JPH0694506A - Differential pressure type water level measuring apparatus - Google Patents

Abstract

PURPOSE:To measure an accurate water level at all times regardless of the fluctuation of pressure in a tank by providing a level switch which detects the varying of water level in a reference level vessel at the low pressure pipe side. CONSTITUTION:A differential pressure type water level measuring apparatus detects pressures of a vapor phase section and a water phase section of a tank 1 by means of a low pressure side detecting pipe 8 and a high pressure side detecting pipe 9 to measure the differential pressure as a water level. A reference level vessel 2 which supplies a reference level, is disposed in the pipe 8. When the pressure in the tank 1 becomes a negative pressure due to the variation of load of a plant, water in the reference level vessel 2 is sucked into the tank 1 so that the reference level goes down. The change of the reference level is detected by a level switch 4 connected to a reference level pipe 6 of which level is the same as that of the reference level vessel 2. On the basis of the signal, a water supply valve 5 disposed in a water supply pipe 7 is automatically controlled between the on/off conditions to open or close so that the reference level in the reference level vessel 2 is restored by supplying water therein by a reduced amount. Thereby, the reference level is maintained at all times so that the accurate water level is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential pressure type water level measuring device, and more particularly to a differential pressure type water level measuring device suitable for measuring the water level in tanks with unstable pressure.

[0002]

2. Description of the Related Art A conventional device is disclosed, for example, in Japanese Patent Laid-Open No. 56-21421.
By installing an orifice at the joint between the reference surface unit installed in the low-pressure side detection pipe and the upstream side (tank side) detection pipe of the reference surface unit as in Publication No. 1, the outflow amount of water in the reference surface unit To reduce the change in the standard head.

Further, conventionally, as in JP-A-59-176626, a total of four pressure gauges are installed near the tank detection seat and near the water level gauge in the low-pressure side and high-pressure side detection pipes, respectively, and a calculator is further provided. Two units were installed and the signal of the pressure gauge was input to the calculator to correct the indication of the water level gauge.

[0004]

In the former prior art, the orifice is installed in order to limit the outflow amount of water in the reference surface device and reduce the decrease in the reference head, but there is no decrease in the reference head. Therefore, there is a problem such as pressure hunting due to blockage and measurement of incorrect water level.

In the latter case, a total of four pressure gauges and two arithmetic units are installed in the high and low pressure detection pipes, and the pressure at each point is detected in response to fluctuations in the reactor pressure, and the water level measurement value is corrected. Although it is a method, it has drawbacks such as a complicated water level measurement configuration.

It is an object of the present invention to provide a differential pressure type water level measuring device which eliminates an inconvenient element in measurement and always measures the water level accurately regardless of the pressure change in the tank.

[0007]

In order to achieve the above object, in the present invention, a level switch for detecting a change in the water level in the reference level is installed in the low-pressure side pipe, and when the reference head is lowered, water is removed. A water supply pipe for supplying water and a make-up water valve that responds to the signal of the level switch are provided, and water is automatically supplied and the reference water head is always maintained.

[0008]

[Function] By providing a level switch that detects changes in the water level in the reference level and installing a make-up water valve that responds to the signal from the level switch in the water supply pipe and the water supply pipe, when the reference water head drops, the water supply line By automatically opening the make-up water valve installed at to the level switch signal, replenishing water and returning to the reference water head, accurate water level can be measured at all times.

[0009]

Embodiments of the present invention will be described below with reference to FIGS.

The present invention measures the water level in the tank 1. The pressures in the gas phase portion and the water phase portion of the tank 1 are detected by the low pressure side detection pipe 8 and the high pressure side detection pipe 9, and the differential pressure is detected. Measure as water level. Further, the reference surface 2 is installed in the low-pressure side detection pipe 8 for the purpose of ensuring the reference water head.

When the pressure of the tank 1 becomes a negative pressure due to the fluctuation of the plant load, the water in the reference surface level is flushed or sucked into the tank side, and the reference water head is lowered. The change in the reference water head is detected by the level switch 4 installed in the reference water head pipe 6 having the same water level as the reference surface device, and the signal is used to automatically turn on / off the makeup water valve 5 installed in the water supply pipe 7. It is possible to restore the reference water head by replenishing the reduced water in the reference surface by opening and closing.

FIG. 2 shows an example of the case where the electrode type level switch 4 is used. In the case of the reference head, when the electrode is energized and a closing signal is output to the makeup water valve 5, and the reference head is lowered, The power supply is cut off, an open signal is output, and the replenishment water valve 5 is opened to replenish the water.

Although an example of the electrode type level switch has been shown, a float type level switch (inner cylinder type, outer cylinder type) or the like can be used.

According to this embodiment, it is possible to always hold the reference water head and obtain an accurate water level.

[0015]

According to the present invention, it is effective to accurately measure and control the water level even in tanks where the pressure is unstable.

[Brief description of drawings]

FIG. 1 is a system diagram of a differential pressure type water level measuring device of the present invention.

FIG. 2 is an explanatory view showing an example using the electrode type level switch of the present invention.

[Explanation of symbols]

1 ... Tank, 2 ... Reference level gauge, 3 ... Water level gauge, 4 ... Level switch, 5 ... Make-up water valve, 6 ... Reference water head pipe, 7 ... Water supply pipe, 8 ... Low pressure side detection pipe, 9 ... High pressure side detection pipe .

Claims (1)

[Claims] Claims: 1. The pressure of the gas phase portion and the water phase portion of the tank is detected by the low pressure side and high pressure side detection pipes, and the differential pressure is measured as the water level, and a reference water head is secured in the low pressure side detection pipes. In a differential pressure type water level measuring device with a level gauge installed, a level switch for detecting a change in the water level in the reference level gauge is installed in the low pressure side detection pipe, and if the reference head is lowered, water supply for replenishing water A differential pressure type water level measuring device comprising a supply water valve responsive to a signal from a pipe and the level switch.