CN207193072U - Activated sludge degassing equipment - Google Patents

Abstract

The utility model discloses an activated sludge degassing device, which relates to a water treatment device, in particular to a device for treating waste water by a biological method. The improved activated sludge degassing device comprises an aeration tank, a secondary sedimentation tank, an air pumping chamber, a water inlet collector, a water outlet collector, a clean water tank, a vacuum pump and an oscillator, wherein the aeration tank is communicated with the clean water tank; an oscillator is arranged on the air extracting chamber, and is selected from a mechanical oscillator, a hydraulic oscillator or an ultrasonic oscillator; the oscillation generator is optimally arranged, so that the collimation line of the oscillation wave is parallel to the liquid level. The improved degassing device can improve the degassing effect which is 2 to 6 times higher than the effect of desorbing gas adsorbed on activated sludge particles by a similar device known at present, and simultaneously improves the safety and the reliability of the operation of the device.

Description

Activated sludge degassing equipment

technical field

The utility model relates to water treatment equipment, in particular to water treatment equipment using biological methods to treat waste water.

Background technique

In the biological treatment of sewage, activated sludge containing various bacterial microorganisms is used. During the treatment process, the activated sludge slurry is stirred with clean water, and after being aerated, it is transported to the secondary settling tank, where it settles and concentrates. The thickened sludge can be reused in sewage treatment, while the supernatant flows into the storage tank.

Devices for sewage biological treatment generally include aeration tanks, double-layer sedimentation tanks, sludge collectors, pneumatic aerators, and piping systems for water supply and drainage (RU 819069, 1987; RU 2057085, 1994).

But these devices have a disadvantage - low efficiency, especially in the case of large volume sewage treatment due to long duration and low sludge separation efficiency. This is due to the insufficient sedimentation of activated sludge. Sludge separation is generally carried out in a storage tank with a depth of more than 4 meters, but the flocculent sludge floating on the water surface and containing air bubbles seriously reduces the sludge separation efficiency. And when the storage tank is very deep, or the storage tank is distributed in multiple stages, it is impossible for the sludge to settle in the secondary settling tank in practical application. In order to eliminate this disadvantage, flocculants are added to the sludge before sludge separation, but this makes the treatment process too long and may lead to the degradation of the sludge. (TUROVSKY I.C. Sewage Sediment Processing.-М.: Stroyizdat, 1982, p. 37; RU 2136610, 1994).

The current sewage treatment technology (RU 2201405, RU 2220112, RU 2228915, 2001) consists of a preliminary aerobic anaerobic biological treatment unit using aerobic activated sludge, after which the preliminary treated sewage enters the aeration tank together with the sludge - activation tank, in which the organic pollutants are completely eliminated, after which the water flows into the sedimentation tank. The remaining sludge settles at the bottom of the sedimentation tank, and the water flows out of the equipment through a porous filter. The disadvantage of this treatment process lies in the complexity of the secondary treatment technology, the insufficient regeneration efficiency of activated sludge, and the need to periodically regenerate the porous filter.

The device closest to our claim is the equipment for processing activated sludge for sewage biological treatment disclosed in the previous patent, including an activated sludge mixture aeration tank, a secondary settling tank, a collector, and an air pumping chamber connected to a vacuum pump. A purified water pipeline is connected to the place 1-2 meters away from the lower end of the water inlet collector; the liquid level of the suspension in the aeration tank is higher than that of the liquid in the secondary sedimentation tank (RU2367619, 2009).

A disadvantage of this device is the lack of efficiency of the degassing system. This is due to the fact that the degassing rate is positively related to the vacuum depth of the pumping chamber where the degassing takes place and the liquid mirror surface. But the value range of the vacuum depth is very small (-0,75-0,95bar), so it is impossible to increase the speed by changing the vacuum depth, and the tube vacuum unit limits the area of the mirror. Increasing the mirror area on an existing structure will increase the geometry and weight of the vacuum unit, which will result in a substantial increase in the structural support.

Utility model content

The problem solved by the inventor is to improve the degassing efficiency without changing the size of the device. In this case, the stage according to which degassing is hindered is generally the stage of bubble formation. Therefore, we speculate that the degassing efficiency will increase when factors that accelerate the rate of this stage are added in the vacuum chamber, such as the local manufacturing inhomogeneity of the liquid.

An activated sludge degassing equipment, including: an aeration tank, a secondary settling tank, an air pumping chamber, an inlet water collector, an outlet water collector, a water purification tank, a vacuum pump and an oscillator, an aeration tank and a water purification tank Connected, the pumping chamber communicates with the water purification tank and the secondary sedimentation tank respectively through the water inlet collector and the water outlet collector, and the vacuum pump is connected to the pumping chamber through a pipeline; an oscillator is installed on the pumping chamber, and the oscillation The oscillator is selected from mechanical oscillators, hydraulic oscillators or ultrasonic oscillators.

Preferably, the directrix of the shock wave of the oscillator is parallel to the liquid level in the pumping chamber.

We achieved the technical result by installing in the vacuum chamber (i.e. the evacuation chamber) a device that creates a vortex, which accelerates the bubble formation process. Such devices can be standard mechanical oscillators, hydraulic oscillators or ultrasonic oscillators; for example, those with outlet nozzles that create high pressure pulsed flow, mechanical screens, vibrating units, acoustic (including ultrasonic) generators, etc.

The best effect can be achieved by adjusting the settings of the oscillator so that the main axis of the wave (the directrix) is parallel to the surface of the mirror (ie, the liquid surface).

Description of drawings

The overall installation diagram is shown in Figure 1, where:

1. Aeration tank, 2. Secondary sedimentation tank, 3. Air pumping chamber, 4. Inlet collector, 5. Outlet collector, 6. Clean water tank, 7. Vacuum pump, 8. Pipeline, 9. oscillator.

Detailed ways

The device works as follows: the vacuum pump 7 is turned on, the sludge mixture enters the pumping chamber 3 through the water inlet collector 4, and the degassing process is performed in the negative pressure area of the pumping chamber 3. In this way, under the action of the oscillator 9, inhomogeneity is caused in the thicker bubble formation region of the liquid, and a vortex region is formed. The size of the air bubbles increases and reaches a value that allows the sludge particles to float up and separate from the liquid. When the vacuum pump 7 is turned on, water flows into the lower part of the water inlet collector 4 from the clean water pool 6, and a liquid layer with a larger specific gravity is formed in the water inlet collector 4 relative to the mud. The liquid layer will form a unique hydraulic seal to ensure rapid and uniform movement of the mud in the pumping chamber 3 at the initial stage of the device's operation. The degassed particles with small buoyancy enter the lower liquid layer and enter the secondary sedimentation tank 2 through the outlet collector 5 . After the device starts to work, the automatic system of liquid flow can be used, and the liquid flows from the aeration tank 1 and the secondary sedimentation tank 2, thereby eliminating the possibility of liquid column breakage and improving the reliability of the device operation.

When the device works abnormally and the liquid column breaks, the liquid starts to flow back into the water inlet collector 4, causing an additional amount of water to flow into the system from the clean water tank 6, forming a hydraulic seal in the water inlet collector 4, The possibility of breaking the liquid column has been eliminated, and the sinking speed of the liquid in the water inlet collector 4 has been reduced, thereby making it possible to take measures to eliminate abnormal conditions.

When it is necessary to change the degassing treatment mode, for example, when the viscosity of the mud flowing into the system changes, the working mode of the vacuum pump 7 needs to be adjusted to obtain the best treatment effect.

The test of our advocated activated sludge treatment process was carried out on industrial experimental equipment with a water output of 10m3/h when the slurry contained 6g/activated sludge particles and 5mg/l adsorbed gas. The result proves that when the vacuum degree is -0.95bar, the amount of gas adsorbed by the mud at the outlet is 0.6mg/l without using the activator; The amount of gas was 1.3 mg/l. This value is 1.8 mg/l when using the closest analogue to this device.

Use an ultrasonically activated generator with a frequency of 21.4 MHz and a radiation power of 250 watts. The wave propagation direction coincides with the long axis of the vacuum unit. When the vacuum degree is -0.95 bar, the amount of residual gas is 1.3 mg/l; when the vacuum degree is - The amount of remaining gas at 0.7 bar is 0.3 mg/l.

Using a mechanical activator (sieve), rotate at a rate of 200 rpm (transmission power 0.5 kilowatts), the amount of residual gas is 0.3mg/l when the vacuum degree is -0.95bar; The amount of gas was 0.6 mg/l.

Five nozzles with a diameter of 1.5mm are installed on the side of the vacuum device. They can produce jets, parallel to the long axis of the tubular vacuum unit, and can provide 0.05m3/h 50bar pressure water flow (power consumption 1.2 kilowatts), in the vacuum degree The amount of remaining gas is 0.2 mg/l when the vacuum is -0.95 bar; the amount of remaining gas is 0.4 mg/l when the vacuum degree is -0.7 bar.

These results show that the improved degassing device can improve the degassing effect, which is 2-6 times higher than the currently known similar devices to desorb the gas adsorbed on the activated sludge particles, and at the same time improve the safety and reliability of the device operation .

Claims (2)

1. A kind of activated sludge degassing equipment, comprising: aeration tank, secondary settling tank, pumping chamber, water inlet collector, outlet water collector, water purification tank, vacuum pump and oscillator, aeration tank and net The pool is connected, the pumping chamber is respectively connected with the water purification tank and the secondary sedimentation tank through the water inlet collector and the water outlet collector, and the vacuum pump is connected to the pumping chamber through the pipeline; it is characterized in that the pumping chamber is equipped with An oscillator selected from mechanical, hydraulic or ultrasonic oscillators. 2. The activated sludge degassing device according to claim 1, characterized in that, the direct line of the shock wave of the oscillator is parallel to the liquid surface in the pumping chamber.