Activated carbon high-temperature desorption and activation regeneration sequencing batch shaft kiln

Abstract

The utility model discloses an activated carbon high-temperature desorption and activation regeneration sequencing batch shaft kiln which comprises a vertical kiln body, a material level controller is arranged on the vertical kiln body, a feeding port is formed in the top of the vertical kiln body, a discharging port is formed in the bottom of the vertical kiln body, closed valves and inert gas stripping devices are arranged at the feeding port and the discharging port respectively, and the vertical kiln body is divided into an upper part, a middle part and a lower part. The upper part is a preheating area, the middle part is a high-temperature area, the lower part is a cooling area, and a gas inlet pipe is arranged at the high-temperature area. According to the utility model, the vertical kiln structure is adopted, and sequencing batch feeding is adopted, so that the activated carbon is uniformly distributed in the vertical kiln body, the hot temperature time, the hot temperature and the activating agent introduction amount can be accurately controlled, and the yield and the activation efficiency of the activated carbon are greatly improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of activated carbon recovery kiln especially relates to a kind of activated carbon high-temperature desorption and activation regeneration sequence batch vertical kiln. BACKGROUND

[0002] Activated carbon effectively governs VOC S With the vigorous development of new energy vehicles, VOC is overflowed in the production process of rubber and spraying of waste gas industry S Gas composition is complex, and high-iodine-value granular activated carbon is often selected as adsorbent in treatment process. Although granular activated carbon has wide absorption spectrum and good mechanical fluidity, it is easy to smolder after adsorbing organic matter. High-boiling-point VOCs and a large amount of atomized tar contained in general waste gas are difficult to completely remove at conventional desorption temperature of granular activated carbon, affecting subsequent reuse.

[0003] According to the previous fixed activated carbon desorption in aerobic environment, after over-saturation adsorption of VOCs, the desorption temperature is quickly raised to 180-200℃, and due to uneven heat conduction of carbon pile, local temperature is abnormally high, and activated carbon is easy to smolder.

[0004] At present, activated carbon desorption mainly uses rotary kiln structure, but in the desorption and activation of rotary kiln structure, activated carbon is unevenly accumulated inside, and is unevenly heated, so that heat temperature time and heat temperature of unit activated carbon are uncontrollable, and the amount of steam of unit activated carbon is uncontrollable, resulting in low yield of activated carbon and poor activation efficiency. INVENTION CONTENTS

[0005] The utility model aims at providing a kind of activated carbon high-temperature desorption and activation regeneration sequence batch vertical kiln.

[0006] The utility model has the innovative points that vertical kiln structure is used in the utility model, and sequence batch feeding is used, so that activated carbon is evenly distributed in vertical kiln body, heat temperature time, heat temperature and activation agent input amount can be accurately controlled, and yield and activity of activated carbon are greatly improved.

[0007] To achieve the above-mentioned utility model purposes, the technical scheme of the utility model is as follows:

[0008] A kind of activated carbon high-temperature desorption and activation regeneration sequence batch vertical kiln, including vertical kiln body, high-level material level controller and low-level material level controller are arranged on the vertical kiln body, the top of the vertical kiln body is provided with feed inlet and exhaust port, the bottom is provided with discharge port, the feed inlet and discharge port are both provided with airtight valve and inert gas stripping device, the vertical kiln body is divided into heating zone in upper part and cooling zone in lower part, and the heating zone is provided with gas inlet pipe.

[0009] Further, the heating zone is divided into preheating zone and high-temperature zone from top to bottom, and the gas inlet pipe is located at the high-temperature zone.

[0010] Further, the preheating zone is provided with heat exchange pipes.

[0011] The steam in the preheating zone is low in and high out, the temperature at the bottom of the preheating zone close to the high temperature zone is higher, which can save the energy loss of the high temperature zone; at the same time, the preheating zone maintains 200℃±25℃, which can early detach and discharge the low boiling point VOCs organic matter, avoid the concentrated release in unit time, trigger the phase burst temperature peak of the post-burning furnace, trigger the program alarm, and inhibit the safety hidden trouble of the system.

[0012] Further, the high temperature zone is externally provided with a heating furnace wrapping the vertical kiln body high temperature zone.

[0013] The high temperature zone is externally coupled with the heating furnace, under the high temperature environment of 800-1000℃, the activator enters the high temperature zone to have a reduction reaction with carbon, a large amount of gas generated is used as a carrier gas, and the VOCs and tar mist detached and activated are used as combustion materials to support the combustion balance heat energy in the heating furnace, which saves the combustion energy and achieves the purpose of burning VOCs, tar and other pollutants.

[0014] Further, the heating furnace is a regenerative thermal oxidation furnace or a regenerative catalytic combustion furnace, and the vertical kiln body is located in the heating furnace, and the inner and outer walls of the vertical kiln body are provided with a plurality of heat exchange fins.

[0015] Air has very poor heat conductivity (λ=0.022-0.026 W / m·K under standard conditions); the heat exchange fin group is extended out of the cavity at the high temperature zone, which facilitates the heat exchange between hot air and the heat exchange fin group, and converts the heat of the combustion engine flame into the temperature increase of the heat exchange fin group.

[0016] Further, the vertical kiln body is internally provided with a plurality of heat exchange fins at the high temperature zone.

[0017] Carbon has very poor heat conductivity (λ=0.17-0.28 W / m·K under standard conditions), which is difficult to fully heat the carbon at the high temperature zone to an average temperature in a short time, and only the heat exchange contact area can be increased; the heat conductivity of metal is very good (λ=73.3 W / m·K under standard conditions), the heat exchange fin is inserted into the inner cavity to fully contact the activated carbon, which facilitates the rapid conversion of heat into the overall average temperature rise of the activated carbon, shortens the unit detachment time, and is beneficial to the flow of carbon particles in the direction of gravity.

[0018] Further, the cross section of the high temperature zone is a polygon, and the cross-sectional area of the high temperature zone is between 0.2 and 30 square meters.

[0019] The specific heat capacity of activated carbon under standard conditions ΔC = 0.4-1.5 J / (g·K) and the thermal conductivity λ = 0.17-0.28 W / (m·K) are not ideal, and it is difficult to heat the larger volume of activated carbon, which may cause uneven heating in the carbon pile, and more unit time is needed. Extremely high temperature can also cause carbon loss, carbon and iron reaction: C + 3Fe = Fe3C; polygonal configuration is more conducive to uniform arrangement of internal heat exchange plates.

[0020] Further, the activated agent introduced by the gas introduction pipe is air, nitrogen, carbon dioxide or water vapor. The gas of the gas introduction pipe can be used as a carrier gas, and also can be used as an activated agent,

[0021] Air, nitrogen, carbon dioxide or water vapor can be reduced with carbon:

[0022] 2C + O2 = 2CO (reaction temperature 700-800℃, insufficient oxygen)

[0023] N2 + 2C = 2CN (reaction temperature 1000℃)

[0024] CO2 + C = 2CO (reaction temperature 700-1000℃)

[0025] H2O(g) + C = CO + H2 (reaction temperature 800℃-1000℃)

[0026] Further, the wall of the preheating zone and the wall of the high temperature zone, the wall of the high temperature zone and the wall of the cooling zone are separated by a heat insulation layer; the wall of the preheating zone and the wall of the high temperature zone, the wall of the high temperature zone and the wall of the cooling zone are connected by flanges and flanges, and the heat insulation layer is located between the flanges and the flanges, and the material of the heat insulation layer is red steel paper, graphite gasket, asbestos aluminum silicate gasket or ceramic gasket.

[0027] The preheating zone only needs 200℃±25℃, which can reach the conventional desorption temperature, and the temperature does not need to be too high; the desorption regeneration zone is 800-1000℃, which needs to lock the heat to ensure the minimum temperature of the reduction reaction, and cannot tolerate a large amount of heat loss; the cooling zone needs to be rapidly cooled to 150-200℃, so the benign heat conduction between the walls needs to be blocked, and the upper and lower connecting parts must be separated by a heat insulation layer;

[0028] Further, the heat insulation layer is used as a sealing gasket and is inserted between the upper and lower flanges, which needs to be resistant to pressure and leakage and corrosion resistant, and the limited material selection involves few types.

[0029] Further, the gas outlet of the gas introduction pipe is located at the bottom of the high temperature zone; the high temperature zone is also provided with a compressed air introduction pipe, and the gas outlet of the compressed air introduction pipe is located in the middle of the high temperature zone.

[0030] The activator is introduced into the bottom of the high-temperature zone, part of which acts as a reducing gas and the other part as a carrier gas. This drives high-boiling-point VOCs, tar mist, and high temperature to the upper exhaust port, while preventing the possibility of oxygen from entering the desorption and regeneration zone from the lower part, thus improving the safety factor.

[0031] Here, compressed air acts as supplemental oxygen, which can oxidize the partially reduced, reactive gases, releasing a large amount of heat, saving energy in the burner, and quickly raising the temperature curve of the high-temperature zone, thus adding a means of control for the artificial intervention system.

[0032] 2H₂ + O₂ == 2H₂O + a large amount of heat

[0033] 2C + O2 == 2CO + a large amount of heat

[0034] CN is stable and does not react with O2.

[0035] The beneficial effects of this utility model are:

[0036] 1. This utility model adopts a vertical kiln structure and sequential batch feeding, which makes the activated carbon evenly distributed in the vertical kiln body. The heating time, heating temperature and the amount of activator introduced can be precisely controlled, and the yield of activated carbon is greatly improved.

[0037] 2. In this utility model, heat exchange tubes are used for preheating in the preheating zone. Low-cost water vapor can be generated in the heat exchange tubes to desorb the organic matter adsorbed in the activated carbon. On the one hand, this can avoid coking in the high-temperature zone, and on the other hand, it can reduce the heat consumption in the high-temperature zone.

[0038] 3. In this utility model, the high temperature zone is flexibly adjusted by using external heat or a combination of external and internal heat. When desorption is required, external heat is selected, and when regeneration and activation are required, internal heat or a combination of internal and external heat is selected.

[0039] 4. This utility model is particularly suitable for continuous batch centralized regeneration of fluid particulate adsorbents, extending the total lifespan of activated carbon adsorption stage, improving equipment utilization, and facilitating uninterrupted production.

[0040] 5. This invention can significantly increase the desorption temperature, releasing more high-boiling-point VOCs pollutants in a shorter unit time.

[0041] 6. Under the premise of ensuring the safe operation of the device, this utility model improves the desorption temperature that the equipment can withstand, thereby expanding the adsorption and activation capacity of the particulate adsorbent, while reducing the batch frequency of adsorbent replacement and saving environmental protection operation and maintenance costs.

[0042] 7. The unique design structure of this utility model uses indirect heating activated carbon, which isolates the hot carbon from the air and reduces the safety hazard of temperature rise during desorption and regeneration.

[0043] 8. The equipment has compact structure, small floor area, can be attached to the outer wall of the factory building, is convenient for hoisting and positioning, and shortens the on-site installation period.

[0044] 9. The equipment is provided with a segmented control temperature sensor and a material level display, relies on an integrated program and an activator quantitative control interlocking linkage, has high mechanical automation degree, and has low failure rate.

[0045] 10. The equipment can cope with VOCs waste gas mixed with some special components, such as waste gas containing oil droplets, metal powder and floating dust, and can also regenerate some waste activated carbon with high water content in a sewage treatment plant.

[0046] 11. The equipment has high operation processing efficiency and low failure rate during desorption, small volume of adsorbent in a single batch processing, small amount of concentrated waste gas released, small VOCs incineration treatment equipment in the later stage, high-temperature area arranged at the center of the incineration equipment, and continuous heating of the high-temperature area by skillfully utilizing incineration heat energy, so that the heat balance of the two is achieved, and the output energy consumption of the incinerator is reduced.

[0047] 12. The equipment has wide application range and can be applied to the regeneration of some specific types of granular adsorbents, such as activated carbon and molecular sieve. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 It is a structural schematic view of the utility model. DETAILED DESCRIPTION

[0049] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings.

[0050] Embodiment 1: A sequence batch type vertical kiln for high-temperature desorption and activation regeneration of activated carbon, comprising a vertical kiln body 1, a high-level material level controller 2 and a low-level material level controller 3 are arranged on the vertical kiln body 1, a feeding port 4 is arranged at the top of the vertical kiln body, a discharging port 5 is arranged at the bottom of the vertical kiln body, airtight valves 6 and inert gas stripping devices 7 are arranged at the feeding port 4 and the discharging port 5, the vertical kiln body is divided into a heating zone at the upper part and a cooling zone 1.3 at the lower part, the heating zone at the upper part is divided into a preheating zone 1.1 and a high-temperature zone 1.2 from top to bottom, a gas inlet pipe 8 is arranged at the high-temperature zone 1.2, and the activator introduced into the gas inlet pipe 8 is air, nitrogen, carbon dioxide or water vapor. The gas outlet of the gas inlet pipe 8 is located at the bottom of the high-temperature zone 1.2, a compressed air inlet pipe 14 is further arranged at the high-temperature zone 1.2, and the gas outlet of the compressed air inlet pipe 14 is located in the middle of the high-temperature zone 1.2.

[0051] The heat exchange pipe 9 is arranged in the preheating zone 1.1. The incineration heating furnace 10 is arranged outside the high temperature zone 1.2 and wraps the high temperature zone 1.2 of the vertical kiln body. The incineration heating furnace 10 is a heat accumulating thermal oxidation furnace or a heat accumulating catalytic combustion furnace. The vertical kiln body 1 is arranged on the outer wall of the incineration heating furnace 10 and is provided with a plurality of heat exchange fin groups 11.

[0052] The vertical kiln body 1 is internally provided with a plurality of heat exchange fins 12 at the high temperature zone 1.2. The cross section of the high temperature zone 1.2 is polygonal. The cross sectional area of the high temperature zone 1.2 is between 0.2 and 30 square meters.

[0053] The wall of the preheating zone 1.1 and the wall of the high temperature zone 1.2, the wall of the high temperature zone 1.2 and the wall of the cooling zone 1.3 are all separated by the heat insulation layer 13. The wall of the preheating zone 1.1 and the wall of the high temperature zone 1.2, the wall of the high temperature zone 1.2 and the wall of the cooling zone 1.3 are connected by flanges. The heat insulation layer 13 is arranged between the flanges. The material of the heat insulation layer 13 is red steel paper, graphite gasket, asbestos aluminum silicate gasket or ceramic gasket.

[0054] Working example:

[0055] In a waste gas treatment project, there are 20 tons of granular activated carbon for adsorption of xylene and a small amount of tar under working conditions. The particle size of the granular activated carbon is 2-4 mm. After adsorption saturation, a total of 1.2 tons of xylene is adsorbed.

[0056] The granular activated carbon high temperature desorption and activation regeneration sequencing batch vertical kiln with a treatment capacity of 200 kg / h disclosed in the specific embodiment is selected for treatment. The square cross section of the high temperature desorption and regeneration zone of the vertical kiln body is 70╳70 cm (cross sectional area 0.49 m 2 ). The height of the preheating zone of the vertical kiln body is 205 cm. The height of the high temperature desorption and regeneration zone is 280 cm. The height of the cooling zone is 210 cm. A total of about 3.4 m 3 of granular activated carbon can be accommodated.

[0057] The temperature is maintained at 200℃ during preheating and is maintained at 850℃ during desorption and regeneration. The heat source of the incineration heating furnace is a natural gas combustion machine (gas consumption is about 150 m 3 / h). A proper amount of steam is used as a preheating agent in the preheating zone and as an activation agent in the high temperature desorption and regeneration zone (steam consumption is about 1 ton / h). The total air volume of the desorbed VOCs+carrier gas is ≤1000 m 3 / h. After continuous operation for 103 h, the granular activated carbon in the plant can be batch regenerated (the loss on ignition of the activated carbon is <10%). The desorption gas concentration is 3.6-4.2 g / m 3 . The desorption and regeneration efficiency can be stably reached above 98%.

[0058] Comparative example

[0059] A VOCs exhaust project has a total volume of 40m 3 of granular activated carbon, which is distributed in 16 adsorption and desorption integrated carbon tanks, each of which has a volume of 2.5m 3 After adsorption saturation, a single carbon tank adsorbs about 60kg of VOCs, and the thickness of the heat insulation material outside the carbon tank is 10cm. Due to the conditions and safety temperature limit of the equipment, the desorption temperature can only be maintained at 80℃, the desorption gas is hot air, the desorption air volume is 3000m 3 / h, each tank takes 5h for desorption, 0.5-1h for cooling, and about 96h for the single tank to be desorbed, after which all the honeycomb carbons complete the regeneration treatment, the desorption gas concentration is 2.8g / m 3 , and the desorption efficiency is only about 70%.

[0060] The described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

Claims

1. A sequential batch high temperature thermal swing adsorption and activated carbon regeneration vertical kiln, characterized in that, The vertical kiln body is provided with high and low material level controllers, and is provided with a feeding port and an exhaust port at the top and a discharging port at the bottom.

2. The activated carbon high temperature thermal desorption and activated regeneration sequencing batch shaft kiln according to claim 1, characterized in that, The heating zone is divided into a preheating zone and a high-temperature zone from top to bottom.

3. The activated carbon high temperature thermal desorption and activated regeneration sequencing batch shaft kiln according to claim 2, characterized in that, The preheating zone is provided with heat exchange pipes.

4. The activated carbon high temperature thermal desorption and activated regeneration sequencing batch shaft kiln according to claim 2, characterized in that, The high-temperature zone is externally provided with a heating furnace wrapping the high-temperature zone of the vertical kiln body.

5. The activated carbon high temperature thermal desorption and activated regeneration sequencing batch shaft kiln according to claim 4, characterized in that, The heating furnace is a regenerative thermal oxidation furnace or a regenerative catalytic combustion furnace, and the vertical kiln body is provided with a plurality of heat exchange fins on the outer wall in the heating furnace.

6. The activated carbon high temperature thermal desorption and activated regeneration sequencing batch shaft kiln according to claim 2, characterized in that, The vertical kiln body is internally provided with a plurality of heat exchange fins in the high-temperature zone.

7. The activated carbon high temperature thermal desorption and activated regeneration sequencing batch shaft kiln according to claim 2, characterized in that, The cross section of the high-temperature zone is polygonal, and the cross-sectional area of the high-temperature zone is between 0.2 and 30 square meters.

8. The activated carbon high temperature thermal desorption and activated regeneration sequencing batch shaft kiln according to claim 1, characterized in that, The activating agent introduced by the gas inlet pipe is air, nitrogen, carbon dioxide or water vapor.

9. The activated carbon high temperature thermal desorption and activated regeneration sequencing batch shaft kiln according to claim 2, characterized in that, The wall of the preheating zone and the wall of the high-temperature zone, and the wall of the high-temperature zone and the wall of the cooling zone are separated by a heat insulation layer; the wall of the preheating zone and the wall of the high-temperature zone, and the wall of the high-temperature zone and the wall of the cooling zone are connected by flanges, and the heat insulation layer is located between the flanges; the material of the heat insulation layer is red steel paper, graphite gasket, asbestos aluminum silicate gasket or ceramic gasket.

10. The activated carbon high temperature thermal desorption and activated regeneration sequencing batch shaft kiln according to claim 2, characterized in that, The gas outlet of the gas inlet pipe is located near the bottom of the high-temperature zone; the high-temperature zone is also provided with a compressed air inlet pipe, and the gas outlet of the compressed air inlet pipe is located in the middle of the high-temperature zone.

Images