CN2315563Y - Vibration Online Viscosity Transmitter - Google Patents

Abstract

A vibrating online viscosity transmitter is composed of mechanical parts and electrical control parts. The mechanical components include a cavity formed by an explosion-proof casing 2 fixed on a flange 5, a vibrating body fixed on a bracket 11 in the cavity, a driving electromagnet 15 and a measuring electromagnet 4, and the rigid driving coupling in the vibrating body The rod passes through the flange, the upper part is fixed with a non-magnetic horizontal beam 9, the lower part is coaxially covered with an elastic outer cylinder 7, and the bottom end is fixed with a spherical probe 8, in which the driving electromagnet 15 and the electric coil in the measuring electromagnet 4 are tapped The output and input terminals of the controllable gain amplifier 18 in the electrical control part, the signal output by the controllable gain amplifier 18 is amplified and compared with the reference voltage, and the difference is fed back to the controllable gain amplifier 18, and the increased output signal represents the fluid viscosity .

Description

Vibration Online Viscosity Transmitter

The utility model relates to a vibrating on-line viscosity transmitter.

In the polymerization process of petrochemical industry, it is an urgent problem to detect the viscosity of the polymer in time. At present, the method of measuring the viscosity widely used in China is the dilution method, that is, after the polymer is diluted, the viscosity is measured with an Ubbelohde viscometer. The method takes 2 hours to measure a sample, which is difficult to meet the needs of production. Therefore, people are in urgent need of on-line viscosity measuring instruments. There are two main types of such instruments. One is the on-line rotational viscometer. Under the effect of shearing force, the inner cylinder will deflect at a certain angle due to the torque, and the torque sensor connected to the inner cylinder will measure the torque value to represent the viscosity value of the measured liquid. Such instruments have a small measuring range and cannot measure the viscosity of viscoelastic substances.

Another type of instrument is a vibrating online viscometer, the principle of which is to measure the viscosity of a liquid through the change in the amplitude of the vibrating body in the measured liquid. USP5,317,908 discloses a vibrating online viscosity transmitter, which can be used to measure the instantaneous viscosity of high-viscosity fluids under high temperature and high pressure. The viscosity transmitter mainly includes a shell and a hollow body extending from the shell. The hollow body is located at Inside the casing, the end of the hollow body far away from the casing is an outer casing with a sensor, and a shaft passing through the hollow body is concentrically sleeved in the outer casing, and the end of the shaft is fixed with the end of the outer casing. Cross arm fixed on the shaft, the electromagnetic driver generates a magnetic field simultaneously with the torsional vibration of the sensor and the shaft, the change in amplitude of the cross arm fixed on the shaft is measured by the detector coil, said detector and driver electromagnetic coils are placed perpendicular to each other , to reduce crosstalk and transmitter size. The sensor inserted into the liquid in the instrument has a thermocouple for temperature measurement, the shell is magnetically shielded, and the electronic control unit includes compensation facilities for the effects of flow rate and liquid pressure. Obviously, the structure of the viscometer is relatively complicated.

The purpose of the utility model is to provide a vibrating online viscosity transmitter with a simple structure, which can measure the instantaneous viscosity value of high-viscosity fluid and has a wide measuring range.

The utility model is designed according to the principle of electromagnetic resonance. Its working principle is that the driving electromagnet, the measuring electromagnet, the vibrating body and the controllable gain amplifier constitute a "tuning fork type" oscillation system. After the spherical probe in the vibrating body is immersed in the measured fluid, due to the action of fluid viscous resistance, the oscillation amplitude decreases, so the output signal of the measuring electromagnet decreases. At this time, due to the feedback effect, the controllable gain amplifier increases the output of the driving signal , so that the vibrating body returns to the original oscillation amplitude. At this time, the meter detects the increased output power, which represents the viscosity of the liquid.

The viscosity transmitter provided by the utility model is composed of mechanical and electrical control components. Specifically, the mechanical components include explosion-proof shells, flanges, vibrating bodies, brackets, and driving electromagnets and measuring electromagnets fixed on the brackets. . The explosion-proof shell is fixed on the flange to form a cavity, and the explosion-proof shell is provided with a straight hole for the cable. The bracket is fixed at the center of the flange in the cavity. It is a cylindrical hollow body with a symmetrical groove at the bottom, and the vibrating body It consists of a rigid drive link, an elastic outer cylinder, a spherical probe and a non-magnetic horizontal beam, wherein the drive permanent magnet and the measurement permanent magnet are symmetrically embedded on the non-magnetic horizontal beam, and the rigid drive link passes through the flange , the upper part is fixed with a non-magnetic horizontal beam that can swing in the groove of the bracket, the lower part is an elastic outer cylinder coaxially sleeved outside it, the upper end of the elastic outer cylinder is vertically sealed with the flange, and the lower end is sealed with the spherical probe Connection, the bottom of the rigid drive link is also sealed with the spherical probe, and its top is fixed on the top surface of the bracket by elastic steel wires arranged in a cross to keep the drive link in a vertical state. The driving electromagnet and the measuring electromagnet are respectively fixed on the two sides of the support corresponding to the positions of the driving permanent magnet and the measuring permanent magnet, and their end faces are parallel to the non-magnetic horizontal beam.

The electrical control components include a controllable gain amplifier, a preamplifier, an amplitude detector, two comparators and a phase shifter. The input and output terminals of the controllable gain amplifier are respectively connected to the measuring electromagnet and the driving electromagnet in the mechanical parts, the input terminal of the pre-amplifier is connected to the input terminal of the controllable gain amplifier, and the output terminal is divided into two channels, one of which is connected to the input terminal of the amplitude detector The other is connected to the phase shifter, the two input terminals of one comparator are respectively connected to the reference voltage and the output terminal of the amplitude detector, the output terminal is connected to the controllable gain amplifier, and the two input terminals of the other comparator The input terminal is respectively connected with the output terminal of the phase shifter and the output terminal of the controllable gain amplifier, and the output signal of the output terminal represents the viscosity value of the measured fluid.

The driving electromagnets and measuring electromagnets fixed on both sides of the bracket in the mechanical parts are two sets of differential connections, which are respectively fixed on the brackets on both sides of the non-magnetic horizontal beam, that is, the two differentially connected driving electromagnets The body is symmetrically fixed on one side of the bracket located on both sides of the non-magnetic horizontal beam, and the two differentially connected measuring electromagnets are symmetrically fixed on the other side of the bracket, and their positions correspond to the driving permanent magnet and the measuring permanent magnet respectively. And the end face is parallel to the non-magnetic horizontal beam with a distance of 0.3 mm.

The bracket is a cylindrical hollow body with two symmetrical grooves at the bottom, made of low carbon steel, and the rigid drive link is a hollow tube.

The driving electromagnet has the same structure as the measuring electromagnet, including a coil wound on the bobbin, a magnetic conductor and a magnetic core body. The magnetic core body is made of a high magnetic permeability material, such as a high-nickel-iron alloy, and its shape is a variable It is a solid cylindrical body with a large diameter, and the thick end part is provided with a lead hole. The magnetizer is cylindrical and connected with the thick end of the magnetic core. The coil is fixed on both sides of the thin end of the magnetic core in the magnetizer.

The explosion-proof case is provided with two symmetrical cable direct holes, so that the input and output ends of the controllable gain amplifier can be connected with the measuring electromagnet and the driving electromagnet through the cable through the straight-lead holes. There are wiring terminal blocks and special grounding terminals for the convenience of measuring and connecting the coil of the driving electromagnet with the cable.

The transmitter of the utility model is suitable for on-line viscosity measurement of high-viscosity fluids, such as polymers, adhesives, pulp, asphalt, jam, petroleum products, paints, printing inks, drilling fluids and other high-viscosity substances in the production process. Viscosity measurement to ensure product quality. The transmitter of the utility model can also be used for viscosity measurement of viscoelastic liquid.

The transmitter of the utility model has a simple structure, and the driving and measuring electromagnets have their own AC and DC magnetic circuits, so they can be arranged side by side, without crosstalk, and have high measurement sensitivity. In addition, the utility model also has a wide measuring range, and can work in the environment of high temperature, high pressure, and large change in flow rate. The output viscosity signal can also be converted into a digital signal and input to the computer, so as to optimize the control of the production process.

Below in conjunction with accompanying drawing, describe the utility model in detail.

Fig. 1 is a structural schematic diagram of the mechanical parts of the utility model.

Fig. 2 is a schematic structural diagram of the measuring electromagnet in Fig. 1 .

Fig. 3 is a schematic cross-sectional view of the installation positions of the measuring electromagnet and the driving electromagnet.

Fig. 4 is a structural block diagram of the electrical control part of the utility model.

As can be seen from Fig. 1, the mechanical parts of the present utility model include explosion-proof casing 2, flange plate 5, support 11, vibrating body, measuring electromagnet 4, driving electromagnet 15 (located on the left side of the support in Fig. 1, and measuring electromagnet axis Symmetrical, see Figure 3 for details). The explosion-proof shell 2 is fixed on the flange 5 to form a cavity, and the center position of the flange 5 in the cavity is fixed with a bracket 11. The bracket 11 is a cylindrical hollow body with two symmetrical grooves at the bottom, and the vibrating body is made of steel. It consists of a drive link 6, an elastic outer cylinder 7, a spherical probe 8, and a non-magnetic horizontal beam 9, wherein the non-magnetic horizontal beam 9 is embedded with mutually symmetrical drive permanent magnets 10 and measurement permanent magnets 16 (see Figure 3 ), the rigid drive link 6 passes through the flange 5, which is a hollow tube, and the upper part is fixed with a non-magnetic horizontal beam 9, which is located between the grooves of the bracket 11 and can swing. The rigid drive link 6 The lower part of the outer cylinder is coaxially covered with an elastic outer cylinder 7, the upper end of the elastic outer cylinder 7 is vertically sealed and welded to the bottom surface of the flange 5, the lower end is sealed and welded to the spherical probe 8, and the lower end of the rigid drive link 6 is also vertically welded to the spherical probe On 8, its top fixes 4 elastic steel wires 12 that are arranged in a cross with a small annular pressure plate, and the other end of four elastic steel wires is fixed on the top surface of the support 11 with a large annular pressure plate. It can be seen from Fig. 3 that on the brackets 11 on both sides of the non-magnetically conductive horizontal beam 9, two measuring electromagnets 4 of differential connection are fixed corresponding to the position of the measuring permanent magnet 16, and the bracket 11 on the other side of the non-magnetically conductive horizontal beam 9 On the top, two differentially connected driving electromagnets 15 are fixed corresponding to the positions of the driving permanent magnets 10 . The end faces of the driving electromagnet 15 and the measuring electromagnet 4 are parallel to the non-magnetic horizontal beam 9 with a distance of 0.3 mm.

The bracket 11 is also provided with a terminal block 3, the coils of the driving electromagnet 15 and the measuring electromagnet 4 can be connected to the terminal block 3, and then respectively connected with the driving and measuring ports of the electrical control components through cables.

In the transmitter provided by the utility model, the driving electromagnet 15 and the measuring electromagnet 4 have the same structure, but have different coil turns. As can be seen from FIG. Coil 25, magnetic core body 28 and magnetic conductor 27, magnetic core body 28 is a variable diameter solid body, thick one end is provided with two lead holes 30, magnetic conductor 27 is cylindrical, and the thick end of magnetic core body 28 Threaded connection can compress the coil 25 on both sides of the thin end of the magnetic core body 28 . The driving electromagnet 15 and the measuring electromagnet 4 can be conveniently fixed on the bracket 11 through the magnetic core locking nut 24 and the magnetic conductor locking nut 26 . The coil is made of enameled wire, the diameter of the enameled wire of the driving electromagnet is 0.3-0.4 mm, and the number of winding turns is 400-450, the diameter of the enameled wire of the measuring coil is 0.07-0.09 mm, and the number of winding turns is 4500-5000. Both the magnetic core body 28 and the magnetizer 27 are made of high-nickel-iron alloy, and the coil bobbin 29 is made of polytetrafluoroethylene.

The electrical control part of the utility model includes a controllable gain amplifier 18, a preamplifier 17, an amplitude detector 19, two comparators 21, 23 and a phase shifter 22, and is provided with two wiring ports for driving and measuring. Its structural block diagram is shown in Fig. 4, and the input terminal of controllable gain amplifier 18 and preamplifier 17 is all connected on the measuring port, and the output terminal of controllable gain amplifier 18 is connected in drive port, and the output of preamplifier 17 is divided into two routes, one road and The input end of the amplitude detector 19 is connected, and the other road is connected with the input end of the phase shifter 22, and the two input ends of the comparator 21 are respectively connected with the output end of the reference voltage 20 and the amplitude detector 19, and the output end is connected with the controllable The gain amplifier 18 is connected, and the two input ends of another comparator 23 are respectively connected with the output end of the phase shifter 22 and the drive port, and the signal output by the output end represents the viscosity value.

When the transmitter of the utility model is used, the mechanical parts can be installed at the entrance of the finished product tank, the coils of the driving electromagnet 15 and the measuring electromagnet 4 are respectively connected to the two terminals on the terminal row 3, and the two four-core The shielded cable is tapped on the above two terminals, and then passed through the cable straight hole 13 to lead out the explosion-proof shell 2, which is respectively connected with the drive and measurement ports in the electrical control components, and fixed on the explosion-proof shell 2 with cable pressure caps 1 and 14. On the shell 2, a gasket is placed between the pressure cap and the cable straight-through hole 13.

The working principle of the transmitter of the utility model is as follows: when there is no load, the weak vibration of the spherical probe 8 in the mechanical part is converted into an electrical signal by the measuring electromagnet 4, which is input into the controllable gain amplifier 18, and then sent to the driving electromagnet 15 after being amplified. The vibrating body vibrates, and when amplified to a certain multiple, the system maintains constant amplitude oscillation. When performing viscosity measurement, the spherical probe 8 in the vibrating body is inserted into the fluid to be measured. Due to the action of fluid shear force, the vibration amplitude decreases and the measurement voltage drops. After the voltage drop signal is amplified by the pre-amplifier 17, it passes through the amplitude detector 19 After detection, it becomes a DC voltage. After the DC voltage is compared with the reference voltage 20 by the comparator 21, the difference is fed back to the controllable gain amplifier 18, and the controllable gain amplifier increases the output of the driving power, so that the vibrating body returns to the original Amplitude, the other signal output by the pre-amplifier 17 is phase-shifted by the phase shifter 22, and after being kept in phase with the driving voltage, the square value of the difference after comparison by the comparator 23 represents the increased output power, which also represents the fluid viscosity.

The controllable gain amplifier 18 in the transmitter adopts the SSM2018 chip, the amplitude detector 19 and the comparators 21 and 23 both adopt the CA3140 chip, the preamplifier adopts the SSM2110 chip, and the phase shifter 22 adopts a conventional phase shifting circuit design.

Claims (6)

1, the online viscosity transmitter of a kind of oscillatory type, comprise the cavity that forms by the explosion-proof shell that is fixed on the ring flange, and be fixed on vibrating mass, the driving electromagnet on the cavity inner support and measure mechanical part and the electrical equipment control device that electromagnet is formed, it is characterized in that:

Explosion-proof shell in the mechanical part (2) is provided with cable and directly draws hole (13), support (11) is fixed on the center of cavity inner flange (5), be provided with the cylindrical, hollow of two grooves symmetrically for the bottom, vibrating mass drives link rod (6) by rigidity, elasticity urceolus (7), spheric probe (8) and non-magnetic conduction horizontal gird (9) are formed, be embedded with symmetrically on the non-magnetic conduction horizontal gird (9) and drive permanent magnet (10) and measure permanent magnet (16), rigidity drives link rod (6) and passes ring flange (5), the fixing non-magnetic conduction horizontal gird (9) that can in the groove of support (11), swing in top, the bottom is overlapped flexible urceolus (7) coaxially, elasticity urceolus (7) upper end is connected with ring flange (5) vertical seal, lower end and spheric probe (8) are tightly connected, the bottom that rigidity drives link rod (6) also is tightly connected with spheric probe (8), the top is fixed on the end face of support (11) by the elastic wire that is cross spread (12), and maintenance plumbness, drive electromagnet (15) and measure electromagnet (4) and be separately fixed at support (11) both sides corresponding to the position that drives permanent magnet (10) and measurement permanent magnet (16), its end face is parallel with non-magnetic conduction horizontal gird (9)

Described electrical equipment control device comprises controllable gain amplifier (18), preceding amplifier (17), amplitude detector (19), two comparers (21), (23) and phase shifter (22), the input of controllable gain amplifier (18), output terminal respectively with mechanical part in measurement electromagnet (4), the coil that drives in the electromagnet (15) links to each other, preceding amplifier (17) input end links to each other with the input end of controllable gain amplifier (18), output divides two-way, respectively with amplitude detector (19), the input end of phase shifter (22) joins, two the input end tap reference voltages (20) of a described comparer (21) and the output terminal of amplitude detector (19), output termination controllable gain amplifier (18), two input end tap phase shifters (22) of another comparator circuit (23) and the output terminal of controllable gain amplifier (18).

2, according to the described transmitter of claim 1, the driving electromagnet (15), the measurement electromagnet (4) that it is characterized in that being positioned at support (11) both sides are two groups of differential connection, are individually fixed on the support (11) on non-magnetic conduction horizontal gird (9) both sides.

3, according to the described transmitter of claim 1, the driving electromagnet (15) that it is characterized in that being fixed in the described mechanical part on the support (11) is parallel with non-magnetic conduction horizontal gird (9) with the end face of measuring electromagnet (4), and at a distance of 0.3 millimeter.

4, according to claim 1 or 2 described transmitters, it is characterized in that described support (11) is the cylindric ducted body that the bottom is provided with two grooves symmetrically, it is hollow tube that rigidity drives link rod (6).

5, according to claim 1 or 2 described transmitters, it is characterized in that described driving electromagnet (15) and measure electromagnet (4) comprising coil (25), magnetic conductor (27) and magnetic core array (28), magnetic core array (28) is a reducing solid cylinder, thick end portion has two fairleads (30), magnetic conductor (27) is a tubular, be threaded with the butt end of magnetic core array (28), coil (25) is fixed in the both sides of the thin end of magnetic conductor (27) inner magnetic core body (28).

6, according to the described transmitter of claim 1, the top that it is characterized in that explosion-proof shell (2) is provided with two cables symmetrically and directly draws hole (13).

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