JP2007218472A - Waste heat-recovering/pressure-reducing device for steam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and inexpensive 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. <P>SOLUTION: A high pressure operation fluid outlet 18 of a liquid pressure-feed member 7 and a suction chamber 12 of a steam ejector 3 are connected by a communication pipe 8. A high-pressure steam pipe 21 branching a steam supply pipe 9, is connected with a high pressure operation fluid inlet 17 of the liquid pressure-feed member 7. The steam supply pipe 9 is connected with the steam ejector 3, and a pressure control valve 10 is mounted. The condensed water supplied from a condensed water supply pipe 2 into the liquid pressure-feed member 7 is partially re-evaporated, and sucked to the steam ejector 3 through a communication pipe 8. The remaining condensed water is pressure fed to a liquid outflow port 16 of the liquid pressure-feed member 7 to a prescribed 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, and a liquid pumping member is arranged below the re-evaporation tank. The re-evaporation vapor in the re-evaporation tank is sucked with a steam ejector. The waste heat of steam can be recovered by supplying it to a predetermined steam use location.

  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, the conventional steam waste heat recovery and decompression device has a problem that the device itself becomes large and expensive because the reevaporation tank and the liquid pumping member are used.
JP 2004-278871 A

  The problem to be solved is to obtain a small and inexpensive steam waste heat recovery and decompression device that can accurately adjust the steam pressure supplied from the steam ejector that sucks the re-evaporated 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 the reevaporation tank is used as a liquid pumping member.

  In the present invention, the pressure control valve is attached to the steam supply pipe of the steam ejector, so that the steam pressure supplied from the steam ejector can be accurately adjusted, and a separate re-evaporation tank is not required and the liquid pressure feeding member is also used. By doing so, the apparatus can be made small and inexpensive.

  The present invention uses a pressure control valve. This pressure control valve is a conventionally known valve, for example, an automatic pressure control valve that combines a pressure sensor and a controller, as long as the pressure can be adjusted and controlled. For example, a self-acting pressure control valve can be used.

  In FIG. 1, a liquid pressure feeding member 7 as a re-evaporation tank, a condensate supply pipe 2 that supplies condensate to the liquid pressure feeding member 7, a steam ejector 3, and a pressure attached to a steam supply pipe 9 of the steam ejector 3. The control valve 10 constitutes a waste heat recovery and decompression device for steam.

The liquid pumping member 7 has a liquid inlet 15, a liquid outlet 16, a high-pressure operating fluid inlet 17 and a high-pressure operating fluid outlet 18, and supplies condensate to the liquid inlet 15 via a check valve 14. Connect the tube 2. The check valve 14 allows the liquid to flow from the condensate supply pipe 2 into the liquid pumping member 7 and blocks the opposite liquid flow. Similarly, a condensate discharge pipe 20 is connected to the liquid outlet 16 via a check valve 19. The check valve 19 has a function of allowing the liquid to flow from the liquid pumping member 7 to the condensate discharge pipe 20 and blocking the opposite flow.

A high-pressure steam pipe 21 branched from the steam supply pipe 9 is connected to the high-pressure operating fluid introduction port 17. On the other hand, the high-pressure operating fluid discharge port 18 communicates with the suction chamber 12 of the steam ejector 3 through the communication pipe 22.

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 at the lower portion, and opens the condensate supply pipe 2. Then, the condensate flows down into the liquid pumping member 7 through the check valve 14 and the liquid inflow port 15, and the vapor in which the condensate re-evaporates inside the liquid pumping member 7 is sucked into the suction chamber 12 of the steam ejector 3.

When condensate accumulates in the liquid pumping member 7 and a float (not shown) is positioned at a predetermined upper portion, the high-pressure operating fluid discharge port 18 is closed to stop the re-evaporated vapor suction, while the high-pressure operating fluid introduction port 17 is Opening and allowing high-pressure pressure-feeding steam to flow into the inside from the high-pressure steam pipe 21, the condensate accumulated therein 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. While being caused to flow down, condensate re-evaporated vapor is sucked into the steam ejector 3. By repeating such an operation cycle, the liquid pumping member 7 functions as a reevaporation tank and pumps the condensate from the condensate supply pipe 2 to a predetermined location.

The steam ejector 3 is communicated by connecting a communication pipe 8 above the liquid pumping member 7. 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. The pressure of the steam supplied to the place where the steam is not used can be accurately adjusted 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 steam in the liquid pumping member 7.

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

2 Condensate supply pipe 3 Steam ejector 7 Liquid pumping member 9 Steam supply pipe 10 Pressure regulating valve 14 Check valve 15 Liquid inlet 16 Liquid outlet 17 High pressure operation fluid inlet 18 High pressure operation fluid outlet 20 Condensate outlet pipe 25 Pressure sensor

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 characterized in that a pressure control valve is attached to the evacuation tank and the reevaporation tank is a liquid pumping member.

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