Automatic Siphon Filter

Overview

The automatic siphon filter is a new generation of water treatment equipment developed by the company based on domestic and international valveless gravity filtration technology. It offers a short construction period, low overall investment, a compact and flexible layout, a small footprint, high effluent quality, and easy operation and maintenance. It is suitable for treating water supply for cities, residential areas and industrial facilities.

Working Principle

The unit consists of a high-rate inclined tube settler and a gravity filter.

1. Inclined tube settler: Raw water passes through a mixer and is dosed with chemicals for coagulation. Suspended impurities form larger flocs and then enter the settling zone. According to the original documentation, when influent turbidity does not exceed 1,000 ppm, turbidity after settling can reach ≤15 ppm.
2. Gravity filter: Settled water passes through the distribution trough, U-pipe and rises through the siphon pipe. A distribution baffle under the tank cover spreads the water evenly over the filter media. Water flows downward through the filter bed, then through a low-resistance collection system into the filtered water tank. When the water level reaches the outlet pipe, the filtered water flows into the clean water tank.

As solids accumulate on the filter media, head loss increases and the water level in the siphon pipe gradually rises. At a set level, the auxiliary siphon pipe draws out air, creating a vacuum that initiates backwashing. Water in the backwash tank flows upward through the filter media, and the backwash water is discharged through the siphon pipe. After about 5 minutes, the water level drops to the siphon breaker, backwashing ends and the unit automatically resumes filtration.

Features

1. The main structure is steel, prefabricated at the factory and shipped to site for installation, shortening the construction period.
2. The design accounts for regional differences in water quality, extending coagulation reaction time and improving tolerance to load fluctuations. The deep-bed filtration system uses a low-resistance water distributor; according to the original documentation, filtered water turbidity reaches ≤3 ppm.
3. Uses hydraulic principles for automatic operation and simple handling. When the filter bed clogs to the set level, the unit starts backwashing automatically.
4. No mechanical backwash pump or water drawn from the clean water tank is needed for backwashing, reducing related equipment and piping.
5. Can be combined with an automatic chemical dosing system, a PLC-controlled sludge discharge system, and water supply and disinfection units for automatic, unattended operation.

Applications

The unit is used for surface water purification; iron and manganese removal from groundwater; side-stream filtration of recirculating water; removal of suspended solids from process wastewater; polishing filtration of organic wastewater after biological treatment and secondary clarification; and filtration of indoor swimming pool water.