JPS6091233A - Sample feeding method to ph meter - Google Patents

Abstract

PURPOSE:To make pH measurement accurate and easy, by supplying a sample including an insoluble material with high temperature into an insoluble material removing tank, and supplying the sample to a pH meter under the cooled state. CONSTITUTION:A partitioning plate 6 is provided between two partitioning plates 4 and 5 in a removable lid 7, and an insoluble-material removing tank 3 is constituted. A sample, which is cooled to some extent, is supplied to the tank 3 through a sample cooling pipe 1. The insoluble material floating in the tank 3 is made to overflow and is removed through a line 8. The sample is supplied to a pH meter 10 through a line 9. Thus the maintenance of the apparatus is made easy.

Description

[Detailed Description of the Invention] In various chemical plants, it is necessary to strictly manage and control the β (in reactors, distillation columns, cleaning towers, etc., as well as inside the piping) to improve production efficiency or ensure safe operation. pT (pT) has also greatly improved in terms of accuracy and ease of operation, making a great contribution to the normal operation of chemical plants. There are a wide variety of types.For example, samples containing high temperature and insoluble substances are also measured using an ordinary meter.For uniform operation, it is necessary to It is not a good idea to adopt one type of meter depending on the nature of the sample.If insoluble material adheres to and accumulates in the supply pipe to the meter, it must be removed periodically. In addition, if insoluble substances adhere to and accumulate on the electrode itself, it will naturally lead to poor accuracy.Furthermore, if the sample is at a high temperature, it will have a negative effect on the life of the electrode.Therefore, normally, Regular removal of waxy substances adhering to the pipes and periodic electrode replacement will be incorporated into standard work to ensure normal operation.

The present inventor has discovered that the p
The present invention has been completed as a result of intensive study on sample supply methods in order to measure H accurately, easily, and economically.

That is, the method for supplying a sample to a pH meter according to the present invention is that when measuring the pH of a high-temperature sample containing undissolved substances using a pH meter, the sample is supplied to an undissolved substance removal tank, the insoluble substances are removed, and then the sample is cooled. This method is characterized in that the sample is supplied to a pI-① meter in a state where the sample is hydrated.

A high-temperature sample containing an insoluble substance to which the present invention can be applied is one in which the sample itself is at a high temperature, and in that state, all or part of the insoluble substance is dissolved in water or an aqueous medium, such as a distillation residue. Examples include samples that contain high boiling point substances along with water.

It has electrodes. The present invention can be effectively applied as long as it is a T-I meter.

In the present invention, Sample F is sufficiently cooled before being supplied to the pH meter. , J (It is preferable to cool the temperature to 40"C or less for measurement purposes. Cooling may be done forcibly, or natural cooling may be carried out by providing a long pipe or 1f. In chemical plants, By passing the piping through the drain, cooling can be conveniently done in terms of the location of the piping and the economy of cooling.However, it is preferable to arrange the piping so that hook-like substances do not adhere and accumulate in the cooling piping. If the cost of electrode replacement and maintenance is compared with the cost of replacing the piping itself, and if the piping is replaced regularly, the problem of insoluble substances adhering to the piping is not important. The insoluble matter removal tank of the present invention needs to have an insoluble matter removal mechanism as well as a sample supply port and a sample discharge port connected to a pH meter.

It may be preferable to cool the sample before supplying it to the undissolved substance removal tank or in the undissolved substance removal tank. That is, if it is cooled after the insoluble M%'4 substance removal tank, insoluble substances may separate.

As a waxy substance removal mechanism, insoluble substances floating on the surface of the removal tank may be mechanically scooped out, or a partition plate may be provided in the removal tank to discharge waxy substances by overflow or to separate them by sedimentation. It's okay.

According to the present invention, it is possible to accurately measure the pH of samples containing insoluble substances at high temperatures over a long period of time, and maintenance of the straight needle and associated equipment becomes easy, and the life of the electrodes of the straight needle is greatly increased. to improve.

The present invention will be specifically explained below using examples.

Example Gaseous methanol was synthesized by contacting a gas mainly composed of hydrogen, carbon monide, and carbon dioxide with a catalyst maintained at an appropriate temperature under pressure, and then the gas containing gaseous methanol was mixed with water. As a result of indirect cooling with a coolant such as Freon liquid or ammonia liquid, the resulting methanol, water and other by-products are condensed, and after separating the condensed methanol and water, the gas is returned to the catalyst layer. In the process of distilling the crude methanol to obtain purified methanol after reducing the pressure of the mixture of methanol and by-products that are circulated and separated, a canister is continuously ejected from the bottom of the distillation column in order to control the material quality of the distillation column. Measure pH. This sample is an aqueous solution at about 90°C containing methanol appM, alkaline substances and small amounts of insoluble substances.

m, ) 1 and then supplied to the insoluble matter removal tank 6. Almost all of the sample cooling pipe 1 is provided in the drainage ditch 2. From this, the sample at about 90°C was cooled to about 35°C. The waxy substance removal tank 6 is made up of two partition plates 4.5 and a removable lid 7 having a partition plate 6. Floating undissolved material is removed by overflowing through line 8. Also, the lid 7 of the removal tank was opened periodically to remove waxy substances adhering to the partition plate 45.6.

The sample thus cooled and freed of undissolved substances is supplied to pT-1 total 10 through line 9.

With the method of the present invention, the conventional sample line cleaning is done once/
What used to be done once a week has now been reduced to once every six months, and the lifespan of the pH meter's electrodes has also been extended from six months to one year.

[Brief explanation of drawings]

Figure 1 shows one of the sample supply methods to the pI meter according to the present invention.
It is an explanatory diagram showing an example. In the figure, 1..., sample cooling tube 200. . Drainage ditch 000. Undissolved substance removal tank 456. Partition plate 7, . . . Removable lid 8 of the removal tank, . . . Overflow line 9. 0. Sample supply line 101. . . pH meter patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (2)

[Claims] (1) When measuring the pH of a high-temperature sample containing insoluble substances using a pH meter, the sample is supplied to an insoluble substance removal tank, and after the insoluble substances are removed, the sample is cooled down to a pH meter.
A method for supplying a sample to a T-1 meter. (2) The method according to claim 1, characterized in that the sample is supplied to the insoluble matter removal tank while cooling the sample.