阅读说明：本技术 一种附污水废气收集的带水塑料薄膜塑化前段工艺及机构 (water-carrying plastic film plasticizing front-stage process and mechanism for collecting waste gas with sewage ) 是由 冯愚斌 于 2019-09-03 设计创作，主要内容包括：本发明公开一种附污水废气收集的带水塑料薄膜塑化前段工艺及机构,所述工艺包括以下步骤：1、将塑料薄膜喂入物理除水区中；2、螺旋送料杆往前推送物料,并将水分挤出；3、塑料薄膜推送至加热水分蒸发区中,加热模块热量传递至加热水分蒸发区中,加热塑料薄膜,使水分汽化并排出；4、塑料薄膜推送至温度更高的加热初始熔融区中,进一步地对残留的水分进行蒸发并排出；5、塑料薄膜送至塑化区中。所述机构包括螺筒、螺旋送料杆和加热模块,螺筒的内腔包括物理除水区、加热水分蒸发区、加热初始熔融区和塑化区,螺旋送料杆依次穿过上述各区。本发明能在塑化之前对塑料薄膜去水和去废气,具有能耗低、易于环保措施的实现和运行过程安全等优点。(The invention discloses a water-carrying plastic film plasticizing front-stage process and a mechanism for collecting waste gas with sewage, wherein the process comprises the following steps: 1. feeding a plastic film into a physical dewatering area; 2. the spiral feeding rod pushes the materials forwards and extrudes the water; 3. pushing the plastic film into a heating water evaporation area, transferring the heat of the heating module into the heating water evaporation area, heating the plastic film, and vaporizing and discharging the water; 4. pushing the plastic film to a higher-temperature heating initial melting area, further evaporating and discharging residual moisture; 5. the plastic film is fed into a plasticizing zone. The mechanism comprises a screw barrel, a spiral feeding rod and a heating module, wherein the inner cavity of the screw barrel comprises a physical dewatering area, a heating water evaporation area, a heating initial melting area and a plasticizing area, and the spiral feeding rod sequentially penetrates through the areas. The invention can remove water and waste gas from the plastic film before plasticizing, and has the advantages of low energy consumption, easy realization of environmental protection measures, safe operation process and the like.)

1. A water-carrying plastic film plasticizing front-stage process for collecting waste gas with sewage is characterized by comprising the following steps:

(1) Feeding the cleaned plastic film into a physical dewatering area;

(2) In the physical water removal area, a screw feeding rod with gradually reduced screw pitch pushes materials in the direction of the heating water evaporation area, the plastic film is physically extruded while being pushed forwards, water attached to the plastic film is extruded out, and the extruded liquid water is discharged through a water discharge hole at the bottom of the screw cylinder;

(3) The plastic film is pushed to a heating water evaporation area by a spiral feeding rod, the plastic film and water in the area are heated by a heating module arranged outside a spiral cylinder, so that the water is quickly evaporated and is discharged from a first exhaust port in a steam form, and the steam mainly contains steam and a small amount of low-boiling organic volatile matters;

(4) The plastic film is pushed to a heating initial melting zone by a spiral feeding rod, the temperature of the heating initial melting zone is controlled between the temperature of a heating water evaporation zone and the temperature of a plasticizing zone, water and low-boiling-point organic matters remained on the plastic film are evaporated, and the part of gas is discharged from a second gas outlet;

(5) The screw feeding rod sends the plastic film to a plasticizing area, the plasticizing area reaches a plasticizing temperature, the plastic film is subjected to melting plasticization, and the molten plastic is discharged from the discharge hole under the extrusion of the screw feeding rod.

2. The pre-stage process for plasticizing a plastic film with water and collecting waste gas with sewage of claim 1, wherein in the step (2), the physical dewatering area is divided into a moisture squeezing area and a solid-liquid isolating area according to the conveying direction of the material, and in the moisture squeezing area, squeezed water is discharged from a first group of water discharging holes at the bottom of the screw barrel; in the solid-liquid isolation area, most of water is firstly gathered in the drainage channel on the inner wall of the screw cylinder and then is drained through the second group of drainage holes at the bottom of the screw cylinder.

3. The mechanism for realizing the water-carrying plastic film plasticizing front-stage process with sewage-attached waste gas collection of any one of claims 1-2 is characterized by comprising a screw barrel, a spiral feeding rod and a heating module, wherein the inner cavity of the screw barrel comprises a physical dewatering zone and a heating zone which are sequentially arranged, and the heating module is used for heating the heating zone; the heating zone comprises a heating water evaporation zone, a heating initial melting zone and a plasticizing zone; one end of the spiral feeding rod is connected with the driving motor, and the other end of the spiral feeding rod sequentially penetrates through the zones; along the feeding direction, the screw pitches of the spiral feeding rod in the physical dewatering area are gradually reduced in sequence;

a feeding hopper is arranged above the head end of the physical dewatering area, and a plurality of drain holes are formed in the bottom of the feeding hopper;

The control temperature in the heating water evaporation area is lower than the temperature in the heating initial melting area, and the control temperature in the heating initial melting area is lower than the temperature in the plasticizing area; and the screw barrel is provided with a first exhaust port for exhausting gas generated in the heating moisture evaporation area and a second exhaust port for exhausting gas generated in the heating initial melting area.

4. The water-carrying plastic film plasticizing front-end mechanism for collecting waste water and waste gas as claimed in claim 3, wherein the physical dewatering area comprises a moisture extrusion area and a solid-liquid isolation area, and the solid-liquid isolation area is positioned behind the moisture extrusion area along the spiral feeding direction;

the drain holes comprise a plurality of first group drain holes arranged at the bottom of the moisture squeezing area and a plurality of second group drain holes arranged at the bottom of the solid-liquid isolation area; and a plurality of drainage grooves communicated with the second group of drainage holes are formed in the inner wall of the solid-liquid isolation area.

5. The plastic film plasticizing front-end mechanism with water and waste gas collecting function of claim 4 is characterized in that the drainage groove is spiral or annular.

6. the water-carrying plastic film plasticizing front-end mechanism for collecting sewage and waste gas as claimed in claim 3, wherein the heating module is used for heating materials in the screw barrel by resistance heating, electromagnetic heating or gas heating.

7. The water-carrying plastic film plasticizing front-end mechanism with waste water and waste gas collection function of any one of claims 3 to 6, characterized in that the heating modules positioned in the heating water evaporation zone, the heating initial melting zone and the plasticizing zone are respectively provided with independent temperature controllers, the temperature in the heating water evaporation zone is lower than that in the heating initial melting zone, and the temperature in the heating initial melting zone is lower than that in the plasticizing zone, wherein the temperature in the plasticizing zone reaches or exceeds the melting point of the plastic film.

8. The water-carrying plastic film plasticizing front-end mechanism with sewage and waste gas collection function of claim 7, wherein the end of the screw cylinder is provided with one or more discharge ports communicated with the plasticizing area.

9. The water-laden plastic film plasticizing front-end mechanism with sewage and waste gas collection function of claim 3, wherein the first exhaust port is communicated with the end of the heating water evaporation zone, and the second exhaust port is communicated with the end of the heating initial melting zone.

10. The water-carrying plastic film plasticizing front-end mechanism with sewage and waste gas collection function of claim 3, further comprising a sewage and waste gas quality separating treatment device, wherein the sewage and waste gas quality separating treatment device comprises a sewage treatment device and a waste gas treatment device, the sewage treatment device comprises a sewage collection tank and a sewage treatment system, and the waste gas treatment device comprises a first waste gas purification device for purifying waste gas discharged from the first exhaust port and a second waste gas purification device for purifying waste gas discharged from the second exhaust port and subsequent processes.

Technical Field

The invention relates to plastic film recycling treatment equipment, in particular to a water-carrying plastic film plasticizing front-stage process and mechanism for collecting sewage and waste gas.

background

The recycling of waste plastic films is an important category in the field of resource recycling; agricultural film, packaging film, plastic film after paper pulp separation of paper-plastic composite, garbage bag, tailings of regeneration paper mill, etc.; among them, in the production process of recycled paper mills, "skim coat" of plastic components such as films carried by waste paper and surface overmolding of paper is the most complicated of various waste plastic films, and the "skim coat" not only has a large water content and many impurities, but also contains ink, oil stains and the like which are difficult to be environmentally treated.

according to the report, tailings generated by national regeneration papermaking reach 1500-1600 ten thousand tons/year, and the glue residues account for about 30 percent of the regeneration papermaking tailings, namely 450 ten thousand tons/year. At present, except incineration treatment, regeneration and utilization are mainly used for low-grade plastic products such as disposable trays, turnover boxes, ceramic wrap angles and the like after granulation and regeneration. The granulation process is high in energy consumption, most manufacturers before 2017 adopt coal, firewood, fuel oil and other heating modes to heat, so that the waste gas temperature is high, the waste gas contains oil, chlorine and the like, most manufacturers in China can not meet the environmental protection requirement so far, and the granulation process is produced in a half-covering and half-covering state.

At present, the regeneration process of the water-bearing waste plastic film has the following defects:

1. the energy consumption is high: the water content of the film to be granulated after washing is up to 40%. Heating and evaporating, wherein the temperature of water is required to be raised to the vaporization temperature (100 ℃ at normal pressure), and a large amount of vaporization heat is absorbed in the evaporation process. The prior art basically adopts coal, fuel oil, biomass and fuel gas, but the requirement of combustion heat supply is high, so that the prior art is basically not adopted. In addition, the electricity cost for supplying heat by electricity is high, and the electricity is not adopted.

2. the environmental protection is difficult to reach the standard: a plurality of waste plastic films are mixed with PVC film clips, the surfaces of the films are provided with printing ink, the films are polluted by residues, and the films cannot be cleaned in the cleaning process. At present, most regeneration plants intensively treat process waste gas, the waste gas is difficult to reach the standard, the production is basically carried out under the condition of 'half covering and half masking', and the waste gas is produced in rare places in a deep hidden way without any environmental protection measures.

3. There is a risk of "blasting": most of the prior similar devices can not evacuate water vapor at the front stage of plasticization, so that high-temperature and high-pressure gas is embedded in the plasticized molten plastic, and the phenomenon of blasting or blasting frequently occurs at a discharge port due to sudden pressure relief; wherein, the high-pressure and high-temperature gas can carry plastic melt with the temperature of about 300 ℃ to splash during blasting, and the plastic melt has great sound and dangerous scene, so that operators are easy to burn.

Disclosure of Invention

The invention aims to overcome the existing problems and provide a water-carrying plastic film plasticizing front-stage process for collecting waste gas with sewage, which can respectively remove water and waste gas from a plastic film before plasticizing, reduce volatilization and decomposition of other substances except water, effectively reduce the content of water vapor in the plasticizing process, and has the advantages of low energy consumption, high environmental protection degree and the like.

The invention also aims to provide a water-carrying plastic film plasticizing front-end mechanism for collecting waste gas with sewage.

The purpose of the invention is realized by the following technical scheme:

A water-carrying plastic film plasticizing front-stage process for collecting waste gas with sewage comprises the following steps:

(1) Feeding the cleaned plastic film into a physical dewatering area;

(2) In the physical water removal area, a screw feeding rod with gradually reduced screw pitch pushes materials in the direction of the heating water evaporation area, the plastic film is physically extruded while being pushed forwards, water attached to the plastic film is extruded out, and the extruded liquid water is discharged through a water discharge hole at the bottom of the screw cylinder;

(3) The plastic film is pushed to a heating water evaporation area by a spiral feeding rod, the plastic film and water in the area are heated by a heating module arranged outside a spiral cylinder, so that the water is quickly evaporated and is discharged from a first exhaust port in a steam form, and the steam mainly contains steam and a small amount of low-boiling organic volatile matters;

(4) The plastic film is pushed to a heating initial melting zone by a spiral feeding rod, the temperature of the heating initial melting zone is controlled between the temperature of a heating water evaporation zone and the temperature of a plasticizing zone, water and low-boiling-point organic matters remained on the plastic film are evaporated, and the part of gas is discharged from a second gas outlet;

(5) the screw feeding rod sends the plastic film to a plasticizing area, the plasticizing area reaches a plasticizing temperature, the plastic film is subjected to melting plasticization, and the molten plastic is discharged from the discharge hole under the extrusion of the screw feeding rod.

in a preferable scheme of the invention, in the step (2), the physical dewatering area is divided into a moisture squeezing area and a solid-liquid isolation area according to the conveying direction of the material, and in the moisture squeezing area, squeezed water is discharged from the first group of water discharging holes; in the solid-liquid isolation area, most of water is firstly gathered in the drainage grooves and then is drained through the second group of drainage holes.

In a preferred embodiment of the present invention, the temperature in the heated moisture evaporation zone is lower than the temperature in the heated initial melting zone, which is lower than the temperature in the plasticizing zone, wherein the temperature in the plasticizing zone reaches or exceeds the melting point of the plastic film.

A water-carrying plastic film plasticizing front-section mechanism for collecting waste gas with sewage comprises a screw cylinder, a spiral feeding rod and a heating module, wherein the inner cavity of the screw cylinder comprises a physical dewatering area and a heating area which are sequentially arranged, and the heating module is used for heating the heating area; the heating zone comprises a heating water evaporation zone, a heating initial melting zone and a plasticizing zone; one end of the spiral feeding rod is connected with the driving motor, and the other end of the spiral feeding rod sequentially penetrates through the zones; in the feeding direction, the screw pitches of the spiral feeding rod in the physical dewatering area are gradually reduced in sequence;

A feeding hopper is arranged above the head end of the physical dewatering area, and a plurality of drain holes are formed in the bottom of the feeding hopper;

The heating temperature in the heating water evaporation area is lower than that in the heating initial melting area, and the heating temperature in the heating initial melting area is lower than that in the plasticizing area; and the screw barrel is provided with a first exhaust port for exhausting gas generated in the heating moisture evaporation area and a second exhaust port for exhausting gas generated in the heating initial melting area.

The working principle of the plasticizing front-section mechanism is as follows:

When the device works, the cleaned plastic film is fed into the feeding hopper, enters the physical dewatering area through the feeding hopper and is pushed forwards by the spiral feeding rod; the screw pitch of the screw feeding rod in the physical water removal area is gradually reduced, so that the plastic film is physically extruded while being pushed forwards, water attached to the plastic film is extruded out, and the extruded water is discharged through the water discharge hole.

After most water extrusion discharges, the screw feeding rod pushes the plastic film to the heating water evaporation area, the heating module transfers heat to the heating water evaporation area, the plastic film in the heating water evaporation area is heated, so that water carried by the plastic film is rapidly evaporated, and evaporated water vapor and a small amount of organic gas (low-boiling ink gas and the like) are discharged from the first exhaust port. Then, the screw feeding rod pushes the plastic film into the heating initial melting area, the heat quantity in the heating initial melting area is larger than that in the heating water evaporation area, namely the temperature in the heating initial melting area is higher than that in the heating water evaporation area, so that the residual water and organic matters with low boiling points of the plastic film can be further evaporated, and the gas is discharged from the second gas outlet, thereby reducing the gas embedded in the gaps of the plastic film and reducing the wrapping probability of the plasticized plastic on the gas.

and finally, the screw feeding rod sends the plastic film to a plasticizing area, the heating temperature in the plasticizing area is higher than that in the heating initial melting area, so that the plastic film is subjected to melting and plasticizing, and the plasticized plastic is output from the discharge hole under the pushing of the screw feeding rod.

In a preferred embodiment of the present invention, the physical dewatering area includes a moisture squeezing area and a solid-liquid isolation area, and the solid-liquid isolation area is located behind the moisture squeezing area along the spiral feeding direction;

The drain holes comprise a plurality of first group drain holes arranged at the bottom of the moisture squeezing area and a plurality of second group drain holes arranged at the bottom of the solid-liquid isolation area; and a plurality of drainage grooves communicated with the second group of drainage holes are formed in the inner wall of the solid-liquid isolation area. Through above-mentioned structure, in moisture extrusion district, the screw feed rod that pitch diminishes gradually extrudees plastic film, tightens up loose plastic film gradually, extrudes moisture simultaneously, and the extrusion rivers are discharged from first group wash port to reach the purpose of material dewatering. In order to prevent the extruded liquid water from flowing into the heating water evaporation area, a solid-liquid isolation area is arranged; this district section of thick bamboo inner wall sets up water drainage tank, enlarges the space of liquid moisture outflow effectively, and the spiral section of thick bamboo is derived to liquid water behind the second group's wash port of water drainage tank flow direction.

Preferably, the drain groove is spiral or annular.

In a preferred embodiment of the present invention, the heating module includes a heating ring for generating heat and a heat transfer plate for transferring heat, the heating ring is disposed in the heat transfer plate, and the heat transfer plate is wrapped on the barrel and located outside the heating moisture evaporation area, the heating initial melting area, and the plasticizing area.

In a preferred embodiment of the present invention, a feeding screw is provided in the feeding hopper, and the feeding screw is in a single-screw extrusion type or a double-screw roll-in type. The concrete structure can be seen in a patent No. ZL201510547055.9 patent disclosure of an integrated soft sheet material forced feeding device of a single-screw extruder and a patent No. ZL201410606227.0 patent disclosure of a forced feeding mechanism and a forced feeding method of a plastic crusher.

In a preferable embodiment of the present invention, the screw cylinder at the screw feeding rod is a twin-screw cylinder, and the first group of drain holes is provided with a plurality of groups. Through above-mentioned structure, plastic film passes through feeding hopper feeding moisture extrusion district, through the space restriction of spiral shell and screw feed rod, and screw feed rod's rotation forms the extrusion force, extrudees plastic film, and moisture is then through the multiunit perforation discharge that is located the bottom.

in a preferred aspect of the present invention, the heating rings located outside the heated water-evaporation zone, the heated initial-melting zone, and the plasticizing zone are provided with independent temperature controllers, respectively, so as to control the temperatures in the respective zones, respectively, such that the temperature in the heated water-evaporation zone is lower than the temperature in the heated initial-melting zone, and the temperature in the heated initial-melting zone is lower than the temperature in the plasticizing zone, wherein the temperature in the plasticizing zone reaches or exceeds the melting point of the plastic film.

In a preferred embodiment of the present invention, the end of the screw barrel is provided with a plurality of discharge ports communicated with the plasticizing area, the molten plastic is extruded from the screw barrel through the discharge ports under the pushing of the screw feeding rod, and the plurality of discharge ports enable the molten plastic to flow out in multiple strands, so that waste gas (mainly volatile matter generated by material decomposition and evaporant of high temperature ink oil) embedded in the molten plastic is discharged as far as possible, and waste gas generation in the next process is reduced.

in a preferred aspect of the present invention, the first exhaust port communicates with the end of the heating water evaporation zone, and the second exhaust port communicates with the end of the heating initial melting zone.

the sewage and waste gas quality-separating treatment device comprises a sewage treatment device and a waste gas treatment device, wherein the sewage treatment device comprises a sewage collecting tank and a sewage purification system, and the waste gas treatment device comprises a first waste gas purification device for purifying waste gas discharged from a first exhaust port and a second waste gas purification device for purifying waste gas discharged from a second exhaust port and subsequent processes. In the structure, the sewage collecting tank is arranged outside the screw cylinder, and the extruded liquid water is collected and enters the sewage treatment system. In the exhaust gas treatment, the first purification device may be referred to as "a multifunctional absorption condenser and an exhaust gas pretreatment method suitable for exhaust gas pretreatment" disclosed in patent publication No. CN109499088A, the exhaust gas discharged from the second exhaust port and the subsequent processes is rich in thermal decomposition products and volatile matters of organic matters, and enters the second exhaust gas purification device as an independent exhaust gas with a higher concentration, and specifically referred to as "a container type low concentration organic exhaust gas purification processing device" disclosed in patent publication No. ZL 201610044861.9.

Compared with the prior art, the invention has the following beneficial effects:

1. In the plasticizing front-stage mechanism, most of moisture is extruded out firstly by utilizing a physical mode through the limitation of a screw barrel and a screw rod and the contraction of the space of materials, and the mechanical energy consumption is much less than the heat consumption required by overcoming the vaporization heat of water through heating and evaporation. According to the consideration of the paper mill glue residues, the moisture content of the incoming material reaches more than 40 percent, most of water is removed through physical extrusion, the energy-saving effect is obvious, and the implementation of environmental protection measures is facilitated.

2. Due to the adoption of a physical extrusion type water removal method, most of cleaning water attached to the plastic film is discharged from the drain holes after being extruded, so that the moisture which needs to be removed through heating and evaporation is reduced, the decomposition and volatilization of waste gas of the cleaning water after being heated can be greatly reduced, and the difficulty of waste gas treatment is reduced.

3. in the heating zone, the quantity and concentration of each section of waste gas are controlled by controlling the temperature in sections, and the difficulty of waste gas purification treatment is reduced, so that the treatment cost is reduced.

4. the temperature of heating is controlled in a heating water evaporation area and a heating initial melting area in a partitioning mode, so that waste gas generated by volatilization of organic volatile matters except water and decomposition of organic matters is reduced, the exhaust gas of the area is mainly water vapor and is intensively exhausted through a first exhaust port, and the gas yield of a subsequent plasticizing area is reduced; meanwhile, the plastic is not completely plasticized, and a gap for sufficient gas to escape is kept in the material to exhaust the gas in the area, so that the danger that the gas is embedded by the molten plastic in a plasticizing section and is shot at a discharge port due to sudden pressure relief is avoided.

5. through the exhaust of plastify anterior segment, the waste gas in plastify district is mainly the evaporant of the vaporization thing of material decomposition, high boiling point printing ink oil, and autonomic gas production is few, and the beneficiary lies in: (1) the phenomenon of 'blasting' caused by sudden pressure relief of steam wrapped at the discharge hole due to plasticized plastic is avoided; (2) because the waste gas volume is few, subsequent waste gas treatment can be directed at, guarantee the treatment effect and reduce treatment cost.

Drawings

FIG. 1 is a schematic structural diagram of a water-carrying plastic film plasticizing front-stage mechanism with sewage and waste gas collection in the invention.

Detailed Description

in order to make those skilled in the art understand the technical solutions of the present invention well, the following description of the present invention is provided with reference to the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.