High-Efficiency Shallow Sand Filter for Wastewater Treatment

Introduction

The Shallow Sand Filter is an advanced water filtration system designed to remove suspended solids, particulate matter, and organic impurities from wastewater and process water. Its efficient and automated cleaning mechanism ensures uninterrupted operation and minimal maintenance. This filter is widely used in industrial water treatment, irrigation systems, aquaculture, and municipal wastewater applications.

Working Principle

The Shallow Sand Filter operates on a depth filtration principle, where water flows through a bed of fine sand, trapping contaminants and suspended particles within the granular media.

1. Filtration Phase:

• Raw water enters the filter through the inlet manifold and flows evenly through the sand bed.

• Suspended particles and impurities are trapped within the sand layers, while the filtered water is collected at the bottom and discharged through the outlet manifold.

2. Backwashing Phase:

• When the pressure difference between the inlet and outlet reaches a preset value, indicating clogging, the automatic       backwash process is initiated.

• The system temporarily switches to backwash mode, using filtered water from other units to flush out the accumulated       particles from the sand bed.

• Backwashing occurs sequentially in each filtration unit to maintain continuous operation.

The automatic cleaning process significantly reduces maintenance and ensures consistent filtration efficiency.

Key Components and Materials

1. Filter Housing:

• Made of carbon steel or stainless steel, resistant to corrosion and pressure.

2. Sand Bed:

• Composed of high-purity quartz sand with excellent filtration capabilities.

3. Inlet and Outlet Manifolds:

• Made from stainless steel to withstand variable water pressures.

4. Automatic Control System:

• Includes pressure sensors and a programmable logic controller (PLC) for automated backwash.

5. Backwash Valves:

• Made from corrosion-resistant materials like stainless steel or brass.

6. Piping and Fittings:

• Utilizes industrial-grade PVC or stainless steel for long-term reliability.

Applications

• Industrial Water Filtration:

• Removes suspended solids from process water and cooling water.

• Agricultural Irrigation:

• Ensures clean water for crop irrigation, reducing clogging in irrigation systems.

• Municipal Wastewater Treatment:

• Provides pre-filtration before biological treatment processes.

• Aquaculture:

• Maintains water quality by filtering out particulate matter and organic debris.

Key Selection Parameters

1. Flow Rate:

• Match the filter capacity to the system's water demand.

2. Filtration Precision:

• Choose based on the particle size to be removed, typically between 20-300 microns.

3. Material Compatibility:

• Select housing and component materials based on water quality and chemical composition.

4. Backwash Frequency:

• Estimate the backwash interval based on the level of contamination.

5. Installation Space:

• Consider the footprint and maintenance access.

6. Automation Requirements:

• Choose manual or fully automated systems according to operational needs.

FAQ

1. What is the filtration accuracy of the Shallow Sand Filter?

• The standard filtration accuracy ranges from 20 to 300 microns, depending on the selected sand grade.

2. How often does the filter perform backwashing?

• Backwashing frequency depends on water quality and can be set manually or automatically.

3. Is the filter suitable for seawater applications?

• Yes, if equipped with stainless steel housing and anti-corrosion components.

4. Can the filter handle high flow rates?

• Yes, the modular design allows for the combination of multiple units to increase capacity.

5. What maintenance is required for the Shallow Sand Filter?

• Routine checks on the control system and periodic sand replacement are recommended.

6. How long does the backwash cycle take?

• Typically, a complete backwash cycle takes 5 to 10 minutes per unit.

7. Can the filter be customized for different water qualities?

• Yes, material choices and filtration precision can be tailored to specific applications.

8. What is the typical service life of the sand bed?

• The sand typically lasts 3-5 years depending on water quality and usage frequency.