RU2544683C2 - Air feed to floatation machine - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to aeration and can be used for purification of industrial waters and effluents. Process of air feed to flotation machine comprises air injection and further dispersion. Said air ejection and dispersion is effected by the bell provided with webs with staggered perforations in diameter about 3 mm.

EFFECT: provision of bubble size required for flotation.

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Description

The invention relates to aeration of a liquid and can be used in the flotation of various materials, wastewater and industrial water treatment.

Known ejection method of saturation of air mechanical flotation machines with subsequent dispersion of air bubbles by an impeller. However, this method is characterized by increased wear of the impeller and cannot be used for flotation of the formed flocs in the wastewater and industrial water treatment processes due to turbulent flows arising from the rotation of the impeller and leading to the destruction of the formed flocs (Meshcheryakov N.F. / Flotation devices and machines // M .: Nedra. - 1982. - 200 p.).

A device for introducing air during flotation with special ejectors is also known. However, either a jet of water or air is supplied under pressure, which does not provide the optimal size of air bubbles (Meshcheryakov NF / Structural flotation machines and apparatus // M .: Nedra. - 1990. - 237 p.).

The closest in technical essence and the achieved effect is a method of flotation wastewater treatment, in which part of the recirculated water is saturated with air during its ejection, which is optional. Of the total air volume (6–9%), 2–3% is introduced into recirculating water when saturated under excess air pressure (A.c. SU 715496, IPC C02F 1/24, B03D 1/06. Flotation water treatment method (Ushomirsky P .I., Anopolsky V.N., Rogov V.M., Tereshchuk A.I. // Publ. 1980. - BI No. 6). According to this method, only 2-3% of the air is introduced without any energy costs, which is then dispersed. However, the authors expose part of the air to dispersion, without indicating how this operation is performed. The remaining (large) part of the air enters the process, forming bubbles large size, which does not contribute to flotation, i.e., the consolidation, according to the authors, of large particles on large bubbles due to significant separation forces arising from the lifting of such a particle-bubble complex (A.S. SU 814878 A2, IPC C02F 1 / 24, C02F 101: 00, C02F 103: 00 / Anopolsky V.N., Ushomirsky P.I., Rogov V.M., Tereshchuk A.I. // Publ. 1981. - BI No. 11 addition to A. S. No. 715496). During the flotation of large particles, several small bubbles are fixed in an amount sufficient to raise them.

The claimed invention is directed to the necessary aeration of the treated water after coagulation of various impurities contained in the water to obtain air bubbles of optimal size for flotation (1-1.5 mm).

The task is achieved by ejection air inlet, after which water containing air bubbles enters the console for dispersion. Air entry and its dispersion is carried out without any energy costs.

The essence of the proposed method is as follows. Wastewater is delivered to the flotation machine. Water passing through a pipe with a pipe for ejection air is directed to a bell, preferably of rectangular cross section, where perforated plates are located. The holes on the plates are staggered in relation to each of the plates. The diameter of the holes is about 3 mm. The size of the bubbles was about 2 mm and below. In each individual case, the size of the bubbles was determined by photographing, and the amount of air introduced by the increase in volume in the tank, where air was introduced in the described way. By introducing a surfactant, its concentration in water, you can adjust the size of the bubbles.

The above method of aeration of wastewater and its dispersion can be explained by the following examples:

Example 1. Air was introduced into the purified water by an ejection method. The increase in the volume of water in the tank was about 4%. The size of the bubbles was 6-8 mm.

Example 2. Air was introduced into the purified water as in Example 1, then water containing air was fed into the bell with perforated plates with a hole diameter of about 3 mm. The size of the bubbles was about 2 mm. The increase in the volume of water in the chamber was 12%.

Example 3. Air was introduced into the purified water as in Example 2. Soap of crude tall oil (about 50 mg / l) was supplied to the sump of the pump. The size of the bubbles was less than 1 mm, and the increase in the volume of water in the chamber was about 15%.

From an analysis of the experimental data and the examples given, it follows that the most favorable conditions for flotation used in wastewater treatment processes are achieved by ejection air inlet and its subsequent dispersion in a special attachment.

The proposed method, compared with the prototype, as shown by experiments, creates better conditions for the flotation of impurities coagulated in water. Air inlet occurs without any energy costs.

Claims (1)

A method of introducing air into a flotation machine, including an ejection air inlet and its subsequent dispersion, characterized in that the air is successively introduced by ejection and dispersed by means of a bell provided with partitions with perforated holes with a diameter of about 3 mm, staggered.