JP2003269400A - Steam ejector device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steam ejector device which reduces a fluctuation in steam pressure supplied from a delivery pipe. <P>SOLUTION: A high pressure driving steam pipe 3 and a low pressure suction steam pipe 4 are respectively connected to a suction chamber 1 of a steam ejector 10. A pressure regulating valve 5 is installed in the driving steam pipe 3. A diffuser 2 is connected to the delivery pipe 6. A pressure sensor 7 is installed in the delivery pipe 6. A bypass passage 11 is arranged in parallel to the steam ejector 10, and a pressure reducing valve 12 is installed as a pressure control valve. When the delivery pipe 6 side steam pressure reduces up to a prescribed value, the pressure reducing valve 12 automatically opens, and supplies high pressure steam in the delivery pipe 6 from the driving steam pipe 3 so that the delivery pipe 6 side steam pressure is maintained in a prescribed range. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam ejector in which a driving steam and a suction steam are mixed and discharged from a diffuser, and more particularly, to a steam having a stable pressure state from a discharge side. The present invention relates to a steam ejector device capable of discharging water. [0002] In various steam-using facilities such as petroleum and chemical plants, paper and pulp, textile factories and food factories, in order to save heat energy, it is necessary to reuse high-pressure steam once used and to reduce Utilization of low pressure steam is being carried out. A steam ejector is widely used for recovering and utilizing low-pressure steam. As a conventional steam ejector, for example, the one shown in FIG. 2 has been used. It comprises a suction chamber 1 with a built-in nozzle and a diffuser 2. A high-pressure driving steam pipe 3 equipped with a pressure control valve 5 is connected to the nozzle of the suction chamber 1, and a low-pressure suction steam pipe 4 is connected to the suction chamber 1. And a discharge pipe 6 connected to the outlet side of the diffuser 2. A pressure sensor 7 is attached to the discharge pipe 6 to
By electrically connecting the steam ejector, the steam pressure on the discharge pipe 6 side can be maintained within a predetermined value range, and the efficiency as a steam ejector can be kept high. [0004] The above-mentioned conventional steam ejector has a problem that the pressure of the steam supplied from the discharge pipe 6 to the location where the steam is used fluctuates. The steam ejector
The driving steam pressure and the discharge steam pressure are used while being maintained at substantially constant predetermined values. However, when the intake steam decreases or the steam consumption at the steam use point on the discharge pipe 6 side increases. In order to increase the supply steam amount by increasing the valve opening of the pressure control valve 5, the supply steam amount can be increased up to a certain range, but after the valve opening of the pressure control valve 5 is fully opened, Further, when the amount of steam to be inhaled is reduced or the amount of steam consumed at the location where steam is used increases, the pressure on the discharge pipe 6 side decreases. [0005] When the pressure on the discharge pipe 6 side is reduced, the steam pressure at the point of use of steam supplied from the outlet fluctuates, and the steam temperature and the amount of heat transferred change to adversely affect the product. [0006] Therefore, an object of the present invention is to provide a steam ejector device capable of reducing fluctuations in the steam pressure supplied from the discharge pipe 6. [0007] In order to solve the above-mentioned problems, the means of the present invention is to supply driving steam to a nozzle, suck suction steam in a suction chamber, and supply the suction steam. In a steam ejector that discharges a mixed steam of steam and driving steam from a diffuser to a predetermined location, a bypass passage is provided in the steam ejector, and a pressure control valve that is controlled to open and close according to the steam pressure discharged from the diffuser is attached to the bypass passage. Things. [0008] By providing a bypass with a pressure control valve that is opened and closed according to the pressure of the steam discharged from the diffuser, the pressure control valve is opened when the pressure of the discharged steam decreases. By supplying high-pressure steam to the discharge side, pressure fluctuation can be prevented. As shown in FIG. 1, a steam ejector, a bypass passage 11, and a pressure control valve 12 constitute a steam ejector device. The same members as those in the conventional example are denoted by the same reference numerals. The steam ejector 10 comprises a suction chamber 1 having a nozzle (not shown) therein and a diffuser 2 therein.
The high-pressure driving steam pipe 3 to which the pressure control valve 5 is attached is connected to the nozzle of the suction chamber 1. On the other hand, the low-pressure suction steam pipe 4 is also connected to the suction chamber 1. A discharge pipe 6 is connected to the outlet side of the diffuser 2, and a pressure sensor 7 for detecting the pressure of steam passing through the pipe is attached to the discharge pipe 6. The discharge pipe 6 is connected to a steam using device (not shown). The pressure sensor 7
Is electrically connected to the pressure control valve 5. The driving steam pipe 3 is branched to provide a bypass 11, and the outlet side thereof is connected to the discharge pipe 6. A pressure control valve 12 is attached in the middle of the bypass 11. As the pressure control valve 12 of the present embodiment, a pressure reducing valve which is a kind of a self-powered adjusting valve can be used. The pressure reducing valve 12 has a pressure responsive member such as a diaphragm or a bellows inside. The pressure responsive member automatically detects the pressure on the outlet side of the pressure reducing valve 12, ie, the pressure inside the discharge pipe 6, and opens and closes the valve body. When the pressure on the discharge pipe 6 side falls below the set pressure of the pressure reducing valve 12, the valve opens automatically,
The high-pressure steam is supplied from the driving steam pipe 3 to the discharge pipe 6 side, and when the outlet pressure of the pressure reducing valve 12 becomes equal to the set pressure, the valve is automatically closed to stop the supply of the high-pressure steam. In this embodiment, the steam pressure of the driving steam pipe 3 is 10 kg / cm 2, and the steam pressure of the discharge pipe 6 is 5.
5 kg / cm 2, and the set pressure of the pressure reducing valve 12 is 5.0
kg / cm2. A high-pressure drive steam is supplied from the drive steam pipe 3 to the steam ejector 10 via the pressure control valve 5, and a low-pressure steam of a low pressure of, for example, about 2 to 3 kg / cm 2 is sucked from the suction steam pipe 4 and discharged. From 6 is sent to a steam-using device (not shown). In this case, the steam pressure on the discharge pipe 6 side is 5.5
The opening degree of the pressure control valve 5 is automatically adjusted so as to be kg / cm2. When the amount of low-pressure steam sucked from the suction steam pipe 4 decreases or the amount of steam used in the steam-using device connected to the discharge pipe 6 increases, the steam pressure in the discharge pipe 6 decreases. This pressure drop is detected by the pressure sensor 7,
By increasing the valve opening of the pressure control valve 5, the steam pressure on the discharge pipe 6 side is maintained at 5.5 kg / cm2. However, if the low-pressure steam from the suction steam pipe 4 further decreases or the amount of steam used in the steam-using device further increases after the valve opening of the pressure control valve 5 is fully opened, Although the steam pressure on the discharge pipe 6 side drops, in this embodiment, when the steam pressure on the discharge pipe 6 side drops to 5.0 kg / cm 2, the bypass passage 11
The pressure reducing valve 12 attached to the valve automatically opens to prevent a further pressure drop. In the present embodiment, an example is shown in which the set pressure of the pressure reducing valve 12 is set to 5.0 and the pressure reducing valve 12 is opened when the steam pressure in the discharge pipe 6 decreases from 5.5 to 0.5 kg / cm 2. However, by making the set pressure of the pressure reducing valve 12 close to 5.5, the fluctuation of the steam pressure in the discharge pipe 6 can be made smaller. Further, in this embodiment, an example in which the pressure reducing valve 12 is used as the pressure control valve is shown. Can also be used. According to the present invention, a bypass path is provided in a steam ejector, and a pressure control valve that is controlled to open and close according to a steam pressure discharged from a diffuser is attached.
Fluctuation in the steam pressure supplied from the discharge pipe can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing an embodiment of a steam ejector device of the present invention. FIG. 2 is a configuration diagram showing a conventional example of a steam ejector device. [Description of Signs] 1 suction chamber 2 diffuser 3 drive steam pipe 4 suction steam pipe 5 pressure control valve 6 discharge pipe 7 pressure sensor 10 steam ejector 11 bypass passage 12 pressure control valve

Claims (1)

Claims: 1. A steam ejector for supplying a driving steam to a nozzle, sucking a suction steam in a suction chamber, and discharging a mixed steam of the suction steam and the driving steam from a diffuser to a predetermined location. , By installing a bypass in the steam ejector,
A steam ejector device, wherein a pressure control valve that is opened and closed according to the steam pressure discharged from a diffuser is attached to the bypass passage.