JP2007218471A - Waste heat-recovering/pressure-reducing device for steam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste heat-recovering/pressure-reducing device for steam capable of regulating steam pressure supplied from a steam ejector sucking re-evaporated steam with high accuracy, and allowing the condensed water to surely flow down from a steam trap mounted on a condensed water supply pipe to a re-evaporation tank. <P>SOLUTION: An upper part of the re-evaporation tank 1 and a suction chamber 12 of the steam ejector 3 are connected. A steam supply pipe 9 is connected with the steam ejector 3, and a pressure control valve 10 is mounted. A pressure control valve 4 is mounted on an upper part of the re-evaporation tank 1 through a pipe conduit 24. The condensed water supplied from a condensed water supply pipe 2 to the re-evaporation tank 1 is partially re-evaporated, and sucked to the steam ejector 3 through a communication pipe 8. The remaining condensed water flows down into a liquid pressure-feed member 7 from a liquid inflow port 15 of the liquid pressure-feed member 7 disposed at a lower part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

 TECHNICAL FIELD The present invention relates to a steam waste heat recovery and decompression device that re-evaporates high-temperature condensate condensed with steam in a re-evaporation tank and reuses it as steam.

 In the conventional steam waste heat recovery and decompression device, a condensate supply pipe is connected to the re-evaporation tank, and a communication pipe is interposed in the steam ejector that sucks the re-evaporated steam of the condensate in the re-evaporation tank. The re-evaporation tank is connected, and a pressure control valve is attached to this communication pipe. The re-evaporation vapor in the re-evaporation tank is sucked with a steam ejector and supplied to a predetermined steam use location. Waste heat recovery can be achieved.

  The conventional steam waste heat recovery and decompression device has a problem that the pressure of steam supplied from a steam ejector to a predetermined steam use location cannot be adjusted with high accuracy.

Further, in the conventional waste heat recovery and decompression device for steam, when the set pressure of the pressure control valve attached to the communication pipe is set high, the pressure in the reevaporation tank also becomes high, and the condensate supply pipe There is a problem that the condensate cannot flow into the re-evaporation tank from the steam trap attached to the tank.
JP 2004-278871 A

  The problem to be solved is that the steam pressure supplied from the steam ejector that sucks the re-evaporated steam can be adjusted with high accuracy, and the condensate reliably flows from the steam trap attached to the condensate supply pipe to the re-evaporation tank. It is to obtain a waste heat recovery and decompression device for steam.

  In the present invention, a condensate supply pipe is connected to a re-evaporation tank, and a steam ejector that sucks vapor re-evaporated from the condensate in the re-evaporation tank is connected, and steam for driving is supplied to the steam ejector. A pressure control valve is attached to the steam supply pipe, and a pressure control valve for maintaining the pressure in the reevaporation tank at a predetermined value is attached to the reevaporation tank.

  The present invention can adjust the steam pressure supplied from the steam ejector with high accuracy by attaching the pressure control valve to the steam supply pipe of the steam ejector, and by attaching the pressure control valve to the re-evaporation tank, By reducing the pressure in the re-evaporation tank to a predetermined value, it is possible to ensure that the condensate flows from the steam trap attached to the condensate supply pipe to the re-evaporation tank.

  Although the present invention uses a pressure control valve and a pressure control valve, both of them are known valves as long as they can control and control pressure, for example, automatic pressure control combining a pressure sensor and a controller. A valve or a self-primary primary pressure control valve can be used.

  In FIG. 1, a re-evaporation tank 1, a pressure control valve 4 disposed at the top of the re-evaporation tank 1, a condensate supply pipe 2 that supplies condensate to the re-evaporation tank 1, a steam ejector 3, and a steam ejector 3 The pressure regulating valve 10 attached to the steam supply pipe 9 and the liquid pumping member 7 constitute a waste heat recovery and decompression device for steam.

The reevaporation tank 1 has a cylindrical sealed shape, and a condensate supply pipe 2 is connected to the upper part of the side surface, and a condensate outlet pipe 5 is connected to the lower part of the side surface. The condensate supply pipe 2 is connected to a condensate generation source such as a steam using device (not shown) through a valve 6 and a steam trap 23. On the other hand, the condensate outlet pipe 5 is connected to the liquid inlet 15 of the liquid pumping member 7 via a check valve 14. The check valve 14 only allows the liquid to flow from the reevaporation tank 1 to the liquid pumping member 7 and does not allow the liquid to pass to the opposite side.

A pipe 24 is connected to the upper part of the reevaporation tank 1 and a pressure control valve 4 is attached. The pressure control valve 4 is a self-acting primary pressure control valve. When the pressure in the reevaporation tank 1 exceeds the set pressure of the pressure control valve 4, the pressure control valve 4 is opened and the pressure in the reevaporation tank 1 is increased. By releasing the pressure, the pressure in the reevaporation tank 1 can be maintained at a set value.

The liquid pumping member 7 has a liquid inlet 15 and a liquid outlet 16, a high-pressure operating fluid inlet 17 and a high-pressure operating fluid outlet 18, and condensate is discharged to the liquid outlet 16 via a check valve 19. While connecting the pipe 20, the high-pressure steam pipe 21 is connected to the high-pressure operating fluid inlet 17. On the other hand, the high-pressure operating fluid discharge port 18 communicates with the upper part of the re-evaporation tank 1 through the pressure equalizing pipe 22.

The liquid pumping member 7 is disposed below the reevaporation tank 1. In addition, the liquid pumping member 7 closes the high-pressure operating fluid introduction port 17 and opens the high-pressure operating fluid discharge port 18 when a float (not shown) disposed therein is located in the lower part, and opens the re-evaporation tank. From 1, the condensate flows down through the check valve 14 and the liquid inlet 15 into the liquid pumping member 7. When condensate accumulates in the liquid pumping member 7 and a float (not shown) is positioned at a predetermined upper portion, the high-pressure operation fluid discharge port 18 is closed, while the high-pressure operation fluid introduction port 17 is opened, and the high-pressure steam pipe The steam for high-pressure pumping is caused to flow from 21 to the inside, so that the condensate accumulated inside is pumped to a predetermined location through the liquid outlet 16, the check valve 19 and the condensate discharge pipe 20.

  When the condensate is pumped and the liquid level in the liquid pumping member 7 is lowered, the high pressure operating fluid inlet 17 is closed again and the high pressure operating fluid outlet 18 is opened, so that the condensate is discharged from the liquid inlet 15. Flow down to the inside. By repeating such an operation cycle, the liquid pumping member 7 pumps the condensate from the reevaporation tank 1 to a predetermined location.

The steam ejector 3 is communicated by connecting a communication pipe 8 to the upper surface of the reevaporation tank 1. A pressure control valve 10 is attached to the steam supply pipe 9 of the steam ejector 3. The pressure control valve 10 uses a combination of a pressure sensor 25 and a pressure controller (not shown). The pressure in the steam supply pipe 9 is detected by the pressure sensor 25, and the valve opening degree of the pressure control valve 10 is automatically controlled so as to reach the set pressure set by the pressure controller. It is possible to accurately adjust the pressure of the steam supplied to the place where the steam is not used to an arbitrary value.

  The upper end of the communication pipe 8 is connected to the suction chamber 12 of the steam ejector 3. The steam ejector 3 generates a predetermined suction force in the suction chamber 12 by the high-pressure steam supplied from the steam supply pipe 9 and sucks the re-evaporated vapor in the re-evaporation tank 1.

A part of the condensate supplied from the condensate supply pipe 2 into the re-evaporation tank 1 is re-evaporated in the re-evaporation tank 1 and sucked into the steam ejector 3 from the communication pipe 8. In this case, the pressure in the reevaporation tank 1 is adjusted by the pressure control valve 4 attached to the pipe line 24 so that the condensate can flow into the reevaporation tank 1 from the steam trap 23, that is, the condensate supply. By setting the pressure in the re-evaporation tank 1 lower than the pressure in the pipe 2 by a predetermined value, the condensate can surely flow down from the vapor trap 23 to the re-evaporation tank 1.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows the Example of the waste heat recovery of steam and the pressure reduction device concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Re-evaporation tank 2 Condensate supply pipe 3 Steam ejector 4 Pressure control valve 7 Liquid pumping member 9 Steam supply pipe 10 Pressure control valve 14 Check valve 15 Liquid inflow port 16 Liquid outflow port 17 High pressure operation fluid introduction port 18 High pressure operation fluid Discharge port 20 Condensate discharge pipe 23 Steam trap 24 Pipe line

Claims (1)

A steam supply pipe that connects a condensate supply pipe to a re-evaporation tank, and a steam ejector that sucks steam re-evaporated from the condensate in the re-evaporation tank, and supplies steam for driving to the steam ejector A steam waste heat recovery and decompression device, wherein a pressure control valve is attached to the reevaporation tank, and a pressure control valve for maintaining the pressure in the reevaporation tank at a predetermined value is attached to the reevaporation tank.

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