Small Sink Tank Calculations? What is the budget of the grit remover tank? And how to calculate?

1. General design principles and parameters of sedimentation tank.

1. Design the flow rate.

The design flow rate of the sedimentation tank is the same as that of the grit tank. In the combined sewage treatment system, when the wastewater flows into the sedimentation tank, the maximum flow rate should be used as the design flow; When lifting with a water pump, the maximum combined flow rate of the pump should be used as the design flow. In the confluence system, it should be checked according to the design flow rate during rainfall, but the sedimentation time should not be less than 30min.

2. The number of sedimentation tanks.

For urban sewage plants, the number of sedimentation tanks should not be less than 2.

3. Empirical design parameters of sedimentation tank.

For urban sewage treatment plants, if there is no measured data of sewage sedimentation performance, the empirical parameters can be selected with reference to (Table 2-5).

4. The relationship between the effective water depth, sedimentation time and surface hydraulic load of the sedimentation tank is shown in Table 2-6.

5. The geometric size of the sedimentation tank.

The sedimentation tank is not less than high; The buffer layer height is adopted; The inclination angle of the inclined wall of the storage mud bucket, the square bucket should not be less than 60, and the round bucket should not be less than 55; The diameter of the sludge discharge pipe is not less than 200mm.

6. The effluent part of the sedimentation tank.

Generally, the weir flow is used, and the level is maintained at the weir mouth. The load of the outlet weir is as follows: for the primary sedimentation tank, it should not be greater than 2 9us·m; For the secondary sedimentation tank, it is generally taken. In some cases, a multi-tank effluent arrangement can also be used to improve the effluent quality.

7. The volume of the mud storage bucket.

Generally, it is calculated according to the amount of sludge not more than 2 days. For the secondary sedimentation tank, the sludge storage time shall not exceed 2 hours.

8. a sludge discharge part.

The sedimentation tank generally adopts hydrostatic pressure to discharge sludge, and the hydrostatic pressure value is as follows: the initial sedimentation tank should not be less than; The secondary sedimentation tank of the activated sludge method should not be less than; The secondary sedimentation tank of the biofilm method should not be less than.

According to the different forms, the sedimentation tank is divided into advection type, vertical flow type, radial flow type, and inclined tube sedimentation tank, and its calculation method is roughly based on the surface load to determine the area and depth of the tank. For detailed calculations, please refer to Volume 5 of the Water Supply and Drainage Design Manual, Urban Drainage.

It is recommended that the questioner first study the calculation method by himself, and then if there is a certain knowledge point that he does not understand, it will be more pertinent to ask questions.

In fact, this does not need to be so precise, basically it is about enough, the key is the size of the water flow, not the size of the pool.

We can't do such a professional question.

It's better to consult the relevant design company.

Can give you better advice.

What kind of grit tank.

1. If it is a rainwater grit tank, the full quota and many local quotas are comprehensive items, that is: according to the standard atlas construction, the budget is directly applied to the comprehensive items, and the "seat" is calculated, that is, the amount of work is a few, no need to calculate carefully, count the number directly from the drawings.

2. If the special grit tank or the pool that is not constructed according to the standard drawing, then it needs to be calculated separately, including earthwork, cushion, pool wall, pool bottom (masonry structure or concrete structure), pool cover, accessories, etc., which are calculated item by item in accordance with the bottom-up construction sequence of the drawings or instructions.

Continue to answer: for example, an axis example is a square pool of 3m, the pool wall is reinforced concrete with a thickness of 200, and the depth is 2m, the concrete workload of the pool wall is cubic meters, and the engineering quantity of the pool wall template is: [(square meters, in fact, the axis is not biased, that is, the length of the axis is equal to the length of the center line only calculated with the center distance, 3x4x2x2 = 48 square meters.

1. Pool type selection;

2.Sedimentation tank (clarification area) area, effective water depth and sludge area volume calculation.

1) Pool surface area a

a=q/q=q/ u

According to the Code for the Design of Outdoor Drainage

The design of the advection grit remover should meet the following requirements:

1 The maximum flow velocity should be, and the minimum flow velocity should be;

2. The residence time of the maximum flow rate should not be less than 30s;

3. The effective water depth should not be greater than that, and the width of each block should not be less than.

The design of the aeration grit tank should meet the following requirements:

1 The horizontal flow velocity is;

2. The residence time of the maximum flow rate is 1 3min;

3 effective water depth is, width to depth ratio is 1;

4. The aeration volume of sewage treated per m3 is air;

5. The direction of the water inlet should be consistent with the direction of the swirl in the pool, and the direction of the water outlet should be vertical with the direction of the water intake, and a baffle should be set.

The caisson construction should be laid because the mud inside is very soft, which increases the pressure. The construction method can generally be divided into two processes: production and sinking. According to different circumstances and conditions (such as caisson height, foundation bearing capacity, construction machinery and equipment, etc.), caisson can be made (poured) at one time and sunk at one time; Segmented production, high connection, one sinking; Or alternate production with sinking.

There are also floating caissons that are made on land, floated to the underwater sinking site and then sunk and connected to the height. In order to spread the weight of the caisson to a larger area and avoid cracks caused by the tilting or uneven settlement of the caisson, for large caissons, when the bearing capacity of the surface soil foundation is very low, a sand cushion should be laid on the surface of the foundation before making the first section of the caisson, and a skid should be laid along the edge of the shaft wall. Before the caisson sinks, the skids should be removed in a partitioned, sequential, symmetrical and synchronous manner.

The method of sinking the caisson depends on the soil layer and hydrogeological conditions through which the caisson passes. Generally, it is divided into two types: drainage subsidence and non-drainage subsidence. When the soil permeability is very small or the water inflow is not large, drainage (or no irrigation) can be used to sink; When the caisson passes through the sub-sand soil or sand layer with a large water inflow, in order to prevent the sand from pouring into the well and affecting the construction, it is sunk without drainage (or irrigation).

Sinking often uses methods such as grabs or hydraulic machinery to remove soil.

It is recommended to take a look at the "Water Supply and Drainage Design Manual for Urban Water Supply and Drainage", which basically determines the parameters such as flow rate and hydraulic residence time.

For example, if you choose 2 groups of grit tanks, each group of 2 grids, that is, 4 grids, then your minimum flow rate is the maximum flow rate, that is, the flow rate when all the pools are working, and the maximum flow rate is the flow rate when the 3 grid pool is overhauled.