JPH03984A - Air compression device - Google Patents

Abstract

PURPOSE:To enable the automatic discharge of remaining pressure and prevent the generation of drain due to the cooling of internal air by providing the drain pipes of an inter-cooler and a steam separator with an open/close valve to be automatically opened, upon unloading or stopping a compressor. CONSTITUTION:The air drawn through a filter 11 and an intake valve 4 and compressed with the first stage cylinder 2, is delivered to an intercooler 6 via a delivery valve 5, and cooled with cooling water 14. Then, the air is sent to the second stage cylinder 3 for further compression, and cooled with an aftercooler 7. Thereafter, the air is introduced to an air reservoir 10 through a steam separator 8. In the aforesaid air compression device, normally close open/close valves 23 are provided in the drain pipes 15 of the intercooler 6, aftercooler 7 and steam separator 8. In addition, each open/close valve 23 is opened with a compressor unloading signal from a pressure switch 16 and a compressor stop signal 24 from a control panel, thereby enabling the discharge of remaining pressure in a line from the intercooler 6 to a non-return valve 9 via the aftercooler 7, through the discharge valve 5 of the first stage cylinder 2.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to an air compression device.

(Prior Art) An air compression device consists of a compressor, a cooler, a storage tank, etc., and supplies pressurized air to various devices such as an air cylinder. In particular, high reliability is required for instrumentation and air compression equipment in power plants, etc., as they are important equipment directly related to the operation of plants and systems, such as various instruments and air-operated valves. FIG. 2 shows a conventional configuration of an air compression device. A first-stage cylinder 2 and a second-stage cylinder 3 are connected to the compressor 1 .

Filter 11. Air sucked in through the suction valve 4 is compressed in the first-stage cylinder 2, and then passes through the discharge valve 5 to the safety valve 20.
The fuel enters the intercooler 6 in which the air is cooled, is cooled by the cooling water 14 flowing through the carrier intercooler 6, and is further compressed in the two-stage cylinder 3. Since the temperature of the compressed air rises again, it is cooled down to a predetermined temperature by the cooling water 14 of the rear cooler 7 via the air pipe 13. After moisture is separated from the cooled compressed air by a collision plate (not shown) in the steam separator 8,
The air is led to an air storage tank 10 via an air pipe 13 and a check valve 9.

A drain pipe 15 is provided in the steam-water separator 8 and the intercooler 6, and a drain trap 12 is provided in the drain pipe 15. The air storage tank 10 is designed to prevent pulsation when supplying compressed air to load-side equipment (not shown), and to be able to supply air at the capacity of the storage tank for intermittent use of air. Therefore, the pressure in the air storage tank 10 gradually decreases depending on the amount of air used on the load side. The operation of the compression ml is controlled so that it can be started and stopped according to changes in the pressure inside the storage tank. That is, when the pressure in the air storage tank 0 reaches a predetermined pressure, the pressure switch IB provided in the air storage tank 1o detects this, switches the three-way valve 17 in response to the detection signal transmitted through the signal line 18, and controls the pressure inside the storage tank. Air pressure is transmitted to the suction valve 4 through instrumentation piping 19. The suction valve 4 is forcibly opened by this air pressure, and even though the compressor 1 is in operation, some of the cylinders 2 are closed.
The air in the two-stage cylinder 3 is not compressed, and therefore the pressure in the air storage tank gradually decreases as it is used on the load side. This is called an unload operation (no-load operation) of the compressor 1.4 On the other hand, when the pressure in the air storage tank 10 drops to a predetermined pressure, a signal from the pressure switch 16 causes the three-way valve 17 to:
The initial state is restored (the state in which the reservoir pressure is not transmitted to the suction valve 4), and the suction valve 4 repeats opening and closing automatically according to the movement of the pistons (not shown) in the cylinders 2 and 2-stage cylinder 3. The inhaled air is compressed and the air is stored in the air storage tank lo.
By supplying compressed air to the tank, the pressure inside the storage tank is increased to a predetermined pressure relief level. This is called compressor load operation. In this way, the compressor 1 repeatedly performs loading operation and unloading operation depending on the amount of air used on the load side.

In addition, compressor 1 generally has two units of the same capacity, and can be used when the operating compressor alone cannot cover the air usage on the load side, when one compressor 1 breaks down, or when maintenance is required. It is structured like this.

(Problems to be Solved by the Invention) In the air compressor configured as described above, drain generated in the intercooler, rear cooler, etc. has conventionally been discharged by a drain trap provided in the drain pipe. However, the drain trap does not operate until a certain amount of drain has accumulated upstream of the trap, creating an atmosphere in which rust is likely to occur inside the equipment's piping and cooler. In particular, during compressor unload operation, the intercooler, rear cooler, and piping are in a state where a certain internal pressure is applied and the air flow is stopped, making it easy for dew condensation to occur on the inside of the equipment. , rust was also likely to occur.

When the compressor load operation starts, some of the rust that occurs under the above conditions is carried downstream by the air flow and adheres to the suction and discharge valves, causing problems. It had become. In particular, if rust adheres to the valve seat of the two-stage cylinder suction valve, the sealing performance of the valve will be incomplete, and some of the air compressed in the two-stage cylinder will flow back to the intercooler side, causing the safety valve to operate. In this case, it would be necessary to stop the compressor for restoration work, which could affect plant operation. Moreover, these rusts also adhered to the trap, causing the trap to malfunction. Therefore, in the past, it was necessary to frequently check the operation and perform maintenance of the trap. There is also a method of using a material that does not easily rust, such as stainless steel, but there are problems such as increased cost.

Furthermore, as mentioned above, two compressors are arranged, one of which is used as a standby, but generally the compressors are switched between operation and standby alternately at intervals of one week to one month.

At this time, in consideration of the stoppage period until the next time the compressor is on the standby side, the conventional method was to manually open the bypass valve of the drain trap at the same time as the stoppage to release the residual pressure inside the device. However, there were problems such as forgetting to operate the valve or forgetting to close the valve once it was opened. In particular, instrumentation air compression equipment in nuclear power plants is essential for plant operation, and if the supply of compressed air is cut off due to a malfunction in this equipment, the plant may eventually come to a halt.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide an air compressor that suppresses the occurrence of rust within the compressor as much as possible and has good operability and maintainability.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a single-stage cylinder that compresses air introduced into the system, and an intermediate cooling system that cools the compressed air within this single-stage cylinder. a second-stage cylinder that recompresses the pressurized air led from the intercooler, a compressor that drives the first-stage cylinder and the second-stage cylinder, and a second-stage cylinder that compresses the air compressed by the second-stage cylinder. The air consists of a rear cooler for cooling, a steam separator for separating moisture in the air cooled by the rear cooler, and an air storage tank for storing the compressed air led from the steam water separator. In the compression device, a drain pipe is arranged in the intercooler and the steam/water separator, and a compressor unload signal and a compressor stop signal are output to the drain pipe when the pressure in the air storage tank reaches a predetermined value. Compressor stop signal output when
To provide an air compression device characterized in that an on-off valve is provided which opens and closes in response to a water level high signal output when a predetermined amount of drain is collected in a drain pipe.

(Function) In air compression equipment configured in this way, when the compressor is unloaded or stopped, the on-off valve opens and discharges the residual pressure, which reduces the amount of condensate generated and prevents problems due to rust. In addition to preventing the occurrence of traps, the time and cost required for maintenance that was previously required can be saved by eliminating the trap.

(Example) The following is an example of an air compressor according to the present invention.
This will be explained with reference to FIG.

In FIG. 1, the same parts as in FIG. 2 are given the same reference numerals, and the explanation of the structure of the parts will be omitted.

The drain pipes 15 of the intercooler 6 and the rear cooler steam/water separator 8 are provided with on-off valves 23 that are normally closed. This on-off valve 23 is connected to a compressor unload signal from the pressure switch 18 or a compressor stop signal 24 from an air compressor control panel (not shown) (a signal issued when the compressor that was being operated is switched to the standby side, etc.) ), the valve is automatically opened, and the first stage cylinder discharge valve 5 is opened to the intercooler 6. From the two-stage cylinder suction valve 4 and the two-stage cylinder discharge valve 5 to the rear cooler 7. The residual pressure up to the check valve 9 is discharged.

The on-off valve 23 is automatically opened by a high or low water level signal from a water level gauge 21 that detects the drain water level of the drain pot 22 provided in the drain pipe 15 of the intercooler 6 and the steam/water separator 8.
It is configured to close and discharge the drain, and also functions as a trap.

〔Effect of the invention〕

According to the present invention, residual pressure is automatically discharged during compression unloading or when the compressor is stopped, suppressing the drain force generated as the internal air is cooled, and manual operation when the compressor is stopped. It is possible to obtain an air compression device with good operability that does not require residual pressure discharge work or periodic trap maintenance work.

[Brief explanation of drawings]

FIG. 1 is a system diagram of an air compression device showing an embodiment of the present invention, and FIG. 2 is a system diagram showing a conventional example of the air compression device. 1... Compressor 2... Single-stage cylinder 3.
... Two-stage cylinder 6 ... Intercooler 7 ... Rear cooler 8 ... Steam separator lO ... Air storage tank 13 ... Air pipe 15 ... Drain pipe 16 ... Pressure Switch 21...water level gauge
22...Drain pot 23...Opening/closing valve
24... Compressor stop signal agent Patent attorney Nori Chika Ken Yudo Ken Daishimaru

Claims (1)

[Claims] A first stage cylinder that compresses the air introduced into the system, an intermediate cooler that cools the air compressed in this first stage cylinder, and a second stage that compresses the pressurized air led from this intermediate cooler again. A cylinder, a compressor that drives the first-stage cylinder and the second-stage cylinder, a rear cooler that cools the air compressed by the second-stage cylinder, and moisture in the air cooled by the rear cooler is separated. In an air compression device comprising a steam/water separator and an air storage tank for storing the compressed air led from the steam/water separator, a drain pipe is provided in the intercooler and the steam/water separator, A compressor unload signal is output to the drain pipe when the pressure in the air storage tank reaches a predetermined value, a compressor stop signal is output when the compressor is stopped, and a condensate collected in the drain pipe reaches a predetermined amount. An air compressor comprising an on-off valve that opens and closes in response to a high water level signal output when the water level is high.