CN117570455A

CN117570455A - Evaporation tail gas heat recovery device for formaldehyde production

Info

Publication number: CN117570455A
Application number: CN202311784369.1A
Authority: CN
Inventors: 孙成海; 郭长发; 段瑜; 陈钰龙; 张家国; 鹿占栋
Original assignee: Shandong Hansheng New Energy Technology Co ltd
Current assignee: Shandong Hansheng New Energy Technology Co ltd
Priority date: 2023-12-23
Filing date: 2023-12-23
Publication date: 2024-02-20

Abstract

The invention relates to a device for recovering heat of evaporation tail gas in formaldehyde production, which comprises a first shell, a second shell, a third shell, a drying module, a buffer module and an input module. According to the invention, the tail gas is dried to improve the combustibility of the tail gas, and the dried tail gas is conveyed to the boiler for combustion, and when the tail gas is produced excessively and conveyed excessively, the tail gas conveyed to the boiler is always kept in a stable range between one increment and one decrement by means of the split-flow speed reduction input and the expansion opening output, so that the tail gas entering the boiler is fully combusted, and the conditions of frying furnaces and the like caused by insufficient accumulation of the tail gas in the boiler are avoided.

Description

Evaporation tail gas heat recovery device for formaldehyde production

Technical Field

The invention relates to the technical field related to formaldehyde production, in particular to a heat recovery device for evaporation tail gas in formaldehyde production.

Background

Formaldehyde is a chemical raw material widely applied to the industries of chemical engineering, medicine and the like. The main raw material for producing formaldehyde is methanol, under the condition of excessive air, methanol gas and air are mixed on a catalyst for oxidation reaction, and the generated gaseous formaldehyde is cooled and absorbed to form formaldehyde solution with the concentration of 37 percent. The tail gas generated by the formaldehyde production process contains about 17 percent of hydrogen, and also contains certain organic components such as carbon monoxide, methane and the like, and the combustible gases can be put into a boiler for combustion, and the generated steam, heat and the like can be put into production and living.

In the existing tail gas recovery process, for example, chinese patent publication No. CN116196711a discloses a tail gas recovery heating device for formaldehyde production system, which comprises a gas filtering barrel, a sealing sleeve, a connecting rod, a driving shaft, a guiding groove and a gas inlet hole, when the device is used, the device is connected with a device for generating tail gas in formaldehyde production through a gas inlet pipe, and the quality of impurities in gas is increased through the contact of the gas and liquid, so that the impurities in the gas can be effectively treated when the device is treated.

In the prior art, the impurity in the tail gas is mainly removed so as to avoid affecting the efficiency of heating the tail gas by subsequent combustion, however, the tail gas quantity generated in the formaldehyde production process is not fixed, the tail gas quantity changes along with the actual production condition, the change of the tail gas generation quantity possibly causes unstable combustion condition in the boiler, the flame in the boiler is large and small, the water heating work is not facilitated, when the quantity of the tail gas is excessive, a large quantity of tail gas flows into the boiler to cause incomplete combustion, the incomplete combustion of the tail gas is remained in the boiler, the incomplete combustion of the tail gas possibly causes incomplete heat release, and the resource waste is caused.

Based on this, the above-mentioned prior art has room for improvement.

Disclosure of Invention

In order to stably and continuously convey tail gas generated in the formaldehyde production process into a boiler for combustion and ensure the sufficiency of tail gas combustion, the application provides a formaldehyde production evaporation tail gas heat recovery device which adopts the following technical scheme:

the utility model provides a formaldehyde production evaporation tail gas heat recovery device, which comprises a first shell, the second casing, the third casing, drying module, buffer module, input module, the right side of first casing is connected gradually and is provided with the second casing, the third casing, drying module sets up in the first casing, drying module improves the flammability of tail gas through getting rid of the vapor in the tail gas, buffer module sets up in the second casing, buffer module possesses and always leads to the station, a reposition of redundant personnel station, buffer module carries out the switching between leading to the station according to the delivery of tail gas, reposition of redundant personnel station is in order to keep the stability of tail gas delivery volume, input module sets up in the third casing, input module is with the continuous stable burning of leading to of tail gas in the boiler, thereby input module and buffer module control the delivery volume of tail gas through the cooperation of linkage module when the tail gas is carried excessively, thereby guarantee the stability of tail gas delivery and tail gas burning sufficiency.

Preferably, the right side wall of the third shell is provided with a first conveying port and a second conveying port from bottom to top in sequence, and the first conveying port and the second conveying port are communicated with the boiler.

Preferably, the drying module comprises molecular sieve drying cylinders, the molecular sieve drying cylinders are arranged in the first shell in parallel, the number of the molecular sieve drying cylinders is two, molecular sieve drying agents are arranged in the molecular sieve drying cylinders, the molecular sieve drying agents are artificially synthesized and have strong adsorptivity to water molecules, the dryer works at room temperature, and the dryer is regenerated at the temperature of three hundred and fifty ℃. Two molecular sieve drying cylinders are connected in parallel, one of the two molecular sieve drying cylinders works, and the other molecular sieve drying cylinder can only perform regeneration treatment. The two molecular sieve drying cylinders work and regenerate alternately to ensure continuous operation of the equipment.

Preferably, the buffer module comprises a main runner, a first split-flow port, a second split-flow port, a split-flow passage, a first partition plate, a second partition plate, a plugging plate, a rotating rod and a switching device, wherein the main runner is arranged in the middle of the second shell, the first split-flow port is symmetrically arranged on the upper bottom surface and the lower bottom surface of the left side of the main runner, the second split-flow port is symmetrically arranged on the upper bottom surface and the lower bottom surface of the right side of the main runner, the first split-flow port and the second split-flow port are communicated through the split-flow passage, the aperture of the split-flow passage is smaller than that of the main runner, the small aperture limits the air inflow of tail gas, the split-flow passage is of a zigzag structure, the distance of the tail gas flowing through is prolonged, so that the flow velocity of the tail gas is reduced, the first partition plate is arranged in the first split-flow port in a sliding mode, the first partition plate and the second partition plate in an initial state are respectively closed, the split-flow port in the main runner is rotationally arranged through the rotating rod, the plugging plate in the main runner, the initial state of the plugging plate and the side wall of the main runner are in parallel, at the side wall of the initial state, the plugging plate and the main runner are connected with the rotating rod and the main runner side wall are in the vertical state, and the main runner side wall is in the vertical state, at the state, and the reset torque spring is arranged.

Preferably, the switching device comprises a driving gear, a first rack plate, a second rack plate and a matching part, wherein the driving gear is sleeved on the periphery of the rotating rod, the first rack plate is arranged on the first partition plate, the first rack plate is meshed with the driving gear, the second rack plate is arranged on the second partition plate, the second rack plate is meshed with the driving gear, the matching part is arranged on the top of the rotating rod, and an extrusion piece matched with the matching part is arranged on the right side wall of the second shell in a left-right sliding manner.

Preferably, the input module comprises a floating plate, a sliding column, a first valve, an extension spring, a blocking piece, a second valve and an air passing hole, wherein the floating plate is arranged in the third shell through the sliding column in a vertical sliding mode, a compression spring is connected between the floating plate and the sliding column and plays a reset role, the first valve is arranged on the right side wall of the third shell through the rotation of an auxiliary piece, the position of the first valve corresponds to the first conveying port, the extension spring is connected between the first valve and the sliding column, the extension spring keeps the trend of pulling the first valve to the left side, the blocking piece is arranged at the lower end of the floating plate, the position of the blocking piece corresponds to the first valve, the blocking piece in an initial state extrudes the first valve to a closed state, the second valve is arranged in the second conveying port in a sliding mode, the second valve is of a hollow cylinder structure with a closed left side, and the air passing hole is uniformly formed in the second valve along the circumferential direction.

Preferably, the linkage module comprises a sliding frame, a reset spring and a pressure trigger mechanism, wherein the sliding frame is arranged at the top end of the third shell in a left-right sliding manner, the left end of the sliding frame is contacted with the extrusion piece, the right end of the sliding frame is connected with the second valve, the reset spring is connected between the sliding frame and the third shell, the reset spring plays a reset role, and the pressure trigger mechanism is arranged on the inner wall of the top of the third shell.

Preferably, the pressure triggering mechanism comprises an air cylinder, a piston, an L-shaped plate, a connecting rod, a movable plate, a locking plate and an unlocking plate, wherein the air cylinder is arranged in the inner wall of the top of the third shell, the piston is arranged in the air cylinder in a sliding manner left and right, the L-shaped plate is arranged at the right end of the piston, the connecting rod is connected between the L-shaped plate and the upper surface of the floating plate through a pin shaft, the rising floating plate drives the L-shaped plate to move leftwards through the connecting rod, the movable plate is arranged at the left end of the air cylinder in a sliding manner left and right, the upper end of the movable plate is arranged at the bottom surface of the sliding frame, the lower end of the movable plate is provided with a mounting groove, the upper and lower sliding of the mounting groove is provided with the locking plate, a return spring is connected between the locking plate and the mounting groove, the return spring plays a resetting role, the bottom surface of the air cylinder is provided with the locking groove corresponding to the position of the locking plate, the locking plate is inserted into the locking groove, the position of the movable plate is temporarily locked, the unlocking plate is arranged in the locking groove, the right side of the bottom end of the unlocking plate is in favor of the extrusion round angle, the left end of the unlocking plate corresponds to the left end position of the L-shaped plate, the L-shaped plate moves leftwards, the L extrusion unlocking plate is pushed upwards, and the unlocking plate moves upwards from the locking groove to the locking groove.

In summary, the beneficial technical effects of the present application are as follows:

according to the evaporation tail gas heat recovery device for formaldehyde production, the tail gas is dried to improve the combustibility of the tail gas, and the dried tail gas is conveyed to the boiler to be combusted;

the first conveying port is a main air port, the tail gas is not conveyed into the boiler immediately after entering the third shell and is accumulated firstly, when the pressure of the tail gas accumulated in the third shell rises to a limiting value, the first valve is opened, the tail gas is conveyed into the boiler for combustion under a relatively stable pressure, and the first valve is always kept in an open state as long as the pressure in the third shell is maintained at or above the limiting value;

the second valve is an overload pressure relief valve, the second valve monitors the pressure in the third shell in real time, when the pressure in the third shell reaches a saturation value, the second valve is immediately opened, and as the pressure in the third shell exceeds the saturation value more, the opening of the second valve is larger, the conveying port conveys more tail gas into the boiler, and when the pressure in the third shell is lower than the saturation value, the second valve is immediately closed.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a cross-sectional view of the overall structure of the present invention;

FIG. 3 is an enlarged view of a portion of FIG. 2A in accordance with the present invention;

FIG. 4 is an enlarged view of a portion of the invention at B of FIG. 2;

FIG. 5 is a schematic view of the structure of the drying module of the present invention;

FIG. 6 is a schematic diagram of the structure of a buffer module of the present invention;

FIG. 7 is a schematic diagram of a switching device according to the present invention;

FIG. 8 is a schematic diagram of the input module of the present invention;

fig. 9 is a schematic view of the structure between the main runner and the plugging plate.

Reference numerals illustrate: 1. a first housing; 2. a second housing; 3. a third housing; 4. a drying module; 5. a buffer module; 6. an input module; 7. a linkage module; 31. a first conveying port; 32. a second conveying port; 51. a main flow passage; 511. a shunt port I; 512. a shunt port II; 52. a sub-runner; 53. a first partition plate; 54. a second partition plate; 55. a plugging plate; 56. a rotating lever; 57. a switching device; 571. a drive gear; 572. a first rack plate; 573. a second rack plate; 574. a mating portion; 61. a floating plate; 62. a sliding column; 63. a first valve; 64. a tension spring; 65. a blocking member; 66. a second valve; 661. air passing holes; 71. a carriage; 72. a return spring; 73. a pressure trigger mechanism; 731. an air pressure cylinder; 732. a piston; 733. an L-shaped plate; 734. a connecting rod; 735. a movable plate; 736. a locking plate; 737. unlocking plate.

Detailed Description

The present application is described in further detail below in conjunction with fig. 1-9.

The embodiment of the application discloses evaporation tail gas heat recovery device for formaldehyde production, through carrying out the flammability that dry promotion tail gas to the tail gas, the tail gas after the drying is carried in the boiler by stability and is burnt, when the tail gas output is too much, carry when the surprise, this application guarantees through reposition of redundant personnel deceleration input, the mode of extension opening output that carry the tail gas in the boiler and remains in a stable within range throughout, guarantees stability, the sufficiency of burning.

Referring to fig. 1 and 2, the device for recovering heat of evaporation tail gas in formaldehyde production comprises a first shell 1, a second shell 2, a third shell 3, a drying module 4, a buffer module 5, an input module 6 and a linkage module 7, wherein the second shell 2 and the third shell 3 are sequentially communicated with the right side of the first shell 1, the drying module 4 is arranged in the first shell 1, the drying module 4 improves the flammability of tail gas by removing water vapor in the tail gas, the buffer module 5 is arranged in the second shell 2, the buffer module 5 is provided with a straight-through station and a shunt station, the buffer module 5 is switched between the straight-through station and the shunt station according to the conveying amount of the tail gas so as to keep the conveying amount of the tail gas stable, the input module 6 is arranged in the third shell 3, the input module 6 continuously and stably feeds the tail gas into a boiler for combustion, and when the conveying amount of the tail gas is excessive, the input module 6 and the buffer module 5 are matched with the linkage module 7 to control the conveying amount of the tail gas so as to ensure the conveying stability of the tail gas and the sufficiency of tail gas combustion.

In the process of actually carrying out heat recovery, tail gas produced in the formaldehyde production process is input into the drying module 4 for drying, the tail gas after drying enters the input module 6 through the buffer module 5, the pressure in the input module 6 is continuously increased, the tail gas starts to be input into the boiler after the pressure in the input module 6 is increased to a certain extent, the tail gas is combusted after entering the boiler, heat produced by combustion is used for heating water, when the tail gas produced in the formaldehyde production process is excessive, the pressure in the input module 6 is continuously increased, after the pressure in the input module 6 is increased to a fixed value, the linkage module 7 is triggered, the linkage module 7 controls the input module 6 to increase the tail gas conveying amount into the boiler, meanwhile, the linkage module 7 controls the buffer module 5 to carry out split-flow speed-reducing and decrement operation on the tail gas entering the buffer module 5, the tail gas finally conveyed into the boiler is ensured to be kept at a relatively stable numerical value in a one-step-up and-down mode, the tail gas combustion in the boiler is ensured to be sufficient, the condition that the tail gas is not fully combusted and accumulated in the boiler is prevented from being possibly caused to be a frying furnace or the like.

Referring to fig. 1 and 2, a first conveying port 31 and a second conveying port 32 are sequentially provided on the right side wall of the third casing 3 from bottom to top, and the first conveying port 31 and the second conveying port 32 are both communicated with the boiler.

Referring to fig. 1 and 2, the drying module 4 includes molecular sieve drying cylinders, the molecular sieve drying cylinders are arranged in the first housing 1 in parallel, the number of the molecular sieve drying cylinders is two, molecular sieve drying agents are arranged in the molecular sieve drying cylinders, the molecular sieve drying agents are artificially synthesized and have strong adsorptivity to water molecules, the dryer works at room temperature, and the dryer is regenerated at the temperature of three hundred fifty ℃. Two molecular sieve drying cylinders are connected in parallel, one of the two molecular sieve drying cylinders works, and the other molecular sieve drying cylinder can only perform regeneration treatment. The two molecular sieve drying cylinders work and regenerate alternately to ensure continuous operation of the equipment.

Referring to fig. 1, fig. 2, fig. 9, the amount of tail gas produced in the formaldehyde production process is unstable, and the condition that the tail gas is too much may appear, for this reason, this application is provided with buffer module 5, buffer module 5 includes main runner 51, shunt port one 511, shunt port two 512, shunt runner 52, first division board 53, second division board 54, shutoff plate 55, dwang 56, switching device 57, main runner 51 sets up in the middle part of second casing 2, shunt port one 511 has been seted up on the upper and lower bottom surface of the left side of main runner 51 in the symmetry, shunt port two 512 have been seted up on the upper and lower bottom surface of the right side of main runner 51 in the symmetry, shunt port one 511, shunt port two 512 are communicated through shunt runner 52, shunt runner 52 is less than main runner 51 aperture, the air input of tail gas has been restricted to the aperture, and shunt runner 52 is the tortuous structure, thereby the velocity of tail gas flow has been prolonged, thereby the velocity of tail gas drops, first division board 53 sliding arrangement is in shunt port one 511, second division board 54 sliding arrangement is in shunt port two 512, first division board 53 in initial state, first division board 53, first division board 54, first division board 55 and second division board 55 sliding arrangement is in the initial state are in the side wall 51 and the shutoff plate 55 has been set up in the shutoff state in parallel with main runner 51, when the side wall 55 and main runner 55 rotates the shutoff device is in the shutoff device, and side wall 51 is in the state, and is in the shutoff device is in the state, side wall 55 has been set up in the state, and side wall 55 has been in the shutoff device, and 55, and side is in the main runner 51 has been in the state, and 55 side is in the main runner side.

In the actual buffering process, the tail gas enters the second shell 2 and enters the third shell 3 through the main runner 51, when the conveying amount of the tail gas is too large, the linkage module 7 is triggered, the linkage module 7 triggers the switching device 57, the switching device 57 drives the rotating rod 56 to rotate, the blocking plate 55 rotates to be perpendicular to the side wall of the main runner 51, the main runner 51 is closed, meanwhile, the switching device 57 enables the first partition plate 53 and the second partition plate 54 to slide out of the first partition plate 511 and the second partition plate 512, the first partition plate 511 and the second partition plate 512 are opened, the tail gas enters the second shell 2 and then can enter the third shell 3 through the partition runner 52, the entering amount of the tail gas is reduced to a certain extent through the partition runner 52, and excessive tail gas is prevented from continuously rushing into the third shell 3.

Referring to fig. 1 and 2, the switching device 57 is provided to switch the pipeline between the main flow channel 51 and the split flow channel 52 smoothly, the switching device 57 comprises a driving gear 571, a first rack 572, a second rack 573 and a matching part 574, the driving gear 571 is sleeved and installed on the periphery of the rotating rod 56, the first rack 572 is installed on the first partition plate 53, the first rack 572 is meshed with the driving gear 571, the second rack 573 is installed on the second partition plate 54, the second rack 573 is meshed with the driving gear 571, the matching part 574 is installed on the top of the rotating rod 56, and the pressing part 575 in press fit with the matching part 574 is arranged on the right side wall of the second shell 2 in a left-right sliding manner.

In the actual switching process, the linkage module 7 presses the mating portion 574 to the left, the mating portion 574 is pressed to enable the rotating rod 56 to rotate ninety degrees, the plugging plate 55 seals the main runner 51, the driving gear 571 rotates, the rotating driving gear 571 enables the first rack plate 572 and the second rack plate 573 to displace, the first partition plate 53 and the second partition plate 54 slide out from the first split port 511 and the second split port 512, and the first split port 511 and the second split port 512 are opened.

Referring to fig. 1 and 2, the present application is provided with an input module 6 for inputting tail gas into a boiler, the input module 6 includes a floating plate 61, a sliding column 62, a first valve 63, an extension spring 64, a blocking member 65, a second valve 66, and an air passing hole 661, the floating plate 61 is disposed in the third housing 3 by sliding the sliding column 62 up and down, a compression spring is connected between the floating plate 61 and the sliding column 62, the compression spring plays a role of resetting, the first valve 63 is disposed on the right side wall of the third housing 3 by rotating an auxiliary member, a position of the first valve 63 corresponds to the first delivery port 31, an extension spring 64 is connected between the first valve 63 and the sliding column 62, the extension spring 64 keeps a trend of pulling the first valve 63 to the left side, the blocking member 65 is mounted at a lower end of the floating plate 61, a position of the blocking member 65 corresponds to the first valve 63, the blocking member 65 in an initial state presses the first valve 63 to a closed state, the second valve 66 is disposed in the second delivery port 32 by sliding, the second valve 66 is a hollow cylinder structure with a left side closed, and the second valve 66 is uniformly opened with air holes 661 along the circumference.

In the process of actually conveying the tail gas, after the tail gas enters the third shell 3, the pressure inside the third shell 3 is continuously increased, the floating plate 61 slides upwards along the sliding column 62 along with the rising of the pressure, the blocking piece 65 is gradually separated from the first valve 63, after the blocking piece 65 is completely separated from the first valve 63, the first valve 63 rotates under the action of the tension spring 64, the first conveying port 31 is opened, the tail gas enters the boiler through the first conveying port 31 for combustion, when excessive tail gas is generated in formaldehyde production, the pressure inside the third shell 3 continuously rises, the floating plate 61 continuously moves upwards, when the floating plate 61 moves upwards to a designated position, the linkage module 7 is triggered, the linkage module 7 pushes out the second valve 66 from the second conveying port 32, the air passing hole 661 is communicated with the inside of the third shell 3, the conveying port two 32 starts conveying the tail gas to the boiler, and the distance of the second valve 66 pushed out from the second conveying port 32 is different along with the pressure change inside the third shell 3, and the communication degree between the air passing hole 661 and the inside of the third shell 3 is different.

Referring to fig. 1 and 2, after the pressure in the third casing 3 rises to a certain extent, the linkage module 7 is triggered to adjust the pressure in the third casing 3, the linkage module 7 comprises a sliding frame 71, a return spring 72 and a pressure triggering mechanism 73, the sliding frame 71 is arranged at the top end of the third casing 3 in a sliding manner, the left end of the sliding frame 71 is contacted with an extrusion part 575, the right end of the sliding frame 71 is connected with the second valve 66, the return spring 72 is connected between the sliding frame 71 and the third casing 3, the return spring 72 plays a role in resetting, and the pressure triggering mechanism 73 is installed on the top inner wall of the third casing 3.

Referring to fig. 1 and 2, the pressure trigger mechanism 73 includes an air cylinder 731, a piston 732, an L-shaped plate 733, a connecting rod 734, a movable plate 735, a locking plate 736, and an unlocking plate 737, the air cylinder 731 is mounted on the top inner wall of the third housing 3, the piston 732 is slidably disposed in the air cylinder 731, the L-shaped plate 733 is mounted on the right end of the piston 732, the connecting rod 734 is connected between the L-shaped plate 733 and the upper surface of the floating plate 61 through a pin shaft, the rising floating plate 61 drives the L-shaped plate 733 to move leftwards through the connecting rod 734, the movable plate 735 is slidably disposed at the left end of the air cylinder 731, the upper end of the movable plate 735 is mounted on the bottom surface of the sliding frame 71, a mounting groove is formed at the lower end of the movable plate 735, the mounting groove is slidably disposed up and down with the locking plate 736, a return spring is connected between the locking plate 736 and the mounting groove, the return spring has a reset function, the bottom surface of the air cylinder 731 is provided with a locking groove corresponding to the locking plate 736, the locking plate 736 is inserted into the locking groove, the position of the movable plate 735 is temporarily locked, the unlocking plate 737 is slidably disposed up and down at the bottom end of the locking plate 737 is pushed out of the locking plate 737, and the left end of the locking plate 737 is pushed up to the left end of the locking plate 737.

In an actual working process, the floating plate 61 slides upwards along the sliding column 62 along with the rising of the internal pressure of the third casing 3, the floating plate 61 sliding upwards makes the L-shaped plate 733 slide leftwards under the action of the connecting rod 734, the piston 732 slides leftwards following the L-shaped plate 733, the distance between the piston 732 and the movable plate 735 gradually decreases, the pressure between the piston 732 and the movable plate 735 gradually increases, when the floating plate 61 slides upwards to a designated position, the L-shaped plate 733 moves leftwards to be in contact with the unlocking plate 737, the unlocking plate 737 moves upwards after being extruded to push the locking plate 736 out of the locking groove so as to unlock the position of the movable plate 735, the movable plate 735 after unlocking moves leftwards under the action of the pressure, the sliding frame 71 moves leftwards, the front end of the sliding frame 71 pushes the extrusion 575 to move leftwards, and the rear end of the sliding frame 71 drives the second valve 66 to move leftwards.

The implementation principle of the embodiment is as follows:

step one: conveying tail gas generated in the formaldehyde production process into the application;

step two: drying the tail gas in a drying module 4 to eliminate the moisture in the tail gas;

step three: the dried tail gas enters an input module 6 through a buffer module 5;

step four: the pressure in the input module 6 is continuously increased, and the tail gas is started to be input into the boiler after the pressure in the input module 6 is increased to a certain degree;

step five: the tail gas enters a boiler for combustion;

step six: when the pressure in the input module 6 rises to a fixed value due to excessive tail gas generated in the formaldehyde production process, the linkage module 7 is triggered, the linkage module 7 controls the input module 6 to increase the tail gas conveying amount to the boiler, and meanwhile, the linkage module 7 controls the buffer module 5 to perform diversion, speed reduction and decrement operation on the tail gas entering the buffer module 5;

step seven: the tail gas is always conveyed to the boiler at a relatively stable speed, so that the tail gas is ensured to be fully combusted in the boiler.

While certain exemplary embodiments of the present invention have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that modifications may be made to the described embodiments in various different ways without departing from the spirit and scope of the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive of the scope of the invention, which is defined by the appended claims.

Claims

1. The utility model provides a formaldehyde production evaporation tail gas heat recovery unit which characterized in that includes:

the right side of the first shell (1) is sequentially communicated with a second shell (2) and a third shell (3);

a drying module (4) provided in the first housing (1), the drying module (4) improving the flammability of the exhaust gas by removing water vapor in the exhaust gas;

the buffer module (5) is arranged in the second shell (2), the buffer module (5) is provided with a straight-through station and a diversion station, and the buffer module (5) is used for switching between the straight-through station and the diversion station according to the conveying amount of the tail gas so as to keep the conveying amount of the tail gas stable;

the input module (6) is arranged in the third shell (3), the input module (6) continuously and stably feeds tail gas into the boiler for combustion, and when the tail gas is conveyed excessively, the input module (6) and the buffer module (5) are matched through the linkage module (7) to control the conveying quantity of the tail gas so as to ensure the stability of tail gas conveying and the sufficiency of tail gas combustion.

2. The heat recovery device for evaporation tail gas in formaldehyde production according to claim 1, wherein a first conveying port (31) and a second conveying port (32) are sequentially arranged on the right side wall of the third shell (3) from bottom to top, and the first conveying port (31) and the second conveying port (32) are communicated with the boiler.

3. A formaldehyde production evaporation tail gas heat recovery apparatus as claimed in claim 1, wherein the drying module (4) comprises;

the molecular sieve drying cylinders are arranged in the first shell (1) in parallel, and the number of the molecular sieve drying cylinders is two.

4. The formaldehyde production evaporation tail gas heat recovery apparatus as claimed in claim 2, wherein the buffer module (5) comprises:

the main runner (51) is arranged in the middle of the second shell (2), the upper bottom surface and the lower bottom surface of the left side of the main runner (51) are symmetrically provided with a first split-flow port (511), the upper bottom surface and the lower bottom surface of the right side of the main runner (51) are symmetrically provided with a second split-flow port (512), and the first split-flow port (511) and the second split-flow port (512) are communicated through a split-flow port (52);

a first partition plate (53) slidably provided in the first split port (511);

a second dividing plate (54) slidably disposed in the dividing port two (512);

a blocking plate (55) rotatably provided in the main flow path (51) by a rotation lever (56), wherein a torque spring is connected between the rotation lever (56) and the main flow path (51);

and a switching device (57) provided in the main channel (51).

5. The formaldehyde production evaporation tail gas heat recovery apparatus as claimed in claim 4, wherein said switching means (57) comprises:

a drive gear (571) which is installed around the outer circumference of the rotating rod (56);

a first rack plate (572) mounted on the first partition plate (53), the first rack plate (572) being in mesh with the drive gear (571);

a second rack plate (573) mounted on the second partition plate (54), the second rack plate (573) being in mesh with the drive gear (571);

and a fitting portion (574) which is mounted on the top of the rotation lever (56), and a pressing member (575) which is press-fitted with the fitting portion (574) is provided on the right side wall of the second housing (2) so as to slide left and right.

6. The formaldehyde production evaporation tail gas heat recovery apparatus as defined in claim 5, wherein said input module (6) comprises:

a floating plate (61) which is provided in the third housing (3) by sliding up and down through a sliding column (62), and a compression spring is connected between the floating plate (61) and the sliding column (62);

the first valve (63) is rotatably arranged on the right side wall of the third shell (3) through an auxiliary piece, the position of the first valve (63) corresponds to the position of the first conveying port (31), and an extension spring (64) is connected between the first valve (63) and the sliding column (62);

a blocking member (65) mounted on the lower end of the floating plate (61), the position of the blocking member (65) corresponding to the position of the first valve (63);

the second valve (66) is arranged in the second conveying port (32) in a sliding manner, the second valve (66) is of a hollow cylinder structure with a closed left side, and the second valve (66) is uniformly provided with air passing holes (661) along the circumferential direction.

7. The formaldehyde production evaporation tail gas heat recovery apparatus as defined in claim 6, wherein the linkage module (7) comprises:

the sliding frame (71) is arranged at the top end of the third shell (3) in a left-right sliding way, the left end of the sliding frame (71) is contacted with the extrusion piece (575), the right end of the sliding frame (71) is connected with the second valve (66), and a return spring (72) is connected between the sliding frame (71) and the third shell (3);

and a pressure trigger mechanism (73) mounted on the top inner wall of the third housing (3).

8. The formaldehyde production evaporation tail gas heat recovery apparatus as defined in claim 7, wherein said pressure trigger mechanism (73) comprises:

an air pressure cylinder (731) installed in the top inner wall of the third housing (3);

a piston (732) which is provided in the air pressure cylinder (731) in a sliding manner, wherein an L-shaped plate (733) is mounted at the right end of the piston (732), and a connecting rod (734) is connected between the L-shaped plate (733) and the upper surface of the floating plate (61) through a pin shaft;

the movable plate (735) is arranged at the left end of the air pressure cylinder (731) in a left-right sliding manner, the upper end of the movable plate (735) is arranged on the bottom surface of the sliding frame (71), the lower end of the movable plate (735) is provided with a mounting groove, the mounting groove is provided with a locking plate (736) in a vertical sliding manner, a return spring is connected between the locking plate (736) and the mounting groove, and the bottom surface of the air pressure cylinder (731) is provided with a locking groove corresponding to the position of the locking plate (736);

the unlocking plate (737) is arranged in the locking groove in a vertical sliding mode, the right side of the bottom end of the unlocking plate (737) is of a round corner structure beneficial to extrusion, and the bottom end of the unlocking plate (737) corresponds to the left end of the L-shaped plate (733).