CN111571862A - Dry cleaning equipment and method for waste plastics in household garbage - Google Patents

Abstract

The invention discloses dry cleaning equipment for waste plastics in household garbage, which comprises a combined dry cleaning system and a micro-negative pressure airflow separation system which are arranged according to a production line; the combined dry cleaning system comprises a roller dry cleaning unit, a hot air flow paper-plastic separation unit, a magnetic separation gravity separation unit, a kneading dry cleaning unit and a micro-negative pressure air flow separation system which are arranged according to a production line; the device also comprises a waste gas treatment system which is used for purifying the waste gas generated by the roller dry cleaning unit, the hot air flow paper-plastic separation unit, the magnetic separation gravity separation unit, the kneading dry cleaning unit and the micro-negative pressure air flow separation system. And a method for dry cleaning waste plastics. The invention has good cleaning effect on the plastic, is convenient for process operation, not only saves a large amount of water resources, but also can remove various pollutants such as inorganic matters, corrodible organic matters, light matters and the like on the waste plastic, provides favorable conditions for further recycling the waste plastic, and has the cleaning efficiency on the pollutants of more than 95 percent.

Description

Dry cleaning equipment and method for waste plastics in household garbage

Technical Field

The invention relates to the technical field of waste plastic waterless cleaning, in particular to dry cleaning equipment and method for waste plastic in household garbage.

Background

Waste plastics in household garbage are generally contaminated with dirt such as oil stains and sandy soil to different degrees, and the quality of regenerated products is seriously affected by the existence of the impurities, so that the impurities attached to the waste plastics are cleaned and removed before the waste plastics are recycled so as to meet the resource utilization requirements of different levels.

At present, the waste plastics are mostly cleaned by a wet method, water is used as a cleaning medium, a large amount of chemical cleaning agents are added into the cleaning medium, and the cleaning agents are used for dissolving out and stripping the pollution or the covering layer on the surface of the waste plastics so as to achieve the effect of removing the dirt. The method has high process cost, wastes water resources, can generate a large amount of polluted wastewater and cause secondary pollution, and needs to be provided with a special sewage treatment system; and the cleaned waste plastics are not easy to dry in the regions with heavy rainy weather, and a drying device is also needed.

In addition, since the waste plastics separated from the domestic garbage contain more pollutants, besides dust, fine sand, inorganic particulate matters, corrodible organic matters and magnetic substances, the domestic garbage also can contain light paper and other substances, the waste plastics are difficult to clean, and the effect of the conventional waste plastics dry cleaning process is poor.

Therefore, how to provide a new waste plastic cleaning technology is a problem to be solved urgently by those skilled in the art.

Disclosure of Invention

In view of the above, the invention provides dry cleaning equipment and method for waste plastics in household garbage, which can effectively remove dust, fine sand, inorganic particulate matters, corrodible organic matters and magnetic substances and also have good removal effect on light matters such as paper.

In order to achieve the purpose, the invention adopts the following technical scheme:

a dry cleaning device for waste plastics in household garbage comprises a combined dry cleaning system and a micro-negative pressure airflow separation system which are arranged according to a production line;

the combined dry cleaning system comprises a roller dry cleaning unit, a hot air flow paper-plastic separation unit, a magnetic separation gravity separation unit and a kneading dry cleaning unit which are arranged according to a production line;

the roller dry-type cleaning unit removes pollutants on the plastic fragments through the friction collision of the plastic fragments and dry-cleaning materials;

the hot air flow paper-plastic separation unit is used for drying the plastic fragments and separating paper from plastic;

the magnetic separation gravity separation unit is used for carrying out magnetic separation on the plastic fragments and air separation on the heavy objects;

the kneading dry-type cleaning unit is used for further removing pollutants on the plastic fragments;

the micro negative pressure airflow separation system is used for winnowing of light objects;

the device also comprises a waste gas treatment system which is used for purifying the waste gas generated by the roller dry cleaning unit, the hot air flow paper-plastic separation unit, the magnetic separation gravity separation unit, the kneading dry cleaning unit and the micro-negative pressure air flow separation system.

The plastic fragments in the roller dry-type cleaning unit are in friction collision with the dry-cleaning materials, so that pollutants which are not easy to fall off on the plastic fragments can be promoted to effectively and quickly fall off and separate; the hot air flow paper-plastic separation unit can dry the plastic fragments, the plastic fragments shrink to a certain extent, the specific surface area is reduced, the shredded paper attached to the surface is easy to fall off from the plastic fragments, and the shredded paper is taken away by the hot air flow with a certain flow rate, so that the separation of the plastic and the paper is realized; the magnetic separation gravity separation unit can separate the plastic fragments from the heavy matters doped with the plastic fragments and remove the magnetic substances; the arrangement of the rubbing dry type cleaning unit can further lead the fine sand and dust remained on the surface of the plastic fragments to fall off and be separated, and the micro-negative pressure airflow separation system further ensures the thorough separation of the pollutants fallen off in the rubbing dry type cleaning unit.

Preferably, the combined dry cleaning system also comprises a pretreatment system, wherein the pretreatment system is arranged at the upstream of the combined dry cleaning system and comprises a dehumidification unit and a crushing unit;

the dehumidification unit is used for dehumidifying the waste plastics;

the crushing unit is used for crushing the dehumidified waste plastics into plastic fragments;

the waste gas treatment system is also used for purifying waste gas generated by the dehumidification unit and the crushing unit.

The humidity difference of the original waste plastics to be processed is large, and if the humidity is too high, pollutants attached to the waste plastics are not easy to fall off, so that the subsequent dry cleaning operation can be ensured to be smoothly carried out by dehumidifying before dry cleaning.

Preferably, the dehumidification unit is an airflow dehumidification device and comprises a device body, a belt type transmission platform, an air distribution pipe, a blower and an air heating pipe;

the device body is provided with a feeding hole of the airflow dehumidifying device, a discharging hole of the airflow dehumidifying device and an air outlet of the airflow dehumidifying device;

the belt type conveying platform is arranged in the device body and is used for conveying waste plastics thrown into the feeding port of the airflow dehumidifying device to the discharging port of the airflow dehumidifying device; the belt type conveying platform is provided with a hole, so that the heating airflow below the belt type conveying platform can conveniently pass through the belt type conveying platform to contact the waste plastics;

the air distribution pipe is distributed in the device body and is provided with an air distribution head for air outlet;

the blower is used for providing air flow;

the air heating pipe heats the air flow generated by the blower and transmits the air flow to the air distribution pipe to heat the air flow;

the air heating pipe is provided with an intelligent temperature controller for adjusting the temperature of the air flow to 45-55 ℃.

The gas distribution pipe is provided with a gas distribution head for discharging gas, and can blow hot gas to take out moisture attached to the waste plastics; and the waste gas is collected to a waste gas treatment system from the air outlet of the airflow dehumidifying device for treatment.

Preferably, the crushing unit comprises a gyratory shear crusher and a hammer crusher.

The blades of the rotary shearing crusher are made of alloy materials with strong hardness and rigidity and adopt variable torque. The rotary shearing crusher crushes the waste plastics obtained by dehumidification by the airflow dehumidification device into plastic fragments with the size (diameter length) of 6-12 cm.

The hammer crusher continuously crushes the plastic chips crushed by the rotary shearing crusher into plastic chips with the size of 3-5 cm.

And the waste gas and dust generated by the crushing unit are uniformly collected to a waste gas treatment system for treatment.

Preferably, the device further comprises a conveying mechanism such as a screw conveyor, a chain scraper conveyor and the like, and the conveying mechanism is used for conveying materials among the devices.

Preferably, the drum dry cleaning unit comprises a drum friction dry cleaner;

the roller friction dry cleaning machine comprises a shell, a roller, a stirring paddle and a motor;

the bottom of the shell is provided with a first discharge hole;

the roller is arranged in the shell and comprises an inner screen drum and an outer screen drum; first sieve holes are distributed on the inner sieve cylinder, one end of the inner sieve cylinder is provided with a roller friction dry cleaning feed inlet, and the other end of the inner sieve cylinder is provided with a second discharge hole; second sieve holes are distributed on the outer sieve cylinder, and the aperture of the first sieve hole is larger than that of the second sieve hole; the wall of the outer screen cylinder is provided with a third discharge hole;

the stirring paddle is arranged inside the inner screen cylinder;

the motor drives the roller and the stirring paddle to rotate.

Preferably, the first mesh opening is smaller than the size of the plastic fragments obtained by crushing by the crushing unit, and the second mesh opening is smaller than the size of the dry-cleaning materials.

Preferably, the first mesh opening size is 25mm and the second mesh opening size is 8 mm.

Preferably, the rotation speed of the roller and the stirring paddle is 280-320 r/min.

Dry-cleaning materials and plastic fragments are thrown into the inner screen drum of the drum, and along with the rotation of the drum and the stirring paddle, impurities such as oil sludge, fine sand, moisture and the like are screened out by the second screen hole and discharged through the first discharge hole; the dry-cleaning materials are screened out by the first sieve holes, intercepted by the second sieve holes and discharged by the third discharge hole; the plastic fragments subjected to friction dry cleaning in the inner screen cylinder can be discharged from the second discharge hole.

Preferably, the device also comprises an elevator and a grabbing bucket, which are used for feeding dry-cleaning materials and plastic fragments into the roller friction dry-cleaning machine.

Preferably, the dry-cleaning material comprises stone, metal, etc. and has a particle size of 1-2 cm.

Preferably, both ends of the outer screen cylinder and the outer shell are respectively provided with a closable opening corresponding to the roller friction dry cleaning feed inlet and the second discharge outlet.

Preferably, the hot air flow paper-plastic separation unit comprises a far infrared drying box and an electric appliance control box;

the far infrared drying box comprises an outer box body, a heat insulation layer, an air duct and an inner box body from outside to inside in sequence;

the inner box body is provided with a drying box feed inlet, a drying box first discharge port, a drying box second discharge port and a drying box air outlet which penetrate out of the outer box body; the first discharge port of the drying box is used for discharging paper scraps separated from the plastic fragments, and the second discharge port of the drying box is used for discharging the plastic fragments;

the far infrared heating pipe is powered by a power supply element, and the centrifugal fan blade provides an air source through a blower motor;

the electrical control box is used for power distribution control of the power supply element and the blower motor.

The waste gas of far infrared drying cabinet is collected waste gas treatment system by drying cabinet air outlet and the first discharge gate of drying cabinet and is handled.

Preferably, the far infrared drying oven further comprises a heat-sensitive element probe and an intelligent temperature control device; the heat-sensitive element probe is arranged in the inner box body and used for monitoring the temperature in the inner box body and transmitting the temperature to the intelligent temperature control device; the intelligent temperature control device receives the temperature signal collected by the heat-sensitive element probe, and controls the operation of the power supply element and the blower motor according to the signal so as to maintain the temperature in the far infrared drying box to be 83-85 ℃.

Preferably, the magnetic separation gravity sorting unit comprises a shell, a magnetic field generating device and a winnowing device;

the top of the shell is provided with a sorting feed port, and the bottom of the shell is provided with a magnetic substance discharge port and a heavy substance discharge port; the side of the shell is provided with an upward inclined channel, and a vibration device is arranged at the channel; the lower end of the channel faces to the heavy material discharge port, and the higher end is a separation discharge port;

the magnetic field generating device is arranged in the shell, is positioned at the bottom of the sorting feed inlet and comprises a roller and a rotary magnet; the rotary magnetic attraction eccentric device is arranged in the roller, so that the magnetic substance is attracted to the roller after being fed, and falls into the magnetic substance discharge port along with the reduction of the magnetic attraction force in the rotating process;

the air separation device is arranged at the bottom of the magnetic field generation device, and the air outlet direction of the air separation device faces the separation discharge hole; the plastic fragments magnetically separated by the magnetic field generating device fall into the passage, heavy objects doped in the plastic fragments fall into a heavy object discharge port through vibration and gravity, and the plastic fragments are discharged from the sorting port through wind power.

Preferably, the rubbing dry cleaning unit includes an outer casing, an inner casing, a bracket, a rotary blade and a blade plate;

the bottom of the outer shell is provided with a kneading dry type cleaning discharge port;

the inner cover body is arranged in the outer shell; the top of the inner cover body is provided with a kneading dry type cleaning feed inlet connected to the top of the outer shell body, and the bottom of the inner cover body is opened; and the side wall of the inner cover body is provided with a plurality of through holes;

the rotating blades are erected in the inner cover body through a bracket and are driven to rotate through a motor;

the blade plate is arranged at the bottom opening of the inner cover body and used for plugging the bottom opening of the inner cover body; and the paddle board has a closable opening.

Preferably, the micro-negative pressure airflow separation system comprises a body, an airflow distributor and an airflow supply device;

the top of the body is provided with a gas flow separation feed inlet, and the bottom of the body is provided with a gas flow separation discharge outlet;

the air flow distributors are multiple and are uniformly distributed in the body;

the airflow supply device supplies airflow to the airflow distributor.

Further preferably, valves are arranged at the feed inlet and the discharge outlet of all the devices.

Preferably, the waste gas treatment system comprises an air collecting device, a cyclone separation device and a dust removal device which are connected in sequence;

the wind collecting device is respectively connected with the dehumidifying unit, the crushing unit, the roller dry type cleaning unit, the hot air flow paper-plastic separation unit, the magnetic separation gravity separation unit, the kneading dry type cleaning unit and the micro-negative pressure air flow separation system. Cyclone separation devices are used to remove large particle dust and the like.

Further preferably, the air collecting device may be mounted to each unit/system (air outlet or discharge port) by means of an air collecting hood or an air suction head, and may be used in cooperation with an induced draft fan, an exhaust fan, or the like to extract the exhaust gas and dust from each unit/system.

A dry cleaning method for waste plastics in household garbage comprises the following steps:

s1, dehumidification:

dehumidifying the waste plastics at 45-55 deg.C; the dehumidification time is determined according to the water content of the waste plastics, and the moisture content after dehumidification is ensured to be 40-45%;

s2, crushing:

pulverizing the waste plastics obtained by dehumidification in S1 into 3-5cm plastic chips;

s3, friction dry cleaning:

adding dry-cleaning materials into the plastic fragments, separating pollutants from the plastic fragments through friction collision between the plastic fragments and the dry-cleaning materials, screening the pollutants by using sieve cylinders with different apertures, separating the plastic fragments from the dry-cleaning materials, and recycling the dry-cleaning materials for S3;

s4, hot air flow paper-plastic separation:

processing the plastic fragments subjected to the friction dry cleaning by S3 by using hot air to separate the paper fragments attached to the surfaces of the plastic fragments from the plastic fragments; the temperature of the hot air flow is 83-85 ℃, and the drying is stopped when the humidity of the plastic fragments is in the range of 18-22%;

s5, magnetic separation and gravity separation:

removing magnetic substances and heavy substances in the plastic fragments through magnetic separation and gravity separation;

s6, self-rubbing dry cleaning:

self-kneading the plastic fragments, and further separating pollutants;

s7, micro-negative pressure airflow separation:

and (3) placing the plastic fragments in a micro-negative pressure airflow separation system, keeping the internal air pressure between-0.5 MPa and-0.2 MPa, and separating pollutants again under the condition that the air flow rate is 15 m/s.

Preferably, the method further comprises: collecting the waste gas generated in the steps S1-S7, and purifying.

According to the technical scheme, compared with the traditional wet cleaning technology taking water as a medium, the dry cleaning equipment and the dry cleaning method for the waste plastics in the household garbage have the advantages that the plastic cleaning effect is good, the process operation is convenient, a large amount of water resources are saved, various pollutants such as inorganic matters, corrodible organic matters and light matters on the waste plastics can be removed, favorable conditions are provided for further recycling of the waste plastics, and the cleaning efficiency for the pollutants reaches more than 95%.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic view of a dry cleaning apparatus for waste plastics in domestic garbage according to the present invention.

FIG. 2 is a schematic view of the structure of the air flow dehumidifying device.

FIG. 3 is a schematic view of the drum friction dry cleaning machine.

FIG. 4 is a schematic structural view of a hot air flow paper-plastic separation unit.

FIG. 5 is a schematic diagram of the magnetic separation gravity separation unit.

FIG. 6 is a schematic view of the kneading dry cleaning unit.

FIG. 7 is a schematic diagram of a micro-negative pressure air flow separation system.

Description of the drawings: 1. an air flow dehumidifying device; 11. a device body; 111. a feed inlet of the airflow dehumidification device; 112. an air outlet of the air flow dehumidifying device; 113. a discharge port of the airflow dehumidification device; 12. a belt conveyor platform; 13. an air distribution pipe; 131. a gas distribution head; 14. a blower; 15. an air heating pipe; 16. an intelligent temperature controller; 21. a gyratory shear crusher; 22. a hammer crusher; 3. a roller friction dry cleaning machine; 31. a housing; 311. a first discharge port; 32. a drum; 321. an inner screen cylinder; 3211. a first screen hole; 3212. roller friction dry cleaning feed inlet; 3213. a second discharge port; 322. an outer screen cylinder; 3221. a second sieve pore; 3222. a third discharge port; 33. a stirring paddle; 331. a rotating shaft; 332. a paddle; 34. an elevator; 35. a material grabbing bucket; 41. a far infrared drying oven; 411. an outer case; 412. a heat-insulating layer; 413. an air duct; 4131. a far infrared heating pipe; 4132 centrifugal fan blades; 414. an inner box body; 4141. a feed inlet of the drying oven; 4142. a second discharge port of the drying box; 4143. an air outlet of the drying box; 415. a power supply element; 416. a blower motor; 417. an intelligent temperature control device; 5. a magnetic separation gravity separation unit; 51. a housing; 511. a sorting feed port; 512. a magnetic substance discharge port; 513. a heavy material outlet; 514. a channel; 515. a sorting discharge port; 52. a magnetic field generating device; 521. a drum; 522. rotating and magnetically attracting; 53. a winnowing device; 54. a vibration device; 6. a rubbing dry cleaning unit; 61. an outer housing; 611. rubbing the dry-type cleaning discharge port; 62. an inner cover body; 621. rubbing and dry-cleaning the feed inlet; 63. a support; 64. a rotating blade; 65. a vane plate; 66. a telescoping device; 7. a micro-negative pressure air flow separation system; 71. a body; 711. a gas flow separation feed inlet; 712. a gas flow separation discharge port; 72. an air flow distributor; 73. an air flow supply device; 81. an air suction head; 82. an air outlet pipe; 83. a bag type dust collector; 84. an induced draft fan.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

As shown in the attached figures 1-7, the dry cleaning equipment for waste plastics in household garbage comprises a pretreatment system, a combined dry cleaning system and a micro-negative pressure airflow separation system which are arranged according to a production line.

The pretreatment system includes a dehumidification unit and a crushing unit.

The dehumidifying unit is an airflow dehumidifying device 1, which comprises a device body 11, a belt type conveying platform 12, an air distribution pipe 13, an air blower 14 and an air heating pipe 15.

The top of the device body 11 is provided with an airflow dehumidifying device feeding port 111 and an airflow dehumidifying device air outlet 112, and the side is provided with an airflow dehumidifying device discharging port 113.

The belt type conveying platform 12 (a conveyor belt) is arranged in the device body 11 and is used for conveying waste plastics thrown into the feeding hole 111 of the airflow dehumidifying device to the discharging hole 113 of the airflow dehumidifying device; the belt conveyor table 12 has apertures therein to facilitate heated air flow beneath the belt conveyor table 12 through the belt conveyor table 12 to contact the waste plastic.

The air distribution pipes 13 are uniformly distributed in the device body 11 along the belt type transmission platform 12, each air distribution pipe 13 is provided with an air distribution head 131, and one or more air outlet holes are formed in the air distribution head 131;

the air distribution pipes 13 are converged and then communicated with an air heating pipe 15, the air heating pipe 15 is connected with an air blower 14, and the air heating pipe 15 is provided with an intelligent temperature controller 16 for adjusting the temperature of the air flow.

A plurality of air suction heads 81 are arranged at the air outlet 112 of the airflow dehumidifying device, and the air suction heads 81 are connected with the bag-type dust collector 83 through an air outlet pipe 82; and the air outlet pipe 82 is provided with an induced draft fan 84 which pumps the waste gas in the air flow dehumidification device into a bag type dust collector 83.

The crushing unit comprises a gyratory shear crusher 21 and a hammer crusher 22.

The blades of the gyratory shear crusher 21 are made of an alloy material having high hardness and rigidity, and have a variable torque. The hammer crusher 22 is disposed downstream of the gyratory shear crusher 21.

The crushing unit can also be provided with a wind collecting cover which is connected with a cyclone separation device through a pipeline with an exhaust fan, and the cyclone separation device is connected with the bag type dust collector.

The combined dry cleaning system comprises a roller dry cleaning unit, a hot air flow paper-plastic separation unit, a magnetic separation gravity separation unit and a kneading dry cleaning unit which are arranged according to a production line.

The roller dry type cleaning unit comprises a roller friction dry cleaning machine 3;

the roller friction dry cleaning machine 3 comprises a shell 31, a roller 32, a stirring paddle 33 and a motor;

the bottom of the shell 31 is provided with a first discharge hole 311, and two ends of the shell 31 are respectively provided with a closable opening for feeding or discharging;

the roller 32 is arranged in the shell 31 and comprises an inner screen drum 321 with the diameter of 2500mm and an outer screen drum 322 with the diameter of 3000mm, first screen holes 3211 with the aperture of 25mm are distributed on the inner screen drum 321, one end of the inner screen drum 321 is provided with a roller friction dry-cleaning feed inlet 3212, and the other end is provided with a second discharge outlet 3213; second sieve holes 3221 with the aperture of 8mm are distributed in the outer sieve cylinder 322, a third discharge hole 3222 is arranged on the wall of the outer sieve cylinder 322, and two ends of the outer sieve cylinder 322 are respectively provided with a closable opening for feeding or discharging.

The stirring paddle 33 includes a rotating shaft 331 and a paddle 332; the rotating shaft 331 is arranged on the central axis in the inner screen cylinder 321; the blades 332 are made of alloy material and have a length of 300mm, and are fixed on the rotating shaft 331 in a staggered manner.

The motor drives the inner screen drum 321, the outer screen drum 322 and the stirring paddle 33 to rotate.

During feeding, a feeding pipeline is arranged at a position of a roller friction dry-cleaning feeding hole 3212; and during discharging, a discharging pipeline is arranged at the second discharging opening. The first discharge hole 311 and the discharge pipeline are provided with a suction head, the suction head is connected with a cyclone separation device through a pipeline with a draught fan, and the cyclone separation device is connected with a bag type dust collector.

Further, a lift 34 and a grab bucket 35 may be provided for feeding dry cleaning material and plastic fragments into the drum friction dry cleaning machine 3. The dry-cleaning material comprises stone, metal, etc., and has particle diameter of 1-2 cm.

The hot air flow paper-plastic separation unit comprises a far infrared drying box 41 and an electric appliance control box 42;

the far infrared drying box 41 comprises an outer box 411, a heat preservation layer 412, an air duct 413 and an inner box 414 in sequence from outside to inside;

the outer case 411 is made of a thin steel plate;

the inner box 414 is provided with a dry box inlet 4141, a dry box first outlet (not shown), a dry box second outlet 4142, and a dry box outlet 4143.

The heat-insulating layer is made of foam plastics.

The air duct 413 is internally provided with a far infrared heating pipe 4131 and a centrifugal fan blade 4132, the far infrared heating pipe 4131 supplies power through a power supply element 415, and the centrifugal fan blade 4132 supplies an air source through a blower motor 416, so that hot air circulates in the air duct 413.

The inner box 414 is provided with a vent or a ventilation pipeline which can be communicated with the inner part of the inner box 414 and the air duct 413 in a closed manner.

The electrical control box 42 is used for power distribution control of the power supply element 415 and the blower motor 416.

The far infrared drying box 41 further comprises a heat-sensitive element probe, a humidity sensing probe and an intelligent temperature control device 417; the heat-sensitive element probe and the humidity sensing probe are arranged in the inner box 414 and used for monitoring the temperature in the inner box 414 and transmitting the temperature to the intelligent temperature control device 417; the intelligent temperature control device 417 receives the temperature signal collected by the heat-sensitive element probe, and controls the operation of the power supply element 415 and the blower motor 416 according to the signal to maintain the temperature in the inner case 414 to 83-85 ℃.

An air collecting cover is arranged at the position of the air outlet 4143 of the drying box and is connected with a cyclone separation device through a pipeline, and the cyclone separation device is connected with a bag type dust collector. The first discharge port (not marked in the figure) of the drying box is provided with an air suction head, the air suction head is connected with a cyclone separation device through a pipeline with a draught fan, and the cyclone separation device is connected with a bag type dust collector.

The magnetic separation gravity separation unit 5 comprises a shell 51, a magnetic field generating device 52 and a wind separation device 53;

the top of the shell 51 is provided with a sorting feed port 511, and the bottom is provided with a magnetic substance discharge port 512 and a heavy substance discharge port 513; the side of the shell 51 is provided with an upward inclined channel 514, and the channel 514 is provided with a vibration device 54; the lower end of the channel 514 faces the heavy material discharge port 513, and the higher end is a sorting port 515;

the magnetic field generating device 52 is arranged in the shell 51, is positioned at the bottom of the sorting feed port 511, and comprises a roller 521 and a rotary magnet 522; the rotary magnet 522 is eccentrically arranged in the roller 521, so that the fed magnetic substance is adsorbed on the roller 521 and falls into the magnetic substance discharge port 512 along with the reduction of the magnetic attraction force in the rotation process;

the winnowing device 53 is arranged at the bottom of the magnetic field generating device 52, and the air outlet direction of the winnowing device 53 faces to the sorting material port 515; the plastic chips magnetically separated by the magnetic field generating device 52 fall into the passage, heavy materials such as stones doped in the plastic chips fall into the heavy material discharge port 513 through vibration and gravity, and the plastic chips are discharged from the sorting port 515 through wind power.

The sorting material port 515 is provided with an air suction head, the air suction head is connected with a cyclone separation device through a pipeline with a draught fan, and the cyclone separation device is connected with a bag type dust collector.

The kneading dry-type cleaning unit 6 includes an outer casing 61, an inner cover 62, a bracket 63, a rotary blade 64 and a blade plate 65;

the bottom of the outer shell 61 is provided with a kneading dry type cleaning discharge hole 611;

the inner cover 62 is mounted in the outer shell 61; the top of the inner cover 62 has a kneading dry cleaning feed 621 connected to the top of the outer case 61, and the bottom of the inner cover 62 is open; and the side wall of the inner cover body 62 is provided with a plurality of through holes with the aperture of 1 cm;

the rotating blade 64 is erected in the inner cover body 62 through a bracket 53, and the bottom of the bracket 53 is connected with a motor;

the louver board 65 is disposed at the bottom opening of the inner cover 62, and blocks the bottom opening of the inner cover 62, and the louver board 65 has a closable opening.

The bottom of the louver 65 is connected to a telescopic device 66, which enables the louver 65 to reciprocate within the inner cover 62 and at the bottom opening of the inner cover 62.

An air suction head is arranged at the position of the kneading dry type cleaning discharge hole 611 and is connected with a cyclone separation device through a pipeline with a draught fan, and the cyclone separation device is connected with a bag type dust collector.

The micro-negative pressure airflow separation system 7 comprises a body 71, an airflow distributor 72 and an airflow supply device 73;

the top of the body 71 is provided with a gas flow separation feed inlet 711, and the bottom is provided with a gas flow separation discharge outlet 712;

the air flow distributors 72 are uniformly distributed in the body 71;

the air flow supply device 73 supplies air flow to the air flow distributor 72.

The air flow separation discharge port 712 is provided with an air suction head, the air suction head is connected with a cyclone separation device through a pipeline, and the cyclone separation device is connected with a bag type dust collector.

The feed inlet, the discharge outlet and the opening of all the devices are provided with openable valves.

Preferably, a screw conveyor and a chain scraper conveyor can be further arranged for conveying materials among the devices.

A dry cleaning method for waste plastics in household garbage comprises the following steps:

s1, dehumidification:

opening the belt type conveying platform 12, putting the waste plastics in the domestic garbage into the airflow dehumidifying device 1, distributing the waste plastics on the whole belt type conveying platform 12, and closing the belt type conveying platform 12; and starting the air blower 14, the air heating pipe 15 and the intelligent temperature controller 16, controlling the temperature of the heating air flow to be 45-55 ℃, and spraying the heating air flow out of the air distribution head 131 through the air distribution pipe 13. The water in the waste plastics is taken out by the heating airflow and enters a bag type dust collector 83 through a suction head 81 and an air outlet pipe 82 above the conveying platform 12 under the action of a draught fan 84; after the dehumidification treatment is carried out until the humidity is 40-45%, the belt type transmission platform 12 is opened, so that the waste plastics subjected to preliminary dehumidification are discharged from a discharge port 113 of the airflow dehumidification device.

S2, crushing:

waste plastics obtained by dehumidification in S1 were thrown into a rotary shear crusher 21 using a screw conveyor and crushed into plastic chips having a size (diameter length) of 6 to 12 cm.

The plastic chips crushed by the rotary shearing crusher 21 are thrown into the hammer crusher 22 and are continuously crushed into plastic chips with the size of 3-5 cm. The generated dust can be collected by the wind collecting cover for subsequent treatment.

S3, friction dry cleaning:

during feeding, the closable openings for feeding on the shell 31 and the outer screen drum 322 and the roller friction dry-cleaning feed inlet 3212 are opened, and a feeding pipeline is placed; the broken plastic chips of S2 and the stone and metal pieces were crushed using elevator 34 and grapple 35 at a ratio of 4: 1: 1 weight ratio is put into a roller friction dry cleaning machine 3; the drum friction dry cleaning feed port 3212 and the closable openings for feeding in the housing 31 and the outer screen drum 322 are closed.

The stirring paddle 33 and the roller 32 rotate at the speed of 300r/min under the action of the motor; the plastic fragments collide with the stone blocks and the metal blocks, so that the pollutants are separated from the plastic fragments, and impurities such as oil sludge, fine sand and water are screened out by the second sieve holes 3221 and discharged through the first discharge hole 311. The dry-cleaning materials are screened out by the first sieve hole 3211 and intercepted by the second sieve hole 3221, after about 30min of treatment, the motor is closed, the third discharge hole 3222 is aligned with the first discharge hole 311, the third discharge hole 3222 is opened, and the stone blocks and the metal blocks are discharged through the third discharge hole. The third discharge port 3222 is closed, the elevator 34 and the grab bucket 35 are used again to throw the stone blocks and the metal blocks into the inner screen drum 321, the motor is turned on to continue cleaning for 20min, and the plastic fragments dry-cleaned by friction in the inner screen drum 321 can be discharged from the second discharge port 3213.

The generated dust can be collected by the suction head for subsequent treatment.

S4, hot air flow paper-plastic separation:

the plastic chips obtained in S3 are conveyed to the inlet 4141 of the drying box by the screw conveyor, the air provided by the blower motor 416 circulates in the air duct by the centrifugal fan 4132, and the cold air passes through the far infrared heating pipe 4131(15kW) to form hot air. The temperature detected by the heat-sensitive element probe is controlled to be 83-85 ℃, and when the temperature is overhigh, the heating and air supply are controlled to stop through the intelligent temperature control device 417. In the drying process, plastic fragments in the inner box body are heated to shrink to a certain extent, the specific surface area is reduced, and shredded paper attached to the surface is easy to fall off from the plastic fragments; the generated water vapor is collected by a wind collecting cover at the air outlet 4143 of the drying box. After drying for about 20min, the humidity of the plastic fragments is 18-22%, an air outlet 4143 of the drying oven is closed, and a ventilation opening or a ventilation pipeline arranged on the inner box 414 is opened to enable hot air to enter the inner box 414; and opening a first discharge port (not shown) of the drying box, and discharging the paper scraps falling off from the plastic scraps through the first discharge port (not shown) of the drying box under the action of hot air. The first outlet (not shown) of the drying oven is closed, heating is stopped, and the plastic chips are discharged from the second outlet 4142 of the drying oven.

S5, magnetic separation and gravity separation:

the magnetic field generating device 52 is started, the roller 521 and the rotary magnet 522 rotate relatively, the screw conveyer is used for conveying the dried plastic fragments S4 to the sorting feed inlet 511 of the magnetic separation gravity sorting unit, the rotary magnet 522 adsorbs magnetic substances in the plastic fragments to the surface of the roller 521, the magnetism is reduced along with the rotation of the roller 521, and the magnetic substances directly fall into the magnetic substance discharge outlet 512; the magnetically attracted plastic fragments fall onto the channel 514 under the centrifugal force of the roller 521 and the self gravity, the vibration device 54 vibrates at the channel 514, and the air separation device 53 blows air towards the sorting material port 515; heavy materials such as stones are heavy and fall into the heavy material outlet 513 under vibration; the plastic chips are light and are discharged from the sorting outlet 515 under the action of wind. The waste gas at the sorting material port 515 is collected by the suction head for subsequent treatment.

S6, self-rubbing dry cleaning:

the plastic chips separated in the step S5 are fed into the kneading dry-type cleaning feed port 611 of the kneading dry-type cleaning unit 6 by using a screw conveyor, the motor drives the rotary blade 64 to rotate at a high speed through the bracket 53, the plastic chips are strongly sheared, torn and hit, and the blade plate 65 moves up and down under the action of the expansion device 66, so that the plastic chips are kneaded between the rotary blade 64 and the blade plate 65; small inorganic and organic particles attached to the plastic chips are thrown out of the plurality of through holes in the side wall of the inner cover 62 by high-speed throwing action and discharged through the kneading dry-type cleaning discharge port 611; after kneading for 30-45min, the opening of the blade plate 65 is opened and aligned with the kneading dry cleaning discharge port 611, and the plastic chips are discharged.

The exhaust gas at the kneading dry-type cleaning discharge port 611 is collected by the suction head for subsequent treatment.

S7, micro-negative pressure airflow separation:

and (3) feeding the S6 self-kneaded plastic chips into an airflow separation feed inlet 711 of a micro negative pressure airflow separation system 7 by using a screw conveyor, opening an airflow distributor 72 and an airflow supply device 73, keeping the internal air pressure of the micro negative pressure airflow separation system between-0.5 and-0.2 MPa and treating for 30-45min at an air flow rate of 15 m/S.

The light pollutants are collected by the suction head at the gas flow separation discharge hole 711 for subsequent treatment. The plastic chips are discharged from the gas flow separation outlet 712.

And (3) measuring the cleaning efficiency:

before cleaning: the total mass of the plastic (containing impurities) is A,

after cleaning: the total mass of the clean plastic is B,

the total impurity amount is C,

the cleaning efficiency was 100%. a-B)/C.

The waste plastics are cleaned by the equipment and the method, the cleaning efficiency is over 95 percent, and is improved by at least 12 percent compared with the conventional dry cleaning method (generally, paper impurities cannot be effectively removed).

The whole assembly line of the invention realizes automatic production, and the whole set of equipment is provided with dust removal and waste gas treatment devices, so that the invention has no air pollution and water pollution and high automation degree.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A dry cleaning device for waste plastics in household garbage, which is characterized in that,

comprises a combined dry cleaning system and a micro-negative pressure airflow separation system which are arranged according to a production line;

the combined dry cleaning system comprises a roller dry cleaning unit, a hot air flow paper-plastic separation unit, a magnetic separation gravity separation unit and a kneading dry cleaning unit which are arranged according to a production line;

the roller dry-type cleaning unit removes pollutants on the plastic fragments through friction collision of the plastic fragments and dry-cleaning materials;

the hot air flow paper-plastic separation unit is used for drying plastic fragments and separating paper from plastic;

the magnetic separation gravity separation unit is used for carrying out magnetic separation on plastic fragments and air separation on heavy objects;

the kneading dry-type cleaning unit is used for further removing pollutants on the plastic fragments;

the micro negative pressure airflow separation system is used for winnowing of light objects;

the device also comprises a waste gas treatment system which is used for purifying the waste gas generated by the roller dry cleaning unit, the hot air flow paper-plastic separation unit, the magnetic separation gravity separation unit, the kneading dry cleaning unit and the micro-negative pressure air flow separation system.

2. The apparatus for dry cleaning waste plastics in household garbage according to claim 1,

the combined dry cleaning system also comprises a pretreatment system, wherein the pretreatment system is arranged at the upstream of the combined dry cleaning system and comprises a dehumidification unit and a crushing unit;

the dehumidification unit is used for dehumidifying the waste plastics;

the crushing unit is used for crushing the dehumidified waste plastics into plastic fragments;

the waste gas treatment system is also used for purifying waste gas generated by the dehumidification unit and the crushing unit.

3. The apparatus for dry cleaning waste plastics in household garbage according to claim 1,

the roller dry type cleaning unit comprises a roller friction dry cleaning machine;

the roller friction dry cleaning machine comprises a shell, a roller, a stirring paddle and a motor;

the bottom of the shell is provided with a first discharge hole;

the roller is arranged in the shell and comprises an inner screen drum and an outer screen drum; first sieve holes are distributed on the inner sieve cylinder, one end of the inner sieve cylinder is provided with a roller friction dry cleaning feeding hole, and the other end of the inner sieve cylinder is provided with a second discharging hole; second sieve holes are distributed on the outer sieve cylinder, and the aperture of the first sieve hole is larger than that of the second sieve hole; and a third discharge hole is formed in the wall of the outer screen cylinder;

the stirring paddle is arranged inside the inner screen cylinder;

the motor drives the roller and the stirring paddle to rotate.

4. The apparatus for dry cleaning waste plastics in household garbage according to claim 1,

the hot air flow paper-plastic separation unit comprises a far infrared drying box and an electric appliance control box;

the far infrared drying box comprises an outer box body, a heat insulation layer, an air duct and an inner box body from outside to inside in sequence;

the inner box body is provided with a drying box feed inlet, a drying box discharge outlet and a drying box air outlet which penetrate out of the outer box body;

the far infrared heating pipe is powered by a power supply element, and the centrifugal fan blade provides a wind source through a blower motor;

the inner box body is provided with a ventilation opening or a ventilation pipeline which can be used for communicating the interior of the inner box body with the air duct in a closed manner;

the electrical control box is used for power distribution control of the power supply element and the blower motor.

5. The apparatus for dry cleaning waste plastics in household garbage according to claim 1,

the magnetic separation gravity separation unit comprises a shell, a magnetic field generating device and a winnowing device;

the top of the shell is provided with a sorting feed port, and the bottom of the shell is provided with a magnetic substance discharge port and a heavy substance discharge port; the side edge of the shell is provided with an upward inclined channel, and a vibration device is arranged at the channel; the lower end of the channel faces the heavy material discharge hole, and the higher end of the channel is a sorting discharge hole;

the magnetic field generating device is arranged in the shell, is positioned at the bottom of the sorting feed inlet and comprises a roller and a rotary magnet; the rotary magnetic attraction is eccentrically arranged in the roller, so that magnetic substances are attracted to the roller after being fed, and the magnetic substances fall into the magnetic substance discharge port along with the reduction of magnetic attraction in the rotating process;

the air separation device is arranged at the bottom of the magnetic field generation device, and the air outlet direction of the air separation device faces the separation discharge hole; the plastic fragments after the magnetic field generating device magnetic separation fall into passageway department, the heavy matter that mixes among the plastic fragments falls into through vibrations and gravity the heavy matter discharge gate, the plastic fragments pass through wind-force by divide the select out discharge gate and discharge.

6. The apparatus for dry cleaning waste plastics in household garbage according to claim 1,

the rubbing dry type cleaning unit comprises an outer shell, an inner cover body, a support, a rotating blade and a blade plate;

the bottom of the outer shell is provided with a kneading dry type cleaning discharge port;

the inner cover body is arranged in the outer shell; the top of the inner cover body is provided with a kneading dry-type cleaning feed inlet connected to the top of the outer shell body, and the bottom of the inner cover body is opened; and the side wall of the inner cover body is provided with a plurality of through holes;

the rotating blades are erected in the inner cover body through a bracket and are driven to rotate through a motor;

the blade plate is arranged at the bottom opening of the inner cover body, blocks the bottom opening of the inner cover body, and is provided with a closable opening.

7. The apparatus for dry cleaning waste plastics in household garbage according to claim 1,

the micro-negative pressure airflow separation system comprises a body, an airflow distributor and an airflow supply device;

the top of the body is provided with a gas flow separation feed inlet, and the bottom of the body is provided with a gas flow separation discharge outlet;

the air flow distributors are uniformly distributed in the body;

the airflow supply device supplies airflow to the airflow distributor.

8. The apparatus for dry cleaning waste plastics in household garbage according to claim 1,

the waste gas treatment system comprises an air collecting device, a cyclone separation device and a dust removal device which are connected in sequence;

the air collecting device is respectively connected with the roller dry type cleaning unit, the hot air flow paper-plastic separation unit, the magnetic separation gravity separation unit, the kneading dry type cleaning unit and the micro-negative pressure air flow separation system.

9. A dry cleaning method for waste plastics in household garbage is characterized by comprising the following steps:

s1, dehumidification:

performing dehumidification treatment on the waste plastics at 45-55 ℃, wherein the dehumidification time is determined according to the water content of the waste plastics, and the moisture content after dehumidification is ensured to be 40-45%;

s2, crushing:

pulverizing the waste plastics obtained by dehumidification in S1 into 3-5cm plastic chips;

s3, friction dry cleaning:

adding dry-cleaning materials into the plastic fragments, separating pollutants from the plastic fragments through friction collision between the plastic fragments and the dry-cleaning materials, screening the pollutants by using sieve cylinders with different apertures, separating the plastic fragments from the dry-cleaning materials, and recycling the dry-cleaning materials for S3;

s4, hot air flow paper-plastic separation:

processing the plastic fragments subjected to the friction dry cleaning by S3 by using hot air to separate the paper fragments attached to the surfaces of the plastic fragments from the plastic fragments; the temperature of the hot air flow is 83-85 ℃, and the drying is stopped when the humidity of the plastic fragments is in the range of 18-22%;

s5, magnetic separation and gravity separation:

removing magnetic substances and heavy substances in the plastic fragments through magnetic separation and gravity separation;

s6, self-rubbing dry cleaning:

self-kneading the plastic fragments, and further separating pollutants;

s7, micro-negative pressure airflow separation:

and (3) placing the plastic fragments in a micro-negative pressure airflow separation system, keeping the internal air pressure between-0.5 MPa and-0.2 MPa, and separating pollutants again under the condition that the air flow rate is 15 m/s.

10. The method for dry cleaning waste plastics in household garbage according to claim 9, further comprising: collecting the waste gas generated in the steps S1-S7, and purifying.

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