JP2000025037A - Fluorocarbon separating method and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorocarbon separating method which can certainly separate fluorocarbon from foamed polyurethane, and an apparatus therefor. SOLUTION: Foamed polyurethane 14 before separation of fluorocarbon is stored in a storage tank 12 to be heated by a heat transfer coil 15 and fluorocarbon contained in the foam of the foamed polyurethane 14 is brought to a gaseous state to bring the foam to an easily destructible state. This foamed polyurethane 14 is ground under heating by the grinding roller 28 of a grinder 24 to certainly destruct them foam. By this constitution, fluorocarbon in the foam can be certainly and efficiently separated from the ground foamed polyurethane powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for separating CFCs, and more particularly to a method and an apparatus for separating CFCs from foamed polyurethane.

[0002]

2. Description of the Related Art Foamed polyurethane used as a heat insulating material for refrigerators and the like is a mixture of isocyanate and polyol mixed with a catalyst and a freon 11 as a foaming agent.
After evaporating and foaming 1, it is molded by curing.

Heretofore, as a method of disposing of this foamed polyurethane, there is a method of burying it in the ground or burning it.

However, in recent years, from the viewpoint of preventing environmental destruction due to chlorofluorocarbon, in order to recover fluorocarbon 11 intervening in the foamed polyurethane foam, the foamed polyurethane is squeezed at normal temperature to destroy the foam, thereby reducing fluorocarbon. Separation is beginning to take place.

[0005] As another method of separating CFCs, a method of compressing foamed polyurethane to destroy the bubbles and separate CFCs has also been used.

[0006]

However, in the conventional chlorofluorocarbon separation method in which foamed polyurethane is squeezed to separate CFCs, the foamed polyurethane having the CFCs is an independent foam having a diameter of about 0.3 mm. By squeezing at room temperature alone, the bubbles are not reliably broken. Therefore, there is a disadvantage that CFCs cannot be reliably separated from the foamed polyurethane.

[0007] Further, since the boiling point of Freon 11 is close to room temperature, there is a drawback that separated Freon 11 adheres to the foamed polyurethane when pressed in an atmosphere at room temperature.

Further, the conventional method for separating CFCs by compressing the foamed polyurethane to separate the CFCs has a disadvantage that the CFCs cannot be reliably separated because the bubbles cannot be reliably destroyed simply by compression.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method and an apparatus for separating CFCs, which can surely separate CFC from foamed polyurethane.

[0010]

According to the present invention, in order to achieve the above object, a foamed polyurethane formed by foaming with chlorofluorocarbon is heated to a predetermined temperature and pulverized so that the fluorinated polyurethane is removed from the foamed polyurethane. And a second step of separating the pulverized foamed polyurethane and the CFC separated from the foamed polyurethane, and a part of the CFC separated in the second step is The method is characterized in that the Freon is recovered in the Freon recovery step and the remaining Freon is circulated to the first step.

Further, in order to achieve the above object, the present invention provides a heating means for heating a foamed polyurethane formed by foaming with chlorofluorocarbon to a predetermined temperature, and sealing the foamed polyurethane heated by the heating means. Crushing means for crushing in the casing, foamed polyurethane crushed by the crushing means, separation means for separating the chlorofluorocarbon separated from the foamed polyurethane, and a ring-shaped space between the crushing means and the separation means. And communicating means for communicating.

According to the present invention, the polyurethane foam heated to a predetermined temperature by the heating means is crushed by the crushing means.
Thus, the foamed polyurethane is pulverized in a state where the pressure in the bubbles is increased, that is, in a state where the bubbles are easily broken, since the fluorocarbon contained in the bubbles becomes gaseous by the heat. Therefore, the air bubbles are surely destroyed when the polyurethane foam is crushed, and CFCs in the air bubbles are separated from the crushed polyurethane foam powder. Since the separated Freon is in a gaseous state, it is separated from the foamed polyurethane powder by the separating means and collected without reattaching to the foamed polyurethane powder.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method and an apparatus for separating CFCs according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a CFC separation apparatus 10 to which the CFC separation method according to the present invention is applied.
According to the figure, a foamed polyurethane 14 before pulverization is stored in a storage tank 12 whose lower part is formed in a hopper shape. A heat transfer coil 15 for preheating the foamed polyurethane 14 is wound around the outer peripheral surface of the storage tank 12.

A valve 1 is provided below the storage tank 12.
The screw conveyor device 18 is connected via the connection 6.
The screw conveyor device 18 has a screw shaft 22 connected to a drive motor 20, and the screw shaft 22 is rotated by the drive motor 20,
The foamed polyurethane 14 stored in the storage tank 12
Can be conveyed toward the crushing device 24.

The crushing device 24 is provided with a crushing roller 28 in a closed casing 26. The crushing roller 28 is connected to a drive motor 30 disposed outside the casing 26 and is rotated by the drive motor 20 to crush the foamed polyurethane 14 conveyed by the screw conveyor device 18. The surface of the grinding roller 28 is heated to a predetermined temperature by a heat transfer device (not shown).

On the other hand, the crusher 24 is connected to a bag filter 34 via a duct 32. This bag filter device 34 has a bag-shaped filter cloth 36 connected to the duct 32. Further, a powder storage tank 40 is attached to a lower portion of the bag filter device 34 via a valve 38. Further, the bag filter device 34 is provided with a blower device 44 via a duct 42, and a fluorocarbon recovery device 48 is attached to the blower device 42 via a branch duct 46.

Next, the operation of the chlorofluorocarbon separator 10 constructed as described above will be described.

First, the foamed polyurethane 1 before the separation of Freon was used.
4 is stored in the storage tank 12 and heated by the heat transfer coil 15. As a result, the foamed polyurethane 14 becomes gaseous due to the heat of the fluorocarbon contained in the bubbles.
The state is such that the pressure in the bubble is increased, that is, the bubble is easily broken.

Next, the valve 16 of the storage tank 12 is opened, and the heated polyurethane foam 14 is supplied to the screw conveyor device 18. Next, the screw conveyor device 18 is operated to convey the foamed polyurethane 14 to the crushing device 24, where the polyurethane is crushed while being heated by the crushing roller 28 of the crushing device 24.

As a result, the foamed polyurethane 14 conveyed in a state where the bubbles are easily broken is surely destroyed during the pulverization, so that the CFC in the bubbles can be efficiently separated from the foamed polyurethane powder. . In addition, by heating the crushing roller 28, the storage tank 1
Since the foamed polyurethane 14 that has not been sufficiently heated to its inside during the storage in step 2 can be pulverized while being heated, CFCs can be efficiently separated from all the bubbles of the foamed polyurethane 14.

Since the separated CFCs are in a gaseous state due to heat, they do not adhere to the foamed polyurethane powder again, but are attached to the bag filter device 34 in the duct 3.
Suctioned through 2. The suctioned Freon gas and the foamed polyurethane powder are mixed with the filter cloth 36 of the bag filter device 34.
Separated by

That is, the foamed polyurethane powder adheres to the filter cloth 36 and hopper 34 of the bag filter device 34.
Then, the powder falls naturally into a, and is stored as powder 50 in the powder storage tank 40 by opening the valve 38. The Freon gas passes through the filter cloth 36 by being suctioned by the blower device 44, and is then recovered by the Freon recovery device 48 via the duct 42 and the branch duct 46.

Therefore, according to the present embodiment, since the foamed polyurethane is pulverized while heating to separate the chlorofluorocarbon, it is compared with the conventional chlorofluorocarbon separation method of pressing and compressing at room temperature to separate the chlorofluorocarbon. Thus, CFCs can be reliably and efficiently separated.

The temperature at which the polyurethane foam 14 is heated is preferably set to the temperature described below.

That is, from the room temperature to 60 ° C., the separation effect by vaporization of the chlorofluorocarbon is large, and at 60 ° C. or more and 150 ° C. or less, the effect by hardening of the foamed polyurethane 14 has a large effect. At a temperature of 150 ° C. or more and 250 ° C. or less, partial vaporization of the components of the polyurethane foam 14 is observed. Further, at about 400 ° C., decomposition of the foamed polyurethane 14 starts. Thereby, although the CFC separation has the respective effects by heating, from the viewpoint that the CFC and the foamed polyurethane 14 can be separated from each other,
It is preferable that the temperature be 100 ° C. or more and 250 ° C. or less.

[0027]

As described above, according to the method and the apparatus for separating CFCs according to the present invention, the foamed polyurethane is heated and pulverized at a predetermined temperature. Can be reliably separated.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a CFC separation device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... CFC separation device 12 ... Storage tank 14 ... Foamed polyurethane 18 ... Screw conveyor device 24 ... Crushing device 28 ... Crushing roller 34 ... Bag filter device 44 ... Blower device 48 ... CFC recovery device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiyuki Takamura 13-5 Kawachi, Kudamatsu City, Yamaguchi Prefecture (72) Inventor Masakatsu Hayashi 1-129, Tamiyacho, Ushiku City, Ibaraki Prefecture 1-8-40 Higashi, Niiza City (72) Inventor Shusuke Narutomi 3715-6 Toho, Fukaya City, Saitama Prefecture

Claims (2)

[Claims] A first step of heating the foamed polyurethane formed by freon foaming to a predetermined temperature and pulverizing the foamed polyurethane to separate the freon from the foamed polyurethane; A second step of separating the CFC separated from the foamed polyurethane, wherein a part of the CFC separated in the second step is recovered in the CFC recovery step, and the remaining CFC is removed from the first CFC. A CFC separation method characterized by circulating in a process. 2. A heating means for heating foamed polyurethane formed by foaming with chlorofluorocarbon to a predetermined temperature; a crushing means for crushing the foamed polyurethane heated by the heating means in a closed casing; Foamed polyurethane crushed by means, separating means for separating the CFC separated from the foamed polyurethane, and communicating means for annularly communicating between the crushing means and the separating means, To separate CFCs.