CS254159B1 - Addition to aqueous medium - Google Patents

Abstract

Reduction of pressure losses due to friction, or hydraulic resistance of flowing water or aqueous solution is achieved by adding 1.10 ~s to 1.10_1 %/o by weight of hydroxyethyl cellulose, or even more of a water-soluble system stabilizer (water-soluble fungicidal and bactericidal agent). The use of the additive is mainly suitable for reducing the consumption of electrical energy for pumping recirculating cooling water in the power industry, in the chemical industry, in the pulp and paper industry and in other sectors.

Description

The invention relates to the use of a defined additive for reducing the hydraulic resistance, respectively. pressure loss by friction of the flowing water or aqueous solution, respectively. also suppressing dissipation of energy in a turbulent flow of water or aqueous solutions, wherein the additive is a technically relatively readily available water-soluble macromolecular substance or mixture of macromolecular substances.

Known [Frenkiel F. N., Landhal Μ. T., Lumley J. L., Structure of Turbulence and Drag Reduction. Am. inst. of Physics, New York (1977)] the effect of some dissolved polymers in water to reduce pressure losses by rubbing the treated water. This is the effect of polyethylene oxide, respectively. polyglycol [Kutateladze S. S., Mironov Β. P .: Eksperimentafnoe the Tracing of the Turnien Turbulent Theories], p. 60-63. Nauka, Novosibirsk (1975); Schowalter N. R .: Mechanics of Mon-Newtonian Fluids, p. 244-249. Parchment Press, Oxford (1978); Sedov L. I., Vaseckaya N.G., Josilevič V. A .: On the growth of turbulent pogranic slogans with small cattle polimers, p. 205-220. Nauka Moskva (1974)] on high molar masses, as well as polyacrylamide [Nikitin, I.K. et al. 93-98. Gidromechanics, Moscow (1971)] and carboxymethylcellulose and even hydroethylcellulose in concentrations of 0.1 to 0.5% by weight. [Lodes A., Zaliberová A., Hudáčková H .: Zhorník of the 4th National Conference on Rheology of Liquids in Industrial Practice, p. 117-182. Vel'ke Karlovice (1981)].

Said processes utilize relatively large amounts of polymers and have a low efficiency or, in addition, only a low efficiency life.

However, the object of the invention is the use of hydroxycellulose in a total amount of dry substance 10.1 ^"6 to 1.10 ^_1% wt., Optionally in addition a more water-soluble stabilizer, preferably a water-soluble fungicidal and / or bactericidal composition, as additives to the aqueous medium, preferably the cooling water in heat and circulating cooling systems to reduce friction pressure losses and / or hydraulic resistance.

The advantage of using an additive, so-called. depressant into aqueous medium to reduce hydraulic resistance, respectively. The pressure loss due to the friction of the flowing water or aqueous solutions of the present invention is its high efficiency at low concentrations and high system stability, ensuring its longevity and thus a significant increase in pump performance, cooling, etc., without increasing energy consumption.

When selecting hydroxyethylcellulose, the molar mass should be as high as possible. A molar mass range of 80,000 to 300,000 g seems to be most suitable. mol ^-6 . The degree of hydroxyethylation of the cellulose should be at least 1.5, most preferably about 2.5.

In addition, it is advisable to add a system stabilizer to prevent hydroxyethylcellulose destruction, especially in cases of reduced pressure by friction of flowing cooling water, since much more than mechanical destruction can cause hydrolysis of hydroxyethylcellulose, especially when water pH and temperature changes and degradation due to ferments, microorganisms and Come. Therefore, it is advisable to apply the additives "buffers" as stabilizers, in particular water-soluble fungicides and bactericides. These include e.g. formaldehyde condensates with alkanolamines, quaternary bases, sodium alkylphenolates, especially sodium cumylphenolate and the like.

Both the hydroxyethylcellulose and the stabilizer can be applied in a single or sequential manner, in portions. Further detailed information on the effects and advantages of the present invention is evident from the examples. Example 1

In the cooling water recirculation circuit, the exchange system pipe with an internal diameter of 50 mm and a length of 1000 m is a water flow of 60,000 kg. h ^_1 . The temperature of the flowing water is 20 + 1 ° C. The coefficient of friction pressure losses is 0.012, the water loss height is 883.8 m, the required water pump capacity is 144.790 W (Js- ¹ ).

In contrast, by adding 5.10 &^lt; ^{2 &gt}; hydroxyethyl cellulose with an average molar mass of 1.04.105 g. mole ¹ into re-injected water at the same volumetric flow rate of 60 000 kg. h = ¹ pressure loss coefficient by friction of water or of the diluted hydroxyethylcellulose solution is 0.009, the loss in flow of the treated water is 663 m and the required pump power is 108 617 W (Js- ¹ ). Thus, the difference in pump output required for pumping virtually pure cooling water and cooling water with an additive of 1.10 ^-3 % by weight. hydroxyethylcellulose is 36173 W (J. s. ¹ ). This saves 37.85 kWh / h of electricity.

A similar difference is also found in the case of water to which, in addition to hydroxyethylcellulose (5.10 ^-2 % w / w), an additional 1.10 ^-2 % by weight is added. sodium p-cumyl phenolate as a bactericidal and fungicidal agent for enhancing the stability of hydroxyethylcellulose.

Example 2

The water-cooled saturated steam is condensed in the tubular heat exchanger. The number of tubes with an inner diameter of 25 mm in a 5 m length exchanger is 86 pieces. For steam condensation with a mass flow rate of 4 600 kg. h ^_1, the consumption of cooling water 270 000 kg. ^_1 h of water at 19 + 1 ° C. Coefficient of friction losses of pressure of water is 0.022 and the otherwise similar conditions in water with addition of 10.5% hydroxyethylcellulose of ^_2 average molecular weight of 94 000 g. mole ^-1 is 0.019. The water flow loss is 60.9 m and 52.5 m hydroxyethylcellulose water. The power requirements of the pumps for pumping cooling currents are 44,821 W (Js ^-1 ) for water alone and 38,663 (Js + for hydroxyethylcellulose water), thus saving 6.2 kWh / h of electric water using hydroxyethylcellulose cooling water. Similar differences are achieved in addition to hydroxyethylcellulose also with the addition of 0.01% by weight of the condensation product of formaldehyde with monoethanolamine as a fungicidal and partly bactericidal composition.

Example 3

The recirculated cooling water flows through a pipe with an internal diameter of 100 mm and a length of 1,000 m in a quantity of 416.67 m ³ . h ^-1 at 20 + 1 ° C. 207 kWh / h of electricity is consumed for pumping; to transfer the same amount of water with an addition of 0.1 wt. of hydroxyethyl cellulose specified in case 2 is needed 164 kWh / h with an addition of 0.2 wt. 140 kWh / h of electricity.

Claims (1)

5,254,159 of the flowing water is 60.9 m and water of hydroxyethylcellulose is 52.5 m. The required pump capacities for the cooling streams are 44,821 W (Js -1) in the case of water alone and 38,663 (J). Thus, the energy saving of using hydroxyethylcellulose with cooling water is 6.2 kWh / h. Similarly, hydroxyethylcellulose and] with 0.01 wt. Example 3 Recirculated cooling water flows through a pipe with an internal diameter of 100 mm and a loading of 1,000 m in an amount of 416.67 m3, h1 at a temperature of 20 ± 1 ° C. pumping requires 207 kWh / h of electrical energy, for the same amount of water to be pumped with 0.1% by weight of hydroxyethylcellulose specified in case 2, 164 kWh / h of 0.2% by weight of 140kWh / h of electricity is required e. OBJECT OF USE The use of hydroxyethylcellulose in the total amount of solids of 1.10-6 to 1.10_1% by weight, optionally in addition to a water-soluble stabilizer, preferably a water-soluble and / or bactericidal agent, as an additive to YNALEZ into an aqueous medium, preferably to a cooling system in heat exchangers and in circulating cooling systems, to reduce pressure friction and / or hydraulic resistance.