Product Catalog
Backwash Filter
Backwash filter is a fully automatic on-line reverse cleaning filtration device. It uses the system’s own working pressure or external auxiliary water source to flush the filter screen in reverse by switching the flow direction, removing contaminants and discharging waste automatically. No shutdown or disassembly is required during the whole process. It serves as core filtration equipment for industrial circulating water, wastewater treatment, oilfield water injection and other industries.
- Parameters
- Drawing
- Application areas
Structural Composition
Filter Housing: Fabricated from carbon steel (Q235) / stainless steel (304/316L), horizontal / vertical pressure-bearing design, compatible with pipeline flange connections.
Screen Assembly: Stainless steel wedge wire screen / woven mesh / sintered mesh with multi-layer composite structure, featuring high mechanical strength, excellent corrosion resistance and anti-clogging performance.
Backwash Mechanism: Hydraulic diverter valve / electric / pneumatic control valve, matched with blowdown valve to switch fluid flow direction.
Cleaning Mechanism: Annular scraper / scraping disc, driven by cylinder for vertical reciprocating motion to strip contaminants from the inner surface of filter screen.
Control System: PLC / microcomputer controller, integrated with differential pressure detection, timing control and manual operation functions, equipped with fault alarm and signal feedback.
Blowdown System: Electric / pneumatic blowdown valve with independent drain outlet design for smooth discharge of contaminants.
Working Principle
Normal Filtration Stage:Water flows into the housing through the inlet and passes through the filter screen from inner side to outer side. Solid contaminants are trapped on the inner wall of the screen, and clean fluid flows out via the outlet.
Backwash Trigger:When screen clogging raises the inlet-outlet differential pressure to the preset value (adjustable range: 0.05–0.2 MPa), or the scheduled cleaning cycle expires (adjustable range: 1–24 h), the control system activates the backwash sequence.
Backwash & Blowdown Stage:The diverter valve switches position to reverse the water flow direction, flushing the screen from outer side to inner side. Simultaneously, the blowdown valve opens. Contaminants adhering to the screen inner wall are stripped off by reverse flow and discharged through the drain outlet together with wastewater.
Reset Stage:Upon completion of backwashing, the diverter valve resets and the blowdown valve closes. The filter resumes standard filtration mode. The entire process operates with continuous flow without shutdown.
Applicable Standards
Design & Manufacturing Standards: HG/T 21637-1991, SH/T 3411
Flange Standards: GB, HG, ANSI, DIN, GOST
Electrical Control Standards: GB/T 14048.1, GB 50054
Core Features
On-line backwashing: No shutdown or screen disassembly required; the backwash process does not interfere with normal water/material supply of the system.
High efficiency & energy saving: Short single backwash cycle (10–60 seconds), low water consumption (≤1% of total flow rate), low operating cost.
Wide application range: Capable of treating fluids containing high suspended solids, sediment, rust and floc contaminants; compatible with water, oil products and chemical media.
Easy maintenance: Simple structure, long service life of filter screen, few wearing parts; only regular inspection of blowdown valves and sealing components is needed.
产品参数
| Item | Parameter Range | Remarks |
|---|---|---|
| Model | ESGF-W Series | Horizontal straight-through / angle type, vertical multi-column type |
| Nominal Diameter | DN50–DN1000 (Common size: DN80–DN500) | Flange connection conforming to HG/T20592, ASME B16.5 |
| Treatment Flow Rate | 10–8000 m³/h (per unit) | Capacity expandable by parallel installation for multi-column type, max. up to 10000 m³/h |
| Working Pressure | 0.1–1.6 MPa (standard); High pressure version up to 2.5–4.0 MPa | Pressure class: PN6/10/16/25 |
| Filtration Accuracy | 5–3000μm | Wedge wire screen: 50–2000μm; Woven mesh: 10–3000μm |
| Operating Temperature | 0–80℃ (standard); High-temperature type ≤150℃ | Carbon steel: ≤380℃; Stainless steel: ≤480℃ |
| Control Mode | Differential pressure (0.05–0.2MPa), Timing (1–24h), Manual | PLC / Microcomputer control; explosion-proof type & remote communication optional |
| Backwash Duration | 10–60 seconds (adjustable) | Standard single backwash cycle: 30 seconds |
| Backwash Water Consumption | ≤1% of total flow rate | Continuous flow maintained during backwashing |
| Housing Material | Carbon steel (Q235) / SS304 / SS316 stainless steel | Duplex steel / titanium alloy available for customization |
| Filter Screen Material | SS304 / SS316L stainless steel wedge wire screen / woven mesh / sintered mesh | Uniform slot precision, anti-clogging performance |
| Blowdown Valve Diameter | DN40–DN100 | Matched with equipment nominal diameter; double blowdown outlets available for high-flow models |
Product Certifications
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