SU759912A1 - Liquid viscosity measuring device - Google Patents

Description

The invention relates to the field of instrumentation, in particular, to devices for continuous measurement of the viscosity of liquids directly in the reaction apparatus, for example, in the chemical, oil refining, paint and varnish industries. . ^five

Known capillary viscometers having a measuring tube, capillary flow and transparent measuring device. The viscosity in such viscometers is judged by the time of filling through the capillary of the measuring tube with a controlled fluid when it is immersed at a certain constant value.

The main disadvantage of these devices is the impossibility of their use for ₅ measuring the viscosity of liquids in the reaction vessels.

The closest to the proposed technical solution is the device comprising a measuring vessel and a capillary tube necks gaeoprovodya- _m, the force transducer in the compressed air pressure comparison element, a pressure setpoint, a separate trigger inputs, the three-way valve and the secondary device. Such

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devices are fire and explosion proof.

The output of such devices, presented in the form of rectangular pulses with a duration proportional to the expiration time, cannot be served without prior conversion to the input used in the manufacture of secondary pneumatic devices, mass-produced by our industry and having an analog input. The introduction of additional transforming devices reduces the accuracy of the measuring device.

The aim of the invention is to improve the measurement accuracy.

To achieve this goal, the trigger output with separate inputs is connected to the pneumatic valve control chamber, the nozzle of which is connected to the pneumatic chamber of the inertial link installed in the negative feedback circuit of the pneumatic relay, the output of which is connected to the control chambers of another pneumatic relay and memory element whose input is connected to the converter force, with the release of the second pneumorel

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connected to one of the trigger inputs with separate inputs, and the output of the memory element is connected to the input of the secondary device.

A device for measuring the viscosity of liquids is shown schematically in the drawing.

A device for measuring viscosity consists of a measuring element containing a measuring vessel 1 with a capillary 2 and connected by a gas supply tube 3 with a transducer 4 of the seat to pressure of compressed air. The output of the transducer 4 is connected to the camera B of the comparison element 5. A control unit 6 is connected to the camera B of the comparison element 5. The output of the comparison element is connected to one of the trigger inputs 7 with separate inputs. The output of the trigger 7 is connected to the control chamber A of the pneumatic valve 8 and to the actuator of the three-way valve 9. A constant overpressure line 10 is connected to one of the valve 9 inputs, a vacuum line is connected to the other input 11. The nozzle of the pneumatic valve 8 is connected to the chamber B of the three-membrane pneumatic relay 12, in the negative feedback of which an inertial link is installed (throttle 13, pneumatic capacitance 14). The output of relay 12 is connected to chamber B of the second pneumorele 15 and chamber B of the memory element 16. Chamber pressure chamber 8, chamber B of the relay 12 and 15 are supplied to chamber B of memory 16. Relay output 15 is connected to another trigger input 7. Memory element input 16 is connected to output of power converter 4 by chambers A and G. Memory element 16 output is connected to input of secondary device 17. Measuring element is enclosed in ₍ protective casing 18 and immersed in controlled liquid, located in a controlled device, ι

A device for determining the viscosity of liquids works as follows.

Suppose that at the initial moment of time there is no liquid in the cavity of the measuring vessel 1. The input of the transducer 4 at the same time affects the minimum force, and therefore, at its output will be the minimum pressure. This pressure enters the chamber B of the reference element. 5. The pressure set by the setpoint device 6 corresponds to the maximum weight of the measuring element with the gas supply tube. At the initial time, the pressure P ₄ coming from the output of the transducer 4 is less than the pressure P ₆ set by setpoint 6. ........

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Therefore, at the output of the comparison element 5 there will be a zero level signal, i.e. P ₅ = ”0”. With such an input signal, a trigger with separate inputs 7 takes on such a state that its output pressure P ₇ = ”0”. Valve 9 when pressure arrives at its input

P ₇ = ”0” connects the vacuum line 11 through the gas supply tube 3 to the cavity of the measuring element.

Controlled fluid when creating a vacuum in the cavity of the measuring element begins to leak into the measuring vessel 1 through the capillary 2.

The pressure P ₇ = 0 does not change the state of the valve 8, at which the chamber B of the pneumorele 12 through the open valve nozzle is connected to the atmosphere. In this case, the output of the relay 12 is the pressure P] _g = ”1”. This pressure covers the nozzle C) of the memory element 16 and the power nozzle C _{2 of the} pneumorelle 15. Through the nozzle C ₍ relay 15, chamber B of the trigger 7 is connected to the atmosphere, i.e. P | ₅ = ”0”. From the output of the memory element 16 to the secondary the device 17 receives the initial pressure P _YO x '= P ₄ =

= 002-MPa.

The filling of the measuring element with the controlled fluid occurs until the pressure P ₄ at the output of the transducer 4 becomes equal to the pressure of the task Pp. With this value of P ₄ at the output of the element of comparison 5 there will be a pressure P ₅ = "1". With this pressure, the trigger 7 is transferred to the state with a single output P ₇ = ”1”, with which the valve 9 connects the compressed air line 10 to the plane of the measuring element. The process of displacing the liquid from the measuring element begins. When this pressure P ₇ = ”1” closes the valve nozzle 8 and in the pneumatic capacity 14 of the inertial element pressure starts to rise to a value determined by the level of operation of the relay 12.

When triggered, the relay 12 pressure at its output P | ₂ ~ ”0”. This pressure resets the memory of element 16 and triggers relay 15. At the same time, from the output of relay 15, the unit pressure enters chamber B of trigger 7, at the output of which the pressure becomes zero. Through the nozzle of the valve 8, the camera B relay 12 is connected to the atmosphere. At the output of the relay 12, the pressure P ₁₂ = ”1” reappears, which is used to memorize the pressure P out, which determines the amount of liquid that has leaked from the measuring element for some constant time.

When a signal arrives at the input of the actuator of the three-way valve P ₇ = ”0”, a negative pressure is again applied to the cavity of the measuring element, which is used to fill the measuring element with a controlled fluid.

In the future, the operation of the measuring device occurs as described above.

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The flow time of the fluid from the measuring element can be changed by changing the conductivity of the choke 13.

In the proposed design of the viscometer, the analysis time is a constant value, which will allow measuring the fluid in a large range of viscosities with a constant pressure drop across the capillary.

The representation of the output signal of the device in analog form will allow the use of pneumatic secondary devices, mass-produced by our industry.

Claims (1)

Claim A device for measuring the viscosity of liquids, containing a measuring vessel with a capillary and a gas supplying tube, a force transducer to compressed air pressure, a reference element, a pressure setting device, a trigger with separate inlets, a three-way valve, and a secondary device that differs by accuracy, the trigger output with separate inputs is connected to the pneumatic valve control chamber inserted, into the nozzle of which the pneumatic chamber of the inertial link, installed in the negative feedback circuit, is connected and a pneumatic relay, the output of which is connected to the control chamber of the second pneumorel and the memory element, the input of which is connected to the output of the force converter, while the output 15 of the second pneumorel is connected to one of the trigger inputs with separate inputs, and the output of the memory element is connected to the input of the secondary device. 759912 / V ‘Edakgor N. Kolyada $ Akaz 5861/31