Suction-scanner self-cleaning — a motor-driven nozzle scanner traverses the screen, vacuuming debris off the surface with minimal water loss.
Self-Cleaning Filter Operation — in depth
The suction scanner is the most common self-cleaning mechanism. A scanner with nozzles traverses the inner screen surface; a small open drain port creates a focused reverse flow that vacuums the captured debris off the mesh and ejects it, all while the filter stays online and passes full flow.
What matters in practice
Nozzles sweep the inner screen face.
A drain port creates local reverse flow.
Only a small ejected volume each cycle.
Full flow maintained during cleaning.
| Step | Action | Note |
|---|---|---|
| Trigger | dP or timer | Starts cycle |
| Scan | Nozzle traverse | Sweeps screen |
| Eject | Open drain | Debris out |
| Resume | Close drain | Online |
Continue across this series
A companion deep-dive in this series.
Read MoreA companion deep-dive in this series.
Read MoreA companion deep-dive in this series.
Read MoreThe overview page this topic expands on.
Read MoreThe wider hub for this subject area.
Read MoreReynolds & Bauhm designs and delivers self-cleaning filter operation solutions backed by process engineering and performance guarantees.
Fundamentals, design drivers and practical guidance
Suction-scanner self-cleaning — a motor-driven nozzle scanner traverses the screen, vacuuming debris off the surface with minimal water loss.
Automatic self-cleaning filters protect downstream equipment by removing suspended solids continuously, cleaning their own screens without interrupting flow. They are specified by screen rating (the micron retention), the design flow and pressure loss, and the cleaning mechanism — and the art is matching all of these to a duty that may swing widely in solids load.
Screen rating sets what is captured: a coarser rating passes more but protects only against larger particles, while a fine rating protects sensitive equipment at the cost of more frequent cleaning. The screen material and construction — wedge-wire, weave or perforate in appropriate alloys — must withstand the differential pressure and the chemistry of the stream over its life.
Cleaning is triggered by accumulated differential pressure across the screen or by a timer, and executed by a backflush or a suction-scanner that traverses the element, drawing the captured solids off a small area at a time while the filter stays online. Sizing balances the clean-screen pressure loss against the dirty-screen trigger point and the backflush volume, so the filter protects equipment without itself becoming a bottleneck or wasting water on over-frequent cleans.
What our engineers assess on every scope of this type
| Parameter | Typical basis | Why it matters |
|---|---|---|
| Mechanism | Backflush / suction-scanner | Cleans while online |
| Reject | Minimised backflush | Saves water |
| Screen rating | Micron retention | Sets what is captured |
| Material | Wedge-wire / weave / alloy | Withstands dP and chemistry |
| Pressure loss | Clean vs dirty envelope | Avoids a bottleneck |
| Trigger | dP or timer | Initiates cleaning |
Common questions on automatic self-cleaning filtration
The filter is sized so its clean-screen loss is low and the dirty-screen trigger point sits within the available head, so it protects equipment without becoming a hydraulic bottleneck in the system.
It cleans a small area of screen at a time — by backflush or a traversing suction-scanner — while the rest of the element keeps filtering. Suction-Scanner Cleaning therefore protects downstream plant continuously, without an offline cleaning stop.
By the sensitivity of the equipment being protected: a fine micron rating guards delicate downstream plant but cleans more often, while a coarser rating passes more solids with less cleaning. The duty's solids load sets the balance.
Accumulated differential pressure across the screen, or an elapsed-time backstop — whichever comes first. Triggering on dP cleans only when needed, which minimises reject water and wear.
Our expertise spans multiple industries with sector-specific water treatment solutions.
Explore closely-related topics, equipment and guides
Send your influent analysis and our engineers assess your process and recommend a tailored treatment solution — free, confidential and no obligation.
Select the regulatory standard for your country — it sets which parameters we need for a compliance-aware process assessment.
Required parameters for the chosen standard are flagged on the sample form. You can still submit a partial set and we will advise what else to test.
Your sample is stored against your company so we can track the project. Provide a company name or email as a minimum.