CN202128952U - Composite flocculating and settling tank suitable for low-turbidity water - Google Patents

Abstract

The utility model provides a compound flocculation sedimentation tank suitable for low turbidity water quality. Including the upper sedimentation area, the middle flocculation area and the lower mud discharge area; the sedimentation area is equipped with an inclined tube sedimentation layer, above the inclined tube sedimentation layer is a clear water area and a water collection device with a water outlet, and below the inclined tube sedimentation layer It is a water distribution area; the flocculation area is equipped with a horizontal shaft mechanical agitator driven by a motor, and the water inlet is set at the lower part of the flocculation area; the mud discharge area is equipped with a mud storage bucket and a perforated mud discharge pipe, and each agitator corresponds to a storage mud bucket. The utility model can simultaneously complete two processes of flocculation and sedimentation, and has broad prospects and application value especially for the treatment of low-turbidity raw water.

Description

A compound flocculation sedimentation tank suitable for low turbidity water quality

technical field

The utility model relates to a water supply treatment device, in particular to a compound flocculation sedimentation tank.

Background technique

At present, domestic water supply plants usually use mixing, flocculation, sedimentation, filtration and disinfection to treat surface water sources. After the raw water is mixed with the coagulant, the flocs are formed through the flocculation equipment, and the flocs are separated from the water by gravity after passing through the sedimentation tank.

Flocculation is one of the important steps in water treatment. Traditional flocculation tanks mainly include hydraulic flocculation tanks and mechanical flocculation tanks. The mechanical flocculation tank completes the flocculation process by agitating the water flow through the agitator paddle. Due to the adjustable speed, it has a strong ability to adapt to changes in water volume and a wide range of adaptation to G value. At the same time, compared with the hydraulic flocculation tank, the design flocculation time of the mechanical flocculation tank is longer, about 20 to 25 minutes.

The inclined tube sedimentation tank is designed using the shallow pool theory, so it has the characteristics of short residence time compared with the advection sedimentation tank, generally within 30 minutes. This settling tank is formed by placing many inclined pipes with a horizontal plane at a certain angle (generally about 60°) in the settling tank. The water flows from bottom to top, and the particles sink to the bottom of the inclined tube. When the particles accumulate to a certain extent, they will slide down automatically. According to the investigation, the inclined tube sedimentation tanks of some water plants are prone to problems such as uneven water distribution during operation.

The surface water in some areas of our country, especially the reservoir water, shows the characteristics of low turbidity. The impurities in the low turbidity water are dissolved in the water in a fine colloidal dispersion system. Due to the low turbidity, the number of colloidal particles is small, and the particles collide and gather. Therefore, the formed flocs are fine, less and light, resulting in poor subsequent sedimentation effect, which in turn affects the quality of effluent water.

Contents of the invention

The purpose of the utility model is to provide a composite flocculation-sedimentation tank suitable for low-turbidity water quality, which can complete two processes of flocculation and sedimentation at the same time, is especially suitable for treating raw water with low turbidity, and can effectively save land occupation.

The purpose of this utility model is achieved in that:

Including the upper sedimentation area, the middle flocculation area and the lower mud discharge area; the sedimentation area is equipped with an inclined tube sedimentation layer, above the inclined tube sedimentation layer is a clear water area and a water collection device with a water outlet, and below the inclined tube sedimentation layer It is a water distribution area; the flocculation area is equipped with a horizontal shaft mechanical agitator driven by a motor, and the water inlet is set at the lower part of the flocculation area; the mud discharge area is equipped with a mud storage bucket and a perforated mud discharge pipe, and each agitator corresponds to a storage mud bucket.

The utility model can also include:

1. Each inclined tube in the inclined tube sedimentation layer is hexagonal.

2. The horizontal-axis mechanical agitator includes multiple units connected in series, each horizontal-axis mechanical agitator is separated by a partition wall, and a certain distance is kept between the horizontal-axis mechanical agitator and the partition wall.

3. The impeller of the horizontal axis mechanical agitator is provided with inner and outer paddles, the width-to-length ratio of the paddles is less than 1; the length of the paddles is not less than 75% of the diameter of the impeller; the total area of the paddles does not exceed 25% of the cross-sectional area of the water flow ; The length of the paddle is not greater than 75% of the diameter of the impeller.

4. The sedimentation zone and flocculation zone respectively include two or more stages, the water outlet of the previous stage of sedimentation zone is connected to the water inlet hole of the latter stage of flocculation zone, and the mud discharge zone is set at the last stage of flocculation lower part of the area.

5. There is an intermediate zone between the water outlet of the previous stage of sedimentation zone and the water inlet hole of the latter stage of flocculation zone.

6. There are two rows of horizontal-axis mechanical agitators in the flocculation zone, and there is a partition between the two rows of horizontal-axis mechanical agitators.

The utility model combines the characteristics and functions of the mechanical flocculation tank and the inclined tube sedimentation tank, and at the same time, according to the condition that the hydraulic retention time of the two is similar, a new type of composite flocculation sedimentation tank is proposed. According to the different flocculation areas, the composite flocculation sedimentation tank is divided into two types: the basic type of single-stage flocculation and the improved type of multi-stage flocculation.

It is divided into three functional areas from top to bottom, namely, sedimentation area, flocculation area and mud discharge area.

The sedimentation area adopts the inclined tube sedimentation process, and each inclined tube is hexagonal, and is installed in the sedimentation area at a certain angle. Above the inclined tube is the clear water area and water collection device, and below the inclined tube is the water distribution area, and the synergistic effect of the higher water distribution area and the flocculation area can overcome the problems of uneven water distribution in traditional inclined tube sedimentation tanks.

The water inlet hole is set at the lower part of the flocculation area, in order to distribute water evenly, and the water can be taken in from the longer side of the tank body. The flocculation area is equipped with a horizontal shaft mechanical agitator, which is driven by a motor. The partition wall is separated, and a certain distance is kept between the agitator and the partition wall. Set up 4 inner and outer paddles each, and the design of the paddles shall meet the following conditions as far as possible: ①The width-to-length ratio of the paddles is less than 1; ②The length of the paddles is not less than 75% of the diameter of the impeller, and the width is The area does not exceed 25% of the cross-sectional area of the water flow; ④The length of the paddle is not greater than 75% of the diameter of the impeller.

There is a mud storage bucket in the mud discharge area, one corresponding to each agitator, and a perforated mud discharge pipe is used to discharge mud.

The raw water enters the tank from the lower part of the flocculation zone after being mixed with chemicals. The water flows from bottom to top and enters the sedimentation zone after flocculation. The particulate impurities in the sedimentation zone slide into the flocculation zone along the inclined tube, which increases the turbidity of the raw water during the flocculation process. , and the increase in the number of particles in the water enhances the collision between particles, and at the same time, the larger particles that slide down from the sedimentation zone can act as a carrier to adsorb smaller flocs. Due to the slow stirring speed, when the formed flocs are large to a certain extent, they will sink to the mud discharge area and be discharged through the perforated mud discharge pipe.

According to the flocculation effect, multiple series of agitators can also be installed in the composite flocculation sedimentation tank along the direction of water flow, and the G value will decrease in turn, that is, the improved composite flocculation sedimentation tank.

The improved compound flocculation sedimentation tank is equipped with three-stage flocculation or multi-stage flocculation, and two or more stages of treatment sections are connected in series along the water flow direction, and each stage of treatment section is set up from top to bottom. The type is similar, but there is no mud discharge area in the lower part of the flocculation area. The rotation speed and G value of the agitator in the flocculation area of each treatment section are reduced in turn, and are separated by partitions, and water holes are set under the partitions. Before the final stage of flocculation, an intermediate zone can be set up. The incoming water is remixed in the intermediate zone after being treated by the front treatment section, and enters from the bottom of the last stage of flocculation zone. unanimous.

For the improvement of this new type of composite flocculation sedimentation tank, in addition to setting an intermediate zone between the last stage of the above-mentioned improved type, there are also many ways, for example: 1. Instead of adding the intermediate zone, multi-stage treatment The sections are all connected in series, and a unified sump is set on the upper part of the inclined pipe; 2. An intermediate zone is added between each treatment section. The specific implementation plan should be determined according to the raw water quality and the actual treatment effect.

Advantages and beneficial effects of the utility model:

① The flocs formed in the flocculation zone, after settling in the sedimentation zone, re-enter the flocculation zone along the inclined pipe, which effectively increases the turbidity of the raw water, and solves the problem that the low-turbidity raw water cannot form compactness due to the lack of collision opportunities between particles during the flocculation process. The problem of flocs.

In addition, the falling flocs have been accumulated on the inclined tube for a certain period of time. After entering the flocculation zone, the large and dense flocs themselves have better adsorption capacity for smaller flocs, and act as The role of the carrier. The formation of dense flocs can not only effectively precipitate the impurity particles in the water, but also improve the removal effect of insoluble organic matter adsorbed on the surface of the flocs. There are problems such as running alum flowers;

②The flocculated water enters the inclined tube evenly from bottom to top under the drive of the agitator, which can solve the problem of uneven water distribution that is easy to occur in traditional inclined tube sedimentation tanks;

③The raw water can be mixed into the compound flocculation and sedimentation tank after being dosed and mixed, and the two processes of flocculation and sedimentation can be completed at the same time, which simplifies the traditional water supply treatment process to a certain extent. occupied land.

④ When the turbidity of the raw water is small, compared with the traditional treatment process, this new type of composite flocculation sedimentation tank can better improve the turbidity removal rate and organic matter removal rate of the effluent, and improve the treatment effect.

Description of drawings

Fig. 1 is the functional area schematic diagram of the present utility model;

Fig. 2 is the basic structural representation of the utility model;

Fig. 3 is a schematic plan view of the flocculation zone;

Fig. 4 is a schematic plan view of layer precipitation area;

Figure 5 is a schematic plan view of the mud discharge area;

Fig. 6 is a kind of improved structure schematic diagram of the utility model;

Figure 7 is a schematic diagram of a stirring paddle.

Detailed ways

The utility model is described in more detail below in conjunction with accompanying drawing example:

Referring to Figure 1, the composite flocculation-sedimentation tank of the present invention can be divided into three functional areas, namely, the sedimentation area, the flocculation area and the mud discharge area.

Referring to Figure 2, the water distribution area 4, the inclined pipe 5, the water collecting channel 7, the sump 8 and the clean water area 6 belong to the sedimentation area. 3 is a flocculation zone, in which an agitator 2 is set. 1 is a water inlet, which is set in the lower part of the flocculation zone. 10 is the mud discharge area, at the bottom of the pool body, wherein 9 is the perforated mud discharge pipe.

Referring to Fig. 3, the agitator 2 in the flocculation zone is arranged in series in several sections, controlled by two motors 12, a waterproof casing 11 is set between the motor 12 and the agitator 2, and a certain distance is left between the agitator and the partition wall.

Referring to FIG. 4 , 5 in the precipitation zone is a hexagonal inclined tube arranged in the precipitation zone. The upper part of the inclined pipe is a water collection channel 7, and the treated water is collected by the water collection channel 8 on one side, and enters the next processing unit through the water outlet pipe 13. The walkway plate 14 is arranged on the uppermost part of the pool, and is used for walking by operators, washing and maintaining equipment.

Referring to Fig. 5, the inlet hole 1 in the bottom mud discharge area is located above the area, and the mud discharge area 10 is mainly composed of several mud discharge buckets, and 9 is a perforated mud discharge pipe therein, which is used to discharge sludge outward.

Example 1

Figure 1-Figure 5 shows a basic type of flocculation sedimentation tank, the direction of water flow is shown by the arrow in Figure 2, after the water is fully mixed with chemicals, it enters the lower part of the flocculation zone 3 from the water inlet 1, and flows from bottom to top Flow, after forming flocs under the slow stirring of the agitator 2, it enters the water distribution area 4. The purpose of setting the water distribution area 4 is to allow the water flow to enter the inclined pipe 5 evenly. During the flow of the inclined pipe 5, the water impurities sink in the inclined pipe 5 Above, the water flows upward into the clear water area 6, and then merges into the water collection channel 7 from the sump 8, and enters the next processing unit from the outlet pipe 13.

Example 2

Figure 6 shows an improved composite flocculation sedimentation tank. It is characterized in that multi-stage flocculation is set in the pool, in Figure 6 it is 3-stage flocculation, after the 1st and 2nd stage flocculation, an intermediate zone 16 is set before the 3rd stage flocculation. The purpose of setting the intermediate zone is that, due to the fast stirring speed of the agitator 2 in the first two stages of flocculation process, the formation of flocs is less, and the satisfactory turbidity removal effect may still not be achieved after sedimentation in the inclined tube 5, so the water in the first, After the second-stage flocculation, it is collected by the water collection channel 7 and then re-enters the third-stage flocculation through the middle area. The arrows in Figure 6 show the direction of water flow.

Whether the intermediate zone 16 is set or not, whether single-stage flocculation or multi-stage flocculation is used, and the height of the water distribution zone 4 should be adjusted according to the raw water quality and actual flocculation conditions.

Example 3

In the flocculation zone 3, flocs with a small volume density will be generated during the slow stirring process of the agitator 2, and these flocs will enter the sedimentation zone with the water flow upwards and deposit in the inclined tube 5. The shape of the flocs slides back into the flocculation zone 3; these larger flocs rotate with the agitator 2, and in this process absorb the newly formed smaller flocs; the bulk density of the flocs will further increase during the adsorption process. Large, finally sink down to the mud discharge area 10, and be discharged from the perforated mud discharge pipe 9. This process requires the stirring speed of the agitator to be slow enough.

Claims (8)

1. a composite flocculation sedimentation basin that is applicable to low-cloudy water matter is characterized in that: comprise the settling zone on top, the flocculation zone at middle part and the sludge discharging area of bottom; Be furnished with the tube settling layer in the settling zone, tube settling layer top is clear water zone and the captation that has delivery port, and tube settling layer below is water distributing area; Be provided with the trunnion axis mechanical agitator by driven by motor in the flocculation zone, the inlet opening is arranged at the bottom of flocculation zone; Sludge discharging area is established storage bucket, perforated sludge discharge pipe, the corresponding down storage bucket of each agitator.

2. the composite flocculation sedimentation basin that is applicable to low-cloudy water matter according to claim 1 is characterized in that: every inclined tube in the tube settling layer is hexagon.

3. the composite flocculation sedimentation basin that is applicable to low-cloudy water matter according to claim 2; It is characterized in that: said trunnion axis mechanical agitator comprises many of series connection; Separate with partition wall in the middle of every trunnion axis mechanical agitator, keep certain distance between trunnion axis mechanical agitator and partition wall.

4. the composite flocculation sedimentation basin that is applicable to low-cloudy water matter according to claim 3 is characterized in that: outside paddle board in the impeller of trunnion axis mechanical agitator is provided with, and the breadth length ratio of paddle board is less than 1; The length of paddle board is not less than impeller diameter 75%; The gross area of paddle board be no more than water flow section long-pending 25%; The length of paddle board is not more than 75% of impeller diameter.

5. according to any one described composite flocculation sedimentation basin that is applicable to low-cloudy water matter of claim 1-4; It is characterized in that: described settling zone, flocculation zone comprise secondary respectively or more than the secondary; The delivery port of previous stage settling zone links to each other with the inlet opening of back one-level flocculation zone, and said sludge discharging area is arranged on the bottom of afterbody flocculation zone.

6. the composite flocculation sedimentation basin that is applicable to low-cloudy water matter according to claim 5 is characterized in that: be provided with the mesozone between the inlet opening of the delivery port of previous stage settling zone and back one-level flocculation zone.

7. the composite flocculation sedimentation basin that is applicable to low-cloudy water matter according to claim 5 is characterized in that: the trunnion axis mechanical agitator comprises two rows side by side in the flocculation zone, between the two row of horizontal shaft mechanical agitators dividing plate is arranged.

8. the composite flocculation sedimentation basin that is applicable to low-cloudy water matter according to claim 6 is characterized in that: the trunnion axis mechanical agitator comprises two rows side by side in the flocculation zone, between the two row of horizontal shaft mechanical agitators dividing plate is arranged.

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