RU2413190C1 - Vibratory pressure gauge - Google Patents

Abstract

FIELD: machine building. ^ SUBSTANCE: vibratory pressure gauge consists of pressure tight closed case, of sensitive element inside case sensing pressure of measured medium through membrane unit. The sensor element forms a closed mechanical oscillating system of a camertone type, of sensor for oscillation recording and of sensor for oscillation excitation, of an amplifier connected with its input to the sensor of oscillation recording, while with its output coupled with the sensor for oscillation excitation. The sensor element is made as a primary converter consisting of two coaxial pipes of similar height and of different diametre interconnected with their lower bases and with their interconnected upper bases fastened to the case via a bellows unit. The sensor of oscillation recording and the sensor of oscillation excitation shifted relative to each other at 90 degrees are screwed into an external pipe of the primary converter. With its output the amplifier is connected to the converter the output of which is tied with the secondary instrument reflecting pressure level of measured medium. ^ EFFECT: upgraded accuracy and reliability of measurement under conditions of pressure tight volume. ^ 2 dwg

Description

The invention relates to measuring equipment and can be used to measure the pressure of a controlled medium - liquid, suspension, gas. In particular, the invention can be used in the petrochemical, food, chemical industries, thermal and nuclear energy, utilities and other industries where it is necessary to measure the pressure of various liquid and gaseous media.

From the patent of the Russian Federation No. 988053 (IPC G01L 11/00, publ. 10.06.2005) a vibration pressure sensor is known consisting of a housing, a sensing element in the form of a primary transducer located inside the housing, which receives the pressure of the medium being measured and made in the form of a thin-walled cylindrical resonator, a vibration excitation sensor and a vibration pick-up sensor. The disadvantages are the insufficient range of operating temperatures, the inability to measure the pressure of liquid media, the lack of resistance to ionizing radiation.

From A.S. USSR No. 658416 (IPC G01L 11/00, G01L 9/00, publ. 04/25/1979) known vibration pressure sensor, consisting of a housing, a sensing element in the form of a primary transducer located inside the housing, receiving the pressure of the medium and made in the form of thin-walled a resonator forming a closed mechanical vibratory system of a tuning fork type, a vibration pickup sensor, a vibration excitation sensor, and a bellows unit. The disadvantages are insufficient accuracy, lack of ability to measure the pressure of liquid media, lack of resistance to ionizing radiation.

From A.S. USSR No. 1493895 (IPC G01L 11/00, G01L 7/12, publ. 07/15/1989) known vibration pressure sensor, which is the closest analogue of the invention. Known vibration pressure sensor consists of a hermetically sealed housing, a sensing element located inside the housing and receiving the pressure of the measured medium through the membrane unit, a vibration removal sensor, an vibration excitation sensor, an amplifier. The sensitive element forms a closed mechanical oscillatory system of the tuning fork type. The amplifier is connected by an input to a sensor for measuring vibration, and an output with a sensor for exciting vibration. Disadvantages are insufficient accuracy and reliability, insufficient range of operating temperatures (-60-70 ° C), lack of resistance to ionizing radiation.

The aim of the present invention is the creation of a vibration pressure sensor for operation in the volume of the pressure zone of a nuclear power plant in conditions of large and small coolant leaks.

The advantages of the invention are.

- The absence of membrane parts in the design of the primary transducer as a transducer element contained in a vibration pressure sensor.

- High operating temperature - up to 300 ° С.

- Resistance to ionizing radiation.

- Long service life - up to 30 years.

- Maintainability.

- Large inter-verification period - 10 years or more.

- Resistance to hostile environment.

- High measurement accuracy - up to 0.01%.

The technical result of the invention is to improve the accuracy and reliability of measurement in a sealed volume of nuclear power plants.

The essence of the invention lies in the fact that the vibration pressure sensor consists of a hermetically sealed housing, a sensing element, a membrane unit, a bellows unit, an oscillation excitation sensor, an oscillation pick-up sensor, an amplifier, a transducer and a secondary device. The sensitive element forming a closed mechanical oscillatory system of the tuning fork type is located inside the housing and receives the pressure of the medium through the membrane unit. The sensing element is made in the form of a primary transducer consisting of two coaxial pipes of the same height and different diameters, connected by lower bases to each other and upper bases to each other, attached to the housing through a bellows unit. An oscillation sensing sensor and an oscillation excitation sensor are screwed into the outer tube of the primary transducer, 90 degrees shifted relative to each other. The amplifier is connected by an input to an oscillation pickup sensor, and an output with an oscillation excitation sensor and a converter. The converter output is connected to a secondary device that displays the pressure value of the medium being measured.

The invention is illustrated in figure 1 and figure 2. Figure 1 shows the design of the vibration pressure sensor, figure 2 - the recording part of the vibration pressure sensor. In this case: 1 - the housing of the vibration pressure sensor; 2 - lower valve block; 3 - upper valve block; 4 - primary converter; 5 - membrane block; 6 - bellows unit; 7 - sensor removal of vibrations; 8 - vibration excitation sensor; 9 - amplifier; 10 - converter; 11 - secondary device.

The vibration pressure sensor consists of a housing 1 made in the form of a vertical cylinder (see figure 1). The lower base of the housing 1 is hermetically sealed by the lower valve block 2, the upper base by the upper valve block 3. Inside the housing 7, a sensing element is fixed in the form of a primary transducer 4, made in the form of two coaxial pipes of the same height and different diameter (external and internal), as a result wherein the outer and inner pipes are spaced apart from each other. The upper bases of the outer and inner tubes of the primary transducer 4, as well as the lower bases of the outer and inner tubes of the primary transducer 4, are connected to each other by means of connecting elements (respectively, upper and lower), forming a closed cylindrical tuning fork in cross section. The lower bases of the outer and inner tubes of the primary converter 4 are attached to the lower valve block 2 by their lower connecting element 2. The upper bases of the outer and inner tubes of the primary converter 4 are attached to the upper valve block 3 of the housing 1 through the bellows block 6 with their upper connecting element. Above the upper connecting element the upper bases of the outer and inner tubes of the primary transducer 4 is fixed membrane unit 5, which receives the pressure of the measured medium. An oscillation pick-up sensor 7, equidistant from the upper and lower bases of the outer tube of the primary transducer 4, and an oscillation excitation sensor 8, equidistant from the upper and lower bases of the outer tube of the primary transducer 4 are screwed into the outer tube of the primary transducer 4 (see Fig. 2). In this case, the vibration removal sensor 7 and the vibration excitation sensor 8 are shifted relative to each other by 90 degrees. An oscillation pickup sensor 7 is connected to the input of the amplifier 9, an oscillation excitation sensor 8 is connected to the output of the amplifier 9. The amplifier 9 is connected to the converter 10, which in turn is connected to the secondary device 11. The secondary device 11 displays an output signal characterizing the pressure value of the medium being measured.

Vibration pressure sensor operates as follows.

Through the lower valve block 2, the primary Converter 4 is filled with alcohol, then the lower valve block 2 is closed. Formed closed mechanical oscillatory system tuning fork type. The measured pressure P through the upper valve block 3 and the membrane unit 5 acts on the primary transducer 4. The primary transducer 4 is excited at the natural resonant frequency using the vibration pick-up sensor 7 and the vibration excitation sensor 8. The oscillation frequency is determined by the design of the vibration sensor and the magnitude of the applied pressure. The signal from the vibration removal sensor 7 is fed to the input of the amplifier 9, the signal from the vibration excitation sensor is transmitted to the output of the amplifier 9. After amplification of the signal on the amplifier 9, it is supplied to the converter 10. The converter 10 converts these signals into a signal characterizing the pressure of the medium being measured, and transmits it to the secondary device 11, which displays the pressure value of the measured medium.

Using the proposed device provides, in comparison with existing devices, the possibility of locating a vibration pressure sensor in the premises of the sealed volume of nuclear power plants, eliminates extended pulse lines, increases the accuracy and reliability of pressure measurement in technological systems of nuclear power plants. The measurement accuracy is increased due to the fact that the axis of vibration passes along the walls of the pipes and the vibration nodes are removed from the attachment points by a distance of not more than half the gap between the pipes.

The device is being prepared for use at nuclear power plants to measure pressure in technological systems.

Claims (1)

A vibration pressure sensor, consisting of a hermetically sealed housing, a sensing element located inside the housing and receiving the pressure of the medium to be measured through the membrane unit, the sensing element forming a closed mechanical vibratory system of the tuning fork type, vibration pick-up sensor and vibration excitation sensor, an amplifier connected to the sensor input removal of vibrations, and the output with a sensor for exciting oscillations, characterized in that the sensitive element is made in the form of a primary a transducer consisting of two coaxial pipes of the same height and different diameters, connected by lower bases to each other and upper bases to each other, attached to the housing through a bellows unit, while the vibration sensor and the vibration excitation sensor are screwed into the outer tube of the primary transducer, shifted relative to each other by 90 °, the amplifier is connected by an output to a converter, the output of which is connected to a secondary device that displays the pressure value of the medium being measured.

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