JPH07333131A - Viscosity measuring method and apparatus for fluid flowing in process - Google Patents

Abstract

PURPOSE:To provide viscosity measuring method and apparatus for fluids flowing in a process, said method and apparatus can carry out the measurement stably at high measurement precision for a long duration even for a plant which is operated intermittently. CONSTITUTION:Normally, while a sample fluid from a process pipeline 1 being made to pass an leading-in flow route 40, a circulating flow route 20, and a discharging flow route 50, viscosity measurement is carried out by a viscosity measuring apparatus 30 and thus the viscosity can be measured continuously. At the time of process stop, the sample fluid is made to circulate in the loop-like circulating flow route 2 to prevent choking and thus the temperature is stabilized and also measurement precision is improved by the viscosity measuring apparatus 30 having a thermostat bath.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring fluid viscosity in a process, and in a petroleum refining plant, a chemical plant, etc., the viscosity of a fluid flowing through the process continuously or intermittently in the process operating state. Can be used when measuring.

[0002]

BACKGROUND ART In the past, in petroleum refining plants, chemical plants, etc., it has been necessary to appropriately monitor the physical properties of oils and fats and chemical fluids used as materials and products, and the viscosity is a typical physical property. is there.

Various measuring methods are used to measure the viscosity of a fluid flowing through a plant. A sample fluid (measurement target fluid) taken out from the plant is measured by a piston type viscometer or the like in accordance with JIS. Measurements are being made. Here, since the accuracy of the viscosity measurement is greatly affected by the temperature conditions, the sample fluid and the viscometer are housed in a constant temperature bath and the measurement is performed at a constant temperature.

On the other hand, in the plant, it is desirable to be able to constantly monitor the physical properties of the circulating fluid as much as possible. Instead of the measurement by taking out the fluid appropriately, a measuring device is attached to the plant and various measurements are continuously or intermittently performed at regular intervals. Activities (in-process measurement, in-line measurement, etc.) are performed. When performing such an in-process measurement, a sample pipe is connected to a part of the plant, a part of the fluid in the plant is led into the sample pipe, and a predetermined measurement process is performed on the fluid in the sample pipe. Things have been done.

When the above-mentioned viscosity measurement is carried out by such in-process measurement, in order to stabilize the temperature at the time of measurement, the entire sample pipe through which the fluid is introduced from the plant is housed in a constant temperature bath.

[0006]

However, in the above-described in-process viscosity measurement, the sample fluid withdrawal is intermittent depending on the operating conditions of the plant such as intermittent operation, the supply condition of the sample fluid changes, and the measurement accuracy is increased. There is a problem that That is, when the plant performs intermittent operation, the sample fluid has the original temperature during operation, but during stoppage, the temperature is different from the original temperature due to cooling due to natural heat dissipation, etc., and measurement under appropriate conditions is possible. This cannot be done and a measurement error will occur.

Further, when the sample fluid is a highly viscous fluid, its viscosity increases when its temperature decreases, which may cause sticking or blockage of the flow path inside the sample pipe. When such sticking occurs, a measurement error may occur due to the inhibition of sample introduction. Then, when the occlusion occurs, not only cannot the subsequent measurement process be performed,
There is a problem that it requires a considerable amount of time and labor for the restoration.

An object of the present invention is to provide a method and apparatus for measuring fluid viscosity in a process, which has high measurement accuracy even in a plant which is intermittently operated and which can perform stable measurement for a long period of time.

[0009]

According to the present invention, a sample pipe is formed into a loop shape, and while a sample supply from a plant is being obtained, measurement is performed while passing a sample fluid, and when the sample supply is stopped. Aims to circulate the sample fluid in the sample pipe to secure its flow state, thereby preventing sticking or blockage in the sample pipe to achieve the above object.

Specifically, the method of the present invention is an in-process fluid viscosity measuring method for measuring the viscosity of a target fluid flowing in an operating process, and is a circulation flow capable of circulating a fluid formed in a loop shape. A passage and a viscosity measuring instrument interposed in the middle of the circulation passage and housed in a constant temperature bath,
At the time of normal measurement, the target fluid in the process is conducted to the location where the viscosity measuring device is installed in the circulation channel, and the viscosity of the target fluid is measured while maintaining the temperature constant in the constant temperature bath, and During the circulation operation, the process and the circulation flow path are shut off, and the fluid in the circulation flow path is driven to circulate.

During the predetermined circulation operation, the viscosity measuring device is in a non-measurement state, and the pressure of the target fluid introduced from the process is in a state of being below a predetermined value. Characterize.

On the other hand, the apparatus of the present invention is an in-process fluid viscosity measuring apparatus for measuring the viscosity of a target fluid flowing in an operating process, and has a circulation flow path formed in a loop and capable of circulating the fluid. A circulation pump that drives and circulates the fluid in the circulation passage, an introduction passage that introduces the fluid from the process into the circulation passage, an introduction valve that can block the introduction passage, and the circulation A discharge flow path for discharging the fluid in the flow path to the process or the outside, and a viscosity measuring device interposed between the introduction flow path and the discharge flow path of the circulation flow path and accommodated in a constant temperature bath, And a control means for controlling the connection and disconnection of the introduction valve and the viscosity measuring device.

Further, the control means has a pressure sensor which is installed in the introduction flow passage and detects the pressure of the circulating fluid, and the control means is such that the pressure detected by the pressure sensor is not more than a predetermined value and the viscosity measuring device is It is characterized in that it is provided with a circulation control section for executing a switching operation to a predetermined circulation state including closing of the introduction valve when detecting the non-measurement state.

[0014]

In the present invention as described above, during the operation of the process in which the sample supply is obtained, the sample fluid is passed through the circulation channel and the viscosity is measured by the viscometer to obtain the same viscosity as in the normal in-process viscosity measurement. A continuous viscosity measurement is performed.
On the other hand, when the sample supply is stopped such as during the process is stopped, the circulation flow path is switched to the loop state, and the sample fluid introduced immediately before is circulated in the circulation flow path, thereby ensuring the flow state of the sample fluid. However, it prevents sticking or blockage in the circulation channel.

As a result, it is possible to prevent sticking or blockage in the circulation path as in the conventional case even if the process is interrupted, so that it is possible to improve the measurement accuracy and ensure long-term operation stability. Further, by accommodating the circulation channel in the constant temperature bath, the temperature of the sample fluid is stabilized, and the measurement accuracy is further improved, thereby achieving the above object.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a process pipe 1 constitutes a part of a plant (not shown), and a predetermined fluid flows therein. The process is intermittently operated, and the fluid in the process pipe 1 is circulated only during plant operation, and is stopped during plant stop.

The in-process viscosity measuring device 10 is constructed according to the present invention, and is provided with a circulation passage 20 constituted by a loop pipe inside a case 11 installed near the process pipe 1. ing. A circulation pump 21 that drives the fluid in the circulation path 20 is provided in the middle of the circulation passage 20.
And a viscosity measuring device 30 for measuring the viscosity of the fluid in the circulation path 20, and the first and second passage bypasses 22 and 23 so as to connect the suction side and the discharge side of the circulation pump 21. Is installed.

First and second shutoff valves 24 and 25 for shutting off the flow of fluid are installed in the passage bypasses 22. In addition, the circulation passage 20 has a first passage bypass 22 on the suction side of the circulation pump 21.
A similar third shut-off valve 26 is installed between the connecting part and the connecting part of the second bypass 23. Further, the circulation pump 21 has a second passage bypass 23 on the discharge side.
A similar fourth shut-off valve 27 is installed between the connection part of and the viscosity measuring device 30.

An introduction passage 40 for introducing a fluid from the process pipe 1 is connected between the third shut-off valve 26 of the circulation passage 20 and a connection portion of the first passage bypass 22 on the suction side of the circulation pump 21. Has been done. In the middle of the introduction channel 40,
Introducing pump 41 that drives the fluid from process pipe 1 to circulation channel 20, pressure sensor 4 that detects the pressure of the fluid
2. A pressure regulating valve 43 for automatically adjusting the pressure of the fluid to be constant,
An introduction valve 44 that connects and disconnects the fluid flow is installed.

Between the fourth shutoff valve 27 of the circulation passage 20 and the connecting portion of the second passage bypass 23 on the discharge side of the circulation pump 21, a discharge passage 50 for discharging the fluid to the process pipe 1. Are connected. In the middle of the discharge flow path 50, a discharge pump 51 for driving the fluid from the circulation flow path 20 to the process pipe 1, a tank 52 for temporary storage for degassing the fluid, and a discharge valve for intermittently circulating the fluid. 53
Is installed.

A first bypass 61 is installed so as to connect the discharge side of the introduction pump 41 (between the pressure sensor 42) of the introduction passage 40 and the vicinity of the connection portion of the process pipe 1 of the discharge passage 50. There is. Further, the second bypass so as to connect the downstream side of the pressure sensor 42 of the introduction flow path 40 (the portion in the case 11 up to the pressure regulating valve 43) and the vicinity of the discharge flow path 50 connection part of the first bypass 61. 62 is installed. A regulating valve 63 is installed in the middle of the second bypass 62.

The above-mentioned first to fourth shut-off valves 24-2
7, the introduction valve 44, and the discharge valve 53 are pneumatically driven, and the air piping system 7 is used to drive them.
0 is provided. The air piping system 70 is an air supply pipe 71 leading to a pressure air supply source (not shown) outside the case 11.
An air pressure regulating valve 72 that automatically adjusts the air pressure supplied from the air supply pipe 71 to a constant value, and a valve drive pipe 73 that supplies pressure-adjusted air to each valve.

An electromagnetic on-off valve 74 is installed near the air pressure regulating valve 72 of the valve drive pipe 73, and the air pressure supply to the valve drive pipe 73 is intermittently switched by an electric external signal. Further, a pump drive pipe 75 leading to the circulation pump 21 is branched and connected between the air pressure regulating valve 72 and the opening / closing valve 74, and an auxiliary opening / closing valve 76 for connecting / disconnecting the air pressure supply is installed in the middle thereof. Here, the circulation pump 21
Is an air-driven type, and the pump operation is performed by the air supplied from the pump drive pipe 75 while the auxiliary opening / closing valve 76 is open. Further, the auxiliary opening / closing valve 76 is the valve drive pipe 73.
It is designed to be opened and closed by the air pressure from.

When the opening / closing valve 74 is opened and air is supplied to the bubble driving pipe 73, the valves 24, 25, 4
4 and 53 are in a flow open state, and the valves 26 and 27 and the auxiliary on-off valve 76 are in a flow closed state. In this state, the process flow path 1 passes through the introduction flow path 40 and the circulation flow path 2
0, the first passage bypass 22, the circulation pump 21 discharge side of the circulation passage 20, the second passage bypass 23, the viscosity measuring device 30, and the discharge passage 50 to return to the process pipe 1. The passing distribution route (indicated by a solid arrow in the figure) is opened. Further, the circulation pump 21 is stopped.

On the other hand, when the opening / closing valve 74 is closed and the air supply to the bubble driving pipe 73 is stopped, the valves 24, 2
5, 44 and 53 are in a closed flow state, and valves 26 and 2 are
7 and the auxiliary on-off valve 76 are in the state of circulation open. In this state, the introduction flow path 40 and the discharge flow path 50 and the first,
The second bypasses 22 and 23 are blocked, and in the circulation flow path 20, the circulation from the viscosity measuring device 30 passes through the first blocking valve 26, the circulation pump 21 and the second blocking valve 27, and returns to the viscosity measuring device 30. Distribution channel (indicated by chain line arrow in the figure)
Is opened. At this time, the circulation pump 21 is in the operating state, and the fluid is driven to circulate.

As described above, the piping system of the present embodiment can switch between two states of fluid passage and circulation by switching the open / close valve 74 by an electric signal. In, the flow of fluid is always secured.

Next, the viscosity measuring device 30 will be described.
In FIG. 2, the viscosity measuring device 30 is a box-shaped thermostatic chamber 31 filled with a liquid heat medium 311 having a large heat capacity such as water, and is suspended from the top plate and immersed in the heat medium 311 inside. The measuring cell 32, the cooler 33, the heater 34, the stirrer 35, and the viscosity measurement controller 36 that processes the detection signal from the measuring cell 32 and controls the heater 34 and the stirrer 35 are provided.

A sample introduction pipe 321 and a sample discharge pipe 322 from the circulation channel 20 are connected to the measurement cell 32 so that the sample fluid circulating in the circulation path 20 is introduced. A heat exchanger 323 immersed in the heat medium 311 in the constant temperature bath 31 is provided in the middle of the sample introduction pipe 321.
Is installed so that the sample fluid introduced into the measurement cell 32 can be adjusted to a constant temperature in advance. A viscosity sensor 324 that measures the viscosity and temperature of the introduced sample fluid is installed in the measurement cell 32, and the measured viscosity signal 325 and temperature signal 326 are connected to a viscosity measurement controller 36.

The cooler 33 is a heating medium 311 in the constant temperature bath 31.
Is a heat exchanger immersed in, and a refrigerant pipe 332 for circulating a refrigerant such as water from the outside is connected to the cooler 31,
The refrigerant pipe 332 is provided with an adjusting valve 333 that adjusts the flow of the internal refrigerant so that the heat medium 311 is appropriately cooled and its temperature is not raised more than necessary.

The heater 34 is an electrothermal type, and generates heat by electric power 341 supplied from the viscosity measuring controller 36. The heater 34 includes a first and a second temperature sensor 34.
2, 343 are installed and temperature signals 344, 3 from each
Each of 45 is connected to the viscosity measurement controller 36.

The stirrer 35 is of a type using a propeller 352 which is rotationally driven by a motor 351.
Is driven by electric power 353 from the viscosity measurement controller 36.

The viscosity measuring controller 36 includes a first temperature control section 361, a second temperature control section 362 and a third temperature control section 3.
63, first relay 364, second relay 365, switching element 366, viscosity signal processing unit 367, central control unit 3
Equipped with 68. Electric power is supplied to the second relay 365 from an external power source (not shown), and part of the electric power from the second relay 365 is electric power 353 to the motor 351 of the agitator 35.
Used as. The other part is used as electric power 341 for heating the heater 34 via the switching element 366 and the first relay 364.

The first temperature control section 361 monitors the temperature signal 344 from the first temperature sensor 342 of the heater 34, judges that the heater 34 is overheated when the value exceeds a certain value, and The relay 364 is cut off and the power supply to the heater 34 is stopped. This first relay 364
The contact state of the central controller 368 is determined by the contact signal 3641.
Will be notified. The second temperature control unit 362 monitors the temperature signal 345 from the second temperature sensor 343 of the heater 34,
When the value reaches a constant value, a contact signal 3621 is output to notify the central controller 368.

The third temperature control section 363 monitors the temperature signal 326 from the viscosity sensor 324 of the measuring cell 32, controls the switching element 366 in response to the increase and decrease of the value, and supplies the temperature signal to the heater 34. Adjust the electric power to control the constant temperature bath 3
The temperature in 1 is kept constant. The temperature signal 326 is sent to the central controller 36 via the third temperature controller 363.
8 have been transmitted. The viscosity signal processing unit 367 performs a predetermined process on the viscosity signal 325 from the viscosity sensor 343 of the measuring cell 32 and transmits it to the central control unit 368.

The central controller 368 is a main controller 8 which will be described later.
1 based on the measurement command signal 811 from the viscosity signal 32
5. The temperature signal 326 is processed and the temperature-corrected viscosity value is calculated and returned as the measurement result signal 812. The second relay 365 is connected and disconnected by the power connection / disconnection signal 813 from the main control unit 81.

The on-off valve 74 and the viscosity measuring device 30 described above
In order to control the above, the in-process viscosity measuring apparatus 10 of the present embodiment has a main control unit 81, a switching control unit 82, and an operation unit 8.
Equipped with 3. The main control unit 81 sends signals 811, 8 to the viscosity measuring device 30 based on the input operation from the operation unit 83.
13 is output, and the measurement result is displayed on the operation unit 83 based on the measurement result signal 812. Also, since the process is stopped, the viscosity measuring device 3
When 0 is set in the standby state, a viscosity measuring instrument standby signal 814 is output to the switching control unit 82, and the switching operation by the opening / closing valve 74 described above is executed as necessary.

The switching control unit 82 receives the viscosity measuring instrument standby signal 814 from the main control unit 81 and the pressure signal 821 from the pressure sensor 42 of the introduction flow path 40, both of which are turned on. Output the switching signal 822 in the state of (the state where the pressure is lowered in the standby state),
The on-off valve 74 is switched to perform the circulation operation.

In FIG. 3, the viscosity measuring instrument standby signal 814 is turned on as the process is stopped, and after a lapse of time T1 from the process stop, the amount of fluid introduced into the introduction channel 40 decreases and the pressure in the introduction channel 40 decreases. Also decreases. Then, the pressure signal 821 is turned on, and the switching signal 82 is turned on at this point.
2 turns on. On the other hand, the operation of the process is restarted, the viscosity measuring instrument standby signal 814 is turned off, and after a lapse of time T2 from the restart of the process operation, the amount of fluid introduced into the introduction passage 40 increases and the pressure of the introduction passage 40 also rises. . Then,
The pressure signal 821 turns off. At this time, the switching signal 822 is turned off when the viscosity measuring instrument standby signal 814 is turned off, the circulation is released, and the normal measurement state (passing operation) is restored.

According to the present embodiment as described above, during the operation of the process in which the sample supply is obtained, the sample fluid from the process pipe 1 is introduced into the introduction passage 40, a part of the circulation passage 20 and the discharge passage 50. When the viscosity is measured by the viscosity measuring device 30, the continuous viscosity measurement similar to the normal in-process viscosity measurement can be performed. On the other hand, when the sample supply is stopped, for example, while the process is stopped, the introduction channel 40
Also, the discharge flow path 50 is shut off, the circulation flow path 20 is switched to a loop state, and the sample fluid introduced immediately before is circulated in the circulation flow path 20, thereby ensuring the flow state of the sample fluid, and the circulation flow path. It is possible to prevent the sample fluid from sticking or clogging due to cooling in 20. Therefore, even if the process is interrupted, the conventional circulation path 20
Since sticking or blockage inside can be prevented, improvement of measurement accuracy and long-term operation stability can be ensured.

Further, in this embodiment, the introduction flow path 40
Since the pumps 41 and 51 are provided in the discharge passage 50,
The sample fluid can be smoothly introduced or discharged from the sample pipe 1 to the circulation channel 20. Further, by providing the bypasses 61 and 62 from the discharge side of the pump 41 of the introduction flow path 40 to the discharge flow path 50 and by providing the pressure regulating valve 43, excessive supply to the circulation flow path 20 can be avoided in advance. And the sample fluid supply can be done properly. Even in this case, since the pressure sensor 42 is on the upstream side of the pressure regulating valve 43, reliable pressure detection can be performed.

Further, by the first passage bypass 22,
When the sample fluid passes, the circulation pump 21 can be bypassed, the useless operation overlapping with the introduction pump 41 can be eliminated, and unnecessary resistance can be prevented even when the circulation pump 21 is stopped. Further, since the direction of the sample fluid passing through the viscosity measuring device 30 is reversed between the passage (measurement) and the circulation by the second passage bypass 23, the flow path of the viscosity measuring device 30 due to the back flow is changed. It can be cleaned.

Each valve 24 for switching the flow path
Since the operations of 27, 44, and 53 can be collectively performed by the air piping system 70, the control is easy, and the circulation pump 21 is an air-driven type, and the intermittent operation (stopping when passing) can be collectively performed. Therefore, waste of power can be eliminated, and control including this interruption can be easily performed. Further, switching between circulation and passage is performed by performing circulation when the pressure drop in the introduction flow channel 40 and the stoppage of the viscosity measuring device 30 are both compatible, so as to prevent obstruction of necessary measurement, blockage, etc. It is possible to realize sufficient circulation operation to prevent the above.

Further, in this embodiment, the circulation channel 20
The temperature of the sample fluid can be stabilized by accommodating the sample in the constant temperature bath 31 and controlling the temperature with the cooler 33, the heater 34, the general devices 35, and the viscosity measurement controller 36.
The accuracy of viscosity measurement can be further improved.

The present invention is not limited to the above-mentioned embodiments, and modifications and the like within the range in which the object of the present invention can be achieved are included in the present invention. That is, the dimensions of each pipe, the connection form, the arrangement of valves and the like may be changed as appropriate, and each bypass and the like may be omitted or changed. For example, when passing, the sample fluid from the introduction flow channel 40 is directly downward in FIG. To the discharge flow path 5 through the viscosity measuring device 30.
It may reach 0.

Further, the control system may be designed appropriately, and the required control may be realized by utilizing the existing sensor technology and microcomputer technology. Further, the present invention can be applied to a petroleum refining plant or a chemical plant, as well as a fluid treatment part of a food manufacturing factory or a machine manufacturing factory.

[0046]

As described above, according to the present invention,
Normally, viscosity measurement is performed while passing sample fluid through, and continuous viscosity measurement can be performed, and blockage can be prevented by circulating the sample fluid in a loop-shaped circulation channel when the process is stopped. Therefore, the measurement accuracy can be improved together with the temperature stabilization by the constant temperature bath.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing details of a part of the embodiment.

FIG. 3 is a timing chart showing the circulation operation of the embodiment.

[Explanation of symbols]

1 Process Piping 10 In-Process Viscosity Measuring Device 20 Circulating Flow Path 21 Circulating Pumps 22 and 23 Passing Bypass 24 to 27, 44, 53 Valve for Switching between Passing and Circulating 30 Viscosity Measuring Instrument 31 Constant Temperature Bath 32 Measuring Cell 40 Introducing Passage 41 Introducing pump 42 Pressure sensor 50 Discharging flow path 51 Discharging pump 70 Air piping system 74 Opening / closing valve 81 Main controller 82 Switching controller

Claims (4)

[Claims] 1. An in-process fluid viscosity measuring method for measuring the viscosity of a target fluid flowing through an operating process, comprising: a circulation flow path formed in a loop and capable of circulating the fluid; A viscosity measuring instrument interposed in the middle and housed in a constant temperature bath is installed in advance, and at the time of normal measurement, the target fluid in the process is conducted to the installation location of the viscosity measuring instrument of the circulation flow path. The viscosity of the target fluid is measured while maintaining a constant temperature in a constant temperature bath, and during a predetermined circulation operation, the process and the circulation flow path are shut off and the fluid in the circulation flow path is driven to circulate. A method for measuring fluid viscosity in a process, comprising: 2. The in-process fluid viscosity measuring method according to claim 1, wherein during the predetermined circulation operation, the viscosity measuring device is in a non-measurement state, and the pressure of the target fluid introduced from the process is A method for measuring fluid viscosity in a process, characterized in that it is in a state of being below a predetermined level. 3. An in-process fluid viscosity measuring device for measuring the viscosity of a target fluid flowing through an operating process, comprising: a circulation flow path formed in a loop and capable of circulating the fluid; A circulation pump that drives and circulates the fluid, an introduction passage that introduces the fluid from the process into the circulation passage, and an introduction valve that can block the introduction passage,
A discharge flow passage for discharging the fluid in the circulation flow passage to the process or the outside, and a viscosity measuring device interposed between the introduction flow passage and the discharge flow passage of the circulation flow passage and accommodated in a constant temperature bath. And an in-process fluid viscosity measuring device comprising: a control means for controlling the connection and disconnection of the introduction valve and the viscosity measuring device. 4. The in-process fluid viscosity measuring device according to claim 3, further comprising a pressure sensor that is installed in the introduction flow passage and detects the pressure of the circulating fluid, and the control means is detected by the pressure sensor. And a circulation control unit that executes a switching operation to a predetermined circulation state including closing of the introduction valve when it is detected that the pressure is below a predetermined value and the viscosity measuring device is in a non-measurement state. An in-process fluid viscosity measuring device characterized by: