JPS61134643A - Viscometer for automatic viscosity measuring instrument - Google Patents

Abstract

PURPOSE:To prevent air bubbles from penetrating a capillary tube by placing an air tube in a position on the vertical line of a sampling hole branching the capillary tube from the air tube with a lower sample storing bulb as the branch point. CONSTITUTION:An air tube 1 is placed in a position on the vertical line of a sampling hole 4, and a capillary tube 2 is branched from the air tube 1 in the part of a lower sample storing bulb 3. The sampling hole 4 of this vertically fixed viscometer is immersed in a sample in a vessel so that the sample is sucked easily from below. Next, the air tube 1 is closed, and the sample is sucked to the middle of an upper sample storing bulb 5 through the capillary tube 2 by pressure reduction. Then, the vessel where the sample is stored is removed from the sampling hole 4, and the viscometer is left still for a prescribed time. Air may penetrate the viscometer from the sampling hole 4 while it is left still, and air bubbles of penetrated air are floated vertically and are joined to air in the air tube 1 and do not penetrate the branched capillary tube 2. Thus, an accurate kinematic viscosity is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a viscometer for an automatic viscosity measuring device in a kinematic viscosity testing method for crude oil and petroleum products.

(Prior art) As shown in Fig. 2, in a conventional viscometer for an automatic viscosity measuring device, a capillary tube 2 has a vertical trunk shape, and a vent tube 1 branching from a lower sample reservoir bulb 3 has a branch shape. It was composed of The kinematic viscosity of crude oil and petroleum products was measured using this glass capillary viscometer (hereinafter referred to as a viscometer) as follows. That is, the sample collection port 4 is immersed in the sample, the ventilation tube 1 is closed with a valve (electromagnetic valve), the sample is sucked from the capillary tube 2 to the middle of the upper sample reservoir bulb 5 with a vacuum aspirator, and the capillary tube 2 is closed with the valve. Obstruction. After the standing time (approximately 10 minutes when measuring at 40°C, approximately 15 minutes when measuring at 100°C), hair? Open the valves of Z 2 and vent pipe 1 to bring the pressure inside the pipe to atmospheric pressure, and allow the sample to flow down naturally. The time taken for the meniscus of the sample to pass from the upper sub-time mark 6 to the lower sub-time mark 7 is electrically measured.

The passage of the sample meniscus between the sub-time markers and the measurement of its flow time are carried out by detecting the passage of the sample meniscus with a liquid level detector installed at the upper sub-time marker 6, and using the electricity emitted there. The signal starts the auto-timer,
When the passage of the sample meniscus is detected by a similar liquid level detector installed at the lower temperature time mark 7, the automatic timer is stopped by the electric signal generated there, and the sample flow time is automatically measured. Ru. Upon completion of the measurement, cleaning of the viscometer automatically begins, followed by drying.

(Problems to be Solved by the Invention) When using a conventional viscometer, if air bubbles enter from the sample collection port during the standing time, the entered air bubbles enter the capillary side.
The sample stays at the top of the secondary sphere, and after a period of standing, the sample reaches a gravity flow process, resulting in a sample that is smaller in volume than the actual sample volume to be measured by the bubble volume. Therefore, the flow time between the sub-time markers becomes shorter, exposing defects that indicate a lower value than the actual viscosity of the sample.

The present invention solves the above-mentioned problems of conventional viscometers, and even if air bubbles enter the sample sampling port, they can be easily guided to the ventilation pipe and separated from the sample, and they can be moved accurately. An object of the present invention is to provide a viscometer capable of measuring viscosity.

(Means for Solving the Problem) In order to achieve this object, the present invention has the following configuration. In other words, the viscometer according to the present invention focuses on the fact that when air bubbles enter through the sample sampling port, the bubbles always float vertically inside the viscometer. By using the bulb as a branching point and making the capillary tube branch-like, it prevents air bubbles from entering the capillary tube.

(effect)
] The operation of the viscometer according to the present invention will be explained with reference to FIG.

At sample sampling port 4 of the viscometer fixed vertically in a thermostatic bath,
Dip a container containing a sample of crude oil or petroleum products in such a way that it is easy to aspirate the sample from below.

Then, the ventilation tube 1 is closed, and the sample is sucked through the capillary tube 2 under reduced pressure to the middle of the upper sample reservoir bulb 5, and the capillary tube 2 is closed.

At this point, the container containing the sample is released from the sample collection port 4, and left standing for a predetermined time so that the entire sample reaches a predetermined temperature uniformly.

The sample in the viscometer is balanced by the reduced pressure air above the middle part of the upper sample holding bulb 5, that is, between the sample meniscus and the valve, thereby preventing the sample from flowing down naturally.

For example, during this standing time, air may enter the viscometer through the sample sampling port 4, and this intruding air forms relatively large bubbles that float vertically through the sample. Even if the bubbles reach the branching point between the capillary tube 2 and the ventilation tube 1, that is, the lower sample reservoir bulb 3, the bubbles will always float above the sample bone vertically upward, even if there are slight changes in the internal diameter and internal structure of the viscometer. Continue to do so.

Since the viscometer according to the present invention has a structure in which the aerator tube 1 is positioned vertically above the sample collection port 4, the bubbles caused by the intruding air float vertically and become integrated with the air inside the aerator tube 1. , and does not enter the capillary tube 2 which is divided into branches. The lower sample reservoir bulb 3 is shaped to guide floating bubbles to the ventilation tube 1, and acts to prevent them from flowing toward the capillary tube 2 side.

(Example) FIG. 1 is a diagram showing an embodiment of the present invention.

In FIG. 1, the vent pipe 1 is located at a position perpendicular to the sample collection port 4, and the capillary tube 2 is located at a position branching from the lower sample reservoir bulb 3.

Air bubbles that entered through the sample collection port 4 during the standing period floated to the surface.
The sample is naturally guided to the ventilation pipe 1 by the three lower sample reservoir bulbs.

Next, three types of lubricating oil samples with different kinematic viscosities were measured at 100°C using a viscometer according to the present invention, a conventional viscometer for automatic viscosity measuring devices, and a manual Ubbelohde viscometer specified in JIS 2283. Examples and comparative examples in which kinematic viscosity was measured are shown in Table 1.

As a result of comparing the measured values in Table 1, the measured values of the product of the present invention and the manual Ubbelohde type are almost the same. The measured values of the conventional product also match those of the manual Ubbelohde type, but this excludes the measured values when air enters the sample, and this viscometer is for automatic measuring devices. Therefore, there is a risk that abnormal values will be reported as they are, and it is difficult to say that they are consistent.

(Effects of the Invention) As explained above, according to the viscometer of the present invention, air bubbles are generated from the sample sampling port during the two static periods for sucking crude oil and petroleum product samples into the viscometer and bringing them to a predetermined temperature. Even if the air bubbles enter the measuring capillaries, they do not enter the branched measuring capillaries, but instead float to the vertical ventilation pipes, which has the effect that anyone can accurately measure viscosity.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a viscometer according to the present invention, and FIG. 2 is a diagram showing a conventional viscometer. In the figure, 1 is a ventilation tube, 2 is a capillary tube, 3 is a lower sample reservoir bulb, 4 is a sample collection port, 5 is an upper sample reservoir bulb, 6 is an upper time mark line,
7 is the lower time mark line, and 8 is the secondary time sphere. (1 other person) Figure 1 Figure 2

Claims (1)

[Claims] 1. In a method for measuring the kinematic viscosity of crude oil and petroleum products using a glass capillary viscometer, the vent tube 1 is a vertical trunk, and the capillary tube 2 is branched from a lower sample reservoir bulb 3. Viscometer for automatic viscosity measurement equipment.