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Filters · High Solids & Slurry Duty

Automatic backwash filters

Applied where solids loading is heavy, the fluid is viscous, or the stream is a slurry, and filtrate supply is required to remain stable throughout. Fluid passes through the element, contaminants accumulate on the filtration surface, and a portion of the flow is reversed to displace and discharge them. Manual and motorised versions are manufactured with basket, wedge wire or disc edge elements, initiated on differential pressure, on a timer, or on demand.

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<Flair automatic backwash filter installed on a process line Photograph of completed unit
Automatic Backwash Filters
Construction & Types

Two operating modes, three element types

An automatic backwash filter is installed on lines carrying heavy solids loading, slurries or viscous fluids where filtrate supply must remain uninterrupted. Fluid passes through the element; retained solids build up on the filtration surface and are periodically cleared by reversing a portion of the flow back through the element.

Manual Infrequent cleaning

Backwash cycle initiated by a hand-operated valve or lever. Suits duties where cleaning is infrequent or where power is not readily available at the installation point.

Motorised Frequent / unattended duty

Backwash cycle initiated automatically on differential pressure or timer, without operator intervention. Recommended where the cycle runs frequently or a delayed response cannot be tolerated.

Wedge Wire Element High solids

Continuous slot construction suited to continuous high solids and slurry duty, resistant to blinding under heavy loading.

Disc Edge Element Fine filtration

Stacked disc construction, preferred for finer filtration down to 50 micron and for viscous fluid duty.

Specification

Standard range

Where a stated range does not cover a particular requirement, equipment is engineered to the customer specification.

Size range 50 mm to 600 mm
Element type Basket, wedge wire or disc edge
Cleaning initiation Differential pressure, timer, or manual
Design code ASME Sec VIII Div 1 where required
Materials Carbon steel, SS 304 and SS 316, others on request
Options PLC control panel, motorised backwash valve, DP transmitter, skid mounting with pump
Materials of Construction

Grades routinely handled

Carbon Steel SS 304 SS 304L SS 316 SS 316L

Alloy steel, duplex stainless and other grades are quoted against the process fluid. Element material is selected against the solids and fluid characteristics, and a carbon steel housing with a stainless element is a routine specification for backwash duty.

Applications

Where these units are installed

Raw water intake at power and process plants Slurry and high solids process streams Viscous fluid duty in chemical and polymer plants Pre-treatment ahead of finer filtration stages Irrigation and horticulture water supply
FAQ

Common questions

A self-cleaning filter scrapes or brushes the element surface and discharges the scraped solids through a small purge valve. An automatic backwash filter reverses a portion of the flow back through the element to dislodge the cake, which suits heavier solids loading, slurries and viscous fluids that a scraper mechanism cannot clear. See our Self-Cleaning Filters page if your duty is lighter.
On differential pressure across the element, on a fixed timer, or on manual demand. Differential pressure initiation is the most common, since it backwashes only when the element actually needs it rather than on a fixed interval, saving both filtrate and downtime.
Yes. Manual units use a hand-operated valve or lever for the backwash cycle and suit duties where cleaning is infrequent or where power is not readily available at the installation point. Motorised units are recommended where the cycle runs frequently or where the process cannot tolerate a delay in response to rising differential pressure.
A portion of the filtrate is diverted to clear the element, and the exact volume depends on element size, solids loading and cycle duration. Send us your flow rate and expected solids loading and we will size the backwash cycle so filtrate supply downstream remains effectively continuous.
It discharges through a dedicated backwash outlet, which is routed to drain, to an effluent treatment system, or recirculated depending on the process. Confirm your site’s effluent handling arrangement at enquiry stage so the outlet connection is sized and positioned correctly.
Basket, wedge wire and disc edge elements are all manufactured, each suited to a different solids characteristic and micron rating. Wedge wire elements suit continuous high solids duty, while disc edge elements are preferred for finer filtration down to 50 micron. Confirm your solids loading and required filtration range and we will recommend the element type.
Yes. The filter, pump, control panel and backwash valve can be supplied as a single skid-mounted assembly, piped and wired, so installation on site is limited to connecting the inlet, outlet and power supply.
Yes. Standard units are built to ASME Sec VIII Div 1, and IBR construction is offered on request where the application requires it. Advise us at enquiry stage so the unit is engineered and documented accordingly from the outset.
Enquiry

Request a quotation for Automatic Backwash Filters

Give us the line size, flow rate, fluid and operating conditions and we will engineer directly against them. Most enquiries are answered the same working day.