Shallow-Bed Sand FilterShallow-Bed Sand Filter for Water Systems
Spherical shell with multi-tank series design, filtration velocity up to 40 m/h, automatic backwash, and a compact footprint that saves space.
The shallow-bed sand filter is an efficient water filtration solution introduced by LANXUN Technology, widely used for suspended-solids filtration in industrial circulating water, cooling water, and HVAC water systems. It uses a spherical shell and a combined series/parallel multi-tank design, with a single-tank filtration velocity of up to 40 m/h, greatly reducing the equipment footprint. A unique upper water distributor and lower collector ensure even water distribution through the media layer without short-circuiting. Backwashing uses an automatic control program and the system's own water pressure to reverse-flush the media, requiring no shutdown and no manual intervention. The media are high-quality quartz sand or anthracite with a long service life and low long-term operating and maintenance costs. The shell is made of rubber-lined carbon steel or FRP with excellent corrosion resistance and a design life of over 20 years.
Key Highlights
Compact Footprint
The spherical tank and shallow-bed design achieves a filtration velocity of 40 m/h, so the footprint is only 1/3 to 1/2 that of a conventional sand filter at the same treatment capacity.
Large Filtration Capacity and High Speed
A single tank handles up to 50 m³/h, and multiple tanks in parallel easily scale to several hundred m³/h, suitable for large-flow industrial water systems.
Automatic Backwash
Backwash is triggered by both PLC and differential pressure. The process automatically switches valves and backwashes tanks one by one without interrupting the continuity of system water supply.
Unique Distribution and Collection Design
An upper mushroom-type water distributor plus a lower multi-arm collector distribute water evenly, avoiding short-circuiting and channeling in the media layer for stable filtration efficiency.
High-Quality Filter Media
Carefully selected 0.45–0.85 mm uniformly graded quartz sand with a mud content of <0.5%; anthracite or activated carbon media are also available to suit different water qualities.
Low Long-Term Maintenance Cost
No wearing moving parts, media replacement every 5–8 years, and backwash water consumption of <3% of the treated water, giving extremely low operating costs.
Excellent Corrosion Resistance and Long Life
The tank is available in rubber-lined carbon steel (acid and alkali resistant) or FRP (never rusts), with a design life of over 20 years and high whole-life cost-effectiveness.
Working Principle and Structural Features
The following content is excerpted from the Shallow-Bed Sand Filter product manual
Working Principle
The shallow-bed sand filter uses a nearly spherical shell and a unique internal design to ensure smooth filtration flow, and using multiple tanks in series gives even better filtration. It is suitable for industrial and commercial HVAC systems with large flows and faster filtration rates, among other applications.
During filtration, pressurized water enters the water distribution system from the filter unit inlet and reaches the filter media layer evenly, where suspended solids are intercepted. A precisely slotted collector at the bottom of the filter evenly collects the clean filtered water and discharges it.
As impurities accumulate, the differential pressure rises. When it reaches the set value or the set cleaning time is reached, the system automatically switches to backwash: pressurized water flows through the collector to scour the filter media layer, detaching and discharging the trapped contaminants. After at least 3 minutes the backwash ends and the system automatically returns to the filtration state.
Four Main Components
The unit consists of four parts: tank, piping, control system, and pump. The tank contains a water distributor, filter media, and water caps, and butterfly valves are fitted at all inlet and outlet ends.
Precise Technical Parameters
Inlet turbidity <50 FTU, outlet turbidity <10 FTU, working pressure <0.6 MPa, working temperature 5–60℃, and inlet-outlet differential pressure 0.1–0.15 MPa.
High-Speed, Low-Consumption Filtration
Normal filtration velocity is about 40 m/h and can reach 60 m/h depending on water quality; backwash water consumption is <1% and backwash duration is 2–3 min. Backwash uses product water, so no booster pump or backwash pump is required.
Homogeneous Filter Media
Refined, carefully selected quartz sand or garnet is used as the filter medium, chosen according to water quality; homogeneous media with a minimum particle size of 0.16 mm can be used.
Unique Distribution and Collection Device
The unique water distribution system and evenly arranged collector keep the water flow laminar throughout filtration, so the sand bed surface remains flat and the outlet water quality stays stable.
Intelligent Automatic Backwash
Backwashing is automatically identified and controlled by the intelligent control system. In multi-tank systems, tanks backwash one by one in turn during normal operation, with no manual intervention, automatically adapting to fluctuations in suspended solids.
Technical Specifications
| Model | Tank Diameter (mm) | Single-Tank Flow (m³/h) | Filtration Area (m²) | Filtration Velocity (m/h) | Working Pressure (MPa) | Backwash Flow (m³/h) | Net Weight (kg) |
|---|---|---|---|---|---|---|---|
| SFS-600 | 600 | 12 | 0.28 | 40 | 0.6 | 8 | 150 |
| SFS-800 | 800 | 20 | 0.50 | 40 | 0.6 | 14 | 260 |
| SFS-1000 | 1000 | 30 | 0.79 | 40 | 0.6 | 20 | 420 |
| SFS-1200 | 1200 | 45 | 1.13 | 40 | 0.6 | 30 | 580 |
| SFS-1400 | 1400 | 62 | 1.54 | 40 | 0.6 | 40 | 760 |
| SFS-1600 | 1600 | 80 | 2.01 | 40 | 0.6 | 52 | 980 |
| SFS-1800 | 1800 | 102 | 2.54 | 40 | 0.6 | 65 | 1250 |
| SFS-2000 | 2000 | 126 | 3.14 | 40 | 0.6 | 80 | 1580 |
Product Gallery
Images are from the Shallow-Bed Sand Filter product manual
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