KR0135489B1 - Abnormal state inspection system of mechanical seal using the change of torque - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for monitoring an abnormal state of a mechanical seal in which a mechanical seal is installed between a housing and a rotating shaft in a rotary machine such as a pump or agitator. The abnormal state of the mechanical seal is monitored by using the fluctuation of the torque applied to the ring, which is a rotary machine in which a gap between the housing 1 and the rotating shaft 3 is sealed by the mechanical seal. Torque sensor 11 installed to detect the torque applied to the fixing ring 2 of the mechanical seal 10, the amplifier 12 for amplifying the torque signal input from the torque sensor 11, the amplifier 12 The comparator 13 monitors the abnormal state of the mechanical seal by comparing the amplified torque signal with the signal level in the normal state, and if the abnormal state of the mechanical seal is detected by the comparator 13, an alarm or Stop motion It consists of a security and control system (14).

Description

Abnormal condition monitoring system of mechanical seal using fluctuation of torque

1 is a cross-sectional view of an installation state of a general mechanical seal for sealing a gap between a rotating shaft and a housing.

2 is a block diagram of an abnormal state monitoring system of a mechanical seal according to the present invention.

Explanation of symbols on the main parts of the drawings

10: mechanical seal, 11: torque sensor,

12: amplifier, 13: comparator,

14: alarm and control system, 15: frequency converter,

111: inner ring, 112: sensing unit,

113: outer ring

[Technical Field]

The present invention relates to a system for monitoring an abnormal state of a mechanical seal installed between a housing and a rotating shaft in a rotary device such as a pump or a stirrer, and more specifically, fixing the mechanical seal during motor rotation. The present invention relates to a system for monitoring an abnormal state of a mechanical seal by using a change in torque applied to a ring.

[Background of invention]

In general, a rotary seal such as a pump or agitator in which a rotating shaft rotates in a sealed housing is provided with a certain hermetic ring between the rotating shaft and the housing. It must be replaced.

A mechanical seal is used as the hermetic ring. The mechanical seal is a kind of sealing device for hermetic sealing. As shown in FIG. 1, a fixing ring 2 and a rotating shaft fixed to the housing 1 are shown. Spring (6), stopper (7) and stopper fixing bolt (8) for bringing the rotary ring (4) and the rotary ring holder (S) rotated together with the (3) to the fixing ring (2) in close contact with the fixed ring (2). ) Therefore, the rotary ring 4 is in close contact with the fixed ring (2) to maintain the air tightness.

However, when the rotary ring 4 is rotated while contacting and rubbing the fixing ring 2, the mechanical seal often leaks due to wear or breakage of its parts. Should be monitored continuously and replaced immediately when an abnormal condition occurs.

Conventionally, the abnormal state monitoring method of the mechanical seal is provided with a displacement sensor or acoustic emission sensor in the vicinity of the mechanical seal, and measures the signal from each sensor and compares it with previously inputted information to determine the abnormal state. In order to have an abnormal state of the mechanical seal by installing an electronic displacement sensor, the absolute wear of the mechanical seal can be monitored, but a plurality of displacement sensors are installed to monitor the rotation state. There is a problem that the detection method by the latter acoustic emission sensor has a problem that it is difficult to monitor in the long term due to the degradation of the sensor sensitivity as the use time elapses due to the characteristics of the acoustic emission sensor.

[Purpose of invention]

The present invention is drawn to solve the above problems of the prior art, by detecting the torque applied to the fixing ring (2) of the mechanical seal to monitor the fluctuation of the torque to wear and break parts of the mechanical seal It is an object of the present invention to provide an abnormal state monitoring system of a mechanical seal that can determine an abnormal state caused by a mechanical seal.

[Summary of invention]

The present invention is a torque sensor installed to measure the torque applied to the fixing ring of the mechanical seal, an amplifier to amplify the torque signal, a comparator for comparing the input torque signal and the signal in the normal state, alarm and rotating equipment when an abnormal condition occurs It consists of an alarm and control system to stop the operation of the system.

[Description of Specific Embodiment of the Invention]

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In the abnormal state monitoring system of the mechanical seal using the fluctuation of the torque of the present invention, as shown in FIG. 2, the clearance between the housing 1 and the rotating shaft 3 is sealed by the mechanical seal. A torque sensor 11 installed on the rotary machine so as to sense torque applied to the fixing ring 2 of the mechanical seal 10, an amplifier 12 amplifying the torque signal input from the torque sensor 11, The comparator 13 monitors the abnormal state of the mechanical seal by comparing the torque signal amplified by the amplifier 12 with the signal level in the normal state, and the alarm is detected when the abnormal state of the mechanical seal is detected by the comparator 13. Or an alarm and control system 14 to stop the operation of the rotary machine.

Torque sensor 11 used in the present invention, as shown in detail in Figure 2, is installed between the housing 1 and the fixed ring (2) to detect the torque applied to the fixed ring (2) General purpose torque sensors available at The general-purpose torque sensor 11 used for torque measurement generally includes an inner ring 111 and an outer ring 113, and a sensing unit 112 for detecting a torsional force is installed therebetween. The sensing unit 112 is a so-called torsion element, and has a strain gauge attached thereto to convert the torque applied to the sensing unit 112 into a corresponding electric signal amount.

In order to install the general-purpose torque sensor 11 to the fixed ring 2, the outer portion of the fixed ring 2 is coupled with the inner ring 111 of the torque sensor 11 and the torque sensor 11 and the outer ring 113 ) Is integrally fixed to the inner surface of the housing 1 to prevent slippage. Accordingly, the outer ring 113 of the torque sensor 11 is integrated with the housing 1, and the fixing ring 2 is integrated with the inner ring 111 of the torque sensor 11. In this way, the torque applied to the fixing ring 2 by the rotation of the motor is immediately converted into an electric quantity by the sensing unit 12 of the torque sensor 11. The converted amount of electricity is input to the amplifier 12 connected to the torque sensor 11.

In the above description of the present invention has been described using a conventionally used torque sensor as shown in Figure 2, the installation structure of the torque sensor to detect the torque applied to the fixing ring (2) is variously changed It is obvious to those skilled in the art. In addition, instead of the torque sensor, it may be configured to provide an arm extending immediately on the fixing ring (2) and to install a load cell (load cell) for generating an electrical signal according to the torque change in the arm to detect the torque.

In addition, it is apparent to those skilled in the art that the present invention can be configured by adding a frequency converter 15 for converting the torque signal output from the amplifier 12 into the frequency domain and outputting the comparator 13.

Effects of the abnormal state detection system of the mechanical seal of the present invention are as follows.

When an abnormality occurs in the mechanical seal such as abrasion or damage of the components constituting the mechanical seal 10, the torque applied to the fixing ring 2 is changed. The present invention is to determine the abnormal state of the mechanical seal by sensing the torque fluctuation. When the torque sensor 11 detects the torque applied to the fixing ring 2 of the mechanical seal 10 and sends an electric torque signal corresponding thereto, the amplifier 12 amplifies the torque signal. To the comparator 13.

The comparator 13 compares the torque signal input from the amplifier 12 with the signal level in the normal state, and if the input torque signal and the signal in the steady state are different, the mechanical seal 10 is configured. Since there is something wrong with the parts, it sends an error signal to the alarm and control system 14. When the alarm and control system 14 receives the abnormal state signal from the comparator 13, the alarm and control of the mechanical chamber 10 or performs the control to stop the operation of the rotating machine.

When the frequency converter 15 is configured in the system of the present invention, when the torque signal amplified by the amplifier 12 is converted into the frequency domain (Fast Fourier Transformation) and sent to the comparator 13, the comparator 13 has a rotation axis. The abnormal state of the mechanical seal 10 is not only monitored by comparing the rotation frequency with the frequency of the combination number (Harmonic Frequency) and the frequency level in the normal state, but also the rotation frequency of the rotation shaft and the frequency of the combination number. By monitoring the remaining frequencies except for can determine the state of the rotating machine itself. At this time, if there is an abnormality in the mechanical seal 10 or the rotary machine itself, an alarm signal is sent to the alarm and control system 14 to control the alarm and the rotary machine.

The abnormal state monitoring system of the mechanical seal 10 of the present invention detects the torque applied to the fixing ring 2 of the mechanical seal 10 and checks the torque and the variation as described above. Since the abnormal state of (10) is to be monitored, there is an advantage that the abnormal state of the mechanical seal 10 can be accurately and accurately determined.

Claims (2)

In a rotary machine in which a gap between the housing 1 and the rotating shaft 3 is sealed by the mechanical seal, an inner ring for sensing the torque applied to the fixing ring 2 of the mechanical seal 10. Torque sensor (111) is coupled to the fixed ring (2), the outer ring 113 is coupled to the inner surface of the housing (1) and having a sensing unit 112 therein, the torque sensor 11 An amplifier 12 for amplifying the torque signal input from the comparator, a comparator 13 for monitoring the abnormal state of the mechanical seal by comparing the torque signal amplified by the amplifier 12 with a signal level in a steady state, and the comparator ( 13) is composed of an alarm and control system 14 for alarming or stopping the operation of the rotary machine when detecting the abnormal state of the mechanical seal, and determines the abnormality of the mechanical seal by monitoring the torque change. The abnormal state monitoring system of the mechanical seal, characterized in that. The frequency converter (15) according to claim 1, further comprising a frequency converter (15) for converting the torque signal output from the amplifier (12) into a frequency signal and outputting the frequency signal to the comparator (13). Abnormal condition monitoring system of mechanical seal.