RU2561370C1 - Disperser of ozone-air mix for drinking water treatment - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: disperser for treatment of drinking water in bubbling contact tank comprises plate-shape case 1 of titanium with cover 2 perforated by laser to face water free surface in contact tank directed towards horizon. Union 4 to receive ozone-air mix into disperser is coupled with disperser base. Detachable perorated fluoroplastic 5-6 mm deep strap 5 is arranged over said cover 2 with clearance of 2-3 mm to allow detachable joint over the edges of cover 2 and alignment of bores in cover perforations if strap 5 and cover 2. Bores 6 in strap 5 are shaped to truncated cone diverging to cover side. Diameter of bores 6 of converged part of truncated cone is selected to make 1.5-2 times larger than maximum diameter of mix bubbles. Diameter of conical bore 6 is taken 25-40% larger than that of outlet section. Thicker parts of the support of said strap 5 have several drain channels 14 to communicate clearance between strap 5 and cover 2 with water in contact tank.

EFFECT: decelerated mineral and biological fouling of cover openings, optimised recycling.

2 dwg

Description

The invention relates to techniques for treating drinking water with ozonation and can be used in industrial bubble contact tanks of water treatment plants in cities and towns as devices that disperse small bubbles of an ozone-air mixture into the treated water.

It is known from the prior art for treating water with ozonation that a high degree of absorption of ozone by water, more than 95%, in industrial contact tanks can be achieved by dispersing small bubbles of an ozone-air mixture of 0.8 ÷ 1.2 mm in size. From the application for invention No. 2012144107 it is known that bubbles of the ozone-air mixture of this size can be obtained by passing the mixture through thin, 0.4 ÷ 0.5 mm thick, perforated plates of dispersants of titanium, in which the holes are made by laser piercing, and the average diameter of the holes set in the range from 65 to 75 microns, and the diameter of any hole in the range from 60 to 80 microns.

Dispersants with laser perforated holes in thin plates can be made in the form of hollow disks with a perforated cover, or in the form of hollow panels with a perforated upper wall with a ratio of length to width from 5: 1 to 6: 1.

The lack of perforated metal plates of dispersants, consisting in a gradual decrease in the throughput of small holes due to mineral and biological fouling during operation, is also known from the experience of drinking water treatment with ozonation. This leads to the need for periodic regeneration of the dispersant caps and increases the cost of water treatment. The necessary concentration of minerals and bacteria at the surface of the dispersant cap is maintained by flowing around with untreated water that continuously enters the contact reservoir during ozonation.

The technical task of the present invention is to develop a method of slowing down the process of mineral and biological fouling of the holes of the dispersant cover and substantially reducing the cycles of its regeneration during operation.

The solution of the technical problem of the invention is achieved by the fact that on top of the perforated dispersant lid, a removable perforated plate made of ozone-resistant material, for example fluoroplastic, 5–6 mm thick with larger holes than in the perforation of the lid is installed in parallel. When installing the cover in the area of perforations, the alignment of the holes in the cover and cover, as well as a gap of 2 ÷ 3 mm between the planes of the cover and cover is ensured. The joint of the lining and the lid is made on the periphery of the lid either by installing gaskets made of ozone-resistant material, or by local thickening of the lining, and several radial drainage channels are provided in several places along the periphery that communicate the gap cavity between the lid and the lining with the volume of water in the contact tank. The holes of the perforation of the lining are made in the form of a truncated cone with an extension towards the lid, the smaller diameter of the outlet being selected 1.5–2 times larger than the maximum diameter of the ozone-air mixture bubbles produced by the holes of the perforation of the lid. The diameter of the inlet in the pad adopted 25 ÷ 40% more than the output.

In the proposed dispersant, untreated water containing minerals and bacteria flows around the outer surface of the perforated lining. The flow of untreated water to the perforation of the dispersant cap is practically excluded. Dispersion and ascent of bubbles of the ozone-air mixture occurs in the stagnant zone of the gap between the plate and the cover and in the volume of tapered tapering holes in the plate. This ensures minimal biological and mineral fouling of the holes, realized only due to the initial concentration of minerals and bacteria contained in the volume of water in the gap and in the conical holes when starting the ozonation unit.

The choice of fluoroplastic as the material for the perforated lining eliminates the biological fouling of the lining holes and provides high resistance to calcium deposits. Possible deposits can not significantly affect the throughput of the lining, since the output holes of the lining perforation are substantially larger (2 ÷ 3 mm) than the holes of the lining perforation (0.07 ÷ 0.10 mm). Maintaining a constant value of the water pressure over the perforation of the lid is provided by radial drainage channels between the cavity of the gap and the volume of water in the contact tank.

The proposed dispersant of the ozone-air mixture for the treatment of drinking water is illustrated by the general view drawings presented in FIG. 1 and 2. The numbers in the drawings indicate:

1 - housing; 2 - cover; 3 - hole perforation of the cover; 4 - fitting; 5 - overlay; 6 - hole perforation pads; 7 - mounting central axis of the cover; 8 - a nut; 9 - mounting guide angle of the cover; 10 - mounting groove pads; 11 - the Central mounting hole pads; 12 - a bracket; 13 - screw; 14 - drainage channel.

The design features of the dispersant, the technology of its manufacture, assembly and performance monitoring are as follows.

The case 1 of a plate-shaped dispersant with a diameter of 150 ÷ 300 mm is stamped from titanium sheet with a thickness of 1 ÷ 2 mm. The cover 2 is made of titanium sheet with a thickness of 0.4 ÷ 0.5 mm with a central hole with a diameter of 15 ÷ 20 mm. On the machine with programmed automatic control, laser piercing of holes 3 with a diameter of 70 ÷ 75 microns is performed in compliance with the specified location of their axes. Then, the central mounting axis 7 is welded into the central hole of the lid, and a guiding mounting square 9 is fastened to the lid by contact welding. The plane of the square perpendicular to the plane of the lid is aligned with the line passing through the axis 7 of the lid and the axis of the perforation holes 3. The overlay 5 is made of fluoroplastic by injection molding. The arrangement of the axes of the holes 6 in the plate corresponds to the perforation of the cover. The manufacture of drainage channels 14 and the mounting groove 10 is provided by the design of the mold. Next, the lid and body are welded on the welding machine around the periphery. The fitting 4 is welded into the body. Tests are carried out for tightness, strength and determination of flow characteristics in air. Next, the lining 5 is installed. In this case, the central mounting hole 11 of the lining is aligned with the axis 7 of the lid, and the groove of the lining 10 with the angle 9 of the lid, which ensures the alignment of the holes of the perforations of the lining and the lid. The pad is fixed to the dispersant with three elastic brackets 12 and screws 13. A control test is conducted on the functioning of the dispersant at a minimum air flow rate.

Claims (1)

Dispersant of the ozone-air mixture (OVS) for the treatment of drinking water in a bubble contact tank, including a disk-shaped housing made of titanium, with a laser perforated lid facing upwards when installed in the contact tank towards the horizon of the free surface of water, a fitting for receiving OVS inside dispersant cavity, docked to the base of the dispersant, characterized in that on top of the perforated cover with a gap of 2 ÷ 3 mm, a removable perforated ozone-resistant pad is installed in parallel 5–6 mm thick plastic material with a detachable support connection along the periphery of the lid and alignment of the holes in the perforations of the lining and the lid, while the holes of the lining perforation are made in the form of a truncated cone with expansion towards the lid, and the diameter of the holes of the narrow output part of the truncated cone is selected 1.5 ÷ 2 times the maximum diameter of the OVS bubbles produced by the perforation openings of the lid, and the diameter of the wide part of the conical hole is adopted by 25 ÷ 40% more than the diameter of the outlet sti, and in the thickened places of the pad support, several drainage channels are made communicating the gap cavity between the pad and the cover with the volume of water in the contact tank.

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