JP2000325711A - Method for washing strainer for polystyrene solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To wash a filter unit without taking out the filter unit from a strainer container. SOLUTION: A strainer 1A is produced by housing a filter unit 8A comprising a filter member 6 and an inner cylinder 5 installed on the outer circumference of the filter member 6 in a strainer container 2 having an inlet 3 in a lower end and an outlet 4 in an upper part side wall. A vent pipe 31 equipped with a vent valve 30 is installed in the tip part of a cover 2a of the strainer container 2 and a blow pipe 20 is connected to an upper part. A sending part of a polystyrene solution 13, a washing tank 25 for storing a solvent 24, and an air sending apparatus 28 are connected to the inlet 3 through a switching apparatus 22. At first, the remaining liquid is discharged by blowing the inside of the strainer container 2, the solvent 24 is injected through a hose from the washing tank 25 by opening the cover 2a, and then air 26 led out of the air sending apparatus 28 is bubbled in the solvent 24 to float dusts 32 in the solvent 24 and them together with the solvent 24, the dust is discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning a strainer for a polystyrene solution for cleaning a filter unit in a strainer container used for filtering a polystyrene solution generated during recycling of waste expanded polystyrene.

[0002]

2. Description of the Related Art Expanded polystyrene (EPS, so-called styrofoam) is lightweight and excellent in water resistance, heat retention and impact buffering properties, and can be processed into any shape.
It is widely used in all fields, including fish transport cases in fish markets, packing materials for electrical products, trays for food in supermarkets, and the like.

[0003] However, when the expanded polystyrene after being used is treated as waste, high temperatures are generated during incineration to shorten the life of the incinerator, or the waste is not decomposed in the soil even if discarded. Therefore, recycling is desired, and in 2000, the recycling of waste expanded polystyrene is obliged by the Containers and Packaging Recycling Law, so that a recycling method has been developed.

[0004] As one of the methods for recycling such waste expanded polystyrene, first, the recovered waste expanded polystyrene is dissolved in a solvent to form a high-viscosity polystyrene solution (PS gel). The solution is filtered to remove dirt mixed into the solution, and then the solvent is evaporated to separate and removed, and the residue is refoamed or used as a raw material for other products as polystyrene pellets. There is a method to collect it.

[0005] Among the above methods, the strainer used for the filtration of the polystyrene solution is shown in FIG.
As shown in (b), an inlet 3 for the polystyrene solution 13 is provided at the top of the lid 2a, and the filtrate 13a is provided at the bottom of the lid 2a.
In the strainer container 2 provided with the outlets 4 of the above, a plurality of filter inner cylinders 5 whose peripheral walls are formed in a porous structure so as to have liquid permeability and whose lower end is closed, and the inner peripheral surface of each of the filter inner cylinders 5 The filter unit 8 includes a filter member 6 made of a steel mesh and a holding plate 7 for integrally holding an upper end of each of the filter inner cylinders 5, and an outer peripheral portion of the holding plate 7 is The pipe 1 connected to the inlet 3 is mounted on a supporting flange 9 protruding from the inner wall surface of the container and detachably attached by bolts 10.
When the polystyrene solution 13 fed into the strainer container 2 through 1 is passed through each filter inner cylinder 5 from the inside to the outside, the dust is removed by the inner filter member 6 and filtered to remove the dust. Later filtrate 13
The strainer 1 has a configuration in which a is discharged through a pipe 12 connected to the outlet 4.

In recent years, as shown in FIGS. 4A and 4B, a polystyrene solution 13 such as the strainer 1 shown in FIGS. A strainer 1A has been proposed in which a polystyrene solution 13 is allowed to flow upward from below in a strainer container 2 to filter the polystyrene solution 13 instead of performing filtration while flowing the solution. That is, in a strainer having a configuration similar to that shown in FIGS. 3A and 3B, a filter unit 8A in which the filter member 6 is disposed on the outer peripheral surface of the filter inner cylinder 5 is provided. The inlet 3 of the polystyrene solution 13 is provided at the bottom, and the filter unit 8
An outlet 4 for the filtrate 13a is provided on the upper side wall above the support flange 9 for supporting the polystyrene solution 13, and when the polystyrene solution 13 pumped from the inlet 3 is passed through each filter inner cylinder 5 from outside to inside, The dust is removed by the filter member 6 and the filtrate 13a is discharged from the outlet 4.

In FIGS. 3 (a) (b) and 4 (a) (b), a jacket 14 allows hot oil 15 to pass through the outside of the strainer vessel 2 in order to maintain the fluidity of the polystyrene solution 13. , 16 is the lid 2 of the strainer container 2
Reference numeral 17 denotes a lifting eyepiece used for opening and closing a, reference numeral 17 denotes a lifting eyepiece for the filter units 8 and 8A, reference numeral 18 denotes a support for the strainer container 2, and reference numeral 19 denotes a heat insulating material covering the entire apparatus. Further, in FIG. 4A, reference numeral 20 denotes a blow pipe, 2
Reference numeral 1 denotes a steadying member connecting the lower ends of the respective filter inner cylinders 5 in the filter unit 8A.

By the way, when the polystyrene solution 13 is filtered by the strainers 1 and 1A, dust mixed in the polystyrene solution 13 is removed by the filter member 6.
Accumulates and becomes clogged. In this case, since the pressure of the polystyrene solution 13 to be sent to the strainers 1 and 1A must be increased, for example, the pressure difference between the pressure of the sent polystyrene solution 13 and the pressure of the filtrate 13a to be sent is increased. When the pressure is about 1 kg / cm ² , the strainers 1 and 1A need to be cleaned.

Conventionally, when cleaning the above strainers 1 and 1A, the supply of the polystyrene solution 13 is first stopped, and then a valve switching operation (not shown) is carried out to obtain the structure shown in FIG. 4), air is blown into the strainer vessel 2 through the pipe 11 and through the blow pipe 20 in the apparatus shown in FIGS. 2a, and then the filter units 8, 8A are suspended outside the strainer container 2. Thereafter, the dirt clogged in the filter member 6 outside the strainer container 2 is removed from the polystyrene solution adhering to the surface of the filter member 6. 13 to remove by scraping or washing, and then the filter unit 8 is suspended in the strainer container 2 and It had so as to fine-housed.

[0010]

However, the work of lifting and hanging the filter units 8, 8A involved in the above-mentioned strainer cleaning work is performed by the filter units 8, 8A.
It is necessary to pay close attention to its handling so that no damage is caused.

The inventor of the present invention has found that the filter unit can be cleaned without taking it out of the strainer container as a result of repeated studies and researches for easier cleaning of the strainer. Done

Accordingly, an object of the present invention is to provide a strainer for a polystyrene solution capable of removing dust accumulated in a filter member more easily without the need for suspending and suspending a filter unit as in the prior art. It is intended to provide a cleaning method.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a filter inner cylinder having a closed lower end and a liquid-permeability, and an outer peripheral surface portion of the filter inner cylinder. Filter member, containing a filter unit comprising a holding plate for holding the upper end of the filter inner cylinder, the polystyrene solution introduced from the lower end of the strainer container, from the outer peripheral side of the filter member In the method for cleaning a strainer for polystyrene solution, which is passed through the inner peripheral side and filtered, a required amount of solvent is injected into the strainer container after blowing, and the solvent is then removed from the strainer container. Bubble with air introduced from the lower end, and then stir for polystyrene solution to discharge the solvent from the lower end of the strainer container. And a method of cleaning over Na.

When the solvent injected into the strainer container after blowing is bubbled with air, the filter member comes into contact with the solvent stirred over the entire surface, and the polystyrene solution adhering to the filter member is removed from the solvent. To lower the viscosity. Therefore, the dust attached to the filter member due to the viscosity of the polystyrene solution is dispersed in the solvent, and then discharged from the strainer container with the discharge of the solvent.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1A, 1B, 2C, 2D, and 2E show an embodiment of the method for cleaning a strainer for a polystyrene solution according to the present invention, and FIG. 2 shows an embodiment of the method of FIG. This shows details of the apparatus, and is provided with a switching unit 22 from a feeding unit (not shown) to the inlet 3 of the strainer container 2 of the strainer 1A having the same configuration as that shown in FIGS. A supply pipe 23 for guiding the polystyrene solution 13, a solvent pipe 26, and an air pipe 29 are connected, and the solvent pipe 26 stores a solvent 24 for dissolving the expanded polystyrene to form the polystyrene solution 13. Cleaning tank 25 to be connected, and the air pipe 29
Is connected to an air supply device 28 for supplying air 27 and the inlet 3 is opened by the switch 22 or the supply pipe 23, the solvent pipe 26, and the air pipe 29
To be able to switch between the state of connection with any one of the above. Further, a vent pipe 31 provided with a vent valve 30 that can be opened and closed is provided at the top of the strainer container 2. Reference numeral 32 denotes refuse that accumulates on the strainer 1A due to the filtration of the polystyrene solution 13. In addition, the same components as those shown in FIGS. 4A and 4B are denoted by the same reference numerals.

When the filtration of the polystyrene solution 13 is performed, as shown in FIG.
Is supplied to the strainer 1A from a supply unit (not shown) through the supply pipe 23, the polystyrene solution 13 is filtered in the same manner as in the related art, and the filtrate 13a is supplied to the outlet 4. It is sent downstream through the pipe 12.

As a result of the filtration of the polystyrene solution 13, dirt 32 accumulates in the filter member 6, and the pressure difference between the polystyrene solution 13 to be sent and the filtrate 13a to be sent out is 1 kg / kg.
It becomes cm ^2, and the cleaning of the strainer 1A is required, firstly, as shown in FIG. 1 (b), to stop the feeding of the polystyrene solution 13 by feed unit (not shown), a strainer container air through blowpipe 20 2, a pressure of about 3 kg / cm ² is applied thereto, and the inside of the strainer container 2 is blown to discharge the remaining liquid of the polystyrene solution 13 from the inlet 3 to the supply pipe 23.

Next, as shown in FIG.
Is closed, the lid 2a is opened, and the solvent 24 introduced from the washing tank 25 is poured into the strainer container 2 through a hose (not shown). At this time, the solvent 24 is in a heated state, and the liquid level of the solvent 24 is set to about half of the inside of the strainer container 2 so as to be positioned 100 to 150 mm below the upper end of the filter member 6. I do.

Next, as shown in FIG. 1D, the vent valve 30 is opened, and the switch 22 is switched so that the air supply device 28 is connected to the inlet 3 so that the air supply device 28 is connected to the air inlet device 3. 28, for example, 3 kg / cm ²
Through the inlet 3 to the strainer vessel 2 to remove the solvent 24 in the strainer vessel 2 for a required time, for example, 3
Bubble for 0 minutes. At this time, the amount of the solvent 24 injected into the strainer container 2 is a sufficient excess with respect to the polystyrene solution 13 remaining after adhering to the strainer container 2 after blowing. Since the entire surface 6 comes into contact with the solvent 24 stirred by bubbling, the highly viscous polystyrene solution 13 adhering to the filter member 6 is dissolved and diluted by the solvent 24 due to the contacting large amount of the solvent 24. To reduce its viscosity. Therefore, the dust 32 attached to the filter member 6 due to the viscosity of the polystyrene solution 13 is dispersed in the solvent 24 and floated.

Thereafter, as shown in FIG.
The switching unit 22 is switched so that the cleaning tank 25 communicates with the cleaning tank 25 so that the solvent 24 is discharged, and the dust 32 floating with the solvent 24 is discharged.

Thereafter, the vent valve 30 is closed so as to obtain the state shown in FIG.
By operating the switch 22 to connect the polystyrene solution 13 to the strainer container 2, the polystyrene solution 13 is fed into the strainer container 2 from the inlet 3 by pressure, and the dirt 32 is washed and the polystyrene solution 13 is filtered by the removed filter member 6. The processing can be performed again.

As described above, the required amount of the solvent 24 is poured into the strainer container 2, and the polystyrene solution 13 attached to the filter member 6 is dissolved and dissolved in the excess amount of the solvent 24 by discharging after bubbling. can do. As a result, the refuse 32 that will be accumulated in the filter member 6 during the filtration of the polystyrene solution 13 is washed with the solvent 24 and discharged together with the solvent 24 in a state of being suspended in the solvent 24. More can be removed. Therefore, it is possible to eliminate the necessity of lifting the filter unit 8 out of the strainer container 2 as in the related art, which required careful attention so as not to cause damage to the filter unit 8A when cleaning the strainer 1A. Thus, cleaning of the strainer 1A can be performed more easily than in the past.

It should be noted that the present invention is not limited to the above embodiment, and the solvent 24 is shown as being injected into the strainer container 2 by opening the lid 2a.
A supply / discharge pump capable of switching between the two directions can be provided in the solvent pipe 26 between the pump 5 and the switch 22 so that the solvent can be injected into the strainer container 2 through the inlet 3.
The injection amount of the solvent 24, the amount of air 27 for bubbling, and the bubbling time may be freely determined so as to obtain a desired cleaning effect. In addition, various changes may be made without departing from the gist of the present invention. Of course.

[0025]

As described above, according to the method for cleaning a strainer for a polystyrene solution of the present invention, the filter inner cylinder having a liquid-permeability closed at the lower end and the outer periphery of the filter inner cylinder are provided in the strainer container. A filter member disposed on the face portion, and a filter unit including a holding plate for holding an upper end portion of the filter inner cylinder are housed therein, and a polystyrene solution introduced from a lower end portion of the strainer container is used as the filter member. In the method of cleaning a strainer for a polystyrene solution, which is passed from the outer peripheral side to the inner peripheral side and filtered, a required amount of a solvent is injected into the strainer container after the blowing, and Bubble with air introduced from the lower end of the strainer container, and then discharge the solvent from the lower end of the strainer container. Because it is a method, the polystyrene solution adhered to the strainer container after blowing can be dissolved in an excessive amount of solvent to have a low viscosity, thereby collecting in the filter member at the time of filtration of the polystyrene solution and reducing the viscosity of the polystyrene solution. The dust that adheres to the filter member can be washed with the above-mentioned solvent, and can be discharged from the strainer container together with the solvent in a state of being suspended in the solvent. The necessity of suspending the filter unit outside the container can be eliminated, and therefore, an excellent effect that the cleaning of the strainer can be performed more easily than before can be exhibited.

[Brief description of the drawings]

FIG. 1 shows a procedure of an embodiment of a method for cleaning a strainer for a polystyrene solution according to the present invention, in which (a) shows a state in which a polystyrene solution is filtered, and (b) blows the inside of the strainer container. (C) is a schematic view showing a state in which the solvent is injected into the strainer container, (d) is a state in which the solvent is bubbled, and (e) is a schematic view showing a state in which dust is discharged together with the solvent. It is.

FIG. 2 is a partially cut-away side view showing details of an apparatus used in the embodiment of FIG. 1;

FIGS. 3A and 3B schematically show an example of a strainer conventionally used for filtering a polystyrene solution. FIG. 3A is a partially cut side view, and FIG. 3B is a partially cut enlarged view of a filter portion.

FIGS. 4A and 4B schematically show an example of a strainer proposed to be used for filtering a polystyrene solution. FIG. 4A is a partially cut-away side view, and FIG.

[Explanation of symbols]

 1A Strainer 2 Strainer container 3 Inlet 4 Outlet 5 Filter inner tube 6 Filter member 7 Holding plate 8 Filter unit 13 Polystyrene solution 13a Filtrate 24 Solvent 27 Air

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01D 29/38 540

Claims (1)

[Claims] 1. A filter inner cylinder having a lower end closed and having a liquid permeability, a filter member disposed on an outer peripheral surface of the filter inner cylinder, and an upper end of the filter inner cylinder in a strainer container. For holding a filter unit consisting of a holding plate and a polystyrene solution introduced from the lower end of the strainer container, the polystyrene solution is to be filtered by passing from the outer peripheral side to the inner peripheral side of the filter member. In the method of cleaning the filter unit in the strainer container in the strainer, a required amount of solvent is injected into the strainer container after blowing, and then the solvent is bubbled by air introduced from the lower end of the strainer container. And thereafter, the solvent is discharged from the lower end of the strainer container. How to clean the solution strainer.