FI116900B - Heat Transfer Fluid Composition - Google Patents

Description

4 Heat Transfer Liquid Composition - Värmeöverföringsvätskesamnu Technical Field

The present invention relates to improvements to antifreeze aqueous fluids containing an alkaline salt of formic acid and / or ethyl propionic acid. Liquids can be used for cooling applications, particularly in applications where leakage prevention is important

Background of the Invention

Aqueous liquids containing the alkaline salt of formic acid and / or vinegar 10 have been used as heat transfer fluids. For example, pat FI-B-101547 describes such a heat transfer fluid which also contains such fluids are also commercially available (e.g., Freezii Chemicals Oy, Finland).

The main problem with aqueous heating / cooling fluids containing alkaline salts of muurah acetic acid and / or propionic acid is leakage.

.. It is an object of the present invention to provide the above mail • *: "leak-proof heat transfer fluid.

DESCRIPTION OF THE INVENTION My heat transfer according to claim 1 has now been invented * · ·

The liquid contains formic acid and / or acetic acid and / or propionic acid * ·· .: and a polyelectrolyte.

Surprisingly, it has been found that the polyelectrolyte decreases the wetting capacity ···. hence the tendency to leak. Good leak protection is already achieved by blocking the pie 2 and the resulting distortion is a clear explanation of the anti-scaling mechanism.

Thus, in accordance with the invention, an excellent heat transfer between the metal surface and the liquid is provided by the leaking liquid. It also prevents corrosion and acts as a lubricant. Corrosion under the scales and deposits inside the pipes. In addition to preventing the formation of salts, the polyelectrolyte also prevents the lubrication and reduces the wear of, for example, pumps 10 by forming only a few molar · layers on the metal surfaces.

The polyelectrolyte is a polymer or copolymer of acrylic acid such as rylate or copolymer of sodium acrylate and acrylamide, Polyma derivative thereof, polymethacrylic acid or a derivative thereof, acacia sodium, carrageenan, tragacanth gum, xanthan gum, collagen, collagen. Of course, mixtures of electrolytes can be used.

The alkali salt content should preferably be 5 to 70% by weight based on the weight of the salt. The amount of polyelectrolyte is 1-1000ppm, 20,100 ppm.

In particular, polyacrylates or · "··· mers may be used as polyelectrolytes.

* · ♦ ·· t · · · Optional materials such as corrosion inhibitors and / or pH buffering agents may be used with this heat transfer fluid.

25 Examples% ·· «« 3

The leak test equipment was filled with either Freezium -15 ° C, Fr + 10ppm Fennopol A 392 or tap water. The test equipment consists of a Swageloc fitting and three pipe fittings that were connected by a series of fittings. Only the end connection on the bottom of the test equipment is tight. All materials were stainless steel AISI 316.

First, the test equipment was filled with tap water. No leaks were observed during the four year period. Thereafter, the test equipment is supplemented with -15 ° C. Approximately two days after the trial period, a spiny and second joint is observed at the top. Freezium -15 ° C from 10 test equipment was then added and Freezium -15 ° C liquid Fennopol A 392 was added. Unexpectedly, there were leaks in the four-day trial period. The test solution was then poured out and the test equipment sold with warm tap water. Freezium was then added at -15 ° C without any additives. After a test period of about two days, h 15 leaks at the top of the first and second joints. Freezium -15 ° C Ki off and Freezium -15 ° C liquid containing 10 ppm Feni was added Even after 10 days of test run no leaks

Apparently, the final solution may use polyacrylates to prevent the solution from penetrating or easily leaking from small leakage points and onto solid surfaces such as pumps, valves and nozzles.

♦ · S **; . ·. The same, very thin layer of polyacrylate also prevents salt formation near the sites. In particular, galvanized steel and zinc are extremely ... for roses under such formate salt deposits.

♦ ·

Viscosity Measurements • · 25 Heat transfer fluid leakage to prevent fluid viscosity. significantly. For the most viscous the heat transfer fluid is, the more

* ll \ heat transfer. Table 1 shows the 10ppm Fennopol A G

4

Table 1. Effect of 10 ppm Fennopol A 392 on Freezium

Freezium at -60 ° C viscosity.

It coalesces at 26 ° C

__cSt

Freezium -15 ° C (24%) __ 1.19

Freezium -60 ° C (50%) __ 2.05

Freezium -15 ° C (24%) + 10 ppm Fennopol A 392__.1.19

Freezium -60 ° C (50%) + 10 ppm Fennopol A 392 2.10

Table 2 shows Fennopol A 392 at 20-50 ppm or viscosity at 5 -15 ° C and Freezium at -40 ° C.

From the experiments it is evident that the viscosity of the Freezium liquid is due to the addition of polyacrylate, so that the liquid still has a real advantage, i.e. low viscosity.

Table 2. Effect of 20.30 and 50 ppm Fennopol A 392 on the viscosity of Fr 10 -15 aC and Freezium -60 ° C.

(# Test solution 22 ° C Change -10

: * 'cSt%: ina cS

«- - i

Freezium -15 ° C 1.15 - 2.1 • - ““ "

Freezium-15 ° C +20 ppm Fennopol A 392 1.15 0.0 2, vol

Freezium -15 ° C + 30 ppm Fennopol A 392 1.17 1.7 3, C

: Freezium -15 ° C + 50 ppm Fennopol A 392 1.46 27.0 3, £ 9 9 9 · ♦ ♦ · -.

Freezium -40 [deg.] C-1.60 _3J

"l \ · Freezium -40 ° C + 20 ppm Fennopol A 392 1.69 5.6 3.1: *** · Freezium -40 ° C + 30 ppm Fennopol A 392 1.79 11.9 3. £

Claims (8)

1. Aqueous heat transfer fluid composition, such as in metal salt of formic acid and / or of acetic acid and / or of propionic acid, in that it contains a polyelectrolyte in the amount of 1-1000 ppm of a polymer comprising a polyelectrolyte which consists of a polyelectrolyte. or a copolymer of sodium polyacrylate or a copolymer of sodium acrylate and acrylic acid or a derivative thereof, polymethacrylic acid or a derivative thereof alginate, carrageenan, tragacanth gum, xanthan gum, collagen, carboxylic glyceryl monostearate or a mixture thereof. Composition according to claim 1, characterized in that pole; a polymer or copolymer of acrylic acid. Composition according to claim 2, characterized in that a copolymer of acrylate and acrylamide. Composition according to any preceding claim, the pitch content of polyelectrolyte is 5-100 ppm by weight of the composition. 5. Composition according to any preceding claim, cinnamon it contains alkali metal salt of formic acid. · * · • «« m ; 6th Composition according to claim 5, characterized in that potassium salt of formic acid. • * * ·· 7. Composition according to any preceding claim, pitcher * ♦ ·: the alkaline salt content of formic acid constitutes 5-70% by weight of the composition in ·· • · • • * 8. Composition according to any preceding claim, the cinnamon composition additionally contains corrosion inhibitors and / or · ;; 25 substances. • ·