JPH04358514A - Dehumidifying method for compressed air - Google Patents

Abstract

PURPOSE:To provide the dehumidifying method for compressed air to dehumidify the compressed air at low cost by a simple device. CONSTITUTION:For the purpose of cooling removing (dehumidifying) the water content in compressed air introduced from a compressor 12, a part of compressed air is separated, and the separated compressed air is heat insulation expanded by an expanding machine 14 and the heat insulation expanded air is introduced into a heat exchanging pipe 22 of a casing 17, and also the compressed air which is not separated is introduced into said casing 17. At that time, the compressed air which is separated is cooled down to the dew point temperature by the heat absorbing section generated in the casing 17 at the of heat insulation expansion of compressed air introduced into the heat exchanging pipe 22. The compressed air which is not separated is condensed and dehumidified by said process, and the dehumidified compressed air is fed to an exhaust outlet by said arrangement.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dehumidifying compressed air, and more particularly to a method for dehumidifying compressed air used for instrument painting and the like.

0002

[Prior art] Compressed air used for instrument painting, etc.
If the compressed air compressed by the compressor is discharged in that state, the compressed air is in a supersaturated state, so there is a drawback that moisture in the compressed air accumulates in the conduit and the measuring instrument, which has a negative effect on the instrument. Therefore, as a conventional method of dehumidifying the compressed air, there is a method in which compressed air compressed by a compressor is introduced into a refrigerator, and the compressed air is cooled to a temperature below the dew point by the refrigerator to cause dew condensation and dehumidification.

Another method is to bring the compressed air into contact with an adsorbent such as silica gel to dehumidify it.

0004

[Problems to be Solved by the Invention] However, the conventional method of dehumidifying compressed air by cooling the compressed air with a refrigerator or the method of dehumidifying the compressed air by bringing it into contact with an adsorbent requires large-sized equipment and is complicated and expensive. The disadvantage is that it is a very expensive facility. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a compressed air dehumidifying method that can dehumidify compressed air using a simple device and at low cost.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention separates a part of compressed air, adiabatically expands the separated compressed air, and absorbs heat generated during the adiabatic expansion. It is characterized in that the compressed air that is not separated from the compressed air is cooled to a dew point temperature or lower and dehumidified.

[0006]

[Operation] According to the present invention, in order to cool and remove (dehumidify) moisture in compressed air with a simple device and at low cost, a part of the compressed air is separated and the separated compressed air is adiabatically expanded. , the compressed air that does not separate out of the compressed air is cooled to below the dew point temperature by the heat absorption effect that occurs during its adiabatic expansion, causing dew condensation.
I tried to dehumidify it.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the method for dehumidifying compressed air according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an embodiment of a compressed air dehumidifying device to which the compressed air dehumidifying method according to the present invention is applied, and this dehumidifying device 10 is composed of a compressor 12, an expander 14, and a heat exchanger 16. .

The compressor 12 is communicated with the left end of the casing 17 of the heat exchanger 16 in the figure via a compressed air introduction pipe 18, and a branch pipe 20 branched from the middle part of the compressed air introduction pipe 18. via the expander 1
4. A corrugated heat exchange pipe 22 is disposed within the heat exchanger 16 . The left end of the heat exchange pipe 22 in the figure is connected to the expander 14, and the right end is connected to the expanded air exhaust pipe 24. Further, a compressed air discharge pipe 26 is communicated with the right side of the casing 17 in the drawing, and this discharge pipe 26 is connected to a utility (not shown). Furthermore, a drain pipe 30 is connected to the bottom opening of the casing 17 via a drain drainer 28 .

Next, the operation of the compressed air dehumidifier constructed as described above will be explained. First, compressor 1
When the compressed air from 2 is introduced into the compressed air introduction pipe 18,
A part of the introduced compressed air flows into the branch pipe 20, and the remaining compressed air is introduced into the casing 17 of the heat exchanger 16. The compressed air flowing into the branch pipe 20 is sent to the expander 14.
and is adiabatically expanded by the expander 14 and introduced into the heat exchange pipe 22 of the casing 17.

At this time, the heat exchange pipe 22 is cooled by the heat absorption effect generated during adiabatic expansion of the compressed air, so that it absorbs heat from the air within the casing 17. Thereby, the compressed air introduced into the casing 17 is cooled to below the dew point by the heat absorption action of the heat exchange pipe 22 while flowing inside the casing 17 in the direction of the discharge pipe 26. Moisture in the compressed air then condenses on the surface of the heat exchange pipe 22.

Therefore, the compressed air introduced into the casing 17 is dehumidified, and the dehumidified compressed air is passed through the discharge pipe 2.
6 to a utility (not shown). Further, the moisture condensed on the surface of the heat exchange pipe 22 becomes water droplets, which fall and can be discharged from the drain pipe 30 via the drain device 28. In this way, in this embodiment, a part of the compressed air is adiabatically expanded and heat exchanged with the remaining compressed air to dehumidify the remaining compressed air. can be dehumidified.

0012

As explained above, according to the method for dehumidifying compressed air according to the present invention, a part of the compressed air is separated, and the separated compressed air is adiabatically expanded. Since the compressed air that is not separated out of the compressed air is cooled to below the dew point temperature and dehumidified by the generated heat absorption, the compressed air can be dehumidified with a simple device and at low cost.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a compressed air dehumidifying device to which the compressed air dehumidifying method according to the present invention is applied.

[Explanation of symbols] 10... Compressed air dehumidifier 12... Compressor 14... Expander 16... Heat exchanger 17... Casing 22... Heat exchange pipe

Claims (1)

[Claims] Claim 1: Separating a part of the compressed air,
A method for dehumidifying compressed air, which comprises adiabatically expanding the separated compressed air, and cooling and dehumidifying the compressed air that is not separated out of the compressed air to below the dew point temperature by absorbing heat generated during the adiabatic expansion.