I. Introduction to Shallow Sand Filter Equipment
A shallow sand filter is a widely used fully automatic media water treatment filtration device, mainly used for the deep purification of suspended solids, colloids, silt, trace impurities, and some organic matter in water. Unlike traditional deep sand filters, this equipment uses shallow media filtration technology, resulting in a thinner filter layer, higher filtration accuracy, and stronger backwashing efficiency. The overall design features a modular, integrated tank structure, with the tank primarily made of corrosion-resistant carbon steel or stainless steel, ensuring exceptional durability. Equipped with fully automatic multi-way control valves, the equipment can achieve fully unattended operation, including automatic filtration, automatic backwashing, and automatic sewage discharge. It is primarily used as a pre-treatment device in water treatment systems, for circulating water purification, and for deep wastewater treatment, effectively protecting downstream precision equipment and reducing subsequent water treatment operation and maintenance pressure. It is a core filtration device in industrial and municipal water treatment projects.
II. Working Principle of Shallow Sand Filter
The shallow sand filter utilizes the mechanical interception, adsorption, and bridging principles of homogeneous quartz sand filter media to purify water. The entire system consists of two main workflows: filtration and backwashing, with fully automated switching between them. Under normal filtration conditions, raw water flows evenly from top to bottom through a shallow quartz sand filter layer. Silt, suspended solids, colloidal particles, and fine impurities in the water are effectively trapped and adsorbed by the filter media. The filtered clean water flows out evenly through the bottom collection system, completing the water purification process.
III. Core Advantages of Shallow Sand Filters
1. Shallow Filtration, Higher Purification Efficiency: Utilizing a specialized shallow filter media formulation, compared to traditional deep sand filtration equipment, the filter layer utilization rate is higher, and there is less likelihood of localized dead zones. It provides better filtration of fine suspended solids and colloidal impurities, resulting in more stable effluent quality.
2. Fully Automatic Operation, Simple Maintenance: Equipped with an intelligent automatic control system, it can automatically start and stop the backwash process based on both differential pressure and time modes. No manual operation or dedicated personnel are required, significantly reducing manual maintenance costs and adapting to unattended operating conditions.
3. Highly Water-Saving and Efficient Backwashing, Preventing Material Loss: The equipment adopts a uniform water distribution and collection structure, ensuring even backwash water flow and thorough rinsing without residual dirt. It effectively avoids the material loss and leakage problems associated with traditional sand filter equipment, resulting in significant water savings.
4. Compact Structure, Smaller Footprint: The integrated design eliminates the need for complex supporting civil engineering facilities, making installation convenient and requiring minimal space. It is highly adaptable to upgrading older equipment and projects with limited space.
5. Stable Performance and Long Service Life: The tank is treated for corrosion and rust prevention, resisting acids and alkalis. The filter media is wear-resistant and durable, allowing for long-term recycling. The equipment has a low failure rate, stable long-term operation, and low overall operating costs.
6. High Processing Capacity and Wide Adaptability: Each unit has a high water throughput capacity and can be used individually or in parallel combinations. It can flexibly adapt to different water volume conditions, meeting the water treatment and purification needs of various scenarios.
IV. Application Areas of Shallow Sand Filters
Shallow sand filters are suitable for various industrial, municipal, and domestic water treatment scenarios, offering exceptional versatility. In the industrial sector, they can be used for pretreatment of production water, industrial circulating water, cooling water purification, and deep wastewater reuse in industries such as chemical, textile, food, pharmaceutical, and machinery. In the municipal sector, they can be used for municipal tap water pretreatment, secondary water supply purification in residential areas, and deep filtration at the back end of sewage treatment plants. In the domestic and agricultural sectors, they can be used for centralized rural water supply, well and river water purification, and irrigation water filtration. They are also widely used in central air conditioning circulating water, heat exchange systems, and landscape water circulation purification, effectively intercepting impurities in the water, protecting downstream precision facilities such as pipes, heat exchangers, pumps, and reverse osmosis equipment, and extending the service life of the entire water treatment system.
V. Shallow Sand Filter Process Flow
Shallow Sand Filter Process Flow Diagram
Raw Water Inlet → Uniform Water Distribution → Shallow Quartz Sand Filter Layer Retention and Purification → Clean Water Collection and Outlet → Impurity Accumulation and Pressure Difference Increase → Automatic Backwashing → Impurity Discharge → Equipment Reset and Circulation
1. Inlet Water Distribution Stage: The raw water to be treated enters the filter tank and is evenly distributed to the entire filter layer cross-section through the top water distribution system to avoid excessively fast local water flow affecting the filtration effect;
2. Shallow Filtration Stage: Water flows from top to bottom through the shallow quartz sand filter media, and the water... Suspended solids, silt, colloids, and other impurities are effectively trapped and adsorbed, purifying the water.
3. Normal Water Supply Stage: The purified water is collected centrally through the bottom collection device and smoothly transported to downstream water use or water treatment equipment.
4. Automatic Backwashing Stage: After the filter layer accumulates impurities to the required standard, the system automatically switches the water path, using reverse water flow to flush the filter layer, loosening and rinsing the filter media and removing attached dirt.
5. Sewage Discharge and Reset Stage: Wastewater and impurities generated during backwashing are discharged through the drain outlet. After backwashing, the system automatically resets, and the equipment re-enters a stable filtration cycle.
DIEN Water Treatment Shallow Sand Filters are custom-made products from the source manufacturer, supporting non-standard customization with different flow rates, materials, and control methods. The equipment undergoes strict quality inspection before leaving the factory, adapting to various complex water qualities and operating conditions. We provide on-site installation, commissioning, and lifetime after-sales service—a one-stop service—making it the preferred equipment for water pretreatment and circulating water purification in various industries.
