(1) Dosing and mixing
The dosing device is a metering pump as the main dosing device. It dissolves the medicine tank, agitator, liquid level gauge, check valve, pressure gauge, buffer, pipeline valve, base, escalator, and electronic control system. It needs to be assembled on a common platform to form a module.
Mixing: Raw water (≥0 07Mpa) first enters the static pipe mixer. The main function of the static mixer is to fully mix the added agent with water to achieve a good Z response effect.
Dissolution: Add solid polyaluminum chloride or polyacrylamide into the medicine dissolving barrel, stir and dissolve it with a stirrer, and formulate it into a certain concentration of coagulant and coagulant aid solution.
Dosing: The coagulant and coagulant aid are dosed by two metering pumps respectively. According to the water quality of the raw water (small test), determine the best dosage of Z, so that the suspended matter and colloidal impurities in the raw water will be followed. The precipitation clarification process is effectively removed.
The dosing volume and dosing pressure of the dosing device can be selected according to the needs of the process. The flow rate is from 1L / h to 8000L / h, and the pressure can be selected from the range of 0.1MPa to 25MPa to the appropriate product. The metering accuracy of the metering pump can be as high as ¡À 1%.
High degree of automation, the dosage can be adjusted according to water quality, saving operating costs;
Independent dosing system, convenient for real-time dosing and low operation difficulty;
Can realize local control, remote automatic control, manual and automatic conversion between each other;
It has the advantages of compact structure, small volume, low noise, stable work, simple installation, convenient operation and so on.
(2) Folding plate / partition flocculation zone
The structure of the folded plate flocculation tank is to place a certain number of parallel folded plates or corrugated plates in the pond.
The Coanda turbulent energy dissipation method mainly caused by the separation of the boundary layer caused by the scaling or turning of the folding plate is used to keep the horizontal uniformity along the course of the flocculation tank and the longitudinally dispersed input of a small amount of sufficient energy to effectively improve the input energy utilization And volume utilization of coagulation equipment, increase the relative movement of liquid flow to shorten the flocculation time and improve the flocculation sedimentation-capacity.
The mathematical description of flocculation is generally divided into two independent processes: migration and adhesion. The migration process produces collisions of particles. Migration is caused by differences in the speed of particles in the water.
In the folding plate flocculation tank, the speed difference is considered to be caused by the following three factors:
(1) Brownian motion of particles (plays a major role in anisotropic flocculation);
(2) Turbulent vortex (co-flocculation);
(3) Difference in sedimentation speed between particles (differential flocculation).
Adhesion depends on transient forces related to the surface properties of the particles themselves.
The influence of the hydraulic characteristics of the folded plate unit on the collision of floc particles is mainly manifested in: the vortex generation of the folded plate unit and the continuous and uniform unit setting improve the distribution of turbulent energy consumption, thereby increasing the value of the flocculation method, and therefore the Flocculation effect. Water flows through the folding plate unit, and under the action of the gradually expanding section and the decreasing section, a symmetrical vortex and a unilateral vortex can be formed. The separation of the current boundary layer at the wave crest is the cause of the vortex. According to the diffusibility of the vortex, it will be further decomposed into small-scale vortices until the Reynolds number associated with the water current micelles is low enough to no longer produce smaller vortices. At the same time, the large-scale vortex draws kinetic energy from the mainstream and is transferred to the smaller-scale vortex during the movement, so that it is transmitted step by step, all the way to the micro-scale vortex. In larger-scale vortex motion, fluid viscosity has almost no effect and can be ignored, so there is almost no energy consumption in kinetic energy transfer; while in micro-scale vortex motion, fluid viscosity will play a major role, which is transmitted to these The energy of the low-level vortex of Z will be converted into thermal energy by viscous effect. There are countless large and small vortices in the water flow at the same time, producing a series of pulsating frequencies with a continuous frequency spectrum.
The grid flocculation tank is formed by a series of vertical shafts. The flocculation tank is divided into many equal squares. The flow of incoming water flows from one grid to the next, and flows up and down until it exits. Within two-thirds of the whole grid, a grid or grid is placed horizontally. When the water flows through the gaps of the grid or grid, the water shrinks and expands after passing through the mesh to form a good flocculation condition.
(3) Sloping tube sedimentation area
The P series inclined pipe sedimentation area is in principle equivalent to the H series inclined pipe sedimentation, except that it is a single layer inclined pipe, and the H series is a double layer inclined pipe.
According to the sedimentation principle of the advection sedimentation tank to remove dispersive particles, under the conditions of a certain flow rate and a certain particle sedimentation speed, the precipitation efficiency of a tank is directly proportional to the plane area of the tank. For this reason, if in the same pond, it is divided into N intervals according to the height, the horizontal area is increased by N times, and the precipitation ability can be increased by N times in theory. After the pond is divided into many horizontal shallow grids, although the sedimentation efficiency can be improved, it is difficult to remove mud. To this end, the horizontal plate is changed to a sloping plate. On the one hand, the horizontal projection area is increased, and one area of mud can automatically fall to the bottom of the pool for easy removal. .
After adding many parallel inclined plates, the wet perimeter of the water cross section of the pool is increased, and the hydraulic radius is reduced. For this reason, at the same horizontal flow velocity v, the Reynolds number Re can be greatly reduced, thereby reducing water turbulence and promoting sedimentation.
The addition of a sloping plate shortens the particle precipitation distance and reduces the precipitation time. The inclined plate and inclined pipe sedimentation tank has achieved good results in production practice, especially the removal effect of dispersive particles is more significant.
(4) Mud collection area and mud discharge
The incoming water slowly enters the flocculation zone, undergoes a thorough coagulation reaction, and then enters the inclined pipe sedimentation zone. Under the action of gravity, the deposited sludge slides down the inclined direction of the inclined pipe, and at the same time, the alum flower that slides down in the diversion inclined pipe Under the action of hydraulic power, it is pushed into the sludge hopper of the water purification device.
The device is provided with a cone mud bucket to collect the mud, which can make the sludge get full contact, gather and compress, and is conducive to thorough dredging. The dredging area adopts gravity dredging, and the dredging valve opens automatically at regular intervals, and flows out through the dredging pipe under the gravity of the water itself. The mud bucket gravity discharges the mud automatically, which is fully controlled and saves water.
(5) Quick filter
The filtering area adopts the traditional quick-filter arrangement, and Z is used as a wide range of water filtration facilities to remove the residual suspended matter in the water after coagulation and sedimentation treatment. The turbidity of the effluent of the fast filter can reach below 3NTU. The filter material is generally a single-layer fine sand grading filter material. The flushing is performed by single water. The flushing water is supplied by a backwash pump.
， Z后经由配水干管、清水支管及干管后进入清水池。 During the filtration, the valve of the branch pipe of the filter is opened, and the raw water passes through the filter material layer and the supporting layer from the top to the bottom, and is collected by the branch pipe of the water distribution system. After Z, it enters the clear water tank through the distribution pipe, the branch pipe and the main pipe. When the effluent water quality does not meet the requirements or the head loss of the filter layer reaches a large value of Z, the filter material needs to be backwashed. In order to make the filter material layer in a suspended state, the backwash water passes through the filter material layer from the bottom to the top of the water distribution system, and is evenly distributed on the plane of the filter tank. The washing wastewater flows into the drainage tank and the muddy water channel and is discharged.
During backwashing, after the sewage has been filtered for a certain period of time, the resistance of the filter layer gradually increases. When the water level rises to a certain height, the automatic backwashing valve and backwashing pump are opened to form backwashing. The backwash lasted 4-5 minutes, and the backwash sewage was discharged into the sewage tank, and led to the sewer or mud pit from the sewage pipe.
Advantages: better flocculation effect, faster sludge discharge, less sludge drainage, stable filtration speed, simple structure, convenient operation and management, less energy loss, etc.
Effect: The effluent is stable, the water quality is good, the backwash water consumption is less than 3%, and the effluent water is less than 3 NTU.