Solar collector for evaporation of aqueous solutions

Abstract

The invention is related to solar collectors intended to perform technological processes and specifically, to solar collectors used for concentration by evaporation of aqueous solutions.

The proposed solar collector concentrates the aqueous solution by combination of heating the upper thin layer of this solution (this heating is accompanied with evaporation a significant part of this layer) and carrying away of the obtained vapors from the internal space of the solar collector by air stream introduced constantly into the internal space. In another version of this invention the obtained vapors are condensing on the surface of cooling water flowing through the solar collector.

Description

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH[0001]Not applicable.BACKGROUND OF THE INVENTION[0002]The invention is related to solar collectors intended to perform technological processes and specifically, to solar collectors used for concentration by evaporation of aqueous solutions.[0003]There are two main systems intended to evaporate an aqueous solution with usage of solar heating this aqueous solution.[0004]Open ponds for concentration and crystallization of brines are widely used in chemical industry. It is a cheap but, at the same time, very extensive process, which requires large-size ponds. On the other hand, if the aqueous solution contains volatile contaminants, then the vapors of these contaminants are entering immediately into the atmosphere.[0005]There are some closed systems disclosed in patent literature, which use combination of heating aqueous solutions by solar radiation with absorption of obtained vapors by a gas stream.[0006]U.S. Pat. No. 4,310,382 “Method of...

AI Technical Summary

Benefits of technology

[0020]It is possible to apply a floating grid from foamed polymer in order to diminish mixing of the layers of the aqueous solution caused by interaction between the surface of the aqueous solution with the flowing air. In such a way, the proposed design of the solar collector utilizes the optical property of water and aqueous solution: with shifting electromagnetic radiation from visible range to infrared range absorption coefficient is increasing in such degree, that the light penetration depth in water changing from 10 m to some millimeters and less (see: W. M. Irvine and J. B. Pollack, “Infrared optical properties of water and ice spheres,” Icarus, 8, 324-360, 1968). As a result, this solar collector provides sharp temperature gradient near the upper surface of the aqueous solution with maximum temperature in the upper layers and effective evaporation process from these upper layers into the internal free space of the lower section of the trough.

Problems solved by technology

It is a cheap but, at the same time, very extensive process, which requires large-size ponds.

However, all these patents are not suitable for concentration by evaporation of aqueous solutions with high degree of concentration of soluble components.

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