JP3224336B2 - Pour point measuring method and measuring device - Google Patents

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 a pour point of a sample of a petroleum product such as crude oil, light oil, lubricating oil and the like.

[0002]

2. Description of the Related Art A pour point test is a quality control item of petroleum products such as crude oil, light oil, lubricating oil and the like. According to JIS K-2269, "a pour point is the lowest temperature at which a sample flows when cooled without stirring by a specified method."
It is defined as For the device that automatically measures the pour point, a rotary type that detects the freezing point, that is, the pour point in the rotating state of the torque detection sensor placed in the sample, a tilt type that automates the JIS measurement method, or a pressurized type In general, a differential pressure type pour point measuring device for detecting a fluctuation of a sample measurement surface in the above is used.

[0003]

However, since the pour point must detect a delicate crystal change of the sample, any of the conventional pour point measuring apparatuses has a complicated structure and is difficult to operate. In addition, there is a problem that maintenance is troublesome.

[0004] Further, the conventional differential pressure type pour point measuring apparatus has a problem that it is difficult to capture the fluctuation of the sample surface during pressurization, and it is difficult to accurately measure the pour point.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to easily and accurately measure a pour point of a sample of a petroleum product such as a crude oil, a light oil, a lubricating oil and the like, and furthermore, a small amount of the sample It is an object of the present invention to provide a method and an apparatus for measuring a pour point, which make it possible to reduce the size of the apparatus and facilitate the cleaning of the apparatus.

[0006]

In order to achieve the above object, a method of measuring a pour point according to claim 1 includes the steps of: changing a sample temperature by a constant unit temperature; A gas at a constant pressure is supplied to the sample, and the change in the sample surface at this time is measured.If there is no change in the sample surface, the change in the gas pressure supplied to the sample is measured. If not, this temperature is determined as the pour point of the sample.

According to this method, even when a change in the sample surface during pressurization cannot be detected, the measurement is further performed based on a change in the gas pressure supplied to the sample. The pour point can be measured more accurately than when the pour point is measured only by the change in the surface.

According to a second aspect of the present invention, there is provided a method for measuring a pour point, wherein the temperature of a sample is changed by a constant unit temperature, and a gas having a constant pressure is supplied into the sample having the fixed unit temperature changed. The change in the surface is measured, and when there is no change in the sample surface, the change in the gas pressure supplied into the sample is measured, and when there is no change in the gas pressure, this pressurized state is maintained for a predetermined time. Changes in the sample surface and / or
Alternatively, a change in gas pressure is measured, and when the sample surface and / or gas pressure has not changed, this temperature is determined as the pour point of the sample.

According to this method, even if it is possible to determine that the pressure of the gas supplied into the sample has not changed and the sample has stopped flowing, the measurement is thereafter performed while maintaining the pressurized state of the sample for a certain period of time. I am going to do it. As a result, even if the sample responds very slowly to the pressure, the change can be reliably detected, and the pour point can be measured more accurately.

According to a third aspect of the present invention, there is provided a pour point measuring device for storing a sample, a temperature controller for cooling and heating the sample in the storage portion, and a thermometer for measuring the temperature of the sample in the storage portion. A pressurizing pipe for supplying gas into the sample in the reservoir, a pressure gauge for detecting a change in the pressure of the gas supplied to the pressurizing pipe, and detecting a change in the sample surface when gas is supplied to the pressurizing pipe. And a controller that automatically determines the pour point of the sample based on the detection results of the sensor and the pressure gauge.

In an apparatus having such a configuration,
The sample is stored in the storage unit, and a gas at a constant pressure is supplied to the sample through a pressurizing tube while changing the sample temperature by a constant unit temperature by a temperature controller.First, a change in the sample surface at this time is detected by a sensor. Detect and measure the pour point.

If a change in the sample surface is detected, the temperature of the sample is changed by a certain unit temperature by a signal to the temperature controller, and the change in the sample surface is detected again. on the other hand,
If the change on the sample surface is not detected, the change in gas pressure in the pressurizing tube is measured based on the detection result of the pressure gauge. Then, the temperature at which the gas pressure stops changing is measured as the pour point of the sample.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a pour point measuring method and apparatus according to an embodiment of the present invention. First, an embodiment of the pour point measuring device of the present invention will be described. FIG. 1 is a sectional view showing a pour point measuring device according to the present embodiment.

In FIG. 1, reference numeral 1 denotes a main body of the measuring apparatus, which has a lid 2 which can be opened and closed at the top. For the main body 1 and the lid 2, it is preferable to use aluminum, copper, or the like that has good heat conduction and is resistant to corrosion. An inverted conical sample storage section 3 is formed at substantially the center of the inside of the main body 1, and the bottom of the storage section 3 is connected to a sample supply pipe 4 via a communication passage 3 a.

When the storage section 3 is formed in an inverted conical shape, dirt is easily removed during washing, which helps to prevent dirt. Also,
A groove 5 is formed on the outer periphery of the storage section 3 of the main body 1, and the groove 5 communicates with the discharge pipe 6.

A temperature controller 7 is provided around the main body 1. This temperature controller 7 has an electronic temperature controller 7a and a cool jacket 7b. Among them, the electronic temperature controller 7a
It utilizes the thermoelectric phenomenon of a Peltier effect element in which a p-type semiconductor and an n-type semiconductor are joined by a metal, and generates heat by changing the direction of a current flowing through the Peltier effect element based on a signal from the control unit 16. The sample is heated and cooled. On the other hand, a coolant is circulated and supplied to the cool jacket 7b from a coolant tank (not shown).

The temperature controller 7 includes a cool jacket 7
A relatively powerful cooling is carried out by flowing a coolant from a coolant tank (not shown) to b, and a delicate temperature control of the sample at a low temperature is performed by the electronic temperature controller 7a.

The lid 2 is provided with an optical sensor 8 comprising a light emitting section 8a and a light receiving section 8b. The light sensor 8 receives the reflected light of the light emitted from the light emitting unit 8a toward the sample surface of the storage unit 3 at the light receiving unit 8b. When the surface of the sample swells, the light emitted from the light emitting unit 8a is irregularly reflected, so that the amount of light received by the light receiving unit 8b is reduced as compared with the case where the sample surface is flat. As a result, the optical sensor 8 detects a change in the surface of the sample, and outputs a detection result to the control unit 16.

Reference numeral 10 denotes a pressurizing tube, which is disposed so as to penetrate the lid 2 so that its tip is immersed in the sample in the storage unit 3.
A communication pipe 11 is connected to the rear end of the pressure pipe 10,
The other side of the communication pipe 11 is bifurcated, one of which is connected to the syringe 12 and the other is open to the atmosphere via a valve 13. The syringe 12 is a stepping motor 12
It has a piston 12b which moves forward and backward by a.

A thermometer 14 for measuring a pour point (measuring the temperature of a sample) is provided at the center of the pressurizing tube 10, and a measuring section 14 a is immersed in the sample in the storage section 3.
As the thermometer 14 for measuring the pour point, for example, a thermocouple is used.

Further, a pressure gauge 15 is attached to an intermediate portion of the communication pipe 11. The pressure gauge 15 is connected to the pressure pipe 10
And outputs the detection result to the control unit 16.

The control section 16 comprises an optical sensor 8, a thermometer 1
4 and a signal for controlling the operation of the temperature controller 7, the optical sensor 8, the stepping motor 12a for the syringe 12, and the valve 13 based on various setting information and measurement information. Output,
In addition, the pour point is measured by performing various measurements and processes. The controller 16 can also display or print out the temperature data, the received light amount data, the received light amount difference data, the pressure in the pressurized pipe, and the like using a display or a printer.

According to the pour point measuring device having such a configuration, the configuration of the entire device becomes compact,
Since only a small amount of sample needs to be used, temperature control becomes easy,
In addition, the temperature controller 7 may be small, easy to handle and maintain, and excellent in portability.

The pour point measuring device of the present invention is not limited to the above embodiment. For example, various actuators other than a stepping motor are used as driving means for operating the piston 12b of the syringe 12, an electric or pneumatic sensor or a camera is used to observe the surface of the sample, and further, As a sample thermometer, a surface thermometer separately mounted from the pressure tube 10 can be used.

Next, an embodiment of the pour point measuring method of the present invention performed by using the above apparatus will be described. 2A and 2B are explanatory diagrams of the pour point measuring method according to the first embodiment. FIG. 2A shows a state where the sample surface is flat, and FIG. 2B shows a state where the sample surface is swollen. FIG. 3 is a flowchart showing a procedure in the present method.

1) First, a sample whose pour point is to be measured is supplied to the storage section 3 inside the apparatus via the sample supply pipe 4. At this time, the sample is supplied in a large amount so as to overflow from the storage unit 3 to keep the sample level constant, so that the lower end position of the pressurizing tube 10 in the sample is always constant. The overflowed sample is discharged through the groove 5 and the discharge pipe 6.

2) Next, the temperature controller 7 is operated to cool the sample in the storage section 3 to near the expected pour point. After that, the temperature controller 7 cools the sample at every fixed unit temperature (2.5 ° C. or 1.0 ° C.), and the thermometer 14 measures the sample temperature at this time and outputs it to the control unit 16 (S1). . In addition,
In a specific example described later, the unit temperature is set to 1.0 ° C.

3) When the control unit 16 confirms that the sample has been cooled at a predetermined unit temperature, it outputs a signal to the stepping motor 12a to move the piston 12b to the A position as shown in FIGS. To adjust the air in the syringe 12 to a constant amount. Next, as shown in FIG. 2B, a closing signal of the valve 13 is output to close the valve 13, and a signal is output to the stepping motor 12a to move the piston 12b of the syringe 12 to the position B. A fixed amount of air is supplied to the pressure tube 10. As a result, a constant pressure is applied to the sample in the storage unit 3 (S
2).

Here, the pressure applied to the sample is 30 × 10
^-3 to 40 × 10 ⁻³ Kg / cm ² is preferable. Note that in a specific example described later, it is about 30 × 10 ⁻³ Kg / cm ² . If the pressure applied to the sample is smaller than the above range, accurate measurement cannot be performed because the pressure is too weak, and if the pressure is larger than the above range, accurate measurement may not be performed due to a hole in the sample. is there. It is preferable that the supply of air to the pressurizing tube 10 be performed slowly so as not to break delicate crystals of the sample.

4) Next, the control section 16 sends an operation signal to the optical sensor 8 to start measuring the sample surface in the storage section 3 (S3). At this time, if the sample does not have fluidity, FIG.
As shown in FIG. 2A, the light from the light emitting portion 8a is regularly reflected while maintaining the flatness of the sample surface, and when the sample has fluidity, the sample surface swells as shown in FIG. 2B. Since the light from the light emitting unit 8a is irregularly reflected, the amount of light received by the light receiving unit 8b differs. The control unit 16 inputs the amount of received light measured by the optical sensor 8 and compares it with the amount of received light of the optical sensor 8 which has been measured before the sample is pressurized. Determine the presence or absence. That is, it is determined that there is no change if the received light amount is equal to the amount of received light before pressurization, and that there is a change if the amount of received light is smaller than the amount of received light before pressurization.

5) As a result, when a change is recognized on the sample surface, it is determined that the sample has fluidity, and the measurement is once stopped. That is, when it is determined that the sample has not reached the pour point, the control unit 16 opens the valve 13 to release the pressure in the pressurizing tube 10 (S4), and sets the inside of the syringe 12 to normal pressure and the stepping motor. At 12a, the piston 12b is retracted to the position A to suck air into the syringe 12, and the apparatus is ready for the next measurement (S1). On the other hand, when no change is observed on the sample surface, the internal pressure of the pressure tube 10 detected by the pressure gauge 15 is compared with a specified value (the pressure applied to the sample) (S5).

6) As a result, when the internal pressure of the pressure tube 10 is smaller than the specified value, it is determined that the sample has fluidity. Then, similarly to the case where a change is recognized on the sample surface, the measurement is once terminated, and the state is prepared for the next measurement (S1). On the other hand, when the internal pressure of the pressurizing tube 10 is equal to the specified value, the pressurized state of the sample at this time is maintained for a certain time (about 5 seconds) (S6).

7) The surface of the sample for a certain time (about 5 seconds) and / or
Alternatively, a change in the internal pressure of the pressure tube 10 is measured (S7).
In a specific example described later, a change in the internal pressure of the pressure tube 10 is measured.

8) As a result, when there is a change in the surface of the sample and / or the internal pressure of the pressurizing tube 10, it is determined that the sample has fluidity, and the measurement is terminated once, and the next measurement (S1)
In a state prepared for. On the other hand, when there is no change in the surface of the sample and / or the internal pressure of the pressurizing tube 10, the sample temperature measured by the thermometer 14 at this time is determined as the pour point of the sample (S8). This ends the measurement.

9) When the measurement is completed, the control unit 16 heats the sample by the temperature controller 7 so as to have fluidity, closes the valve 13 and operates the aspirator to store the sample in the storage unit 3 and the storage unit 3. The sample is discharged from the sample supply pipe 4. Next, the valve 13 is opened, and the cleaning liquid is supplied from the inlet of the tube connected to the open side of the valve 13 to wash and discharge the sample at the lower end of the pressure tube 10.

10) Thereafter, the cleaning liquid is supplied from the sample supply pipe 4 while the valve 13 is closed or the inlet of the pipe connected to the open side of the valve 13 is closed with a finger or the like. 4, storage unit 3 and measuring unit 1 of thermometer 14
4a and the like are washed. Thereafter, the cleaning liquid is discharged and drying is performed. This allows pour point measurement of another sample.

According to the pour point measuring method having such a procedure, even when the change in the sample surface during pressurization cannot be detected by the optical sensor 8, the measurement is further performed based on the change in the internal pressure of the pressurizing tube 10. Since the pour point is measured, the pour point can be measured more accurately than when the pour point is measured only by the change of the sample surface during pressurization.

Even when the internal pressure of the pressurizing tube 10 is equal to the specified value, the measurement is performed while maintaining the pressurized state of the sample for a certain period of time.
Even for a sample that responds very slowly to pressure, the change can be reliably detected, and the pour point can be measured more accurately.

[0039]

EXAMPLES The pour points of several kinds of petroleum products were measured by the pour point measuring method of the above embodiment, and the following results were obtained. The unit temperature was 1.0 ° C. and the pressure applied to the sample was about 30 × 10 ⁻³ Kg / cm ² . Sample name Invention JIS method ─────────────────────── Fuel oil A (light oil) + 8 ℃ + 8 ℃ ───────────燃料 Fuel oil B (LGO) -4 ℃ -3 ℃ ─────────────────────── Fuel oil C (HGO) + 26 ℃ + 27 ℃ 潤滑 Lubricating oil -19 ℃ -17 ℃ ──────────── ─────────── As a result, it became clear that the pour point was measured very accurately, in accordance with the JIS method.

The pour point measuring method of the present invention is not limited to the method of the above embodiment. For example, when the gas at a certain pressure is supplied into the sample as the second embodiment and the internal pressure of the pressurizing tube 10 does not change, the temperature at that time is determined as the pour point of the sample, and the measurement is terminated. It is good also as making it do. According to this method, it is possible to efficiently measure the pour point while ensuring a certain degree of accuracy.

[0041]

As described above, according to the pour point measuring method of the present invention, the pour points of petroleum products such as crude oil, light oil and lubricating oil can be easily and accurately measured by a simple procedure. Further, according to the pour point measuring apparatus of the present invention, the above method can be easily performed, and the pour point measurement can be automated. Further, since the measurement can be performed with a small amount of sample, the size of the apparatus can be reduced, and the apparatus can be easily cleaned.

[Brief description of the drawings]

FIG. 1 is a view showing a pour point measuring device according to an embodiment of the present invention.

FIGS. 2A and 2B are explanatory diagrams of a pour point measuring method according to an embodiment of the present invention. FIG. 2A shows a state where the sample surface is flat, and FIG. 2B shows a state where the sample surface is swollen. Show.

FIG. 3 is a flowchart showing a procedure in the pour point measuring method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Lid 3 Storage part 4 Sample supply pipe 5 Groove 6 Discharge pipe 7 Temperature controller 8 Optical sensor 8a Light emitting part 8b Light receiving part 10 Pressurizing pipe 11 Communication pipe 12 Syringe 12a Stepping motor 12b Piston 13 Valve 14 Thermometer 14a Measurement Unit 15 Pressure gauge 16 Control unit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01N 25/04

Claims (3)

(57) [Claims] 1. A method in which a sample temperature is changed by a constant unit temperature, a gas at a constant pressure is supplied into the sample having the fixed unit temperature changed, and a change in the sample surface at this time is measured. A method for measuring a pour point, comprising: measuring a change in the gas pressure supplied to the sample when there is no change in the sample; and determining the temperature as the pour point of the sample when the gas pressure does not change. 2. The method according to claim 1, further comprising: changing the sample temperature by a constant unit temperature, supplying a gas having a constant pressure into the sample having the constant unit temperature changed, and measuring a change in the sample surface at this time. When there is no change in the pressure, the change in the gas pressure supplied into the sample is measured, and when there is no change in the gas pressure, this pressurized state is maintained for a predetermined time, during which the change in the sample surface and / or the gas pressure Is measured, and when the sample surface and / or gas pressure is not changed,
A method for measuring a pour point, comprising determining the temperature as a pour point of a sample. 3. A storage section for storing a sample, a temperature controller for cooling and heating the sample in the storage section, a thermometer for measuring a temperature of the sample in the storage section, and a gas in the sample in the storage section. A pressure gauge for detecting a change in the pressure of the gas supplied to the pressure pipe, a sensor for detecting a change in the surface of the sample when gas is supplied to the pressure pipe, the sensor and the pressure gauge And a control unit for automatically determining a pour point of the sample based on the detection result of the pour point.