JP2003071239A - Organic solvent recovery system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recover organic solvent gas by efficiently condensing and liquefying the same and to prevent the corrosion of a cooling pipe. SOLUTION: The organic solvent recovery system is equipped with a suction pressurizing means 4 for sucking the organic solvent gas to pressurize the same, a precooling condenser 5 comprising a coil pipe 5a for cooling the organic solvent gas pressurized by the suction pressurizing means, a condenser tank 6 having a discharge pipe 5b of the precooling condenser arranged therein and the cooling pipe 16a wound around the coil pipe 5a of the precooling condenser and the outer wall of the condenser tank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic solvent recovery system capable of efficiently recovering an organic solvent generated from a cleaning facility for semiconductors, electronic devices, etc. or a laboratory.

[0002]

2. Description of the Related Art Non-flammable solvents containing halogen elements, acetonitrile, acetone, methyl ethyl ketone, ethyl acetate, methyl acetate, toluene, methanol, hexane,
Benzene, isopropyl alcohol, ethanol, TH
Flammable solvents such as F are used in large amounts as cleaning agents for semiconductors and electronic devices, and as organic solvent. Since most of these organic solvents are toxic and have a low boiling point and a high vapor pressure, they have the property of evaporating and volatilizing into the atmosphere during the use process, causing environmental pollution and adverse effects on the human body. ,
Since the consumption of the organic solvent is increased, these organic solvents have been conventionally collected and reused.

As a method for recovering a solvent component in a gas such as a vapor stream generated by heating an organic solvent or an exhaust gas, a pressure / cooling condensation method in which the gas is cooled while being pressurized and liquefied Is widely known (for example, Japanese Patent Publication 7
-112522, JP-A-11-147001).

[0004]

However, since the conventional method is a method in which the cooling pipe through which the refrigerant gas flows is arranged in the condenser, the heat exchange efficiency when condensing the organic solvent gas is the surface area of the cooling pipe. Therefore, there is a problem that it is necessary to upsize the capacitor when the exhaust amount of the gas containing the organic solvent component is large. Further, there is a problem that the cooling pipe is corroded because the organic solvent gas exchanges heat with the cooling pipe in the condenser.

The present invention solves the above-mentioned conventional problems, and an organic solvent recovery system capable of efficiently condensing and recovering an organic solvent gas and at the same time preventing corrosion of a cooling pipe. The purpose is to provide.

[0006]

In order to achieve the above object, an organic solvent recovery system according to claim 1 of the present invention comprises:
A suction pressurizing means for sucking and pressurizing the organic solvent gas, a precooling condenser consisting of a coil pipe for cooling the organic solvent gas pressurized by the suction pressurizing means, and a discharge pipe of the precooling condenser are provided therein. A condenser tank, a coil tube of the pre-cooling condenser, and a cooling tube wound around an outer wall of the condenser tank are provided, and the invention according to claim 2 is the method according to claim 1, wherein the condenser tank has a plurality of condenser tanks. The condenser tank according to claim 3, wherein the condenser tanks are connected by connecting pipes. Further, the invention according to claim 3 is such that, in claim 1, the cooling pipe is directly or indirectly cooled or heated by a heat pump. It is possible to cool or heat the precooling condenser and the condenser tank by flowing the refrigerant. That.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show one embodiment of an organic solvent recovery system of the present invention, FIG. 1 is a schematic diagram showing the overall configuration, and FIG. 2 is a cross-sectional view of the main part of FIG.

In FIG. 1, a source 1 of an organic solvent generated from cleaning equipment such as semiconductors and electronic equipment or a laboratory is a buffer tank 2 for pressure buffering, a filter 3 as a foreign matter removing means, and a suction pressurizing means. It is connected to the pre-cooling condenser 5 composed of the coil tube 5a via the vacuum pump 4. An air compressor or a blower may be used instead of the vacuum pump 4.

The tip of the discharge pipe 5b of the precooling condenser 5 is
The first condenser tank 6 is arranged so as to be located at a lower position, the upper end of the first condenser tank 6 is connected to one end of the connecting pipe 7, and the other end of the connecting pipe is connected to the second condenser tank 8. It is connected so as to come to the lower position inside. The pre-cooling condenser 5 and the first and second condenser tanks 6 and 8 are made of materials having excellent pressure resistance and corrosion resistance.

First and second condenser tanks 6, 8
The bottom of is connected to a drain tank 12 and an organic solvent recovery tank 13 via a drain pipe 9 and opening / closing valves 10 and 11, respectively. An exhaust pipe 14 that is open to the atmosphere is connected to the upper part of the second condenser tank 8 and
A pressure regulating valve 15 is provided in the.

A cooling pipe 16a extending from the heat pump 16
Is the outer circumference of the coil tube 5a of the precooling condenser 5, the first
Condenser tank 6 and second condenser tank 8
Wrapped around the outer wall of the capacitor to allow cooling or heating of these capacitors. In addition, the coolant of the heat pump may flow directly into the cooling pipe 16a, or the (indirect) coolant (for example, water) that has exchanged heat with the heat-exchanger of the use side of the heat pump may flow.

In FIG. 2, the periphery of the precooling condenser 5 and the first condenser tank 6 is covered with a heat insulating material 17, and similarly, the periphery of the second condenser tank 8 is also covered with the heat insulating material 1.
It is covered with 8. Coil tube 5a of precooling condenser 5
A cooling pipe 16a from the heat pump 16 is wound around the outer peripheral surface of the first condenser tank 6 and the outer peripheral walls of the first and second condenser tanks 6 and 8.

In the organic solvent recovery system of the present invention having the above structure, the organic solvent is recovered as follows. First, the heat pump 16 is operated in the cooling mode, the refrigerant cooled to about −30 to −40 ° C. is caused to flow in the cooling pipe 16a, and the precooling condenser 5 and the first condenser tank 6 are operated.
And the second condenser tank 8 is cooled. At this time, the opening / closing valve 10 is closed and the opening / closing valve 11 is opened.

After each condenser is sufficiently cooled, the vacuum pump 4 is driven to suck the organic solvent gas of the generation source 1,
This is pressurized by the discharge pressure of the pump and pre-cooled condenser 5
It is sent to the coil tube 5a. The organic solvent gas is rapidly pressurized and cooled in the coil tube 5a, and a part of the gas is liquefied to form a gas-liquid mixed state from the tip of the discharge tube 5b to the first condenser tank 6
It is exhaled inside. At this time, the organic solvent gas is suddenly decompressed and is self-cooled by its heat of vaporization, and the organic solvent gas is condensed into a liquid. Subsequently, even in the first condenser tank 6, the synergistic effect of the pressure in the tank and the cooling by the refrigerant efficiently and promptly liquefy, and the liquefied organic solvent is drained from the bottom of the first condenser tank 6. It is recovered in the organic solvent recovery tank 13 through the pipe 9 and the opening / closing valve 11.

The organic solvent gas that has not been condensed in the first condenser tank 6 is discharged into the second condenser tank 8 through the connecting pipe 7, and the pressure-cooled gas-liquid self-cools by its heat of vaporization. Then, the organic solvent gas is condensed into a liquid and is recovered from the bottom of the second condenser tank 8 into the organic solvent recovery tank 13 through the drainage pipe 9 and the opening / closing valve 11.

When the recovery operation of the organic solvent is continued as described above, the coil tube 5a of the precooling condenser 5 and the discharge tube 5 are
Moisture contained in the organic solvent gas freezes on the inner wall of b and the inner walls of the first and second condenser tanks 6 and 8, and the cooling efficiency decreases.

Therefore, the heat pump 16 is operated in the heating mode to flow the heated refrigerant in the cooling pipe 16a to heat the precooling condenser 5, the first condenser tank 6 and the second condenser tank 8. At this time, the on-off valve 11
And the on-off valve 10 is closed. As a result, the ice frozen in each condenser is melted and collected in the drain tank 12 via the drain pipe 9 and the opening / closing valve 10.

The embodiment of the present invention has been described above, but the present invention is not limited to this, and various modifications can be made. For example, in the above embodiment, 2
Although one condenser tank is used, three or more condenser tanks may be used, or one condenser tank may be used.

Further, in the above embodiment, the precooling condenser 5 is arranged on the upstream side of the first condenser tank 6, but the precooling condenser 5 is also provided between the first condenser tank 6 and the second condenser tank 8. The capacitor 5 may be provided.

[0020]

As is apparent from the above description, according to the present invention, a suction pressurizing means for suction pressurizing the organic solvent gas, and a coil for cooling the organic solvent gas pressurized by the suction pressurizing means. Since a pre-cooling condenser composed of a pipe, a condenser tank in which a discharge pipe of the pre-cooling condenser is arranged, and a cooling pipe wound around the coil pipe of the pre-cooling condenser and the outer wall of the condenser tank are provided, an organic solvent gas Can be efficiently condensed and liquefied and recovered, and the corrosion of the cooling pipe can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an overall configuration as an embodiment of an organic solvent recovery system of the present invention.

FIG. 2 is a cross-sectional view of a main part of FIG.

[Explanation of symbols]

4 ... Vacuum pump (suction pressurizing means) 5 ... Pre-cooled condenser 5a ... Coil tube 5b ... Discharge pipe 6 ... Condenser tank 16 ... Heat pump 16a ... Cooling pipe

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C07C 49/08 C07C 255/03 253/34 B01D 53/34 117F 255/03 (72) Inventor Naruaki Nakajima Noah Shibuya Part 2 Building 501, 21-21, Udagawa-cho, Shibuya-ku, Tokyo F-Term (Reference) within Daiwa Giken Co., Ltd. 4D002 AB03 BA12 BA13 CA20 EA02 FA01 GA03 GB03 4D076 AA12 BC03 BC25 DA08 EA12Y EA14Y HA04 HA05 HA12 HA14 JA02 4H006 AA02 AD18 4K053 QA04 RA32 RA40 RA42 RA48 RA57 XA15 YA10

Claims (3)

[Claims] 1. A suction pressurizing means for sucking and pressurizing an organic solvent gas, a precooling condenser comprising a coil pipe for cooling the organic solvent gas pressurized by the suction pressurizing means, and a discharge pipe of the precooling condenser. An organic solvent recovery system comprising: a condenser tank disposed inside; a coil tube of the precooling condenser; and a cooling tube wound around an outer wall of the condenser tank. 2. The organic solvent recovery system according to claim 1, wherein the condenser tank comprises a plurality of condenser tanks, and the condenser tanks are connected by connecting pipes. 3. The precooling condenser and the condenser tank can be cooled or heated by flowing a refrigerant cooled or heated directly or indirectly by a heat pump in the cooling pipe. Organic solvent recovery system.