CN102954926B - Capillary viscometer - Google Patents

Abstract

The present invention provides a narrow tube viscometer, which can eliminate the flow disturbance of the measured fluid generated on the constant flow pump and the delivery pipe, make the measured fluid flow in the thin tube for pressure difference detection in a laminar flow state, and can utilize the pressure The differential sensor accurately detects the pressure difference between the inlet end and the outlet end of the thin tube for pressure difference detection, thereby enabling reliable viscosity measurement. On the upstream side of the capillary for differential pressure detection, a flow control chamber having a flow channel cross-sectional area larger than that of the capillary for differential pressure detection is provided.

Description

Capillary Viscometer

technical field

The present invention relates to a capillary viscometer configured such that a fluid to be measured, such as A heavy oil (MDO) or light oil (MGO), flows through a capillary for differential pressure detection, and a differential pressure sensor detects the capillary for differential pressure detection. The pressure difference between the inlet end and the outlet end of the pipe is used to determine the viscosity of the fluid.

Background technique

Conventionally, thin tube viscometers have been used. When a viscous fluid flows in a thin tube with a constant inner diameter in a laminar flow state at a constant flow rate, the pressure difference and flow rate generated between the upstream and downstream sides of the narrow tube According to the relationship of Hagen-Poiseuille (Hagen-Poiseuille) flow law, to continuously find the viscosity.

That is, the so-called Hagen-Poiseuille flow formula utilizes the following property: When a certain fluid flows in a thin tube with an inner diameter radius (r) and a length (l) in a laminar flow state of a flow rate (q), The pressure difference (ΔP) between the inlet port and the outlet port of the thin tube is proportional to the viscosity (η) of the fluid, as expressed by Equation 1 below.

Mathematical formula 1:

$\mathrm{<span\; class="notranslate">\; \&eta;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&pi;r</span>}}^{\mathrm{<span\; class="notranslate">\; 4</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;P</span>}}{\mathrm{<span\; class="notranslate">\; 81</span>}\mathrm{<span\; class="notranslate">\; q</span>}}$

As shown in the above formula 1, if the shape and flow rate of the capillary are known, the viscosity (η) of the fluid can be measured by detecting the capillary for differential pressure detection (ΔP) of the capillary.

FIG. 6 is a schematic diagram showing a conventional thin-tube viscometer using the Hagen-Poiseuier flow equation.

As shown in FIG. 6 , a conventional capillary viscometer 100 is configured such that a constant flow pump 104 draws a fluid to be measured through a suction pipe 102 from a tank, piping, etc. that stores a fluid to be measured (not shown).

Furthermore, the fluid to be measured is pumped by the constant flow pump 104 to flow through the delivery pipe 106 in a laminar flow state in the thin tube 108 for differential pressure detection, and is discharged from the discharge pipe 110 .

On the other hand, the high pressure detection tube 112 branches from the inlet end 108a of the thin tube 108 for differential pressure detection, and is connected to the outlet end 108b of the thin tube 108 for differential pressure detection via the differential pressure sensor 114 and the low pressure detection tube 116. Therefore, the pressure is transmitted to the differential pressure sensor 114 .

Thus, the differential pressure sensor 114 detects the pressure difference between the pressure of the high-pressure detection pipe 112 and the pressure of the low-pressure detection pipe 116 , and converts the pressure difference using Equation 1 to calculate the viscosity.

prior art literature

Patent Document 1: Japanese Patent No. 3796330

However, in recent years, in order to prevent environmental damage, for example, exhaust gas regulation has been strengthened in land vehicles, thermal power plants, and the like. This exhaust gas regulation is not an exception for ships at sea, and regulation has already begun in some sea areas.

That is, light oil (MGO) which is lower in sulfur (LSA) than A heavy oil (MDO) used hitherto is compulsorily used for the fuel of a ship in the offshore of land. This light oil (MGO) is a very low-viscosity fluid whose viscosity at 15° C. is 2 mPa·s or less.

However, in the conventional capillary viscometer 100 that detects the pressure loss that occurs when a viscous fluid passes through the capillary and measures the viscosity, it is important that the flow of the fluid to be measured in the capillary for pressure difference detection 108 be laminar. conditions of.

When the viscosity of the fluid to be measured is high, laminar flow is formed over a short distance, but when the viscosity of the fluid to be measured is low, a long distance is required to form laminar flow.

In addition, in order to reduce the size of the capillary viscometer 100, as shown in FIG. When the viscosity of the fluid to be measured such as light oil (MGO) is low, a side flow (secondary flow) occurs in the curved portion, and the measurement fluid is disturbed by this side flow so that laminar flow does not occur. As a result, the flow of the fluid to be measured in the thin tube for pressure difference detection 108 does not become a laminar flow, which greatly affects the measurement.

Therefore, when the viscosity of the fluid to be measured such as light oil (MGO) is low, if the delivery pipe 106 of the fluid to be measured is arranged in a straight line from the constant flow pump 104 to the thin tube 108 for differential pressure detection, Furthermore, if the distance is made longer, the flow of the fluid to be measured becomes laminar in the delivery pipe 106 and no secondary flow (secondary flow) occurs.

However, if the delivery pipe 106 of the fluid to be measured from the constant flow pump 104 to the capillary for differential pressure detection 108 is arranged in a straight line, and the distance thereof is increased, the capillary viscometer 100 will be large in size. In addition, there are many cases where the structure cannot be arranged in a straight line.

Therefore, Patent Document 1 (Patent No. 3796330) discloses a viscometer unit in which a double gear pump is attached, and a capillary for viscosity measurement is helically formed on the outer periphery of the pump. Compactly form the whole device.

However, in the viscosity detector unit of Patent Document 1, it is necessary to arrange a double gear pump, so that the structure is complicated, and when the viscosity of the fluid to be measured is low, such as light oil (MGO), there is a risk of bending. A side flow (secondary flow) is generated in a part, which has a great influence on the measurement.

Contents of the invention

In view of such circumstances, the present invention aims to provide a narrow tube type viscometer that can eliminate the need for constant flow pumps, delivery pipes, etc. The flow of the fluid to be measured is disturbed, and the fluid to be measured flows in the thin tube for pressure difference detection in a laminar flow state, and the differential pressure sensor can be used to accurately measure the difference between the inlet end and the outlet end of the thin tube for pressure difference detection. To detect the pressure difference between the two, so that the viscosity can be measured reliably.

In addition, an object of the present invention is to provide a thin-tube viscometer that can eliminate the turbulence of the flow of the fluid to be measured even if the delivery pipe is in a state of secondary flow (secondary flow) or turbulent flow, and can complicate By bending the delivery tube, thinner piping can be used, and it can also be attached to a complex structure, thereby increasing the degree of freedom in design.

In addition, since the present invention once becomes a stable flow in the flow control chamber, it is possible to shorten the start-up interval until the laminar flow in the pressure difference detection capillary is completed, thereby providing a compact capillary viscometer.

The present invention was made to achieve the above-mentioned problems and objects in the prior art, and the capillary viscometer of the present invention is constituted as follows:

The fluid to be measured flows in the thin tube for differential pressure detection, and the pressure difference between the inlet end and the outlet end of the thin tube for differential pressure detection is detected by the differential pressure sensor, thereby measuring the viscosity of the fluid. The characteristics of this narrow tube viscometer is that

On the upstream side of the capillary for differential pressure detection, a flow control chamber having a flow channel cross-sectional area larger than that of the capillary for differential pressure detection is provided.

With this configuration, the flow control chamber having a flow channel cross-sectional area larger than the flow channel cross-sectional area of the pressure difference detection capillary is provided on the upstream side of the pressure difference detection capillary, so the fluid to be measured flows into the flow control chamber, and the This flow control chamber can function as a damper, reducing the flow velocity within the flow control chamber and making the fluid a smooth flow.

Therefore, even when the viscosity of the measured fluid such as light oil (MGO) is low, the flow disturbance of the measured fluid generated on the constant flow pump and the delivery pipe can be eliminated, and the measured fluid can flow in a laminar flow. The state flows in the thin tube for differential pressure detection, and the differential pressure sensor can accurately detect the pressure difference between the inlet port and the outlet port of the thin tube for differential pressure detection, so that the viscosity can be measured reliably.

In addition, it is possible to provide a narrow tube type viscometer that can eliminate the turbulence of the flow of the fluid to be measured even if the inside of the delivery tube is in a state of secondary flow (secondary flow) or turbulent flow, and the delivery tube can be bent complicatedly. , so that thinner piping can be used, and it can also be installed in complex structures to increase the degree of freedom in design.

In addition, since the flow is once stable in the flow control chamber, it is possible to shorten the start-up interval until laminar flow in the pressure difference detection capillary is completed, thereby providing a compact capillary viscometer.

In addition, the capillary viscometer of the present invention is characterized in that at least a part of the capillary for differential pressure detection is disposed in the flow control chamber.

As described above, since at least a part of the capillary for differential pressure detection is arranged in the flow control chamber, the flow control chamber is surrounded by the capillary for differential pressure detection, and the capillary viscometer can be configured compactly.

In addition, the narrow tube type viscometer according to the present invention is characterized in that the inlet of the high-pressure-side detecting tube of the branch pipe in which the differential pressure sensor is arranged is arranged on the downstream side of the flow control chamber.

In this way, by arranging the inlet of the high-pressure side detecting pipe of the branch pipe of the differential pressure sensor on the downstream side of the above-mentioned flow control chamber, there is a smooth flow on the downstream side of the flow control chamber, and the turbulence of the flow disappears, so that the differential pressure sensor can be used. To detect the correct pressure on the high pressure side, as a result, the viscosity can be measured reliably.

In addition, the capillary viscometer of the present invention is characterized in that the inlet of the high-pressure-side detection tube of the branch pipe in which the differential pressure sensor is disposed is disposed on the downstream side of the flow control chamber, and is disposed in the capillary for differential pressure detection. near the upstream end of the

In this way, since the inlet of the high-pressure-side detecting pipe of the branch pipe of the differential pressure sensor is disposed on the downstream side of the flow control chamber and near the upstream end of the differential pressure detection capillary, the flow control chamber On the downstream side, especially in the vicinity of the upstream end of the thin tube for differential pressure detection, there is a smooth flow, and the turbulence of the flow disappears, so that the correct pressure on the high pressure side can be detected by the differential pressure sensor. As a result, it can be reliably performed. Viscosity determination.

The effects of the present invention are as follows.

According to the present invention, since the flow control chamber having a flow channel cross-sectional area larger than that of the pressure difference detection capillary is provided on the upstream side of the pressure difference detection capillary, the fluid to be measured flows into the flow control chamber, Thus, the flow control chamber can function as a damper, and the flow velocity is reduced in the flow control chamber to make the fluid flow smoothly.

Therefore, even when the viscosity of the measured fluid such as light oil (MGO) is low, the flow disturbance of the measured fluid generated on the constant flow pump and the delivery pipe can be eliminated, and the measured fluid can flow in a laminar flow. The state flows in the capillary for differential pressure detection, and the differential pressure sensor can accurately detect the pressure difference between the inlet port and the outlet port of the capillary for differential pressure detection, thereby enabling reliable viscosity measurement.

Description of drawings

Fig. 1 is a schematic diagram showing a narrow tube type viscometer of the present invention.

Fig. 2 is a sectional view taken along line A-A of the thin tube viscometer in Fig. 1 .

FIG. 3 is an enlarged view of the flow control chamber of the slim tube viscometer of FIG. 1 .

Fig. 4 is a schematic view showing a narrow tube viscometer according to another embodiment of the present invention.

Fig. 5 is an enlarged view of a flow control chamber of a narrow tube viscometer according to another embodiment of the present invention.

Fig. 6 is a schematic diagram showing a conventional narrow tube type viscometer.

In the picture:

10—thin tube viscometer, 12—suction pipe, 14—constant flow pump, 16—delivery pipe, 16a—downstream end, 18—thin tube for differential pressure detection, 18a—mouth port, 18b—outlet port, 20— Discharge pipe, 22—high pressure detection pipe, 22a—inlet port, 24—pressure difference sensor, 26—constant flow pump, 28—low pressure detection pipe, 30—control room, 30a—front end, 30b—rear end, 30c— Downstream end, 30d—upstream end, 30e—upper end, 30f—lower end, 100—thin tube viscometer, 102—suction pipe, 104—constant flow pump, 106—delivery pipe, 108—thin tube for differential pressure detection, 108a - inlet port, 108b - outlet port, 110 - discharge pipe, 112 - high pressure detection tube, 114 - differential pressure sensor, 116 - low pressure detection tube.

Detailed ways

Hereinafter, embodiments (examples) of the present invention will be further described in detail based on the drawings.

Example 1

Fig. 1 is a schematic view showing the capillary viscometer of the present invention, Fig. 2 is a sectional view of the line A-A of the capillary viscometer of Fig. 1 , and Fig. 3 is an enlarged view of the flow control chamber of the capillary viscometer of Fig. 1 .

In FIG. 1 , reference numeral 10 denotes the whole thin tube type viscometer of the present invention.

As shown in FIG. 1 , the capillary viscometer 10 is configured to use a constant flow pump 14 to pass through a suction pipe 12 , a tank (not shown) that stores a low-viscosity fluid to be measured, such as light oil (MGO), Piping, etc., to extract the fluid to be measured.

Furthermore, a flow control chamber 30 is provided on the upstream side of the pressure difference detection capillary 18 , and the fluid to be measured pumped out by the constant flow pump 14 flows into the flow control chamber 30 through the delivery tube 16 .

That is, the downstream end 16a of the delivery pipe 16 is connected to the longitudinal rear end portion 30b of the flow control chamber 30 (the upstream side of the right flow control chamber 30 in FIG. 1 ).

In addition, a high-pressure detection tube 22 is branched at a front end portion 30 a in the longitudinal direction of the flow control chamber 30 (in FIG. 1 , the downstream side of the left flow control chamber 30 ). That is, the inlet end 22a of the high pressure detection tube 22 is disposed near the upstream end of the differential pressure detection capillary 18 , that is, near the inlet end 18a of the differential pressure detection capillary 18 .

Further, the high-pressure detection tube 22 is connected to the outlet end 18 b of the thin tube 18 for differential pressure detection via a differential pressure sensor 24 and a low-pressure detection tube 28 , thereby transmitting pressure to the differential pressure sensor 24 .

On the other hand, at least a part of the differential pressure detection capillary 18 is arranged in the flow control chamber 30 so that the inlet port 18a of the pressure difference detection capillary 18 is located near the longitudinal front end 30a of the flow control chamber 30 .

Furthermore, the fluid to be measured flowing into the flow control chamber 30 through the delivery tube 16 flows in the thin tube 18 for differential pressure detection in a laminar flow state, and is discharged from the discharge tube 20 .

Thus, the pressure difference between the pressure of the high pressure detection pipe 22 and the pressure of the low pressure detection pipe 28 is detected by the differential pressure sensor 24 , and the pressure difference is converted using Equation 1 to calculate the viscosity.

In this case, as shown in FIGS. 1 and 2 , the flow channel cross-sectional area of the flow control chamber 30 is formed to have a larger flow channel cross-sectional area than the flow channel cross-sectional area of the narrow tube 18 for pressure difference detection.

With such a configuration, as shown by the arrow in FIG. 1 , the fluid to be measured that is drawn out through the suction pipe 12 by the constant flow pump 14 passes through the delivery pipe 16, from the downstream end 16a of the delivery pipe 16, to the longitudinal direction of the flow control chamber 30. The rear end 30b flows in.

Then, the fluid to be measured flowing into the flow control chamber 30 flows toward the front end portion 30 a of the flow control chamber 30 in the longitudinal direction.

At this time, since the flow channel cross-sectional area of the flow control chamber 30 has a flow channel cross-sectional area larger than the flow channel cross-sectional area of the thin tube 18 for differential pressure detection, by measuring the flow of fluid into the flow control chamber 30, the flow control chamber can be used as The snubber functions to reduce the flow velocity within the flow control chamber 30 and bring the fluid into a smooth flow.

Therefore, even when the viscosity of the fluid to be measured is low such as light oil (MGO), the disturbance of the flow of the fluid to be measured generated on the constant flow pump 14 and the delivery pipe 16 can be eliminated, so that the fluid to be measured can be measured at a low viscosity. The laminar flow state flows in the thin tube 18 for differential pressure detection, and the pressure difference between the inlet port 18a and the outlet port 18b of the thin tube 18 for differential pressure detection can be accurately detected by the differential pressure sensor 24, so that the viscosity can be reliably measured. Determination.

In this case, since the inlet end 22a of the high-pressure detection tube 22 is disposed near the upstream end of the thin tube 18 for differential pressure detection, that is, near the inlet end 18a of the thin tube 18 for differential pressure detection, the flow control chamber The downstream side of 30, especially in the vicinity of the upstream side end of the thin tube 18 for differential pressure detection, is a smooth flow, and the turmoil of the flow disappears, so that the pressure on the high pressure side can be accurately detected by the differential pressure sensor 24. As a result, Enables reliable viscosity measurement.

In this case, for example, as shown in FIG. 3 , when the length L1 of the thin tube 18 for differential pressure detection is about 150 mm, the ratio L1:L2 of the length L1 of the thin tube 18 for differential pressure detection to the length L2 of the flow control chamber 30 In the case of 3:2, as shown in Figure 2, the ratio S1:S2 of the flow channel cross-sectional area S1 of the thin tube 18 for differential pressure detection to the flow channel cross-sectional area S2 of the flow control chamber 30 is 1:30~1: 50. At this time, the fluid to be measured flows in the thin tube 18 for differential pressure detection in a laminar flow state, which is preferable.

In addition, as shown in FIG. 2 , the relationship between the inner diameter d1 of the differential pressure detection thin tube 18 , the outer diameter d2 of the pressure difference detection thin tube 18 , and the inner diameter d3 of the flow control chamber 30 is preferably set as follows.

That is, the inner diameter d1 of the thin tube 18 for differential pressure detection is calculated by the discharge rate of the constant flow pump 14, and the Reynolds number Re is preferably set to be the number Re<2300, so that when the dynamic viscosity of the fluid to be measured is 1 mm ² /s (cSt), the fluid to be measured flowing through the thin tube 18 for differential pressure detection reliably becomes a laminar flow.

In this case, in order to calculate the Reynolds number, it may be calculated according to the following Reynolds number calculation formula.

Re=vd/v

Here, v is the flow velocity, d is the inner diameter of the thin tube 18 for differential pressure detection, and ν is the dynamic viscosity of the fluid to be measured.

In addition, it is preferable to set the inner diameter d3 of the flow control chamber 30 to about 6 times the outer diameter d2 of the pressure difference detection capillary, and the flow velocity of the fluid to be measured flowing in the flow control chamber 30 is set to be used for pressure difference detection. About 1/30 of the flow velocity in narrow tube 18.

As a result, the Reynolds number Re of the fluid to be measured at 1 mm ² /s flowing in the flow control chamber 30 is Re≈200, and the flow becomes smooth, so that the fluid to be measured flowing in the thin tube 18 for differential pressure detection is reliably become laminar flow.

For example, it is preferable to set the inner diameter d1 of the thin tube 18 for differential pressure detection to about Set the outer diameter d2 of the thin tube 18 for differential pressure detection to about Set the inner diameter d3 of the flow control chamber 30 to about

In addition, as shown in FIG. 3 , it is preferable to set the length L1 of the thin tube 18 for differential pressure detection to be longer than the start-up interval until the laminar flow state of the fluid to be measured is completed.

In this case, the length L1 of the thin tube 18 for differential pressure detection may be set by the following formula for calculating the start-up interval.

L1＝k·Re/d

Wherein, Re is the Reynolds number, d is the inner diameter of the thin tube 18 for pressure difference detection, and the coefficient k is 0.06-0.065.

In addition, the length L2 of the flow control chamber 30 does not need to be the length to achieve laminar flow in the flow control chamber 30, but only needs to be such that the secondary flow (secondary flow) and turbulent flow generated on the constant flow pump 26 and the delivery pipe 16 The length of the distance over which the state disappears.

In addition, by connecting the downstream end 16a of the delivery pipe 16 to the rear end 30b in the longitudinal direction of the flow control chamber 30 (the upstream side of the flow control chamber 30 on the right in FIG. The distance over which the flowing fluid to be measured smoothly flows becomes longer. In addition, replacement of the fluid to be measured in the flow control chamber 30 is also quickened.

According to the experiment, as shown in Figure 2, it can be known that the inner diameter d1 of the capillary tube 18 for differential pressure detection is about Make the outer diameter d2 of the thin tube 18 for differential pressure detection be about Make the inner diameter d3 of the flow control chamber 30 be about In the case of the flow control chamber 30, it is sufficient to set the length L2 of the flow control chamber 30 to about 1/2 of the length L1 of the thin tube 18 for differential pressure detection, but it is preferable to set it to 2/2 of the length L1 of the thin tube 18 for differential pressure detection in order to have ample room. 3.

That is, the ratio L1:L2 of the length L1 of the thin tube for pressure difference detection 18 to the length L2 of the flow control chamber 30 is preferably 3:2.

Furthermore, the gap L3 between the downstream end 30c of the flow control chamber 30 (in FIG. 1 , the downstream end 30c of the flow control chamber 30 on the left side) and the inlet end 18a of the thin tube 18 for differential pressure detection is preferably set to be equal to The outer diameter d2 of the thin tube 18 for differential pressure detection is about the same size so that the flow velocity of the fluid to be measured does not change substantially.

In addition, the ratio L3:L2 of the gap L3 between the downstream end 30c of the flow control chamber 30 and the inlet end 18a of the thin tube for pressure difference detection 18 and the length L2 of the flow control chamber 30 is preferably 1:25.

For example, it is preferable to set the length L1 of the thin tube 18 for differential pressure detection to about 150 mm, the length L2 of the flow control chamber 30 to be about 100 mm, and connect the downstream end 30c of the flow control chamber 30 to the thin tube 18 for differential pressure detection. The gap L3 between the inlet ports 18a was set at about 4 mm.

And, as shown in FIG. 3 , for the position where the downstream end 16 a of the delivery pipe 16 is connected to the flow control chamber 30 , the distance L4 from the upstream end 30 d of the flow control chamber 30 is preferably set to be the length of the flow control chamber 30 . Within 1/10 of the length L2.

In addition, in this embodiment, the case where the cross-sectional shape of the flow control chamber 30 is circular has been described, but the flow passage cross-sectional area of the flow control chamber 30 has a flow passage cross-sectional area larger than the flow passage cross-sectional area of the thin tube 18 for differential pressure detection. The cross-sectional area of the flow channel is sufficient, and may be, for example, elliptical, triangular, rectangular, polygonal, etc., and is not particularly limited, and may be appropriately set based on the criteria described above.

Example 2

Fig. 4 is a schematic view showing a narrow tube viscometer according to another embodiment of the present invention.

The narrow tube viscometer 10 of this embodiment basically has the same configuration as the narrow tube viscometer 10 shown in FIGS.

In the capillary viscometer 10 of the above-mentioned embodiment 1, at least a part of the capillary 18 for differential pressure detection is arranged in the flow control chamber 30, but in the capillary viscometer 10 of this embodiment, it may be as shown in FIG. As shown in FIG. 4 , the thin tube 18 for differential pressure detection is not located in the flow control chamber 30 .

That is, in the capillary viscometer 10 of this embodiment, as shown in FIG. The upstream side of chamber 30) is connected.

In addition, the inlet end 18a of the thin tube 18 for differential pressure detection is connected to the downstream end 30c of the flow control chamber 30 (in FIG. 4 , the downstream end 30c of the flow control chamber 30 on the right side).

And, at the rear end portion 30b in the longitudinal direction of the flow control chamber 30 (in FIG. 4 , the downstream side of the flow control chamber 30 on the right side), that is, near the inlet end 18a of the thin tube 18 for differential pressure detection, a There is an inlet port 22a of the high pressure sensing tube 22 .

Also in the capillary viscometer 10 of this embodiment, it is possible to make the turbulence of the flow of the fluid to be measured generated in the constant flow pump 26 and the delivery pipe 16 into a smooth flow.

However, the thin tube 18 for differential pressure detection needs to have a constant length, and the length L2 of the flow control chamber 30 cannot be increased.

Therefore, for example, the length of the flow control chamber 30 in the depth direction is increased on the page of FIG. The length L2 of the flow control chamber 30 can be shortened, but this is not shown.

Example 3

Fig. 5 is an enlarged view of a flow control chamber of a narrow tube viscometer according to another embodiment of the present invention.

The capillary viscometer 10 of this embodiment basically has the same configuration as the capillary viscometer 10 shown in FIG. 4 , and the same components are assigned the same reference numerals, and detailed description thereof will be omitted.

In the capillary viscometer 10 of the above-mentioned embodiment 2, if the conveying pipe 16 and the capillary for pressure difference detection 18 are arranged in a straight line (horizontal direction), it is necessary to consider The influence of the disturbance of the flow at end 16a) on the thin tube 18 for differential pressure detection.

In this way, in the capillary viscometer 10 of the above-mentioned embodiment 2, the flow control chamber 30 is formed so that the longitudinal direction is the horizontal direction, but in this embodiment, the flow control chamber 30 is vertically vertical as shown in FIG. 5 . configuration.

That is, the downstream end 16a of the delivery pipe 16 is disposed near the upper end 30e of the flow control chamber 30 , and the inlet end 18a of the thin tube 18 for differential pressure detection is disposed near the lower end 30f of the flow control chamber 30 .

With such a configuration, the installation positions of the delivery tube 16 and the pressure difference detection capillary 18 are shifted, and a distance is combined to stabilize the flow of the fluid to be measured flowing in the flow control chamber 30 .

The preferred embodiment of the present invention has been described above, but the present invention is not limited thereto. For example, in the above-mentioned examples, it is used for a fluid to be measured with low viscosity such as light oil (MGO), but it may also be used in For example, when measuring the viscosity of high-viscosity fluids such as A heavy oil (MDO) and C heavy oil (MFO), and other fluids other than oil, it can be used in various ways without departing from the purpose of the present invention. species change.

Industrial availability

It can be used in a capillary viscometer configured to detect differential pressure with a differential pressure sensor by flowing a fluid to be measured such as A heavy oil (MDO) or light oil (MGO) in a capillary for differential pressure detection The pressure difference between the inlet port and the outlet port of the thin tube is used to measure the viscosity of the fluid.

Claims (2)

1. A narrow tube type viscometer, which is constituted by making the fluid to be measured flow in the narrow tube for differential pressure detection, and using a differential pressure sensor to detect the pressure difference between the inlet end and the outlet end of the thin tube for differential pressure detection, thereby To measure the viscosity of the fluid, the capillary viscometer is characterized in that, A flow control chamber is provided on the upstream side of the thin tube for differential pressure detection. The flow control chamber has a flow channel cross-sectional area larger than that of the thin tube for differential pressure detection. The flow control chamber reduces the flow rate of the fluid. flow rate and make the above fluid flow smoothly, In the flow control chamber, at least a part of the thin tube for differential pressure detection is disposed. 2. capillary viscometer according to claim 1, is characterized in that, An inlet of a high-pressure side detection pipe in which the branch pipe of the differential pressure sensor is arranged is arranged on the downstream side of the flow control chamber.