JP2013167453A - Viscosity measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a viscosity measuring apparatus whose maintenance can be easily performed.SOLUTION: The viscosity measuring apparatus for continuously measuring viscosity of fluid flowing in a conduit line includes: flow velocity distribution measuring means connected to the conduit line to measure flow velocity distribution of the fluid; mass flow velocity measuring means connected to the conduit line to measure mass flow velocity of the fluid; and viscosity calculation means for calculating the viscosity of the fluid on the basis of a Reynolds number of the fluid which is calculated from the flow viscosity distribution and a measurement value of the mass flow velocity.

Description

  The present invention relates to a viscosity measuring apparatus that continuously measures the viscosity of a fluid flowing through a pipe line.

  A capillary viscometer has been put to practical use as a viscosity measuring device for continuously measuring the viscosity of a process fluid such as resin, oil, fat, solution, paint, foodstuff and the like flowing through a pipeline. FIG. 4 is a functional block diagram showing a configuration example of a conventional viscosity measuring apparatus.

  A differential pressure gauge 20 is connected to the conduit 10 through which the fluid L flows in the direction of the arrow, and the pressure loss between the upstream pressure guided through the pressure guiding tube 21 and the downstream pressure guided through the pressure guiding tube 22 is measured. The viscosity μ is calculated by the viscosity calculating means 30 based on the value ΔP. As an arithmetic algorithm, for example, the Hagen-Poiseuille equation is known.

JP2010-151452A JP-A-7-181069

  In the conventional apparatus, if the thickness of the pressure guiding pipes 21 and 22 is reduced so as not to affect the flow of the fluid L, the fluid L having a high viscosity may be clogged in the pressure guiding pipe 21, “22”. Maintenance is required to monitor and respond to clogging, and management becomes complicated.

  An object of the present invention is to provide a viscosity measuring apparatus that is easy to maintain.

In order to achieve such a subject, the present invention has the following configuration.
(1) In a viscosity measuring device that continuously measures the viscosity of a fluid flowing through a pipeline,
A flow velocity distribution measuring unit connected to the pipe and measuring the flow velocity distribution of the fluid;
A mass flow rate measuring means connected to the conduit for measuring the mass flow rate of the fluid;
Viscosity calculating means for calculating the viscosity of the fluid based on the Reynolds number of the fluid calculated from the flow rate distribution and the measured value of the mass flow rate;
A viscosity measuring device comprising:

(2) The viscosity measuring apparatus according to (1), wherein the flow velocity distribution measuring means is an ultrasonic flowmeter using a reflection correlation method.

(3) The viscosity measuring apparatus according to (1), wherein the flow velocity distribution measuring means is an ultrasonic flowmeter using a pulse Doppler method.

(4) The viscosity measuring device according to (1), wherein the mass flow rate measuring means is a Coriolis type mass flow meter.

(5) The viscosity measuring apparatus according to (1), wherein the flow velocity distribution measuring unit is connected to an upstream side of the pipe, and the mass flow rate measuring unit is connected to a downstream side of the pipe. .

  According to the present invention, the ultrasonic flowmeter that is the flow velocity distribution measuring means and the Coriolis mass flowmeter that is the mass flow measuring means normally have no pressure loss and no protrusions on the pipeline, so Even in such a case, the viscosity of the fluid can be stably measured without clogging.

It is a hardware block diagram which shows one Example of the viscosity measuring apparatus to which this invention is applied. It is a functional block diagram explaining operation | movement of the viscosity measuring apparatus to which this invention is applied. It is a characteristic view which shows the example of a measurement of flow velocity distribution. It is a functional block diagram which shows the structural example of the conventional viscosity measuring apparatus.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a hardware configuration diagram showing an embodiment of a viscosity measuring apparatus to which the present invention is applied. The same elements as those in the conventional configuration described with reference to FIG.

  A flow velocity distribution measuring means 100 is connected to the upstream side of the conduit 10. As the flow velocity distribution measuring means 100, a well-known ultrasonic flow meter capable of measuring the flow velocity distribution using the reflection correlation method can be used. Regarding the reflection correlation method, Patent Document 1 discloses a technical disclosure.

  A mass flow rate measuring means 200 is connected to the downstream side of the conduit 10. As this mass flow rate measuring means 200, a well-known Coriolis type mass flow meter can be used. Regarding Coriolis mass flowmeters, Patent Document 2 discloses a technical disclosure.

  The viscosity calculating means 300 acquires the fluid Reynolds number Re calculated by the flow velocity distribution measuring means 100 and the fluid mass flow rate ρVD output from the mass flow measuring means 200, calculates the viscosity μ, and outputs it externally. To do.

  FIG. 2 is a functional block diagram for explaining the operation of the viscosity measuring apparatus to which the present invention is applied. The flow velocity distribution measuring means 100 realized by the ultrasonic flowmeter using the reflection correlation method calculates the flow velocity distribution V (a) by the flow velocity distribution measuring circuit 101. The Reynolds number calculation circuit 102 calculates the Ray nozzle number Re from the flow velocity distribution V (a) and passes it to the viscosity calculation means 300.

  FIG. 3 is a characteristic diagram showing a measurement example of the flow velocity distribution. When the coordinate of the central axis of the pipeline 10 is 0 and the inner diameter is D, the flow velocity distribution V (a) as shown in FIG. 3 is obtained for a sufficiently developed turbulent flow.

  This flow velocity distribution V (a) is a function of the Reynolds number Re shown in Equation (1), and the Reynolds number arithmetic circuit 102 obtains the Reynolds number Re from the flow velocity distribution of the fluid measured so that the error is minimized. Can do.

Where V (a): Flow velocity distribution
a: Position in the pipeline (center axis is 0)
Re: Reynolds number
V0: Center flow velocity.

  Returning to FIG. 2, the mass flow rate measuring means 200 realized by the Coriolis type mass flow meter calculates the mass flow rate ρVD of the fluid by the mass weight calculation circuit 201 and passes it to the viscosity calculation means 300. The viscosity calculation means 300 calculates the viscosity μ based on the input Reynolds number Re and the mass flow rate ρVD, and outputs it to the display means 400 that is an external device.

The relationship between the Reynolds number Re, the mass flow rate ρVD, and the viscosity μ is defined by a well-known formula (2).
Re = ρVD / μ equation (2)
Therefore, the viscosity calculating means 300 can calculate the viscosity μ based on the equation (2).

  In the embodiment, an ultrasonic flowmeter by the reflection correlation method is exemplified as the flow velocity distribution measuring unit 100, but a method of obtaining the flow velocity distribution by an ultrasonic flowmeter using a pulse Doppler method is also possible.

DESCRIPTION OF SYMBOLS 10 Pipe line 100 Flow velocity distribution measuring means 101 Flow velocity distribution measuring circuit 102 Reynolds number calculating circuit 200 Mass flow measuring means 201 Mass flow calculating circuit 300 Viscosity calculating means 400 Display means

Claims (5)

In a viscosity measuring device that continuously measures the viscosity of a fluid flowing through a pipeline,
A flow velocity distribution measuring unit connected to the pipe and measuring the flow velocity distribution of the fluid;
A mass flow rate measuring means connected to the conduit for measuring the mass flow rate of the fluid;
Viscosity calculating means for calculating the viscosity of the fluid based on the Reynolds number of the fluid calculated from the flow rate distribution and the measured value of the mass flow rate;
A viscosity measuring device comprising:   The viscosity measuring apparatus according to claim 1, wherein the flow velocity distribution measuring unit is an ultrasonic flowmeter using a reflection correlation method.   The viscosity measuring apparatus according to claim 1, wherein the flow velocity distribution measuring means is an ultrasonic flowmeter using a pulse Doppler method.   The viscosity measuring apparatus according to claim 1, wherein the mass flow rate measuring unit is a Coriolis type mass flow meter.   The viscosity measuring apparatus according to claim 1, wherein the flow velocity distribution measuring unit is connected to an upstream side of the pipe line, and the mass flow rate measuring unit is connected to a downstream side of the pipe line.

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