Multi-column Automatic Backwash Filter for Industrial Circulating Water Filtration

Product Introduction

This multi-column automatic backwash filter is an advanced, easy-to-operate automatic filtration solution widely adopted across metallurgy, chemical, petroleum, paper, pharmaceutical, food, mining, power and municipal water supply industries. It is perfectly suited for filtering industrial condensate, washing water, wastewater and circulating water, including metallurgical continuous casting water systems, blast furnace water circuits and high-pressure descaling systems for hot rolling lines. Assembled with heavy-duty water filter housing, the self-cleaning filter consists of a pressure vessel body, multiple filter elements, rotating backwash assembly, differential pressure controller and electrical control cabinet. Each filter column uses high-strength Johnson wedge wire screen or metal woven mesh as the filter medium, delivering stable particle retention performance under continuous flow and fluctuating working pressure.

Working Principle

The core components of this filter include shell, filter cartridges, backwash rotating mechanism, differential pressure controller and electric control unit. The filter elements are made of robust Johnson wedge wire screens or metal woven mesh. Two trigger modes are available: differential pressure control and time-based control. When impurities accumulate on the inner surface of filter elements, the pressure difference between inlet and outlet gradually rises. Once the differential pressure hits the preset threshold (such as 1 kgf/cm²), or the timer reaches the scheduled cycle, the electric controller sends a signal to activate the backwash rotating mechanism. When the suction port of the backwash assembly aligns with the inner side of one filter element, the blowdown valve opens to release pressure and drain water. A negative pressure zone forms inside the filter element, with backwash differential pressure maintained at 3 to 4 times the normal filtration differential pressure. Clean water from outside the screen reversely flows inward, stripping off impurity particles attached to the inner wall of the filter screen. The contaminants flow into the suction tray and are discharged through the blowdown pipeline. Crucially, only one single column is backwashed at a time. All remaining filter columns keep running normally, so the main water supply never stops during the whole cleaning sequence.

Technical Specifications

Core Advantages

1. Microprocessor program control: 

automatic filtration, differential pressure detection, automatic backwashing and automatic blowdown, low running cost.

2. Non-stop continuous operation: 

cleans filter columns one by one, the main filtration process remains uninterrupted.

3. High efficiency and low energy consumption: 

large effective filtration area, low backwash frequency, little blowdown water consumption and minor pressure loss.

4. Superior backwashing performance: 

special screen structure and optimized control logic provide strong reverse flushing strength for thorough cleaning.

5. Wide applicability: 

available precision ranges cover 10 micron to 3000 micron to match diverse raw water quality.

Modular multi-column layout, flexible flow capacity expansion according to customer pipeline requirements.

Minimal wearing parts, simple maintenance schedule and less downtime for industrial production lines.

Application Scenarios

1. Metallurgy Industry

Filtration of heavy metal scrap cleaning recycling water, cooling circulating water and condensate water. It protects nozzles and water pumps, stabilizes water quality to guarantee product quality and long-term system operation. Typical use cases: continuous casting water, blast furnace water, hot rolling high-pressure descaling water.

2. Chemical & Petrochemical Industry

Removal of particulate impurities from brine, process water and circulating cooling water, purifying chemical medium and improving finished product quality.

3. Power Plant & Thermal Power Plant

Filtration of wet electrostatic precipitator spray water, ash recycling circulating water, condensate water and desulfurization wastewater. It shields spray nozzles and pumps from abrasive particles to prevent clogging and equipment damage.

4. Oilfield Wastewater Treatment

Captures suspended solids in oilfield produced water, ensuring qualified water quality for reinjection.

5. Other Sectors

Paper making, food & beverage, pharmaceutical, mining and municipal water supply for raw water pretreatment and circulating water side-stream filtration.

FAQ

Q1: Will the whole pipeline stop supplying water during backwashing?

A1: No. The filter cleans one filter column at a time while all other columns keep filtering. The main water flow is never interrupted, which is critical for 24-hour continuous industrial production.

Q2: What is the difference between this multi-column backwash filter and brush type self-cleaning filter?

A2: This multi-column suction backwash design suits higher flow rates and heavier particle loads. It is widely used in large metallurgy, power and petrochemical circulating water systems, while brush-type models are more common for smaller cooling water pipelines.

Q3: Can I choose different precision for different filter columns inside one unit?

A3: Normally all filter elements inside one vessel adopt the same precision. If you need graded filtration, we can design a two-stage filter system for your project.

Q4: Is Johnson wedge wire screen easy to replace after long service time?

A4: Yes. Each filter column can be taken out separately for inspection, cleaning or replacement without dismantling the whole pressure vessel.

Q5: Which control mode is recommended for most circulating water projects?

A5: Differential pressure automatic control is the preferred option. It only triggers backwash when clogging occurs, saving water and energy compared with fixed-time backwashing.

Recommended Products

XF Series auto self cleaning strainer 

S304 S316 stainless steel fully Automatic Backwash Water 

316L Stainless Steel Brush Self-Cleaning Filter for Corrosive Water 

Heavy Duty Brush Type Self-Cleaning Strainer | Customizable Size & Material 

Brush Type Self-Cleaning Filter | Automatic Backwash Filter for Industrial Water Treatment