CN211522118U

CN211522118U - Movable bed type pyrolysis system for waste printed circuit boards subjected to secondary catalysis

Info

Publication number: CN211522118U
Application number: CN201921893049.9U
Authority: CN
Inventors: 马洪亭; 杜娜; 杨明畅; 农奥兵
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2019-11-05
Filing date: 2019-11-05
Publication date: 2020-09-18
Anticipated expiration: 2029-11-05

Abstract

The utility model discloses a abandonment printed circuit board moving bed formula pyrolysis system of secondary catalysis, this system include spiral feed arrangement, stove spiral rotating device and spiral discharging device. Heating resistance wires are uniformly arranged on the outer wall of the inner container of the pyrolysis furnace. The pyrolysis system comprises a primary catalyst inlet and a multi-empty container for containing a secondary catalyst. The pyrolysis gas outlet pipe of the system is wrapped with a glass fiber heating belt, and the outlet of the pyrolysis gas outlet pipe is communicated with a water-cooling condensing double-pipe heat exchanger. A plurality of sleeve heat exchangers can be used in series to collect pyrolysis oil condensed by pyrolysis gas at different temperatures. The system can realize continuous pyrolysis of the printed circuit board and improve the pyrolysis efficiency of the device. The utility model discloses use second grade catalytic pyrolysis printed circuit board, can improve the light component content of pyrolysis oil, promote the quality of pyrolysis oil, reduce the cost of recovery. Furthermore, the utility model discloses use temperature control's method to retrieve pyrolysis oil in grades, promote the purity of target product, reduce the separation cost in result later stage.

Description

Movable bed type pyrolysis system for waste printed circuit boards subjected to secondary catalysis

Technical Field

The utility model relates to a moving bed formula pyrolysis system, in particular to secondary catalysis's abandonment circuit board moving bed formula pyrolysis system.

Background

Printed wiring boards are the foundation of the electronics industry, and it is estimated that waste printed wiring boards account for 3% of the electronic waste. Printed circuit boards contain nearly 20 kinds of nonferrous metals and rare and precious metals, but the potential hazards to soil, environment, and living beings caused by heavy metals and brominated flame retardants contained in the circuit boards cannot be underestimated. Therefore, how to recycle and dispose the waste into harmless resources is an urgent need for the development of the current electronic products.

Pyrolysis treatment technology is an efficient energy conversion and material recovery process. At present, pyrolysis technology has been well applied and developed in the fields of waste plastics, tires, biomass and municipal domestic waste. The application and research on the aspect of processing the waste printed circuit board are late, mainly because the printed circuit board contains a large amount of metal substances, the components are complex, and the recovery difficulty is high; in addition, the printed circuit board contains brominated flame retardants, which can generate brominated polycyclic aromatic hydrocarbons and other toxic and harmful substances in the pyrolysis process, and the substances not only pollute the environment and corrode treatment equipment, but also reduce the quality of pyrolysis oil. Therefore, secondary pollution control and product debromination are problems that circuit board pyrolysis must pay attention to and solve.

Chinese patent No. ZL201820387313.0 discloses "a vertical abandonment printed circuit board removes bed pyrolysis system", including the pyrolysis oven, there is the vibration axis mechanism that has helical blade that pneumatic striking hammer strikes in furnace, porous orifice plate is installed to the bottom in pyrolysis oven furnace, the shaft of furnace above porous orifice plate is opened has a plurality of mounting holes that lead to pyrolysis oven furnace, installs pyrolysis oven thermocouple in every mounting hole, be provided with the pyrolysis gas outlet duct with pyrolysis oven furnace intercommunication on the bell, the export of pyrolysis gas outlet duct link to each other with pyrolysis gas condensation collecting system, the bottom of pyrolysis oven furnace through high temperature nitrogen gas intake pipe in proper order with the heater in pipeline and self-pressurization nitrogen gas jar intercommunication. The system has the problems that 1, the continuous feeding can not be carried out in the furnace, and the pyrolysis residue in the pyrolysis furnace can not realize the continuity of the pyrolysis process of the printed circuit board because the length of the spiral blade of the spiral discharging device is not enough; 2. the printed circuit is indirectly heated by heating nitrogen through the electric heater, and the heating mode consumes great energy; 3. in the pyrolysis process, the printed circuit board can produce tar with very high viscosity, and under the continuous operation working condition, the continuous falling of the material can not be ensured only by the vibration of the pneumatic hammer.

Disclosure of Invention

An object of the utility model is to overcome the not enough of prior art, provide a realize that abandonment printed wiring board handles and the innoxious, minimizing and the secondary catalysis's of resourceization abandonment circuit board moving bed formula pyrolysis system of retrieving.

In order to achieve the above purpose, the utility model discloses a technical scheme is:

the utility model discloses a waste printed circuit board moving bed type pyrolysis system of secondary catalysis, including the pyrolysis oven, the pyrolysis oven include the furnace shaft that is enclosed by the shell, be fixed with the bell at the furnace shaft top, install high temperature resistant insulating brick in the furnace shaft bottom, the furnace shaft in the middle of install the pyrolysis oven furnace chamber that is enclosed by the inner bag, evenly arranged the heating resistor silk on the inner bag outer wall, the heating resistor silk be connected with the controller; the high-temperature-resistant heat-preservation brick at the bottom of the hearth of the pyrolysis furnace is provided with a dust-removal channel, the dust-removal channel is internally provided with an ash-removal pipe, an ash-removal opening of the ash-removal pipe is arranged outside the pyrolysis furnace, a second motor is connected with a spiral feeder, the spiral feeder is communicated with a discharge opening of a feeding pipeline of a printed circuit board provided with a first valve, a gas outlet of a self-pressurizing nitrogen tank is sequentially connected with a nitrogen pressure reducing valve, a body vortex flowmeter and an ash-removal opening of the ash-removal pipe through a gas conveying pipeline, the top of the inner wall of the hearth of the pyrolysis furnace is connected with the hearth cover through a flange, the hearth cover and the furnace are fully paved with high-temperature-resistant heat-preservation cotton, one end of a feeding pipe provided with a second valve at the feeding opening respectively penetrates through the furnace cover, the high-temperature-resistant heat-preservation cotton and the hearth cover to be, High temperature resistant heat preservation cotton and furnace lid and pyrolysis oven furnace intercommunication are located outside the pyrolysis oven furnace the pipeline of pyrolysis gas outlet duct on the parcel have the glass fiber heating band, the export and the water-cooling condensing double-pipe heat exchanger intercommunication of pyrolysis gas outlet duct, its characterized in that: the pyrolysis gas pipeline of the water-cooling condensing double-pipe heat exchanger is provided with a thermometer, a spiral rotating device comprises a spiral rotating shaft which is arranged in a pyrolysis furnace hearth along the vertical direction, the spiral rotating shaft penetrates through a hearth flange cover and a furnace cover, the upper end of the spiral rotating shaft is connected with a first motor arranged on the furnace cover, a spiral discharger penetrates through a mounting hole at the bottom of a furnace body and is inserted into the pyrolysis furnace hearth to be close to the inner wall of the hearth for clearance fit, the bottom of the spiral rotating device is arranged above the spiral discharger, the rotating shaft of the spiral discharger is connected with a third motor, the discharge hole of the spiral discharger arranged outside the pyrolysis furnace is communicated with a discharge storage device, the spiral discharger and the horizontal plane are arranged at 15 degrees, a porous pore plate is arranged in the pyrolysis furnace hearth below the spiral discharger, and the discharge hole of the spiral feeder is communicated with the upper part of a feed pipe through a discharge pipe, the feed inlet of the feed pipe is used for adding a primary catalytic additive, and a porous container for containing a secondary catalytic additive is arranged on the bottom wall of the hearth cover at the position communicated with the pyrolysis gas outlet pipe.

Compared with the prior art, the utility model discloses following beneficial effect has:

1. the utility model uses the pyrolysis system to realize the continuous pyrolysis of the printed circuit board through the spiral feeding device, the spiral rotating device in the furnace and the spiral discharging device, and improves the pyrolysis efficiency of the device;

2. the first-level catalytic additive used by the utility model is fully mixed with the material, which can effectively reduce the viscosity of tar produced by the pyrolysis of the printed circuit board in the pyrolysis furnace and promote the flow of material particles;

3. the second-stage catalytic additive used by the utility model is separated from the particles of the printed circuit board, so that the separation, recovery and reutilization of the second-stage catalyst can be easily realized;

4. the utility model discloses use second grade catalytic pyrolysis printed circuit board, can improve pyrolysis oil light component content, promote pyrolysis oil's quality, improve pyrolysis oil's recycle value, simultaneously, reduce bromo polycyclic aromatic hydrocarbon's content, reduce the environmental secondary pollution risk that printed circuit board pyrolysis brought;

5. the utility model recovers the pyrolysis oil by stages by using a temperature control method, improves the purity of the target product, and reduces the separation cost of the product in the later stage;

6. the system uses low-cost additives such as quick lime, natural zeolite, shell powder, natural clay and the like in primary catalysis; the secondary catalysis uses additives with higher cost, such as active alumina, HY molecular sieve, HZSM5 molecular sieve, MCM41 molecular sieve and the like, so that the cost of resource recovery of the waste printed circuit board can be greatly reduced.

Drawings

Fig. 1 is a schematic structural diagram of a moving bed type pyrolysis system for a secondary catalytic waste printed circuit board of the present invention.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1 the utility model discloses a bed formula pyrolysis system is removed to abandonment printed circuit board of secondary catalysis, including pyrolysis oven 5, pyrolysis oven 5 include the stack shell that encloses by the shell the stack shell top be fixed with bell 7 stack bottom install high temperature resistant insulating brick 6 the stack shell in the middle of installing the pyrolysis oven furnace 4 that encloses by the inner bag outer wall on evenly arranged heating resistor silk 8, heating resistor silk and controller 34 be connected, the controller can control opening of pyrolysis oven and stop, heating rate, incubation time and heating termination temperature.

The high-temperature-resistant insulating brick 6 at the bottom of the pyrolysis furnace hearth 4 is provided with an ash removal channel, an ash discharge pipe is arranged in the ash removal channel, an ash removal port 11 of the ash discharge pipe is arranged outside the pyrolysis furnace 5, and dust falling from a pore plate of the pyrolysis furnace hearth is cleaned through the ash discharge pipe.

A second motor 19 is connected to the screw feeder 18 which is in communication with the outlet of a printed circuit board feed line 20 which is fitted with a first valve 21.

The gas outlet of a self-pressurization nitrogen tank 1 is sequentially connected with a nitrogen pressure reducing valve 2, a body vortex flowmeter 3 and an ash cleaning port of an ash discharge pipe through a gas conveying pipeline.

The top of the inner wall of the pyrolysis furnace hearth is connected with a hearth cover 12 through a flange, and high-temperature-resistant heat-preservation cotton 17 is fully paved between the hearth cover and the furnace cover. One end of a feeding pipe 13 provided with a second valve 23 at the feeding port 22 respectively penetrates through the furnace cover, the high-temperature-resistant heat-preservation cotton and the furnace cover to be communicated with the pyrolysis furnace hearth 4. One end of a pyrolysis gas outlet pipe 9 penetrates through the furnace cover, the high-temperature-resistant heat-preservation cotton and the hearth cover 12 to be communicated with the pyrolysis furnace hearth 4. And a glass fiber heating belt 36 is wrapped on a pipeline of the pyrolysis gas outlet pipe positioned outside the hearth of the pyrolysis furnace, so that the loss of collected pyrolysis oil caused by pyrolysis gas condensation is reduced, and the outlet of the pyrolysis gas outlet pipe is communicated with the water-cooling condensing type double-pipe heat exchanger 27. A temperature meter 29 is arranged on a pyrolysis gas pipeline 28 of the water-cooling condensing type double-pipe heat exchanger and used for detecting the temperature of pyrolysis gas and adjusting the temperature of the condensed water of the double-pipe and the flow of the condensed water according to the temperature.

The structure of the water-cooled condensing double-pipe heat exchanger 27 can be seen in patent ZL 201820387313.0. The double-pipe heat exchanger can be used in series to collect pyrolysis oil of pyrolysis gas at different temperatures.

A screw rotation device 15 comprises a screw rotation shaft arranged in the furnace chamber 4 of the pyrolysis furnace along the vertical direction, the screw rotation shaft penetrates through the flange cover and the furnace cover of the furnace chamber and the upper end of the screw rotation shaft is connected with a first motor 16 arranged on the furnace cover.

A spiral discharging device 24 penetrates through a mounting hole in the bottom of the furnace body and is inserted into the pyrolysis furnace hearth 4 to be close to and in clearance fit with the inner wall of the hearth, the bottom of the spiral rotating device 15 is arranged above the spiral discharging device 24, a rotating shaft 35 of the spiral discharging device 24 is connected with a third motor 25, and a discharging hole of the spiral discharging device 24, which is arranged outside the pyrolysis furnace, is communicated with a discharging storage 26. The spiral discharging device is arranged at an angle of 15 degrees with the horizontal plane.

A porous orifice plate 10 is arranged in the hearth 4 of the pyrolysis furnace below the spiral discharging device 24.

The discharge port of the screw feeder 18 is communicated with the upper part of the feeding pipe 13 through a discharge pipe. The feed inlet 22 of the feed pipe 13 is used for adding a first-stage catalytic additive, and the first-stage catalytic additive is a low-cost additive, such as quicklime, natural zeolite, shell powder and natural clay. A porous container 14 for containing secondary catalytic additives is arranged on the bottom wall of the hearth cover 12 at the position communicated with the pyrolysis gas outlet pipe 9, and the secondary catalysts are additives with higher cost, such as active alumina, HY molecular sieve, HZSM5 molecular sieve, MCM41 molecular sieve and the like.

The use method of the system comprises the following steps:

the secondary catalytic additive is placed into the container 14 in advance. And opening a first valve 21 of a feeding pipeline 20, opening a second motor 19, driving a screw feeder 18 through the second motor 19, and transporting the crushed waste printed circuit boards to the hearth 4 of the pyrolysis furnace. At the same time, the second valve 23 is opened and the primary catalyst is fed into the furnace through the feed port 22. The top of the inner wall of the pyrolysis furnace hearth is then flanged to the hearth cover 12 and the furnace lid 7 is closed. Then, the nitrogen pressure reducing valve of the self-pressurizing nitrogen tank 1 is opened, the nitrogen pressure reducing valve 2 is adjusted, the vortex shedding flowmeter 3 is observed, and nitrogen is introduced into the pyrolysis furnace for about 20 minutes. Nitrogen enters the hearth through the porous plate 10, and the whole pyrolysis system is kept in an oxygen-free environment. Then, the electric heating wire 8 starts to heat by setting the heating rate, the heating final temperature and the holding time by the controller 34. In the heating process of the pyrolysis furnace, the spiral rotating device 15 in the hearth of the pyrolysis furnace is driven by the first motor 16 to continuously rotate, so that the downward movement of the materials in the hearth is promoted. When the temperature of the pyrolysis furnace reaches the pyrolysis final temperature, the third motor 25 drives the rotating shaft 35 of the spiral discharging device 24 to rotate, and the solid product is collected in the discharging storage 26. During the pyrolysis process, volatile matters are generated by heating the organic matters in the circuit board, and the volatile matters are discharged from the gas outlet pipe 9 of the pyrolysis furnace along with the nitrogen flow and then enter the condenser 27. In the pyrolysis process, the glass fiber heating belt 36 outside the pyrolysis gas outlet pipe enables the temperature of the pyrolysis furnace outlet pipe to be maintained at 220-260 ℃. The condenser 27 is a double-pipe water-cooled condenser, and condensed water flows in from a water inlet 27 of the double-pipe heat exchanger and flows out from a water outlet 31. The temperature of the condensed water in the casing and the flow of the condensed water are adjusted according to the indication of the temperature meter 29 on the pyrolysis gas pipeline 28 of the casing heat exchanger. The pyrolysis oil condensed out in the pyrolysis gas pipeline of the condenser enters a collecting bottle 32 at the lower part, and the non-condensable gas part is collected in a gas collecting bag 33 at the outlet of the pyrolysis gas pipeline for testing the components of the pyrolysis oil.

Claims

1. A movable bed type pyrolysis system for a secondary catalytic waste printed circuit board comprises a pyrolysis furnace (5), wherein the pyrolysis furnace comprises a furnace body surrounded by a shell, a furnace cover (7) is fixed at the top of the furnace body, a high-temperature-resistant insulating brick (6) is installed at the bottom of the furnace body, a pyrolysis furnace hearth (4) surrounded by an inner container is installed in the middle of the furnace body, heating resistance wires (8) are uniformly arranged on the outer wall of the inner container, and the heating resistance wires are connected with a controller (34); pyrolysis furnace (4) bottom high temperature resistant insulating brick (6) on open and to have the deashing passageway in install the ash discharge pipe, the deashing mouth (11) of ash discharge pipe set up outside the pyrolysis furnace, a second motor (19) link to each other with spiral feeder (18), spiral feeder with install the discharge gate intercommunication of printed circuit board feed pipeline (20) of first valve (21), the gas outlet of a self-pressurization nitrogen gas jar 1 connects gradually nitrogen gas relief valve (2), body vortex street flowmeter (3) and the deashing mouth of ash discharge pipe through gas conveying pipeline, pyrolysis furnace's inner wall top and furnace lid (12) pass through flange joint, furnace lid and bell between full spread high temperature resistant insulating cotton (17), one end of inlet pipe (13) of installing second valve (23) in feed inlet (22) department respectively passes bell, high temperature resistant heat preservation cotton and furnace lid and pyrolysis oven furnace (4) intercommunication, the one end of a pyrolysis gas outlet duct (9) is passed the bell, high temperature resistant heat preservation cotton and furnace lid and pyrolysis oven furnace intercommunication, is lieing in outside pyrolysis oven furnace pyrolysis gas outlet duct's pipeline on the parcel have glass fiber heating tape (36), pyrolysis gas outlet duct's export and water-cooling condensing double-pipe heat exchanger (27) intercommunication, its characterized in that: a temperature meter (29) is arranged on a pyrolysis gas pipeline (28) of the water-cooling condensing double-pipe heat exchanger, a spiral rotating device (15) comprises a spiral rotating shaft which is arranged in a hearth (4) of the pyrolysis furnace along the vertical direction, the spiral rotating shaft penetrates through a hearth flange cover and a furnace cover, the upper end of the spiral rotating shaft is connected with a first motor (16) arranged on the furnace cover, a spiral discharger (24) penetrates through a mounting hole at the bottom of the furnace body and is inserted into the hearth of the pyrolysis furnace to be close to the inner wall of the hearth for clearance fit, the bottom of the spiral rotating device (15) is arranged above the spiral discharger, a rotating shaft (35) of the spiral discharger is connected with a third motor (25), the spiral discharger is arranged at the discharge hole outside the pyrolysis furnace and is communicated with a discharge storage device (26), the spiral discharger is arranged at an angle of 15 degrees with the horizontal plane, and a porous pore plate (10) is arranged in the pyrolysis furnace below the spiral discharger, the discharge hole of the spiral feeder (18) is communicated with the upper part of the feeding pipe (13) through a discharge pipe, the feeding hole of the feeding pipe (13) is used for adding a primary catalytic additive, and a porous container (14) for containing a secondary catalytic additive is arranged on the bottom wall of the hearth cover (12) at the position communicated with the pyrolysis gas outlet pipe (9).