METHOD FOR PREVENTING EVAPORATION OF A LIQUID FROM A BASIN AND SPREADING OF PARTICULATE MATERIAL CARRIED BY VAPOR DROPS TO THE SURROUNDINGS

Abstract: The invention relates to a method for preventing the evaporation of liquiid from a basin (1) and the spreading of particulate material in vapor drops into the surroundings. Ionization points (3) are used above the liquid surface (2) in such a manner that a strong ion field is produced above the liquid surface.

Description: Method for preventing evaporation of a liquid from a basin and spreading of particulate material carried by vapor drops to the surroundings The present invention relates to a method for preventing the evaporation of a liquid from a basin and the spreading of par¬ ticulate material carried by vapor drops into the surroundings. In very many places, industries use open basins or conveying canals which contain toxic liquids. Furthermore, since the temperature of the liquid in such a basin is often high, the evaporation is extensive and detrimental to the environment. In anodizing, nickel plating, and other similar processes, heavy metals are spread into the surroundings in vapor drops in toxic clouds. In metal processing, nickel sulfate and sodium sulfate spread into the surroundings, and all of the said substances are highly hazardous to health. Attempts have been made, by means of hoods placed above the basins, to direct the vaporiz¬ ing gases out from the actual industrial halls, but thereby the problem gases have only been shifted from one place to another. Attempts have also been made to spread floating plastic spher¬ ules on the surface of the liquid, but even these do not cover the surface entirely and, owing to the high temperatures, they melt away. It is an object of the invention to eliminate the disadvantages described above. The method according to the invention is characterized in that ion-producing points are used above the liquid surface so that a strong ion field is obtained above the liquid surface. By means of ionization, the drops which form and condense above the liquid surface and contain the said particles will, immedi¬ ately upon raising from the surface, arrive in an electric charge field having the same polarity as the said drops have, and therefore they will immediately return to the liquid. This serves to prevent the evaporation of the liquid and the spread- ing of particulate materials carried by vapor drops into the surroundings. The volume of the liquid in the basin may thus remain almost constant. In the area of the basins it will be possible to inhale clean air without using a mask. One embodiment of the invention is characterized in that ioniz¬ ation points are installed in the form of a matrix above the liquid surface so that the ions departing from the ionization points will produce a cover over the entire surface of the liquid. Another embodiment of the invention is characterized in that the ionization points, which are made up of suspended cable ends, are mounted on horizontal rails in such a manner that they can be pushed aside along the rails, away from above the basin, when other work stages are being carried out above the basin, such as placing pieces into the basin or lifting pieces out of the basin by means of a hoist. The hoist may additional¬ ly have some simple gripping member which will return the ion¬ ization points to above the liquid surface when the hoist moves away from above the basin. One embodiment of the invention is further characterized in that the ion-producing points are mounted at a distance of 10- 150 cm from the liquid surface and that a voltage of 4-160 kV is fed to the ion-producing points. The higher the voltage, the higher above the surface the ionization points can be. The invention is described below with the help of an example, with reference to the accompanying drawings, in which Figure 1 depicts a cross section of the basin, Figure 2 depicts a longitudinal section of the basin, Figure 3 depicts the transfer of the ionization points to the side of the basin, Figure 4 depicts a plan view of the basin, and Figure 5 depicts an ionization point above the liquid surface. The apparatus used in the method consists of ionization points 3 suspended above the liquid surface 2 in the basin 1. By means of the ionization points 3, an ion field is produced above the liquid surface 2. The ionization points 3 are installed above the liquid surface 2 in the form of a matrix 3 x 4 so that the ion beams departing from the ionization points will cover the entire surface area 2 of the liquid. The ionization points 3, which consist of downwardly suspended cable ends, are mounted on horizontally positioned rails 4 in such a manner that they can be pushed aside along the rails, as is shown in Figure 3, in the manner indicated by arrow 5. All of the ionization points 3 are connected by means of cables 6 to a high-voltage source 7. In Figure 5, the small arrows show how the small particles vaporizing from the surface rise upwards, obtain an electric charge, and are returned to the liquid by means of an ion field of the same polarity. In the metal-processing in¬ dustry, in which the size of the basins may be, for example, 25 m x 15 , the ionization points are placed at a distance of approximately 100-150 cm from the liquid surface 2. In this case, voltages which may be 100-160 kV are used in the ioniza¬ tion points. The operating method according to the invention is suitable for any industry in which it is desired to prevent the evaporation of liquids from basins and the spreading of particulate mate¬ rials in vapor drops into the surroundings.

Claims: Claims 1. A method for preventing the evaporation of a liquid, for example, from a basin (1) and the spreading of a particulate material in vapor drops into the surroundings, characterized in that ion-producing points (3) are used above the liquid surface (2) in such a manner that a strong ion field is obtained above the liquid surface. 2. A method according to Claim 1, characterized in that ionization points (3) are mounted above the liquid surface (2) in the form of a matrix, in such a manner that the ions depart¬ ing from the ionization points (3) will produce a cover over the entire surface area (2) of the liquid. 3. A method according to Claim 1 or 2, characterized in that the ionization points (3) , which are made up of suspended cable ends, are mounted on horizontally positioned rails (4) in such a manner that they can be pushed along the rails (5) away from above the basin surface (2) when other work stages are being performed above the basin, such as placing pieces in the basin or lifting pieces out of the basin by means of a hoist. 4. A method according to any of the above claims, charac¬ terized in that the ionization points (3) are mounted at a distance of 10-150 cm from the liquid surface (2). 5. A method according to any of the above claims, charac¬ terized in that a voltage of 4-160 kV is fed to the ionization points (3) .

Inventors: ILMASTI VEIKKO, ILMASTI, VEIKKO
Applicants: ILMASTI VEIKKO, ILMASTI, VEIKKO
Application year: 1992
Main classification: C25D17
IPC codes: B01J19, C25D21