JPH01277101A - Vacuum vapor generator - Google Patents

Abstract

PURPOSE:To enable an easy and speedy modification of a temperature setting for a fluid passed through a nozzle of an ejector, by sending a setting signal to an actuator part for modifying a pressure set on a pressure-reducing valve, and sending an ON/OFF signal to a control valve based on the setting signal and the temperature of water in a tank. CONSTITUTION:At the time of setting an operating temperature of a heater 1, namely, a vapor pressure in a vacuum system, a set pressure is inputted from a controlling part 21, whereby the temperature of water in a tank 8, namely, a water temperature for ensuring that a suction pressure generated at a nozzle part 12 of an ejector-type vacuum pump 4 will be equal to a saturated pressure at the temperature of a fluid passed through the nozzle part 12 and the set pressure and the saturated pressure will be equal is calculated, and injection of cooling water from a control valve 16 is conducted or stopped so as to obtain the water temperature. Therefore, the temperature of the fluid passed through the nozzle 12 is automatically controlled according to a modification of the pressure set on a pressure-reducing valve 3, and the temperature of the fluid can be modified easily and speedily, even when the set pressure is frequently modified.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a vacuum steam generator that supplies vacuum steam for efficiently heat-treating objects to be heated at temperatures of 100° C. or lower.

Heat treatment is widely and commonly performed in various production processes;
Heating is often performed at higher temperatures than above, using a pressurized heating device that directly utilizes steam from a boiler.

On the other hand, in chemical factories, food factories, and the like, there are many applications in which objects to be heated must be heated at relatively low temperatures of 100° C. or lower in order to maintain product quality.

Prior Art Therefore, a vacuum steam generator such as that proposed in Japanese Patent Application No. 62-200714 has been used in the past. This allows the suction pressure generated in a part of the ejector to be set arbitrarily by placing a pressure reducing valve on the primary side of the indirect heating container and controlling the temperature of the fluid passing through the ejector nozzle on the secondary side. This is a vacuum steam generator connected to an ejector type vacuum pump that can be used, and by making the suction pressure generated in a part of the ejector the same as the set pressure of the pressure reducing valve, excessive steam is supplied to the indirect heating container through the pressure reducing valve. This makes it possible to efficiently generate vacuum steam without steam loss. Furthermore, in actual production processes, it is often necessary to change the operating temperature, that is, the vacuum steam pressure.

Problems to be Solved by the Present Invention In the case of the above-mentioned prior art, each time the setting pressure of the pressure reducing valve is changed, the temperature setting of the fluid passing through the nozzle must also be changed. Changing the set pressure, that is, the operating temperature, is complicated and takes time, which often results in a decrease in productivity.

Therefore, a technical problem of the present invention is to enable the temperature setting of the fluid passing through the nozzle of the ejector to be changed easily and in a short time in accordance with the change in the set pressure of the pressure reducing valve.

Means for solving the problems The technical means of the present invention taken to solve the above problems are as follows:
A pressure reducing valve is arranged on the primary side of the heating container, and on the secondary side, the diffuser of the ejector and the suction port of the centrifugal pump are communicated via a tank, and the ejector and the discharge port of the centrifugal pump are communicated with each other. A cooling water supply passage is provided to supply cooling water to the tank, and an ejector-type vacuum pump equipped with a control valve that opens and closes depending on the water temperature in the tank is installed in the passage to control the temperature of the fluid circulating through the ejector and the centrifugal pump. In the vacuum steam generator that is designed to control, an actuator unit for changing the set pressure is attached to the pressure reducing valve, and a setting signal is sent to the actuator unit, and the control valve is controlled based on the setting signal and the water temperature in the tank. It is equipped with a control section that sends opening/closing signals to the terminal.

When changing the set pressure of the pressure reducing valve, a setting signal is sent from the control section to the actuator section and the setting signal is changed, and the control valve changes the temperature of the fluid passing through the nozzle based on this setting signal and the water temperature in the tank. is opened and closed.

Effects of the Invention Since the temperature of the fluid passing through the nozzle is automatically adjusted as the set pressure of the pressure reducing valve changes, the temperature of the fluid can be easily and quickly changed even when the set pressure is frequently changed. I can do it.

Embodiment An embodiment illustrating a specific example of the above technical means will be described. (
(See FIGS. 1 and 2) FIG. 1 is a system diagram of the vacuum steam generator of the present invention. A pressure reducing valve 3 for regulating steam pressure is attached to a steam passage 2 that supplies steam to a heating device 1.

The pressure reducing valve 3 (see Fig. 2) is a vacuum pressure reducing valve that operates a pressure setting spring 51 under tension, and has an inlet 52 and an outlet 53.
A diaphragm 56 and an actuator section 19 are provided in a valve section 3 having a valve 54 and a valve 54. Actuator part 1
The pressure is set by rotating the adjusting screw 57 at 9 to adjust the tensile force of the pressure setting spring 51.

The outlet side end of the steam passage 2 communicates with an ejector part 5 of an ejector-type vacuum pump 4. The ejector-type vacuum pump 4 communicates the differential user part 9 of the ejector part 5 with the suction lower of the centrifugal pump 6 via the tank 8, and connects the discharge port 10 of the centrifugal pump 6 with the nozzle part 12 of the ejector part 5. They are formed in communication with each other through a circulation passage 11. J! at one end of the circulation passage 11! A discharge passage 13 for discharging water and cooling water is provided, and a control valve 14 for adjusting the discharge amount is attached. If there is no large variation in the discharge amount, the control valve 14 is not necessarily required. A cooling water supply passage 15 for supplying cooling water to the tank 8 is installed via a control valve 16. The water temperature inside the tank and the nozzle part 1 are measured at the bottom of the tank 8.
A temperature sensor 17 is attached to detect the temperature of the fluid passing through 2. Actuator 18 of control valve 16
The actuator section 19 of the pressure reducing valve 3 and the temperature sensor 17 are connected to the control section 21 by a signal line 20.

The control unit 21 includes a pressure setting unit (not shown) that transmits a set pressure signal to the actuator unit 19 of the pressure reducing valve 3, and a calculation unit (not shown) that calculates the required water temperature in the tank 8 from the set pressure.
, a transmitting section (not shown) that issues an opening/closing signal to the seven-actuator section 18 of the control valve 16 based on the calculation result and the water temperature in the tank 8.

A water level sensor 2 for detecting the water level in the tank 8 is installed in the actuator section 22 of the control valve 14 attached to the discharge passage 13.
The discharge amount is adjusted by inputting the signal from 3. Further, a communication pipe 24 communicating with the atmosphere is attached to the upper part of the tank 8 via a valve 25.

When setting the operating temperature of the heating device 1, that is, the vacuum steam pressure, input the set pressure from the control unit 21. The water temperature is calculated so as to be equal to the saturation pressure at the temperature of the fluid passing through the section 12 and to make the set pressure and the saturation pressure the same, and the cooling water is injected or stopped from the control valve 16 so as to reach this water temperature. .

[Brief explanation of the drawing]

FIG. 1 is a system diagram of the vacuum steam generator of the present invention, and FIG. 2 is a schematic sectional view of the pressure reducing valve shown in FIG. 1. 1: Heating device @ 3: Pressure reducing valve 4: Ejector type vacuum pump 5: Part of the ejector 6: Centrifugal pump 8: Tank
9: Diff user part 12: Nozzle part 15
: Cooling water supply passage 16: Control valve 17: Temperature sensor 18, 19, 22: Actuator section 21: Control section 24: Communication pipe

Claims (1)

[Claims] 1. A pressure reducing valve is arranged on the primary side of the heating container, and on the secondary side, the diffuser of the ejector and the suction port of the centrifugal pump are communicated via a tank, and the ejector and the discharge port of the centrifugal pump are communicated, A cooling water supply passage for supplying cooling water to the tank is provided, and an ejector-type vacuum pump equipped with a control valve that opens and closes depending on the water temperature in the tank is installed in the passage to control the temperature of the fluid circulating between the ejector and the centrifugal pump. In the vacuum steam generator that is designed to control, an actuator unit for changing the set pressure is attached to the pressure reducing valve, and a setting signal is sent to the actuator unit, and the control valve is controlled based on the setting signal and the water temperature in the tank. A vacuum steam generator equipped with a control unit that sends open/close signals to the