

[0029] Preferably, the rotation speed of the internal heat rotary regeneration furnace is 1-3 revolutions per minute, and the gas pressure in the furnace is controlled to be a slightly negative pressure (50Pa-80Pa).

[0030] This application has achieved the following beneficial technical effects:

[0031] This application adds a gas cooler so that the high-temperature powdered activated carbon and the flue gas reaching this point can directly exchange heat with the cooling water in the shell. For example, if the high-temperature powdered activated carbon is 800°C, it will be reduced to 300°C after non-oxidative cooling in the gas cooler, so that the 300°C powdered activated carbon will not be easily burned out at high temperature, which reduces the high-temperature burning out of the powdered activated carbon and improves the quality of the powdered regenerated carbon.

[0032] This application adds a flue gas cooler. The high-temperature flue gas (about 300°C) is mixed with regenerated powdered activated carbon. The function of the flue gas cooler is to lower the temperature of the flue gas and the powdered activated carbon in the flue gas. Then the powdered activated carbon will settle in the subsequent bag-type collector, and the flue gas filtered by the bag-type collector will enter the subsequent equipment.

[0033] The present invention provides an internal heat regeneration system for waste powdered activated carbon. This internal heat regeneration system is completely controlled by a PLC control system, which changes the old production method in the past, saves manpower, is labor-saving and safe.

[0034] The most important feature of this internal heat regeneration system is the internal heat rotary regeneration furnace. Different from the previous internal heat regeneration method, this internal heat rotary regeneration furnace is designed with a gas cooler on the basis of the previous one. The main function of this gas cooler is to quickly cool the gas after pyrolysis activation and regeneration to below 300℃, which can greatly reduce the high temperature burnout of powdered activated carbon, improve the regeneration rate, and greatly improve the quality of activated carbon.

[0035] Different from the previous regeneration internal heat method, this internal heat regeneration system is equipped with a flue gas cooler and a bag filter, which can further capture the regenerated activated carbon mixed with the flue gas, thereby improving the product yield and avoiding the waste of resources.

[0036] Secondly, during the high-temperature regeneration process of powdered activated carbon, high-temperature flue gas is generated from the internal heat rotary regeneration furnace, and then passes through the gas cooler, flue gas cooler, bag filter, secondary combustion chamber, quenching tower, dry deacidification tower, bag dust collector, spray tower, exhaust chimney, and finally discharged into the air;

[0037] This internal heat regeneration system can be used in factories, which solves the problem that powdered activated carbon is difficult to regenerate and greatly reduces the cost of powdered activated carbon regeneration. This internal heat regeneration system has high thermal efficiency, high regeneration rate, high safety factor, long equipment service life and low regeneration cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of the structure of an internal heat regeneration system for waste powdered activated carbon provided in an embodiment of the present application ( Figure 1 The arrows in the figure represent the direction of smoke flow);

[0039] In the figure: 1 feeding silo, 2 closed conveyor, 3 buffer silo, 4 screw feeder, 5 internal heat rotary regeneration furnace, 501 gas cooler, 502 burner, 503 water-cooled converter, 6 flue gas cooler, 7 bag catcher, 8 choke fan, 801 choke device, 9 secondary combustion chamber, 10 waste heat boiler, 11 quenching tower, 12 dry deacidification tower, 13 bag dust collector, 14 spray tower, 15 main fan, 16 exhaust chimney. DETAILED DESCRIPTION

[0040] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be understood that the terms "center", "axial", "radial", "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the pyrolysis device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0042] like Figure 1As shown in the figure: feeding bin 1, closed conveyor 2, buffer silo 3, screw feeder 4, internal heat rotary regeneration furnace 5, gas cooler 501, burner 502, water-cooled converter 503, flue gas cooler 6, bag catcher 7, choke fan 8, choke device 801, secondary combustion chamber 9, waste heat boiler 10, quenching tower 11, dry deacidification tower 12, bag dust collector 13, spray tower 14, main fan 15, exhaust chimney 16.

[0043] The present application provides an internal heat regeneration system for waste powdered activated carbon, comprising a feeding system, an internal heat rotary regeneration furnace 5, a burner 502, a flue gas cooler 6, a bag filter 7, a choke fan 8, a choke device 801, a secondary combustion chamber 9, a waste heat boiler 10, and an exhaust gas treatment system;

[0044] The discharge port of the feeding system is communicated with the feeding port of the furnace head of the internal heat rotary regeneration furnace 5, so that the feeding system supplies the waste powdered activated carbon to the feeding port of the furnace head of the internal heat rotary regeneration furnace 5;

[0045] The internal heat rotary regeneration furnace 5 is a horizontal furnace and is inclined downward by 2-4 degrees from the furnace head to the furnace tail;

[0046] The internal heat rotary regeneration furnace 5 is provided with a burner 502 at the furnace head;

[0047] The tail section of the internal heat rotary regeneration furnace 5 is provided with a gas cooler 501, and the gas cooler 501 is a shell and tube heat exchanger structure. The tail end of the furnace body of the internal heat rotary regeneration furnace 5 is sealed and welded with the head end (head end) of the gas cooler 501 so that the furnace body of the internal heat rotary regeneration furnace 5 and the gas cooler 501 are an integrated structure, and the furnace of the furnace body of the internal heat rotary regeneration furnace 5 and the tube side of the gas cooler 501 are interconnected. The high-temperature powdered regenerated carbon (powdered activated carbon) and the flue gas move in the tube side of the gas cooler 501, and the circulating cooling water flows in the shell side of the gas cooler 501. The heat of the powdered regenerated carbon (powdered activated carbon) and the flue gas in the gas cooler 501 is transferred to the circulating cooling water so that the powdered regenerated carbon (powdered activated carbon) and the flue gas are cooled and cooled.

[0048] The furnace of the internal heat rotary regeneration furnace 5 is divided into four sections, namely the drying section, the carbonization and pyrolysis section, the activation section, and the non-oxidation cooling section in the gas cooler 501;

[0049] The top outlet of the tail end of the gas cooler 501 is connected to the air inlet of the flue gas cooler 6, and the bottom outlet of the tail end of the gas cooler 501 is connected to the top feed port of the water-cooled converter 503;

[0050] The flue gas cooler 6 is a shell and tube heat exchanger structure. The high-temperature flue gas moves in the tube side of the flue gas cooler 6, and the circulating cooling water flows in the shell side of the flue gas cooler 6. The heat of the flue gas in the flue gas cooler 6 is transferred to the circulating cooling water, so that the flue gas is cooled down.

[0051] The air outlet of the flue gas cooler 6 is communicated with the air inlet of the bag-type catcher 7, the air outlet of the bag-type catcher 7 is communicated with the air inlet of the choke fan 8, the bottom discharge port of the bag-type catcher 7 is used to discharge powdered regenerated carbon, the air outlet of the choke fan 8 is communicated with the air inlet of the choke device 801, the air outlet of the choke device 801 is communicated with the air inlet of the secondary combustion chamber 9, the air outlet of the secondary combustion chamber 9 is communicated with the air inlet of the waste heat boiler 10, and the air outlet of the waste heat boiler 10 is communicated with the air inlet of the exhaust gas treatment system.

[0052] In one embodiment of the present application, the feeding system includes a feeding bin 1, a closed conveyor 2, a buffer bin 3 and a screw feeder 4;

[0053] The bottom discharge port of the feeding bin 1 is connected to the bottom feed port of the closed conveyor 2, the top discharge port of the closed conveyor 2 is connected to the top feed port of the buffer bin 3, the bottom discharge port of the buffer bin 3 is connected to the right feed port of the screw feeder 4, and the left discharge port of the screw feeder 4 is connected to the furnace of the furnace head of the internal heat rotary regeneration furnace 5.

[0054] In one embodiment of the present application, the tail gas treatment system includes a quenching tower 11, a dry deacidification tower 12, a bag filter 13, a spray tower 14, a main fan 15 and an exhaust chimney 16;

[0055] The air outlet of the waste heat boiler 10 is communicated with the air inlet of the quenching tower 11, the air outlet of the quenching tower 11 is communicated with the air inlet of the dry deacidification tower 12, the air outlet of the dry deacidification tower 12 is communicated with the air inlet of the bag-type dust collector 13, the air outlet of the bag-type dust collector 13 is communicated with the bottom air inlet of the spray tower 14, the top air outlet of the spray tower 14 is communicated with the air inlet of the main fan 15, the air outlet of the main fan 15 is communicated with the bottom air inlet of the exhaust chimney 16, and the top air outlet of the exhaust chimney 16 is used for exhausting.

[0056] The present application provides a method for regenerating waste powdered activated carbon, using any one of the above-mentioned internal heat regeneration systems for waste powdered activated carbon;

[0057] During the regeneration process, the temperature of the drying section is 300-500°C, which thermally decomposes and evaporates the water and low-boiling-point organic matter in the waste powdered activated carbon.

[0058] The temperature of the carbonization and pyrolysis section is 500-700°C, which decomposes the organic matter adsorbed in the waste powdered activated carbon at high temperature. The combustible gas generated by the pyrolysis reacts with oxygen in the internal heat rotary regeneration furnace 5 to release heat, carbonizing the adsorbed volatile substances and high-boiling-point organic matter remaining in the pores of the activated carbon. The high-boiling-point organic matter is decomposed and carbonized in the adsorbed state and remains in the form of fixed carbon.

[0059] The temperature of the activation section is 700°C-850°C. In this section, the powdered activated carbon is fully in contact with water vapor. In the presence of oxygen, fuel gas and water vapor, the residual carbon generated during the carbonization process undergoes an activation reaction, wherein the water vapor comes from the pyrolysis of the powdered activated carbon. The powdered activated carbon is gradually opened by water vapor activation under the action of high temperature, and the organic elements and halogens undergo oxidation reactions to generate stable oxides. The occurrence of chemical reactions causes the carbon atoms on the capillary surface of the activated carbon to gasify, expand the capillary pores, and form new active surfaces. In addition, a large amount of combustible gas is released in the process, and the combustible gas reacts with the introduced oxygen to release a large amount of heat energy, which serves as a heat source for maintaining the furnace temperature. The adsorbed substances are carbonized, activated or burned at high temperature, completing the regeneration process. If the heat energy is insufficient during the regeneration process, the heat energy is supplemented by the burner 502 at the burner head.

[0060] The high-temperature powdered activated carbon in the tube side of the non-oxidative cooling section directly exchanges heat with the circulating cooling water in the shell side. After the non-oxidative cooling, the temperature of the powdered regenerated carbon drops to 300° C. or below, and the cooled powdered activated carbon is not easily burned.

[0061] In one embodiment of the present application, the particle size of the waste powdered activated carbon is 300-350 mesh, the feed rate is 0.2-1 t / h, and the water content is 40wt%-50wt%.

[0062] In one embodiment of the present application, the flue gas cooler 6 cools the high-temperature flue gas and powdered activated carbon mixed in the flue gas. The inlet flue gas temperature of the flue gas cooler 6 is 280°C-350°C, and the outlet flue gas temperature of the flue gas cooler 6 is 100°C-120°C.

[0063] In one embodiment of the present application, the filter mesh number of the bag of the bag catcher 7 is 500-600 mesh, water vapor fire protection is provided, and the bag has a temperature resistance of 200°C.

[0064] In one embodiment of the present application, the rotation speed of the internal heat rotary regeneration furnace 5 is 1-3 revolutions per minute, and the gas pressure in the furnace is controlled to be a slightly negative pressure (50Pa-80Pa).

[0065] In this application, the function of the air supply system is: the air supply system collects dust from places where the feed is prone to dust and places where the discharge is dusty with a fan, and then sends it to the secondary combustion chamber 9. This can not only solve the problem of air supply and oxygen supply in the secondary combustion chamber 9, but also remove dust.

[0066] In the present application, the function of the choke fan 8 (preferably a centrifugal fan) is as follows: (1) Flue gas is generated in the internal heat rotary regeneration furnace 5, and the choke fan 8 provides power for the flow of flue gas; (2) First, the volatile gas releases heat at high temperature in the internal heat rotary regeneration furnace 5 to form high-temperature flue gas, which, under the action of the choke fan 8, flows to the gas cooler 501, the furnace tail, the flue gas heat exchanger, and the bag catcher 7, and continuously flows to the subsequent process equipment. The choke fan 8 is installed in the secondary combustion chamber 9 and the bag catcher. 7, the bag-type catcher 7 is afraid of fire. During the actual operation of the secondary combustion chamber 9, the internal temperature will reach 1100℃ and above. The choke fan 8 is installed here to ensure that the high-temperature flue gas in the secondary combustion chamber 9 will not flow back into the bag-type catcher 7 in the event of system abnormality, otherwise the bag-type catcher 7 will catch fire and cause a fire; (3). The choke fan 8 and the one-way choke device 801 are used to doubly ensure that the high-temperature flue gas in the secondary combustion chamber 9 will not flow back, will not cause the bag-type catcher 7 to catch fire, and ensure that no fire will occur.

[0067] In this application, the purpose of the secondary combustion chamber 9 is: the secondary combustion chamber 9 is a secondary combustion chamber, which is used to burn the harmful gases volatilized from the internal heat rotary regeneration furnace 5 and the gases that have not been completely burned. The process requirements of the secondary combustion chamber 9 are: the operating temperature is greater than or equal to 1100°C, and the flue gas is guaranteed to stay in the secondary combustion chamber 9 for ≥2 seconds.

[0068] The present invention provides an internal heat regeneration system for waste powdered activated carbon, comprising a feeding system, a regeneration furnace system, a cooling device, an exhaust gas treatment system, an air supply system, etc.

[0069] This internal heat regeneration system transports the powdered activated carbon to the internal heat rotary regeneration furnace 5 through the feeding system. When the internal heat rotary regeneration furnace 5 is installed, it forms a 2.5-degree angle with the ground, with the furnace head high and the furnace tail low. Under the action of the rotation of the internal heat rotary regeneration furnace 5, the powdered activated carbon slowly moves from the furnace head to the furnace tail, and passes through the drying section - carbonization and pyrolysis section - activation section - non-oxidation cooling section in sequence, and finally falls from the furnace tail. The powdered activated carbon falls into the water-cooled converter 503 under the action of gravity, and then the powdered activated carbon cooled to 50°C or below by the water-cooled converter 503 can be packaged and stored;

[0070] At the same time, during the regeneration process of powdered activated carbon, a small amount of powdered activated carbon will be mixed in the high-temperature pyrolysis flue gas. This activated carbon has undergone high-temperature pyrolysis activation, indicating that it is a regenerated activated carbon that meets the standards. Therefore, a flue gas cooler 6 is provided above the furnace tail. The purpose of this flue gas cooler 6 is to cool the flue gas to below 130°C. The powdered activated carbon mixed in the flue gas is also cooled down at the same time. At this time, the low-temperature powdered activated carbon is captured in the subsequent bag catcher 7 and transported out by the screw conveyor at the bottom of the bag catcher 7. It can be packaged and stored. In summary, this is the direction of the powdered activated carbon in the internal heat rotary regeneration furnace 5.

[0071] Secondly, during the high-temperature regeneration process of powdered activated carbon, high-temperature flue gas is generated from the internal heat rotary regeneration furnace 5, and then passes through the gas cooler 501, flue gas cooler 6, bag filter 7, choke fan, secondary combustion chamber 9, waste heat boiler, quenching tower 11, dry deacidification tower 12, bag dust collector 13, spray tower 14, main fan 15, and exhaust chimney 16, and is finally discharged into the air.

[0072] This internal heat regeneration system provides heat for the internal heat regeneration system at the burner head. There are multiple ways to provide heat sources, such as burning natural gas, diesel, etc.

[0073] Unlike previous regeneration furnaces, this application: First, during the design process, the internal heat rotary regeneration furnace 5 and the gas cooler 501 are designed as one body; second, a flue gas cooler 6 and a bag catcher 7 are designed for the powdered activated carbon mixed in the high-temperature flue gas, which can greatly improve the regeneration rate of the powdered activated carbon. This is the first case of this structure and this process. This internal heat regeneration system has high thermal efficiency, high regeneration rate, high safety factor, long equipment service life and low regeneration cost.

[0074] The process flow of the regeneration method of waste powdered activated carbon in this application is as follows:

[0075] (1) Waste powdered activated carbon - feeding bin 1 - closed conveyor 2 - buffer bin 3 - internal heat rotary regeneration furnace 5 - gas cooler 501 - water-cooled converter 503 - transfer, packaging and storage;

[0076] (2) High-temperature flue gas is generated in the internal heat rotary regeneration furnace 5 - gas cooler 501 - flue gas cooler 6 - bag filter 7 - choke fan 8 - choke device 801 - secondary combustion chamber 9 - waste heat boiler 10 - quenching tower 11 - dry deacidification tower 12 - bag filter 13 - spray tower 14 - main fan 15 - and finally discharged into the air through the chimney 16;

[0077] (3) The powdered activated carbon mixed in the high-temperature flue gas is transported out, packaged and stored in the gas cooler 501, flue gas cooler 6, bag catcher 7 and the screw conveyor at the bottom of the bag catcher 7.

[0078] The working principle of the internal heat regeneration system of this application is low energy consumption and high thermal efficiency:

[0079] Because a large amount of organic matter is adsorbed in the waste powdered activated carbon, the organic matter decomposes at high temperature to produce a large amount of combustible components, such as hydrogen, methane, carbon monoxide, etc. After these combustible components are pyrolyzed, they will burn first than the activated carbon when encountering high temperature and oxygen in the internal heat rotary regeneration furnace 5. This can not only ensure that the activated carbon is not burned, but also provide heat for the regeneration of the activated carbon, thereby reducing energy consumption and increasing thermal efficiency.

[0080] The working principle of the internal heat regeneration system of this application with high regeneration rate:

[0081] First, because this internal heat regeneration system is designed with a gas cooler 501 on the basis of the internal heat rotary regeneration furnace 5, the purpose of designing this gas cooler 501 is to allow the regenerated powdered activated carbon to be directly cooled without an intermediate link, and there is no problem of high-temperature carbon burning, so the regeneration rate is high;

[0082] Secondly, because of this internal heat regeneration system, a flue gas cooler 6 is provided above the tail of the internal heat rotary regeneration furnace 5, and a bag catcher 7 is provided behind the flue gas cooler 6, which can reduce the temperature of the regenerated finished powdered activated carbon mixed in the flue gas to below 130°C, and then it is captured by the bag catcher 7 and transported out through the screw conveyor under the bag catcher 7, so that a part of the regenerated finished powdered activated carbon can be obtained, so the regeneration yield is high.

[0083] The working principle of the internal heat regeneration system of this application with high safety factor:

[0084] Because this internal heat regeneration system uses an internal heat process to regenerate waste powdered activated carbon, the combustible components produced by the high-temperature decomposition of the waste powdered activated carbon, such as hydrogen, methane, carbon monoxide, etc., can be burned in the regeneration furnace before the powdered activated carbon at the first time, and there is no need to transfer to subsequent equipment, thus preventing the risk of explosion caused by excessive concentration of combustible gas.

[0085] The long-life working principle of the internal heat regeneration system of this application:

[0086] Because this internal heat rotary regeneration furnace is made of refractory materials and is in direct contact with powdered activated carbon, there will be no corrosion or high-temperature oxidation on the main steel structure of the equipment, so it has a long service life.

[0087] The methods and devices not fully described in the present invention are all prior art and will not be described in detail.

[0088] For a better understanding of the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as limiting the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above invention content are also considered to fall within the scope of protection of the present invention.

[0089] Example 1

[0090] A method for regenerating waste powdered activated carbon, using the above-mentioned internal heat regeneration system for waste powdered activated carbon;

[0091] The temperature of the drying section is 300°C-350°C, the temperature of the carbonization and pyrolysis section is 650°C-700°C, the temperature of the activation section is 800°C-850°C, and the non-oxidation cooling section reduces the temperature of the powdered regenerated carbon and the flue gas to 300°C or below;

[0092] The particle size of waste powdered activated carbon is 320-350 mesh, the feed rate is 0.8-1t / h, and the water content is 40wt%-45wt%;

[0093] The inlet flue gas temperature of the flue gas cooler 6 is 280°C-300°C, and the outlet flue gas temperature of the flue gas cooler 6 is 100°C-110°C;

[0094] The filter mesh of the bag catcher 7 is 500-550 mesh, with water vapor fire protection, and the bag temperature resistance is 200°C;

[0095] The rotation speed of the internal heat rotary regeneration furnace 5 is 2.5 revolutions per minute, and the gas pressure in the furnace is controlled to be a slightly negative pressure (50Pa-60Pa).

[0096] Example 2

[0097] In Example 2, the rest is the same as in Example 1 except for the following:

[0098] A method for regenerating waste powdered activated carbon, using the above-mentioned internal heat regeneration system for waste powdered activated carbon;

[0099] The temperature of the drying section is 310°C-360°C, the temperature of the carbonization and pyrolysis section is 650°C-690°C, the temperature of the activation section is 790°C-840°C, and the non-oxidation cooling section reduces the temperature of the powdered regenerated carbon and the flue gas to 300°C or below;

[0100] The particle size of waste powdered activated carbon is 310-340 mesh, the feed rate is 0.7-0.9t / h, and the water content is 40wt%-45wt%;

[0101] The inlet flue gas temperature of the flue gas cooler 6 is 280°C-300°C, and the outlet flue gas temperature of the flue gas cooler 6 is 100°C-105°C;

[0102] The filter mesh of the bag catcher 7 is 550-600 mesh, with water vapor fire protection, and the bag temperature resistance is 200°C;

[0103] The rotation speed of the internal heat rotary regeneration furnace 5 is 3 revolutions per minute, and the gas pressure in the furnace is controlled to be a slightly negative pressure (50Pa-65Pa).

[0104] Example 3

[0105] In Example 3, the rest is the same as in Example 1 except for the following:

[0106] A method for regenerating waste powdered activated carbon, using the above-mentioned internal heat regeneration system for waste powdered activated carbon;

[0107] The temperature of the drying section is 300°C-330°C, the temperature of the carbonization and pyrolysis section is 630°C-670°C, the temperature of the activation section is 820°C-850°C, and the non-oxidation cooling section reduces the temperature of the powdered regenerated carbon and the flue gas to 300°C or below;

[0108] The particle size of waste powdered activated carbon is 330-350 mesh, the feed rate is 0.6-0.7t / h, and the water content is 45wt%-50wt%;

[0109] The inlet flue gas temperature of the flue gas cooler 6 is 280°C-290°C, and the outlet flue gas temperature of the flue gas cooler 6 is 105°C-110°C;

[0110] The filter mesh of the bag catcher 7 is 560-590 mesh, with water vapor fire protection, and the bag temperature resistance is 200°C;

[0111] The rotation speed of the internal heat rotary regeneration furnace 5 is 2 revolutions per minute, and the gas pressure in the furnace is controlled to be a slightly negative pressure (55Pa-70Pa).

[0112] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An internal heat regeneration system for waste powdered activated carbon, characterized in that: Including feeding system, internal heat rotary regeneration furnace, burner, flue gas cooler, bag filter, choke fan, secondary combustion chamber, waste heat boiler, tail gas treatment system; The discharge port of the feeding system is communicated with the feeding port of the furnace head of the internal heat rotary regeneration furnace, so that the feeding system supplies the waste powdered activated carbon to the feeding port of the furnace head of the internal heat rotary regeneration furnace; The internal heat rotary regeneration furnace is a horizontal furnace and is inclined downward by 2-4 degrees from the furnace head to the furnace tail; The internal heat rotary regeneration furnace is provided with a burner at the furnace head; The tail section of the internal heat rotary regeneration furnace is provided with a gas cooler, which is a shell and tube heat exchanger structure. The tail end of the furnace body of the internal heat rotary regeneration furnace is sealed and welded with the head end of the gas cooler so that the furnace of the furnace body of the internal heat rotary regeneration furnace and the tube side of the gas cooler are interconnected. The high-temperature powdered regenerated carbon and flue gas move in the tube side of the gas cooler, and circulating cooling water flows in the shell side of the gas cooler. The heat on the powdered regenerated carbon and the flue gas in the gas cooler is transferred to the circulating cooling water so that the powdered regenerated carbon and the flue gas are cooled and lowered in temperature. The internal heat rotary regeneration furnace is divided into 4 sections, namely the drying section, the carbonization and pyrolysis section, the activation section, and the non-oxidation cooling section in the gas cooler; The top air outlet at the tail end of the gas cooler is connected to the air inlet of the flue gas cooler, and the bottom discharge port at the tail end of the gas cooler is connected to the top feed port of the water-cooled converter; The flue gas cooler is a shell and tube heat exchanger structure. The high-temperature flue gas moves in the tube side of the flue gas cooler, and the circulating cooling water flows in the shell side of the flue gas cooler. The heat of the flue gas in the flue gas cooler is transferred to the circulating cooling water, so that the flue gas is cooled down. The air outlet of the flue gas cooler is connected to the air inlet of the bag-type catcher, the air outlet of the bag-type catcher is connected to the air inlet of the choke fan, the bottom discharge port of the bag-type catcher is used to discharge powdered regenerated carbon, the air outlet of the choke fan is connected to the air inlet of the secondary combustion chamber, the air outlet of the secondary combustion chamber is connected to the air inlet of the waste heat boiler, and the air outlet of the waste heat boiler is connected to the air inlet of the exhaust gas treatment system.

2. The internal heat regeneration system of waste powdered activated carbon according to claim 1, characterized in that: The feeding system includes a feeding bin, a closed conveyor, a buffer bin and a screw feeder; The bottom discharge port of the feeding bin is connected to the bottom feed port of the closed conveyor, the top discharge port of the closed conveyor is connected to the top feed port of the buffer bin, the bottom discharge port of the buffer bin is connected to the right feed port of the screw feeder, and the left discharge port of the screw feeder is connected to the furnace of the furnace head of the internal heat rotary regeneration furnace.

3. The internal heat regeneration system for waste powdered activated carbon according to claim 1, characterized in that: The tail gas treatment system includes a quenching tower, a dry deacidification tower, a bag dust collector, a spray tower, a main fan and an exhaust chimney; The air outlet of the waste heat boiler is connected to the air inlet of the quenching tower, the air outlet of the quenching tower is connected to the air inlet of the dry deacidification tower, the air outlet of the dry deacidification tower is connected to the air inlet of the bag-type dust collector, the air outlet of the bag-type dust collector is connected to the bottom air inlet of the spray tower, the top air outlet of the spray tower is connected to the air inlet of the main fan, the air outlet of the main fan is connected to the bottom air inlet of the exhaust chimney, and the top air outlet of the exhaust chimney is used for exhausting.

4. A method for regenerating waste powdered activated carbon, characterized in that: An internal heat regeneration system for waste powdered activated carbon using any one of claims 1 to 3; During the regeneration process, the temperature of the drying section is 300-500°C, which thermally decomposes and evaporates the water and low-boiling-point organic matter in the waste powdered activated carbon. The temperature of the carbonization and pyrolysis section is 500-700°C, which decomposes the organic matter adsorbed in the waste powdered activated carbon at high temperature. The combustible gas generated by the pyrolysis reacts with oxygen in the internal heat rotary regeneration furnace to release heat, carbonizing the adsorbed volatile substances and high-boiling-point organic matter remaining in the pores of the activated carbon. The high-boiling-point organic matter is decomposed and carbonized in the adsorbed state and remains in the form of fixed carbon. The temperature of the activation section is 700°C-850°C. In this section, the powdered activated carbon is fully in contact with water vapor. In the presence of oxygen, fuel gas and water vapor, the residual carbon generated during the carbonization process undergoes an activation reaction, wherein the water vapor comes from the pyrolysis of the powdered activated carbon. The powdered activated carbon is gradually opened by water vapor activation under the action of high temperature, and the organic elements and halogens undergo oxidation reactions to generate stable oxides. The occurrence of chemical reactions causes the carbon atoms on the capillary surface of the activated carbon to gasify, expand the capillary pores, and form new active surfaces. In addition, a large amount of combustible gas is released in the process. The combustible gas reacts with the introduced oxygen to release a large amount of heat energy, which serves as a heat source for maintaining the furnace temperature. The adsorbed substances are carbonized, activated or burned at high temperature to complete the regeneration process. If the heat energy is insufficient during the regeneration process, the heat energy is supplemented by the burner at the burner head. The high-temperature powdered activated carbon in the tube side of the non-oxidative cooling section directly exchanges heat with the circulating cooling water in the shell side. After the non-oxidative cooling, the temperature of the powdered regenerated carbon drops to 300° C. or below, and the cooled powdered activated carbon is not easily burned.

5. The method for regenerating waste powdered activated carbon according to claim 4, characterized in that: The particle size of the waste powdered activated carbon is 300-350 mesh, the feed rate is 0.2-1 t / h, and the water content is 40wt%-50wt%.

6. The method for regenerating waste powdered activated carbon according to claim 4, characterized in that: The flue gas cooler cools high-temperature flue gas and powdered activated carbon mixed in the flue gas. The inlet flue gas temperature of the flue gas cooler is 280°C-350°C, and the outlet flue gas temperature of the flue gas cooler is 100°C-120°C.

7. The method for regenerating waste powdered activated carbon according to claim 4, characterized in that: The filter mesh number of the bag of the bag catcher is 500-600 meshes, it is equipped with water vapor fire protection, and the bag is temperature-resistant at 200°C.

8. The method for regenerating waste powdered activated carbon according to claim 4, characterized in that: The rotation speed of the internal heat rotary regeneration furnace is 1-3 revolutions per minute, and the gas pressure in the furnace is controlled to be a slightly negative pressure (50Pa-80Pa).

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