RU2572131C1 - Method for cleaning drains and suspensions - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: drains and suspensions are supplied into bubble chamber by pipes with further mixing, with coagulant being supplied by gravity due to strong differential pressure into formed narrowing of drain-supplying pipe. In the place of tube narrowing turbulent mixing of drains and coagulant takes place. Formed large agglomerations of pollutant particles precipitate in form of sediment on retaining profile in bubble chamber.

EFFECT: increased efficiency of drain purification from coarsely disperse and finely disperse particles, reduction of energy consumption and expenditures on additional equipment.

1 dwg

Description

The invention relates to the field of environmental protection and can be used for dehydration of organic and mineral solutions, suspensions in the mining, oil refining and agriculture.

- масса частицы объема V, плотностью ρ₁, υ - скорость осаждения частицы.The easiest way to clean the effluent is a storage pond. It uses both gravitational sedimentation of particles in bottom sediments and biological treatment [Wastewater treatment in natural conditions. Website vod-v-estestvennykak-usloviaykh]. Particles are precipitated by gravity P = mg. The opposite force of gravity is directed by the buoyancy force of Archimedes: F = ρ ₂ Vg, where ρ ₂ is the density of water and Stokes force: F = 6πηRυ, where η is the dynamic viscosity of the fluid, R is the radius of the spherical object, υ is the particle velocity, V is the volume of the submerged body. Here $$m={\rho }_{\mathrm{one}}V={\rho }_{\mathrm{one}}\frac{\mathrm{four}}{3}\mathrm{<figure-callout\; id="3"\; label="\pi \; R"\; filenames="00000009.png"\; state="\{\{state\}\}">\pi \; </figure-callout>}{R}^{}{}^3$$

is the mass of a particle of volume V, density ρ ₁ , υ is the particle deposition rate.

The particle deposition rate is described by the differential equation:

The solution to the equation:

- скорость равномерного падения,Where $${\upsilon }_0=\frac{g}{b}$$

- uniform fall rate,

- характеристический параметр. $$b=\frac{9\eta }{2R^2\left(\mathrm{one}-\frac{{\mathrm{<figure-callout\; id="2"\; label="\rho "\; filenames="00000009.png"\; state="\{\{state\}\}">\rho </figure-callout>}}_2}{{\rho }_{\mathrm{one}}}\right)}$$

- characteristic parameter.

For a lead particle, ρ ₂ = 11300 kg / m ³ , ρ ₁ = 1000 kg / m3, R = 10 ^-6 m = 1 μm, η = 10 ^-3 Pa s, i.e. b = 5 * 10 ⁹ , i.e. particle falls uniformly with speed $${\upsilon }_0=\frac{10}{5\ast {10}^9}=2*{10}^{-9}m/\mathrm{from}$$

секунд очень велико, т.е. очистка от мелкодисперсных частиц не проходит.Deposition time to depth h = 1 meter $$t_0=\frac{h}{{\upsilon }_0}=\frac{{10}^9}{2}=5\ast {10}^8$$

seconds is very long, i.e. fine particle cleaning does not work.

Disadvantage: drains are cleaned only of particles with radii greater than 20 microns.

Known Venturi technology, which allows to measure the flow of liquids and mix chemical concentrates with solvents. This technology is based on a vacuum created by different flow rates in a venturi, which has the shape of an inverted funnel with a smooth change in cross section [GOST 8.986.4-2005. Measurement of flow rates of liquids and gases using standard constricting devices. Part 4 of the venturi pipe. M .: Standartinform, 2006]. Also, devices are manufactured by Hydronva Europe (England). The method of mixing Venturi substances adopted as a prototype.

Venturi technology is effectively used when mixing solutions, but cannot be used to treat effluents and suspensions for the following reason. Due to the pressure drop, a chemical reagent is mixed with a solvent, which is necessary for various chemical processes. There is no turbulent bubbling in the venturi. Only fine particles can be cleaned, which can be filtered in a simpler way, for example, with a mesh.

The task to which the proposed method is aimed is to increase the efficiency of wastewater and suspension treatment by removing all particles, including fine particles.

The technical result is achieved due to a sharp narrowing of the pipe for supplying untreated wastewater to the bubbler chamber, where the coagulant is fed by gravity, and turbulent mixing of wastewater and coagulant is realized, as a result of which coagulation of all particles, including fine ones, occurs. They precipitate on the retention profile in the bubble chamber.

An example implementation of the proposed method is shown in the drawing, which shows a diagram of a device for its implementation. The crude effluent is fed through a pipe 1, which ends with a sharp narrowing in the area 2 of the bubble chamber 5. In the narrowing area, a sharp drop in pressure occurs, due to which a coagulant is fed by gravity through the pipe 3. In this area, the contaminant particles coalesce into large agglomerations. The deposition of agglomerations occurs on the profile 4, after which the purified liquid is discharged through the pipe 6.

Turbulent mixing in the proposed method is as follows. The untreated wastewater is fed through a supply pipe 1 with a section S ₁ under pressure into one atmosphere P ₁ with a speed of υ ₁ . In the bubble chamber due to the narrowing of the pipe to the cross-section S _{2, the} speed increases to υ ₂ = (S ₁ / S ₂ ) / υ ₁ . The pressure at the pipe narrowing point is P = 0.5ρ (υ ₁ ² -υ ₂ ² ) + P ₁ = 0.5ρυ ₁ ² (1- (S ₁ / S ₂ ) ² + P ₁ ).

When the density of polluting particles ρ = 1050 kg / m ³ and the cross section S _{2 is} reduced three times relative to the input S _{1, the} pressure in the constriction drops to 0.24 atm, and coagulant flows into the bubble chamber 5. Coagulation of the particles of pollutants takes place in the bubble chamber substances, which are then deposited on a variable profile 4. The particle deposition rate is determined by expression (3). Treated effluents are discharged through a pipe 6.

The differences and features of the process are that the supply of coagulant is carried out without energy costs, without the cost of additional equipment (compressor), but only due to the pressure difference when narrowing the section of the supply pipe, which leads to an increase in the contact surface during turbulent mixing of untreated effluents drains and coagulant. The increase in the contact surface of effluents and coagulant allows you to quickly get large agglomerations of pollutants that precipitate.

Coagulated coarse particles are subjected to further chemical treatment to extract useful components.

Claims (1)

The method of purification of effluents and suspensions by bringing them into a bubbler chamber through pipes with subsequent mixing, characterized in that the coagulant is fed into the formed narrowing of the inlet pipe drain by gravity and due to a sharp drop in pressure at the pipe narrowing point, turbulent mixing of the effluent and coagulant occurs, and large agglomerations of particles of pollutants precipitate on the retaining profile in the bubble chamber.

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