CS233916B1 - Process for preparing a heat transfer fluid - Google Patents

Abstract

The invention relates to a method for preparing a synthetic heat transfer fluid. The essence of the method is that triethanolamine is mixed with a corrosion inhibitor and, after sedimentation and possible filtration and pH adjustment, 1,2-propanediol and a heat absorbent are added. Optionally, water and an indicator are added.

Description

The invention relates to a process for the preparation of a non-toxic heat transfer fluid comprising 20 to 95% by weight of mono-, di-, tri- 1,2-propanediol or a mixture thereof, 1 to 10% by weight of a neutralizing product of an organic or inorganic acid, preferably phosphorous or boric, with triethanolamine, 0.1 to 3% by weight of a corrosion inhibitor, selected from the group consisting of alkali salts of 2-mercaptobenzothiazole, and up to 5% by weight of a thermal abmorbent, such as chromolane blue GG or active carbon black; % by weight may contain water.

The essence of the process for preparing this synthetic liquid is to mix the triethanolamine with a corrosion inhibitor, preferably an alkali salt of mercaptobenzothiazole, for at least one hour at 60-80 ° C, which at the same time prevents microbial deterioration. The pH of the solution is adjusted to a value of 7 to 10 (depending on the type of metals used) by addition of an organic or inorganic acid, preferably phosphoric acid or an acid, and a measured amount of mono-, di-, tri- 1,2-propanediol or mixtures thereof and a thermal absorbent, such as chromolan blue GG or active carbon black, prepared beforehand by thorough mixing with a small amount of diol, optionally. In addition, an indicator (eg fluorescein) can be added, especially to synthetic liquids intended for the heating of drinking water. The liquid is either prepared in a concentrated state and used either undiluted or diluted with water before use. In this case, the liquid prepared as described above is diluted with water in the desired ratio and

It is advantageous to dispense the corrosion inhibitor together with the amount of water. It is also necessary to pre-dilute the thermal abaorbent with the addition of a small amount of water. production.

EXAMPLE 1

4.1% by mass, triethanolamine is emitted with 0.2% by mass, 2-mercaptobenzothiazole sodium salt is homogenized for 1 hour at 15 to 80 ° C and then left to sediment. The solution is filtered, pH adjusted to 7 by addition of phosphoric acid and mixed % and 56 wt. 0.06% by weight of a mixture of mono- and di-1,2-propanediol. Gromogen blue G G and 0.04 X wt., fluoro esine. The solution is thoroughly homogenized.

Example 2

7.1 wt. % of triethanolamine and e is mixed with 0.2 wt. 2-mercaptobenzothiazole with addition of 0.2 wt.%, Water and 0.1 wt. After 1 hour homogenization at 75-80 ° C and subsequent sedimentation, the solution is filtered. By addition of boric acid, the pH of the solution is adjusted to 7 and mixed with 90 wt. 0.17% by weight of mono- 1,2-propanediol is added. of active compounds pre-mixed with 0.01% by weight. % of detergent and 0.18 wt. % water and 0.04 X wt. fluorescein. The mixture is homogenized.

Claims (4)

A process for the preparation of a poisonous synthetic Impaliay for heat transfer, comprising 20 to 95% by weight of aono-, di-, tri- 1,2-propanediol or a mixture thereof, 1 to 10% by weight of a neutralizing product of an organic or inorganic acid, preferably phosphoric or boric acid, with triethanolaine, 0.1 to 3% by weight of a corrosion inhibitor, selected from the group consisting of alkali salts of 2-mercaptobenzothiazole; is chromolan blue GG or active carbon black and may contain water as a residue up to 100% by weight, characterized in that the triethanolamine is mixed with a corrosion inhibitor such as the alkali salt of mercaptobenzothiazole for at least 1 hour at 60 to 80 ° C, if necessary, the pH is adjusted to 7 to 10, the mono * in di-, tri- 1,2-propanediol or a mixture thereof and the heat absorbent prepared _from a pre-perfected solution are added by stirring with a small portion of the total amount of diol, the mixture being diluted in the desired ratio with water and water mogenize · 2 · lj method according to claim wherein said indicator is optionally added, preferably fluorescein, and the mixture zhooogenizuje ₀ I o 3. A process according to claims 1 and 2, wherein the mixing with the corrosion inhibitor is carried out with the addition of a small amount of water. 4. A method according to claims 1, 2 and 3, characterized in that. the pre-dilution of the heat absorbent is carried out with a small amount of water and possibly detergent.