CN
CN
MENU

Product Center

Green Innovation · Scientific and Technological Development · Industrial Responsibility · Joint Construction of Civilized Ecology

Secondary sedimentation tank scraper suction machine

The secondary sedimentation tank scraper suction machine is the core equipment of the secondary sedimentation tank in the activated sludge process of sewage treatment plants. It is used to scrape and discharge the settled activated sludge, achieve sludge reflux or residual discharge, and at the same time skim off the floating slag. Widely used in urban sewage treatment plants, industrial wastewater treatment (chemical, printing and dyeing, pharmaceutical, food, etc.), water treatment plant sedimentation tanks, reclaimed water reuse projects, and sludge concentration tanks.

National Service Hotline：400-611-6861
Product Introduction

The secondary sedimentation tank scraper suction machine is suitable for radial flow circular sedimentation tanks, mainly composed of a working bridge (full bridge/half bridge), a transmission device, a scraper mechanism (logarithmic spiral scraper), a suction system, a central support, a stabilizing cylinder, an overflow weir plate, a floating slag scraper collection device, and an electrical control system. The transmission device drives the working bridge to rotate around the pool, and the scraper plate scrapes the sludge at the bottom of the pool towards the suction port. The sludge is discharged from the pool through siphon or pump suction formed by the water level difference, while the floating slag is skimmed into the slag discharge hopper. Divided into peripheral transmission (full bridge/half bridge) and central transmission (suspension/gantry) according to the transmission mode; According to the discharge method, it can be divided into scraping type and scraping suction type.

Technical Advantage
Thoroughly scraping mud and reliable operation
The scraper adopts a logarithmic spiral design, with uniform force distribution. When encountering obstacles, it automatically releases the rake, and with torque protection, it has high safety performance.
High sludge discharge efficiency and stable sludge concentration
The suction type utilizes the water level difference to suction sludge while walking, resulting in high sludge concentration and good sludge discharge effect; The full bridge scraping cycle is short and suitable for situations with large sludge volumes.
low energy consumption
Compared to devices of the same specifications, it can save about 50% electricity and has lower operating costs.
High degree of automation
Supports local/remote control and microcomputer networking, enabling fully automatic operation.
Complete overload protection
Set up mechanical and electrical dual overload protection for safe and reliable operation.
Easy maintenance
The scraper type suction port has a simple structure and is not easy to block. The underwater components can be made of stainless steel, which has a long corrosion resistance life.
Adaptable
Suitable for primary sedimentation tanks, secondary sedimentation tanks, and concentration tanks with a diameter of 13~60m. The surface load of high-density sedimentation tanks can reach 15~25m/(m ² · h).
Process Selection

1. Selection based on pool type: For circular radial flow secondary sedimentation tanks, center drive or peripheral drive scraping and suction machines are preferred. For tank diameters ≤ 18m, center drive type (compact structure, low energy consumption) is selected. For tank diameters>20m, peripheral drive full bridge type (large transmission torque, wide coverage) is selected; The rectangular laminar flow secondary sedimentation tank adopts a gantry crane type scraper suction machine.

2. Selection based on treatment scale: For small-scale sewage treatment plants (with a daily treatment capacity of less than 50000 tons), central drive or half bridge peripheral drive scraper suction machines are selected; Large and medium-sized sewage treatment plants (with a daily processing capacity of ≥ 50000 tons) use full bridge peripheral transmission or gantry crane scraper suction machines.

3. Selection based on sludge properties: Conventional activated sludge process secondary sedimentation tanks use siphon or static pressure suction machines; Industrial wastewater secondary sedimentation tanks with high sludge concentration (>6g/L) or high sand content should use pump suction scraping and suction machines.

4. Selection based on installation conditions: For underground or semi underground secondary sedimentation tanks, central or peripheral transmission scraping and suction machines are preferred; The above ground rectangular secondary sedimentation tank adopts a gantry crane type scraper suction machine; Modular assembly equipment can be used for the renovation of existing sedimentation tanks, without the need for large-scale civil construction.


Equipment Selection

Parameter Description and Selection Points

Equipment type selection: pool diameter ≤ 20m, priority center drive; Priority is given to peripheral transmission when the pool diameter is ≥ 20m. Choose full bridge type for large processing capacity and good sludge settling performance; Half bridge type is preferred for low sludge volume and high cost. For the secondary sedimentation tank and biochemical tank, the central transmission single tube/double tube suction machine has better working performance than the peripheral transmission

Accurately measure the diameter of the sedimentation tank, and the equipment model should strictly correspond to the tank diameter

The depth of the pool is generally 2.5~5.5m. When selecting, it is necessary to confirm the depth size of the civil engineering pool body

The conventional slope of the pool bottom is 1:10 (about 5.7 °), and it should be clearly selected to maintain a reasonable gap between the scraper and the pool bottom

Drive power peripheral transmission: pool diameter of 20-28m is about 0.37kW, 30-40m is about 0.55kW, 45-55m is about 0.75kW, 60-80m is about 1.5kW; central transmission: commonly used 0.37-1.5kW

The peripheral line speed is generally ≤ 3m/min, with a pool diameter of 20-25m of about 1.6-1.7m/min, 30-35m of about 1.8-2.0m/min, and 45-55m of about 2.2-2.4m/min

Material selection for water-based parts: carbon steel hot-dip galvanized/epoxy anti-corrosion/304 stainless steel; Underwater section: 304 or 316L stainless steel

Siphon suction method (requires vacuum pumping, energy-saving, suitable for conventional secondary sedimentation tanks); Pump suction (forced sludge discharge, suitable for primary sedimentation tanks); Gas lift+siphon composite (suitable for physical and chemical sludge with concentration ≤ 4%)

The number of sludge discharge pipes includes single pipe (for small and medium-sized tanks), double pipe (for large and medium-sized tanks, especially for incoming and outgoing tanks), and multiple pipe (for tanks with a diameter of ≥ 40m)

The scum scraping system is configured according to the process requirements, and the position and method of the slag discharge outlet are clearly defined

Overload protection: mechanical overload protection (spring type over torque mechanism or shear pin)+electrical overload protection, dual protection

The underwater transmission part of the sealing system should adopt a reliable sealing structure

Installation method: create new embedded parts; Anchoring after renovation requires verification of structural strength

Control mode: local+remote, can be equipped with microcomputer networking interface; Outdoor electrical control box protection IP55, stainless steel shell

Following the standards CJ/T 540-2019 "Suspended Central Drive Thickener for Gravity Sludge Thickener", CJ/T 443-2014 "General Technical Conditions for Grid Cleaners for Water Supply and Drainage" (reference frame standard, specific equipment does not have special strong standards), GB50014-2021 "Outdoor Drainage Design Standard" (basic parameters for sedimentation tank design)


Friendship Link
Huapu Environmental Protection Huapu Water Treatment Equipment