CN101285641B - Film drying line and method for removing moisture from film surface using the line - Google Patents

Abstract

The invention discloses a film drying assembly line for dynamically drying film surface moisture with hot air, comprising: at least two hot air drying devices and at least one cold air cooling device sequentially connected in series, each hot air drying device includes a serial The corrugated tube, the cyclone silo, the automatic temperature-regulating heater and the blower are connected together, and the cold air cooling device includes the corrugated tube, the cyclone silo and the blower connected in series, wherein: the cyclone silo is a cyclone structure. The invention also discloses a method for removing water on the surface of the film by utilizing the assembly line and using hot air higher than the melting point of the film under the conditions of proper wind speed and pipeline length. The water content of the film dried by this method is less than 3%, and it can be directly used for granulation without drying, which greatly shortens the production cycle and improves the production efficiency.

Description

Film drying line and method for removing moisture from film surface using the line

technical field

The invention relates to a film drying line and a method for removing moisture on the film surface by using the line.

Background technique

At present, in the process of recycling and granulating waste plastics, in order to ensure the quality of the produced pellets, the recycled waste plastics must first be cleaned, and then dehydrated by a film dehydrator. The water content of the film after the above treatment is It is usually between 15% and 25%, which cannot meet the needs of granulation. At this time, the film needs to be dried naturally, so that the water content of the film is below 3%, which meets the needs of granulation. Because natural airing requires a long cycle, thereby prolonging the production cycle, the production efficiency is low; and in the natural airing process, due to the inevitable presence of dust and other pollutants in the air, the cleaned film is polluted again.

Contents of the invention

A technical problem to be solved by the present invention is to provide a film drying line which uses hot air to dynamically dry the moisture on the film surface.

In order to solve the above technical problems, the technical solution adopted by the present invention is: a film drying line, including: at least two hot air drying devices and at least one cold air cooling device, and the at least two hot air drying devices and at least one cold air cooling device are sequentially Connected in series, each hot air drying device includes a corrugated pipe, cyclone silo, automatic temperature-regulating heater and blower, and the corrugated pipe, cyclone silo, automatic temperature-regulating heater and blower of the hot air drying device are connected in series , each cold air cooling device includes a corrugated tube, a cyclone silo and a blower, and the corrugated tube, cyclone silo and blower of the cold air cooling device are connected in series; wherein: the cyclone silo is a cyclone structure, and its specific structure is: in the cyclone A small cylinder is also arranged inside the upper cylindrical shell of the silo, and the annular gap between the small cylinder and the shell communicates with the wave pipe.

There are three hot air drying devices, and one cold air cooling device.

A collection bag is arranged below the cyclone feed bin in the cold air cooling device.

The automatic temperature-regulating heater includes: a temperature controller, a heater and a temperature sensor.

The method for removing moisture from the film surface by using the above-mentioned film drying line, the steps are: send the cleaned film to a film dehydrator for dehydration, then send the dehydrated film to the film drying line, and pass the automatic temperature adjustment heater Ensure that the hot air temperature in the pipeline of the hot air drying device is ≥ film melting point + 30°C and ≤ film melting point + 100°C, and keep the wind speed in the entire pipeline between 1000 cubic meters per hour and 10000 cubic meters per hour. The diameter of the corrugated tube is between 159 mm and 300 mm, and it is ensured that the time for the film to stay in the assembly line is between 8 and 12 minutes. The final dried film is discharged from the cyclone silo in the cold air cooling device, and Collected by the collection bag located below the cyclone silo.

The beneficial effects of the present invention are: the present invention uses the film drying assembly line to dry the film dehydrated by the film dehydrator with hot air higher than the melting point of the film, and finally discharges the material from the cyclone silo in the cold air cooling device to obtain film after drying. Such a film can be directly used for granulation, thereby eliminating the natural drying process and eliminating secondary pollution, which not only greatly shortens the production cycle and improves production efficiency; but also improves the quality of the pellets.

Description of drawings

Fig. 1 is the structural representation of film drying assembly line of the present invention;

In the figure: 1. Film dehydrator, 2. Wave pipe, 3. Wave pipe, 4. Wave pipe, 5. Wave pipe, 6. Blower, 7. Blower, 8. Blower, 9. Blower, 10. Collection bag, 11, cyclone silo, 12, cyclone silo, 121, shell, 122, small cylinder, 13, cyclone silo, 14, cyclone silo, 21, automatic temperature-regulating heater, 22, automatic temperature-regulating heater, 23. Automatic thermostat heater.

Detailed ways

Below in conjunction with accompanying drawing, describe technical scheme of the present invention in detail:

As shown in Figure 1, the film drying assembly line of the present invention includes: three hot air drying devices and a cold air cooling device connected in series, each hot air drying device includes wave tubes connected in series, Cyclone silo, automatic temperature-regulating heater and blower, that is: the first hot air drying device is composed of wave tube 2, cyclone silo 11, automatic temperature-regulating heater 21 and blower 6 connected in series, the second The hot air drying device is composed of the corrugated tube 3 connected in series, the cyclone hopper 12, the automatic temperature adjustment heater 22 and the blower 7, and the third hot air drying device is composed of the corrugated tube 4 connected in series, the cyclone silo 13. An automatic temperature-regulating heater 23 and a blower 8 are formed. The cold air cooling device includes a wave pipe 5 connected in series, a cyclone hopper 14 and a blower 9. The cyclone hoppers 11, 12, 13 and 14 are all cyclone structures. Taking the cyclone silo 12 as an example here to illustrate, a small cylinder 122 is also arranged in the inside of the upper cylindrical shell 121 of the cyclone silo 12, and the annular gap (cyclone passage) between the small cylinder 122 and the shell 121 ) communicates with the corrugated tube 12. In this embodiment, a collecting bag 10 is arranged below the cyclone silo 14; the automatic temperature-regulating heaters 21, 22 and 23 are common techniques in the art, and are mainly composed of a temperature controller, a heater and a temperature sensor . In actual application, the feed port of the first hot air drying device is connected with the discharge port of the film dehydrator 1 .

The method for removing moisture from the film surface by using the above-mentioned film drying line, the steps are: send the cleaned film to the film dehydrator 1 for dehydration, then send the dehydrated film into the film drying line, and pass through three automatic The temperature adjustment heater ensures that the hot air temperature in the pipeline of the hot air drying device is ≥ film melting point + 30°C and ≤ film melting point + 100°C, and makes the entire pipeline (including the hot air pipeline and cold air in the hot air drying device) cool The wind speed in the cold air pipeline in the device) is kept between 1000 cubic meters per hour and 10000 cubic meters per hour, and the diameters of wave pipes 2, 3, 4 and 5 are between 159 mm and 300 mm - the wave pipe The pipe diameter depends on the output, and it is guaranteed that the film stays in the assembly line for 8 to 12 minutes. The final dried film is discharged from the cyclone silo 14 in the cold air cooling device, and is placed in the cyclone material. The collection bag 10 below the bin 14 collects.

Take LLDPE film as an example below to describe in detail the method for removing moisture on the surface of LLDPE film by using a film drying assembly line according to the present invention. Put the fragmented LLDPE film into the film dehydrator 1 to remove part of the water, so that The water content of the LLDPE film is about 20%. Then, the first hot air drying device sucks the LLDPE film coming out of the discharge port of the film dehydrator 1 into the wave pipe 2, and the part of the moisture on the surface of the LLDPE film is automatically adjusted. The hot air formed by the warm heater 21 and the blower 6 heats and evaporates. When these water vapors pass through the cyclone silo 11, they escape from the small cylinder inside the cyclone silo 11, and then pass through the second and third hot air drying. device (its working process is exactly the same as that of the first hot air drying device, and will not be repeated here), and removes most of the moisture on the surface of the LLDPE film. As we all know, the melting point of LLDPE film is about 110°C, and the softening degree is 80°C. For such LLDPE film, the temperature of the hot air in the hot air pipeline is usually controlled at about 170°C, and the entire pipeline (including the hot air pipeline and The wind speed in the cold air pipeline) is controlled at 7000 cubic meters per hour, and the residence time of the LLDPE film in the entire assembly line is guaranteed to be about 10 minutes. The material is discharged from the feed port and collected by the collection bag 10 located below the cyclone silo 14 . The water content of such LLDPE film is usually below 3%, which can be directly used for granulation, eliminating the need for natural drying process, thereby eliminating secondary pollution, not only greatly shortening the production cycle, improving production efficiency; The quality of pellets.

Claims (5)

1. film drying streamline, comprise: at least two hot-air seasoning devices and at least one cold wind cooling device, described at least two hot-air seasoning devices and at least one cold wind cooling device are serially connected successively, each hot-air seasoning device comprises the wave pipe, cyclone feed bin, automatic temperature-control heater and air blast, the wave pipe of hot-air seasoning device, cyclone feed bin, automatic temperature-control heater and air blast are serially connected, each cold wind cooling device comprises the wave pipe, cyclone feed bin and air blast, the wave pipe of cold wind cooling device, cyclone feed bin and air blast are serially connected; Wherein: cyclone feed bin is the cyclone type structure, and its concrete structure is: the inside at the top cylinder shape shell of cyclone feed bin also is provided with a little cylinder, and little cylinder communicates with the wave pipe with annular gap between the shell.

2. film drying streamline as claimed in claim 1 is characterized in that: described hot-air seasoning device is three, and described cold wind cooling device is one.

3. film drying streamline as claimed in claim 1 or 2 is characterized in that: the below of the cyclone feed bin in the described cold wind cooling device is provided with collecting bag.

4. film drying streamline as claimed in claim 1 or 2 is characterized in that: described automatic temperature-control heater comprises: temperature controller, heater and temperature sensor.

5. utilize the described film drying streamline of claim 3 to remove the method for film surface moisture content, the steps include: the film after cleaning sent in the film dehydrator and dewater, film after will dewatering is then sent in the film drying streamline, and guarantee by the automatic temperature-control heater in the pipeline of hot-air seasoning device hot blast temperature 〉=film melting point+30 ℃ and≤film melting point+100 ℃, and the wind speed in the whole pipeline is remained between 1000 cubic metres/hour to 10000 cubic metres/hour, the diameter of wave pipe is between 159 millimeters to 300 millimeters, and the time that the assurance film is detained in described streamline is between 8～12 minutes, the cyclone feed bin discharging of film from the cold wind cooling device of final oven dry, and by the collecting bag collection that is positioned at this cyclone feed bin below.

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