CN109675410B

CN109675410B - Operation method of cyclic regeneration process system for treating VOCs waste gas

Info

Publication number: CN109675410B
Application number: CN201910181996.3A
Authority: CN
Inventors: 史邦玺; 杨松
Original assignee: Shaanxi Anjin Technology Development Co ltd
Current assignee: SHAANXI ANJIN TECHNOLOGY DEVELOPMENT Co.,Ltd.
Priority date: 2019-03-11
Filing date: 2019-03-11
Publication date: 2021-08-06
Anticipated expiration: 2039-03-11
Also published as: CN109675410A

Abstract

The invention relates to the technical field of environmental protection, in particular to an operation method of a cyclic regeneration process system for treating VOCs waste gas. The method is characterized in that: the VOCs waste gas is effectively treated and the adsorbent is recycled through the desorption pyrolysis furnace, the chain transmission grate bed and the adsorbent moving bed.

Description

Operation method of cyclic regeneration process system for treating VOCs waste gas

Technical Field

The invention relates to the technical field of environmental protection, in particular to an operation method of a cyclic regeneration process system for treating VOCs waste gas.

Background

The industrial gaseous pollutants are the main sources of atmospheric environmental pollutants, wherein Volatile Organic Compounds (VOCs) are gaseous pollutants having serious harmful effects on the environment, and are also the sources of occupational disease harmful factors affecting the health of operators in workplaces, and the Volatile Organic Compounds (VOCs) are widely from the chemical industries of paints, coatings, lubricating oils, rubbers and the like. Due to the huge destructive effect on human bodies and natural environment, the state has come out of relevant laws and regulations to strictly control the treatment and discharge of the pollutants. The organic waste gas treatment technology commonly used at present comprises a combustion method, a chemical oxidation method, a chemical absorption method, an adsorption method, a biological method and the like. Because the VOCs waste gas that discharges in the actual production process is low concentration gaseous pollutant, usually adopt the adsorption method to administer, but the adsorbent adsorbs behind the VOCs saturation, becomes solid discarded pollutant, and the common way is with its regeneration. The Chinese invention patent (patent application number is 201210077796.1, the patent name is an electric heating type purification filter element for treating large-air-volume VOCs waste gas) discloses an electric heating type purification filter element for treating large-air-volume VOCs waste gas, which comprises a building enclosure and an adsorption bed layer filled in the building enclosure, and is characterized in that: the electric heating type purifying filter element is in a box-type polyhedral structure with a parallel air inlet surface and an air outlet surface, the air inlet surface and the air outlet surface are one or more layers of porous sieve plates or sieve meshes, and the enclosure structure comprises a sealing part and the air inlet surface and the air outlet surface; the adsorption bed layer is formed by compressing and superposing active carbon mesh cloth or porous active carbon fiber cloth through planes, any two opposite end faces or positions close to the two opposite end faces of the adsorption bed layer are provided with an electrode A and an electrode B, current can be introduced into the adsorption bed layer, a galvanic couple is arranged in the adsorption bed layer, and the temperature of the adsorption bed layer is tested in the process of electric heating; or, the appearance of the electric heating type purifying filter element is a cylinder, the enclosure structure consists of an inner cylinder, an end cover and an outer cylinder, the inner cylinder and the outer cylinder are respectively an air inlet surface and an air outlet surface, the inner cylinder is a hollow porous cylinder with one closed end, activated carbon mesh cloth or porous activated carbon fiber cloth is tightly wound on the inner cylinder to form an adsorption bed layer, the outer cylinder is made of one or more layers of net-shaped or porous materials, the end cover is used as an electrode or an electrode A and an electrode B are arranged on the upper end surface and the lower end surface of the adsorption bed layer or close to the upper end surface and the lower end surface of the adsorption bed layer, current can be introduced into the adsorption bed layer, a galvanic couple is arranged in the adsorption bed layer, and the temperature of the adsorption bed layer is tested in the electric heating process; the mesh shape of the activated carbon mesh cloth is circular, oval or polygonal, the inner diameters of any two longitudinally adjacent holes are larger than the hole walls of the two holes, and an adsorption bed layer is formed by adopting a longitudinal tight winding or plane compaction stacking mode; or the inner diameters of any two holes adjacent in the transverse direction are larger than the hole walls, and the adsorption bed layer is formed by adopting a transverse tight winding or plane compaction stacking mode; the porous activated carbon fiber cloth has round, oval or polygonal holes, the inner diameters of any two longitudinally adjacent holes are larger than the hole distance, and an adsorption bed layer is formed by adopting a longitudinal tight winding or plane compaction stacking mode; or the inner diameter of any two adjacent holes in the transverse direction is larger than the hole distance, and the adsorption bed layer is formed by adopting a transverse tight winding or plane compaction stacking mode; or the porous activated carbon fiber cloth has one or more of the shapes of long strips, X shapes, cross shapes, crescent shapes, arc shapes and L shapes, and circularly appears in a row along the longitudinal direction, the projections of any hole and the hole closest to the position in the adjacent row in the longitudinal and transverse directions are overlapped, and the adsorption bed layer is formed by adopting a longitudinal or transverse tightly winding or plane pressing and overlapping mode; or the projections of the holes in the transverse direction are overlapped, the projection length of the holes in the transverse direction is longer than the projection distance between two adjacent holes in the transverse direction in the longitudinal direction, or the projections of the holes in the longitudinal direction are overlapped, the projection length of the holes in the longitudinal direction is longer than the projection distance between two adjacent holes in the longitudinal direction in the transverse direction, and the adsorption bed layer is formed by adopting a mode of alternately and tightly winding the holes in the longitudinal direction and the transverse direction or pressing and overlapping the holes in a plane mode. The Chinese invention patent (patent application number 201510779318.9, patent name a composite VOCs adsorption concentration runner and its use method) discloses a composite VOCs adsorption concentration runner and its use method, which is characterized in that: the device is formed by coaxially and butt-jointing a molecular sieve rotating wheel and a honeycomb activated carbon rotating wheel with the same diameter, wherein the honeycomb activated carbon rotating wheel is positioned at the inlet side of VOCs (volatile organic compounds), each rotating wheel is provided with an adsorption area, a desorption area and a cooling area, a joint of the two rotating wheels is provided with an isolating ring, and the isolating ring is used for isolating the adsorption area, the desorption area and the cooling area of the two rotating wheels, and re-distributing air and reducing the wind resistance; the molecular sieve rotating wheel is obtained by attaching VOCs adsorbent on a honeycomb-shaped rotating wheel body in a spraying, leaching or dipping mode.

The prior art provides a technical solution of an enclosure structure and an electrothermal purification filter element with an air inlet surface and an air outlet surface which are one or more layers of porous sieve plates or adsorption bed layers filled with sieves for treating the actual problem of the large-air-volume VOCs waste gas, but does not provide a solution on how to replace the electrothermal purification filter element in normal production after the VOCs waste gas is saturated; in the second prior art, a technical solution of adsorption, desorption, concentration and combustion of the VOCs waste gas by adopting a molecular sieve rotating wheel and a honeycomb activated carbon rotating wheel is provided for solving the practical problem of VOCs waste gas treatment, and a technical solution of replacing the adsorbent after VOCs waste gas adsorption saturation is undoubtedly feasible by adopting a mechanical rotating wheel method, but the sealing problem must be solved by rotating wheel moving equipment, and particularly the problem of VOCs waste gas leakage caused by sealing failure under the continuous production condition in the rotating wheel replacing process is solved.

Disclosure of Invention

Aiming at the problems, the invention aims to provide an operation method of a cyclic regeneration process system for treating VOCs waste gas, which is characterized by comprising the following steps:

firstly, carrying out static test operation debugging and air induction system debugging of a desorption pyrolysis furnace and a chain transmission grate bed and joint debugging of an adsorbent moving bed before operation, firstly filling high-aluminum ball filler with the diameter of 20-25 mm into a flame path in the desorption pyrolysis furnace, conveying adsorbent to be desorbed to a vertical path in the desorption pyrolysis furnace body through a feeding system, filling the vertical path and a dipleg with adsorbent particles, cutting off a collection flue to test the working condition of the desorption pyrolysis furnace body, introducing airflow through an air injection collection box to sweep from a storage tank to the vertical path, ensuring that the airflow does not flee from the bottom of the dipleg and smoothly flows into a smoke discharge collection box through the flame path through grate bricks, adjusting the rotating speed of a chain wheel of the chain transmission bed to enable the adsorbent particles to be uniformly paved on the chain transmission grate bed row with the thickness not more than 10mm, wherein the chain transmission grate bed row comprises the chain wheel, the chain, the grate bed row and a grate bed row and an air distribution plate, the grate bed row comprises transverse pins and grate bed row sheets, the grate bed row sheets penetrate through the transverse pins one by one to be arranged into a string, the front grate bed row sheet and the rear grate bed row sheet are correspondingly connected in a staggered mode through the transverse pins to form the grate bed row, two ends of the transverse pins are fixedly connected to the chain, the chain wheel drives the chain to rotate so as to drive the grate bed row to move, air flow introduced into the sweeping grate bed row from the air distribution plate is observed, and an adsorbent particle layer on the grate bed row is required to present regular wave fluctuation, so that the static trial operation step is completed; and then filling the adsorbent moving bed body, the conical hopper and the material sealing pipe with the adsorbent, starting a driving device to drive a material unloading disc to rotate, discharging the adsorbent from the material sealing pipe normally, introducing VOCs waste gas into the central cylinder through the supporting arch, recording pressure drop data in the adsorbent moving bed body, adjusting the height of an adsorbent bed layer according to the pressure drop data, and debugging an induced draft system for introducing tail gas of an exhaust cylinder of the adsorbent moving bed into an air distribution plate of the chain transmission grate bed to operate normally.

And secondly, building a flame path and a vertical path of the desorption pyrolysis furnace body in a way of being adjacent to each other, dividing the desorption pyrolysis furnace body into an upper region, a lower region, a desorption pyrolysis region and a lower region by a middle partition arch coupon, namely dividing the flame path into an upper chamber, a lower chamber, a pyrolysis chamber and a heat storage chamber, dividing the vertical path into an upper chamber, a lower chamber, a desorption chamber and a sealing chamber, allowing high-temperature flue gas to enter the heating desorption pyrolysis furnace body from a flue collecting channel, keeping the temperature of the high-temperature flue gas at 260-280 ℃, and adjusting the excess air coefficient of the high-temperature flue gas to enable the oxygen content of the.

And step three, starting a feeding system to feed the vertical passage, continuously moving the adsorbent in the vertical passage from top to bottom under the action of gravity, blowing the adsorbent in the vertical passage by the air injection collection box to recycle the tail gas discharged by the flame passage, mixing the adsorbent with the desorbed VOCs waste gas, sending the mixture to the pyrolysis chamber through a grate brick at the bottom of the desorption chamber for oxidative pyrolysis, sending the high-temperature flue gas to the pyrolysis chamber through the smoke collection passage to mix with the desorbed VOCs waste gas, performing oxidative pyrolysis by using excessive oxygen in the high-temperature flue gas, enabling the tail gas to flow into the smoke exhaust collection box, and then discharging the tail gas to a chimney after waste heat recovery.

And step four, the desorbed adsorbent continuously moves under the action of gravity and is uniformly spread on the chain transmission grate bed rows through the dipleg, at the moment, the temperature of the adsorbent is higher than 250 ℃, the exhaust tail gas treated by the adsorbent moving bed is introduced by the air distribution plate, VOCs pollutants in the tail gas are adsorbed and purified, the desorbed adsorbent is excellent inert gas, the activation and regeneration of the adsorbent are not influenced, the adsorption efficiency is ensured, the temperature of the tail gas is equivalent to the ambient temperature, the tail gas is excellent coolant, the tail gas flows into the gaps of the adjacent grate bed row sheets to be blown, cooled and spread on the adsorbent on the chain transmission grate bed rows, the mass and heat transfer process with the adsorbent particles is rapidly completed, and then the tail gas is discharged through a smoke outlet of the kiln box.

Step five, the adsorbent activated and regenerated by the chain transmission grate bed is sent into an adsorbent moving bed body, a distributing device and a driving device are operated, the adsorbent moves and falls under the help of gravity and a discharging disc, VOCs waste gas is introduced into a central cylinder through a supporting arch and is spread to an adsorbent bed layer through a vent hole, the adsorbent adsorbs the VOCs waste gas to be saturated, particles carried by the trapped VOCs waste gas fill gaps among the particles to increase the pressure drop of the bed layer, the adsorbent continuously supplemented and updated through the distributing device keeps the designed pressure drop value, the adsorbent moves and is collected to a cone hopper and then is discharged through a material sealing pipe, then the adsorbent is sent to a desorption pyrolysis furnace for desorption pyrolysis treatment, the adsorbent is discharged from the material sealing pipe and is simultaneously used as filler seal to prevent VOCs waste gas from channeling to the bottom of the adsorbent moving bed body, therefore, VOCs waste gas is guided to be upwards purified by the adsorbent bed layer and then discharged from the exhaust funnel, and a small amount of accumulated ash in the central cylinder falls through the ash leakage port and is discharged along with the adsorbent.

The inventor discovers, it lasts purifies VOCs waste gas technical problem under the continuous production condition to solve, need to pack the adsorbent and constantly keep the looks contact with VOCs waste gas, and in time break away from the contact before the saturation, can adopt the grained layer to remove bed filter theory of operation, the adsorbent top-down continuous movement under the effect of gravity promptly, VOCs waste gas constantly carries from bottom to top and keeps the looks contact and mass transfer efficiency with the adsorbent, the adsorbent removes the bed body and can finely solve sealed problem for quiet equipment, the current practical problem of continuous production has been solved to adsorbent and VOCs waste gas continuous keeping the looks contact. Because the design of the adsorbent bed layer has a certain height, how to evenly distribute air in the adsorbent bed layer and ensure that the air distribution pipeline does not cause pipeline blockage due to sedimentation and dust deposition of particulate matters carried by VOCs waste gas is another practical technical problem to be solved, therefore, a central cylinder is designed in the adsorbent moving bed body, the peripheral wall of the central cylinder is evenly distributed with inclined downward ventilation holes, the top of the central cylinder is designed to be conical, and the bottom of the central cylinder is provided with a dust leakage hole. The center cylinder is positioned at the center of the adsorbent moving bed body through a support arch, the support arch is of a hollow structure, and VOCs waste gas can be introduced into the center cylinder. The adsorbent removes to collect after falling to the awl fill, for preventing that waste gas from fighting through the awl, has designed longer material seal pipe, and the adsorbent has blockked VOCs waste gas to adsorbent removal bed body bottom scurrying as packing seal when from the discharge of material seal pipe to guide VOCs waste gas upwards to discharge from the aiutage after the adsorbent bed purifies.

The inventor finds that after VOCs waste gas is purified by the adsorbent bed, the pressure drop of the VOCs waste gas passing through the adsorbent bed is increased, while the VOCs waste gas with different concentrations and the pressure drop of the adsorbent bed have a linear relation, in other words, under the condition that the ventilation flow of the VOCs waste gas is kept unchanged, the concentration of the VOCs waste gas and the pressure drop of the adsorbent bed can form a working curve, and the purposes of efficiently utilizing the adsorbent and continuously purifying the VOCs waste gas can be realized by adjusting the feeding amount of the adsorbent.

The inventor finds that the waste gas of VOCs, which is widely discharged from the chemical industries of paint, coating, painting, lubricating oil, rubber and the like, is mainly characterized by low concentration and large air quantity, and if the waste gas is purified by a reliable method of oxidation combustion, the consumed heat energy is high, and the principle of energy conservation and economy is not met. And desorption after the adsorbent is adsorbed to saturation, on the one hand, the adsorbent is regenerated and recycled, the generation of solid waste is avoided, on the other hand, the concentration of VOCs waste gas generated by desorption is higher, the process that the concentration of the original low-concentration VOCs waste gas is realized can be understood, and the condition of oxidation combustion purification treatment is possessed.

The inventor finds that the adsorbent is the basis for realizing the adsorption and separation process of the VOCs waste gas, and the adsorbents commonly used in the field of the adsorption and separation of the VOCs waste gas at present mainly comprise molecular sieves, activated carbon, silica-alumina gel, carbon molecules and the like. In the actual use process, the activated carbon is preferably used because of the following characteristics: one is the only industrial adsorbent used to accomplish the separation and purification process that does not require prior moisture removal; secondly, the activated carbon has a very large inner surface, and can adsorb more nonpolar and low-polar organic molecules than other adsorbents; the adsorption heat or bond strength of the three kinds of activated carbon is generally lower than that of other adsorbents, so that the adsorbed molecules are easy to analyze, and the energy consumption of the adsorbents in regeneration is also lower. The waste gas of VOCs generated in the chemical industries of paint, coating, painting, lubricating oil, rubber and the like has high humidity, and typical pollutants such as benzene, paraxylene and carbon tetrachloride are nonpolar and weakly polar organic molecules and need to be adsorbed and purified by adopting activated carbon.

The inventor finds that the VOCs waste gas is generally desorbed and regenerated by a heating method after being adsorbed to saturation by an active carbon adsorbent, and generally can not be regenerated by a mode of directly contacting with high-temperature flue gas, because the ignition point of the active carbon adsorbing the VOCs waste gas is lower, the active carbon is very easy to be oxidized (combusted), the desorption of the active carbon is realized by an indirect heating mode, in a desorption pyrolysis furnace, the desorbed VOCs waste gas is led out to be mixed with the high-temperature flue gas, and pollutant components in the VOCs waste gas, namely organic molecules are oxidized (combusted) to generate CO harmless to the environment₂、H₂O; the activated carbon moves to the chain transmission grate bed, the tail gas discharged after being treated by the adsorbent moving bed is recycled, and the activated carbon is swept and cooled by the tail gas, so that desorption and regeneration of the activated carbon adsorbent are realized.

The inventor finds that the Volatile Organic Compounds (VOCs) generally refer to volatile organic compounds with the melting point lower than room temperature and the boiling point between 50 ℃ and 250 ℃, that is, the desorption temperature of the adsorbent is higher than 250 ℃, the adsorbent must be cooled to reach room temperature after desorption, so that the desorption regeneration process is completed, and the tail gas discharged after being treated by the adsorbent moving bed is recycled as the coolant, so that the tail gas is utilized at a high value and is more economical.

The inventor finds that the VOCs waste gas adsorbent desorption pyrolysis furnace is designed with a flame path and a vertical path, the flame path is used for high-temperature flue gas to flow, the vertical path is used for the adsorbent to move and fall, and the flame path and the vertical path are adjacently built. The middle partition arch coupon divides the desorption pyrolysis furnace body into an upper region and a lower region, namely an upper region desorption pyrolysis region and a lower region heat accumulation region. The corresponding flame path is also divided into an upper chamber and a lower chamber, the lower chamber is a heat storage chamber and is responsible for introducing high-temperature flue gas of the flue collecting channel into the upper chamber, the upper chamber is a pyrolysis chamber and accumulates high-alumina ball particles, the high-temperature flue gas is mixed with the desorbed VOCs waste gas introduced through grate bricks at the bottom of the pyrolysis chamber, the high-temperature flue gas is oxidized and pyrolyzed by excessive oxygen in the high-temperature flue gas, tail gas flows into a smoke exhaust collection box, and the tail gas is discharged to a chimney after waste heat recovery; corresponding perpendicular way of the same reason also divide into two upper and lower rooms, and the lower chamber is the seal chamber, and the effect prevents that the VOCs waste gas of desorption from erecting the way bottom and scurrying, and the upper chamber is the desorption chamber, is connected with feed system, and top-down continuous movement in perpendicular way is said to the adsorbent under the effect of gravity, and feed system includes the storage tank, annotates wind collection box and introduces the tail gas of the emission of flame path and sweeps the adsorbent, mixes with the VOCs waste gas of desorption again and send to pyrolysis chamber oxidation pyrolysis through desorption room bottom grate brick.

The inventor finds that the ignition point of the activated carbon adsorbing the VOCs waste gas is lower, the activated carbon is very easy to be oxidized (combusted), activated carbon desorption is realized by adopting an indirect heating mode, in a desorption pyrolysis furnace, a flame path and a vertical path are adjacently built, high-temperature flue gas flows through the flame path, the activated carbon heating of the vertical path is realized, the desorbed VOCs waste gas is sent to a pyrolysis chamber through a grate brick at the bottom of the desorption chamber for oxidative pyrolysis, the purged airflow comes from the tail gas discharged from the flame path, the tail gas discharged from the flame path is inert gas with lower oxygen content, the activated carbon is ensured not to be oxidized and keep activity, and high-value utilization is realized while the recycling of the tail gas discharged from the flame path reduces pollutant discharge.

The inventor finds that the adsorbent after heating desorption must be cooled to reach room temperature to release adsorption heat so as to complete the desorption regeneration process, the cooling airflow comes from the tail gas discharged after the adsorbent moving bed treatment, and the recycling of the tail gas discharged after the adsorbent moving bed treatment is mainly due to the following reasons: firstly, the tail gas is discharged to the environment after being treated by the adsorbent moving bed, VOCs pollutants in the tail gas are adsorbed and purified, and the tail gas is excellent inert gas for the adsorbent after being desorbed and has no influence on the activation and regeneration of the adsorbent, thereby ensuring the adsorption efficiency; secondly, the temperature of the tail gas is equivalent to the ambient temperature, and the tail gas is an excellent coolant. The two characteristics enable the tail gas to be in direct contact with the adsorbent after heating desorption for full mass and heat transfer.

The inventor finds that, because the adsorbent needs to bear the scouring of air flow and the change of temperature and pressure, and needs higher strength and wear resistance, a cooling and activating device is designed to avoid the mutual collision and friction of adsorbent particles as much as possible so as to achieve the purpose of preventing the adsorbent particles from being broken, and a chain transmission grate bed is one of the solutions capable of solving the problems in the prior art. The chain transmission grate bed is provided with a material leg and a chain transmission grate bed body. The desorbed adsorbent continuously moves under the action of gravity and is uniformly spread on a chain transmission grate bed row through a dipleg, and meanwhile, the adsorbent is used as a filler in the dipleg to play a sealing role, so that the desorbed VOCs waste gas pollutants are prevented from escaping from the dipleg. The kiln box and the chain transmission grate bed row are designed on the chain transmission grate bed body, the kiln box is provided with a smoke exhaust port, the chain transmission grate bed row comprises a chain wheel, a chain, a grate bed row and a wind distribution plate, the grate bed row comprises transverse pins and grate bed row sheets, the grate bed row sheets penetrate through the transverse pins one by one to be arranged into a string, the front grate bed row sheet and the rear grate bed row sheet are connected in a staggered and corresponding mode through the transverse pins to form the grate bed row, two ends of the transverse pins are fixedly connected to the chain, and the chain wheel drives the chain to rotate so as to drive the grate bed row to move. The exhaust gas treated by the adsorbent moving bed is introduced by the air distribution plate, is sent into the kiln box through the gap between the adjacent grate bed row sheets, blows and cools the adsorbent spread on the chain transmission grate bed row, and is exhausted through the exhaust port.

Compared with the prior art, the invention at least has the following advantages: firstly, Volatile Organic Compounds (VOCs) generally refer to volatile organic compounds with a melting point lower than room temperature and a boiling point between 50 and 250 ℃, that is, the desorption temperature of an adsorbent is higher than 250 ℃, the adsorbent must be cooled to reach room temperature after desorption, so that the desorption regeneration process is completed, and the discharged tail gas after being treated by an adsorbent moving bed is recycled as a coolant, so that the tail gas is used at a high value and is more economic; secondly, the ignition point of the activated carbon adsorbing the VOCs waste gas is low, the activated carbon is very easy to oxidize (burn), the activated carbon desorption is realized by adopting an indirect heating mode, a flame path and a vertical path are adjacently built in a desorption pyrolysis furnace, high-temperature flue gas flows through the flame path, the activated carbon of the vertical path is heated, the desorbed VOCs waste gas is sent to a pyrolysis chamber through a grate brick at the bottom of the desorption chamber for oxidative pyrolysis, the swept airflow comes from the tail gas discharged from the flame path, and the tail gas discharged from the flame path is inert gas with low oxygen content, so that the activated carbon is ensured not to be oxidized and keep activity, and the recycling of the tail gas discharged from the flame path reduces the emission of pollutants and simultaneously realizes high-value utilization; thirdly, the adsorbent after heating desorption must be cooled to reach room temperature to release adsorption heat so as to complete the desorption regeneration process, the cooling airflow comes from the tail gas discharged after the adsorbent moving bed treatment, and the recycling of the tail gas discharged after the adsorbent moving bed treatment is selected mainly has the following main reasons: firstly, the tail gas is discharged to the environment after being treated by the adsorbent moving bed, VOCs pollutants in the tail gas are adsorbed and purified, and the tail gas is excellent inert gas for the adsorbent after being desorbed and has no influence on the activation and regeneration of the adsorbent, thereby ensuring the adsorption efficiency; secondly, the temperature of the tail gas is equivalent to the ambient temperature, and the tail gas is an excellent coolant. The two characteristics enable the tail gas to be in direct contact with the adsorbent after heating desorption for sufficient mass and heat transfer; and fourthly, adopting a working principle of a granular layer moving bed filter, namely continuously moving the adsorbent from top to bottom under the action of gravity, continuously conveying VOCs waste gas from bottom to top to keep the contact and mass transfer efficiency with the adsorbent, well solving the sealing problem for static equipment by a movable adsorbent bed body, and continuously keeping the contact between the adsorbent and the VOCs waste gas to solve the existing practical problem of continuous production.

Drawings

FIG. 1 is a schematic view of the structure of the circulating regeneration process for treating VOCs waste gas according to the present invention.

FIG. 2 is a schematic diagram of the arrangement structure of the section A-A of the operation method of the cyclic regeneration process system for treating VOCs waste gas.

FIG. 3 is a schematic diagram of a partial enlarged structure B of the operation method of the VOCs-treating waste gas recycling process system of the present invention.

FIG. 4 is a schematic diagram of a partial enlarged structure C of the operation method of the VOCs-treating waste gas recycling process system of the present invention.

FIG. 5 is a schematic diagram of a partial enlarged structure D of the operation method of the VOCs-treating waste gas recycling process system of the present invention.

FIG. 6 is a schematic diagram of the arrangement structure of the E-E section of the operation method of the cyclic regeneration process system for treating VOCs waste gas.

FIG. 7 is a schematic diagram of a partial enlarged structure F of the operation method of the VOCs-treating waste gas recycling process system of the present invention.

I-desorption pyrolysis furnace II-chain transmission grate bed III-induced air system IV-adsorbent moving bed

1-feeding system 2-storage tank 3-air injection header 4-smoke exhaust header

5-desorption pyrolysis furnace body 6-vertical passage 7-fire passage 8-grate brick 9-middle partition arch coupon

10-flue collection channel 11-pyrolysis chamber 12-desorption chamber 13-heat storage chamber 14-sealing chamber

15-dipleg 16-chain transmission grate bed body 17-smoke outlet 18-kiln box 19-chain

20-air distribution plate 21-chain wheel 22-chain transmission grate row 23-grate row sheet 24-transverse pin

25-grate bar 26-drive device 27-discharge tray 28-support arch

29-adsorbent moving bed 30-central cylinder 31-vent 32-distributor

33-exhaust funnel 34-material sealing pipe 35-cone 36-ash leakage port.

Detailed Description

The invention is further described with reference to the following detailed description of embodiments and drawings.

As shown in fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, fig. 6 and fig. 7, an operation method of a cyclic regeneration process system for treating VOCs waste gas is characterized in that:

firstly, carrying out static test operation debugging on a desorption pyrolysis furnace I and a chain transmission grate bed II and joint debugging of an induced air system III and an adsorbent moving bed IV before operation, firstly filling a flame path 7 in the desorption pyrolysis furnace I with high-alumina ball filler with the particle diameter of 20-25 mm, conveying an adsorbent to be desorbed to a vertical path 6 in a desorption pyrolysis furnace body 5 through a feeding system 1, filling the vertical path 6 and a dipleg 15 with the adsorbent particles, cutting off a collection flue 10 to test the working condition of the desorption pyrolysis furnace body 5, introducing airflow through an air injection collection box 3 to sweep from a storage tank 2 to the vertical path 6, ensuring that the airflow does not flee from the bottom of a dipleg 15 and smoothly flows into a smoke discharge collection box 4 through the flame path 7 through a grate brick 8, adjusting the rotating speed of a chain wheel 21 of the chain transmission grate bed II, and uniformly spreading the adsorbent particles on a chain transmission bed row 22 with the thickness not more than 10mm, the chain transmission grate bed row 22 comprises a chain wheel 21, a chain 19, a grate bed row 25 and an air distribution plate 20, the grate bed row 25 comprises a transverse pin 24 and grate bed row pieces 23, the grate bed row pieces 23 penetrate through the transverse pin 24 one by one to be arranged in a string, the front grate bed row piece 23 and the rear grate bed row piece 23 are correspondingly connected in a staggered mode through the transverse pin 24 to form the grate bed row 25, two ends of the transverse pin 24 are fixedly connected to the chain 21, the chain wheel 21 drives the chain 19 to rotate so as to drive the grate bed row 25 to move, the air flow introduced into the grate bed row 25 from the air distribution plate 20 is observed, and an adsorbent particle layer on the grate bed row 25 is required to present regular wave fluctuation, so that the static test operation step is completed; and then filling the adsorbent moving bed body 29, the conical hopper 35 and the material sealing pipe 34 with the adsorbent, starting the driving device 26 to drive the material discharging disc 27 to rotate, discharging the adsorbent from the material sealing pipe 34 normally, introducing VOCs waste gas into the central cylinder 30 through the supporting arch 28, recording pressure drop data in the adsorbent moving bed body 29, adjusting the height of an adsorbent bed layer according to the pressure drop data, and debugging and conveying tail gas of the exhaust cylinder 33 of the adsorbent moving bed IV into an air induction system III of the air distribution plate 20 of the chain transmission grate bed II to run normally.

And secondly, a flame path 7 and a vertical path 6 of the desorption pyrolysis furnace body 5 are adjacently built, the desorption pyrolysis furnace body 5 is divided into an upper region, a desorption pyrolysis region and a lower region by a middle partition arch coupon 9, the upper region is a desorption pyrolysis region, the lower region is a heat storage region, the flame path is divided into an upper chamber, a lower chamber, a pyrolysis chamber 11 and a heat storage chamber 13, the vertical path 6 is divided into an upper chamber, a lower chamber, a desorption chamber 12 and a sealing chamber 14, high-temperature flue gas enters the heating desorption pyrolysis furnace body 5 from a flue 10, the temperature of the high-temperature flue gas is kept at 260-280 ℃, and the excess air coefficient of the high-temperature flue gas is adjusted to enable the oxygen content of the high-temperature flue gas to be not lower than 14%.

And step three, starting the feeding system 1 to feed the vertical channel 6, enabling the adsorbent to continuously move in the vertical channel 6 from top to bottom under the action of gravity, blowing the adsorbent in the vertical channel 6 by the air injection header 3 to recycle the tail gas discharged by the flame channel 7, mixing with the desorbed VOCs waste gas, sending the mixture to the pyrolysis chamber 11 through a grate brick 8 at the bottom of the desorption chamber 12 for oxidative pyrolysis, sending the high-temperature flue gas to the pyrolysis chamber 11 through a flue gas collecting channel 10 to be mixed with the desorbed VOCs waste gas, carrying out oxidative pyrolysis on the excessive oxygen in the high-temperature flue gas, enabling the tail gas to flow into a smoke exhaust header 4, and then discharging the tail gas to a chimney after waste heat recovery.

And step four, the desorbed adsorbent continuously moves under the action of gravity and is uniformly spread on the chain transmission grate bed row 22 through the dipleg 15, at the moment, the temperature of the adsorbent is higher than 250 ℃, the exhaust tail gas treated by the adsorbent moving bed IV is introduced through the air distribution plate 20, VOCs pollutants in the tail gas are adsorbed and purified, the desorbed adsorbent is excellent inert gas and has no influence on the activation and regeneration of the adsorbent, the adsorption efficiency is ensured, the temperature of the tail gas is equivalent to the ambient temperature and is excellent coolant, the tail gas flows into the gap of the adjacent grate bed row sheets 23 to be purged, cooled and spread on the chain transmission grate bed row 22, the process of mass and heat transfer with the adsorbent particles is rapidly completed, and then the tail gas is discharged through the smoke outlet 17 of the box 18.

Step five, the adsorbent activated and regenerated by the chain transmission grate bed II is sent into an adsorbent moving bed body 29, a distributing device 32 and a driving device 26 are operated, the adsorbent moves and falls under the help of gravity and a discharging disc 27, VOCs waste gas is introduced into a central cylinder 30 through a supporting arch 28 and is spread to an adsorbent bed layer through a vent hole 31, the adsorbent adsorbs the VOCs waste gas to be saturated, particles carried by the trapped VOCs waste gas are filled in gaps among the particles to cause the increase of bed layer pressure drop, the adsorbent continuously supplemented and updated through the distributing device 32 keeps a designed pressure drop value, the adsorbent moves and is collected into a cone hopper 35 and then is discharged through a material sealing pipe 34, then the adsorbent is sent to a desorption pyrolysis furnace I for desorption pyrolysis treatment, the adsorbent is discharged from the material sealing pipe 34 and is used as filler seal to prevent the VOCs waste gas from flowing out to the bottom of the adsorbent moving bed body 29, so that the VOCs waste gas is guided upwards to be purified through an exhaust pipe 33 and then discharged from the exhaust pipe 33, a small amount of accumulated ash in the central cartridge 30 falls through the ash leakage port 36 and is discharged with the adsorbent.

Variations and modifications to the above-described embodiments may occur to those skilled in the art, which fall within the scope and spirit of the above description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. A method for operating a cyclic regeneration process system for treating VOCs waste gas is characterized by comprising the following steps: firstly, carrying out static test operation debugging and air induction system and adsorbent moving bed joint debugging of a desorption pyrolysis furnace and a chain transmission grate bed before operation, firstly filling high-aluminum ball filler with the diameter of 20-25 mm into a flame path in the desorption pyrolysis furnace, conveying adsorbent to be desorbed to a vertical path in the desorption pyrolysis furnace body through a feeding system, filling the vertical path and a dipleg with adsorbent particles, cutting off a collection flue to test the working condition of the desorption pyrolysis furnace body, introducing airflow through an air injection collection box to sweep from a storage tank to the vertical path, ensuring that the airflow does not flee from the bottom of the dipleg and smoothly flows into a smoke discharge collection box through the flame path through grate bricks, adjusting the chain wheel rotating speed of the chain transmission bed to enable the adsorbent particles to be uniformly paved on the chain transmission grate bed row with the thickness not more than 10mm, observing the airflow introduced from an air distribution plate to the sweeping grate bed row, wherein the adsorbent particle layer on the chain transmission grate bed row is in regular wave, thereby completing the static commissioning step; filling the adsorbent moving bed body, the conical hopper and the material sealing pipe with the adsorbent, then starting a driving device to drive a material unloading disc to rotate, wherein the adsorbent is normally discharged from the material sealing pipe, then introducing VOCs waste gas into a central cylinder through a supporting arch, recording pressure drop data in the adsorbent moving bed body, adjusting the height of an adsorbent bed layer according to the pressure drop data, and debugging an induced air system for introducing tail gas of an exhaust cylinder of the adsorbent moving bed into an air distribution plate of a chain transmission grate bed to normally operate; step two, designing a flame path and a vertical path for circulating high-temperature flue gas by the VOCs waste gas adsorbent desorption pyrolysis furnace, wherein the vertical path is used for allowing the adsorbent to move and fall down, the corresponding flame path is also divided into an upper chamber and a lower chamber, the lower chamber is a heat storage chamber and is responsible for introducing the high-temperature flue gas of the flue collection channel into the upper chamber, the upper chamber is a pyrolysis chamber and accumulates high-alumina ball particles, the high-temperature flue gas is mixed with the desorbed VOCs waste gas introduced through a grate brick at the bottom of the pyrolysis chamber, the high-temperature flue gas is oxidized and pyrolyzed by excessive oxygen in the high-temperature flue gas, the tail gas flows into a smoke exhaust collection box, and the tail gas is discharged to a chimney after waste heat recovery; in the same way, the corresponding vertical channel is also divided into an upper chamber and a lower chamber, the lower chamber is a sealed chamber and is used for preventing desorbed VOCs waste gas from escaping from the bottom of the vertical channel, the upper chamber is a desorption chamber and is connected with a feeding system, an adsorbent continuously moves in the vertical channel from top to bottom under the action of gravity, the feeding system comprises a storage tank and an air injection header, the air injection header introduces tail gas discharged by a fire channel into a blowing adsorbent and then is mixed with the desorbed VOCs waste gas and sent to a pyrolysis chamber through a grate brick at the bottom of the desorption chamber for oxidative pyrolysis, the high-temperature flue gas enters a heating desorption pyrolysis furnace body from a flue and keeps the temperature of the high-temperature flue gas at 260-280 ℃, and the excess air coefficient of the high-temperature flue gas is adjusted so that the oxygen content of the high-temperature flue gas is not lower than 14%; starting a feeding system to feed to the vertical passage, continuously moving the adsorbent in the vertical passage from top to bottom under the action of gravity, blowing the adsorbent in the vertical passage by using an air injection collection box to recycle the tail gas discharged from the flame passage, mixing the adsorbent with the desorbed VOCs waste gas, sending the mixture to the pyrolysis chamber through a grate brick at the bottom of the desorption chamber for oxidative pyrolysis, sending the high-temperature flue gas to the pyrolysis chamber through a flue collection channel to be mixed with the desorbed VOCs waste gas, performing oxidative pyrolysis by using excessive oxygen in the high-temperature flue gas, enabling the tail gas to flow into a smoke discharge collection box, recycling waste heat and then discharging the tail gas to a chimney, enabling the ignition point of the activated carbon adsorbing the VOCs waste gas to be lower, enabling the activated carbon to be easily oxidized, realizing activated carbon desorption by adopting an indirect heating mode, building the flame passage and the vertical passage in the desorption pyrolysis furnace adjacently, enabling the high-temperature flue gas to flow through the flame passage, realizing heating of the activated carbon in the vertical passage, and sending the desorbed VOCs waste gas to the pyrolysis chamber through the grate brick at the bottom of the desorption chamber for oxidative pyrolysis, the blown gas flow comes from the tail gas discharged by the flame path, and the tail gas discharged by the flame path is inert gas with low oxygen content, so that the activated carbon is ensured not to be oxidized and keeps activity, and the recycling of the tail gas discharged by the flame path reduces the emission of pollutants and simultaneously realizes high-value utilization; step four, the adsorbent after being heated and desorbed is cooled to reach room temperature, adsorption heat is released, the desorption and regeneration process can be completed, cooling air flow comes from tail gas discharged after being treated by the adsorbent moving bed, the desorbed adsorbent continuously moves under the action of gravity and is uniformly spread on the chain transmission grate bed row through the dipleg, the temperature of the adsorbent is higher than 250 ℃, the exhaust gas discharged after being treated by the adsorbent moving bed is introduced by the air distribution plate, the tail gas flows into the gaps of the adjacent grate bed row sheets to be blown, cooled and spread on the chain transmission grate bed row, the mass and heat transfer process with the adsorbent particles is rapidly completed, and then the exhaust gas is discharged through a smoke outlet of the kiln box; step five, the adsorbent activated and regenerated by the chain transmission grate bed is sent into an adsorbent moving bed body, a distributing device and a driving device are operated, the adsorbent moves and falls under the help of gravity and a discharging disc, VOCs waste gas is introduced into a central cylinder through a supporting arch and is spread to an adsorbent bed layer through a vent hole, the adsorbent adsorbs the VOCs waste gas and tends to be saturated, particles carried by the trapped VOCs waste gas fill mutual gaps to cause increase of bed layer pressure drop, the adsorbent continuously supplemented and updated through the distributing device keeps a designed pressure drop value, the adsorbent moves and is collected to a cone hopper and then is discharged through a material sealing pipe, then the adsorbent is sent to a desorption pyrolysis furnace for desorption pyrolysis treatment, the adsorbent is discharged from the material sealing pipe and also serves as filler sealing to prevent the VOCs waste gas from flowing out to the bottom of the adsorbent moving bed body, so that the VOCs waste gas is guided to be discharged from an exhaust cylinder after being purified by the adsorbent bed layer upwards, a small amount of accumulated ash in the central cylinder falls through an ash leakage port and is discharged along with the adsorbent, the technical problem of continuous purification of VOCs waste gas under continuous production conditions is solved by continuously keeping adsorbent packing in contact with the VOCs waste gas continuously and timely separating from the contact before saturation, and adopting the operating principle of a granular layer moving bed filter, namely, the adsorbent continuously moves from top to bottom under the action of gravity, VOCs waste gas is continuously conveyed from bottom to top and keeps in contact with the adsorbent and mass transfer efficiency, an adsorbent moving bed body is a static device and can well solve the sealing problem, the continuous keeping in contact with the VOCs waste gas solves the existing practical problem of continuous production, because the adsorbent bed layer is designed with a certain height, how to uniformly distribute air in the adsorbent bed layer and ensure that an air distribution pipeline is not blocked due to sedimentation and dust accumulation of particulate matters carried by the VOCs waste gas, a central cylinder is designed in the adsorbent moving bed body, the periphery wall of the central cylinder is uniformly provided with downward inclined vent holes, the top of the central cylinder is designed to be conical, the bottom of the central cylinder is provided with an ash leakage opening, the central cylinder is positioned at the center of the adsorbent moving bed body through a supporting arch, the supporting arch is internally provided with a hollow structure, VOCs waste gas can be introduced into the central cylinder, the adsorbent moves down and is collected into a conical hopper, a longer material sealing pipe is designed for preventing the waste gas from channeling out through the conical hopper, the adsorbent is discharged from the material sealing pipe and also used as a filler seal to prevent the VOCs waste gas from channeling out to the bottom of the adsorbent moving bed body, and therefore the VOCs waste gas is guided to be upwards purified through an adsorbent bed layer and then discharged from an exhaust funnel.

2. The method of claim 1 for operating a cyclic regeneration process system for treating VOCs exhaust gas, wherein the cyclic regeneration process system comprises: the chain transmission grate bed row comprises a chain wheel, a chain, a grate bed row and an air distribution plate, the grate bed row comprises transverse pins and grate bed row pieces, the grate bed row pieces penetrate through the transverse pins one by one to be arranged into a string, the front grate bed row piece and the rear grate bed row piece are correspondingly connected in a staggered mode through the transverse pins to form the grate bed row, two ends of the transverse pins are fixedly connected to the chain, and the chain wheel drives the chain to rotate so as to drive the grate bed row to move.

3. The method of claim 1 for operating a cyclic regeneration process system for treating VOCs exhaust gas, wherein the cyclic regeneration process system comprises: the flame path and the vertical path of the desorption pyrolysis furnace body are adjacently built, the middle partition arch coupon divides the desorption pyrolysis furnace body into an upper region and a lower region, namely, the upper region desorption pyrolysis region, the lower region heat accumulation region divides the flame path into an upper chamber and a lower chamber, namely, a pyrolysis chamber and a heat accumulation chamber, and divides the vertical path into an upper chamber and a lower chamber, namely, a desorption chamber and a sealing chamber.

4. The method of claim 1 for operating a cyclic regeneration process system for treating VOCs exhaust gas, wherein the cyclic regeneration process system comprises: VOCs pollutants in the tail gas are adsorbed and purified, the adsorbent after desorption is excellent inert gas, the activation and regeneration of the adsorbent are not affected, the adsorption efficiency is ensured, the temperature of the tail gas is equivalent to the ambient temperature, and the adsorbent is excellent coolant.