The self-cleaning device of roller screen
As an efficient equipment in raw material handling ,Roller screen can deal with sticky and high-moisture materials easily . In ROM power plant or open-pit mine , almost every major process involved roller screen utilization , one of many advantage it had is self-cleaning system that provided great performance on deal with clogging and blinding .
What is a roller screen and why do we need it
Especially in lignite and coal handling area, which the raw material mostly contained a great quantities of moisture and ash , without proper pre-screening , it could be a real problem that prevent your business from profit , so screening the material before further process is essential , through roller screen , this process are dramatically simplified.
Roller screens’ operation is achieve through rotating shafts equipped with screen discs ,creating a dynamic screen surface.
The shaft is staggered arranged and disc is customizable to suit vary input material or ideal out put size. The rotation of shafts gave a momentum to lumps and blocks to moving on the screen surface and between the gap formed by discs allows smaller materials to drop through ,thus separate raw material into different size.
After doing so , we can make sure the material won’t contain any debris or lumps might cause harm to after stream equipment like crusher or conveyor ,avoid potential system failure risks
Other screening equipment like liner screen or vibration screen, when handling sticky or wet materials like lignite or coal , clogging and blinding always exist as huge problem , they can cause a lower operating efficiency , they can damage downstream equipment, they can cause major malfunction of whole system , generally speaking ,clogging and blinding could leads to more maintenance and operation costs.
Factors could affect roller screen’ normal operation
Generally speaking , major factors affecting roller screens’ normal operations can be sorted into two categories ,
Material Characteristics
Surface moisture : Often brought by rain or washing process , commonly , surface water is the most effective factor in screening process.
Muddy material : Similar to high-surface moisture materials , muddy material rise more problem to screening , like clogging and blinding are more often to happen , the material can adhere on the rotating shafts and discs even can cause drive overload.
Mechanical performance of the equipment
Static Screening method : Trommel screen are widely used in screening process, but both are facing a persisting problem, accumulated materials will eventually block the screening opening, causing serious inefficient.
Dynamic Screening method: By using a dynamic screening openings , roller screen is performed well when handling wet and sticky materials like lignite and clay, also can separate larger debris more efficiently.
Necessity of Self-Cleaning Device
Consistent Material Flow: By prevent clogging and screen aperture blockages , self-cleaning devices ensuring a continuous material output. Very essential for process sequence where flow interruptions can disrupt downstream operations and reduce overall plant productivity.
Provide protection for Critical Drive Components: Without material buildup on shafts and disc, self-cleaning mechanisms can reduce imbalance loading ,which can transmit abnormal stresses to bearings, gearboxes and motors, which could result in core component wear or failure.
Screening Efficiency Maintaining: Self-cleaning device maintain aperture openness which ensuring that fines pass through as intended, thus preserving product quality. But clogging can reduce the effective screening area, impairing separation accuracy.
Manual Cleaning Reduced: Fully automated self-cleaning process throughout whole screening cycle, significantly reduce labor demands and improve operational safety.
What is a self-cleaning system of a roller screen
Comb shaped scraper made of wear and abrasive-resistance alloy steel mounted beneath each shaft, as shaft rotate, the scraper can remove materials adhered to the screen disc continuously , ensure screening effect of the roller screen.
Staggered arranged screen discs will create intermeshed movement to agitates the materials and preventing large lumps and debris from settling and reducing blockage.
Working principle of a self-cleaning system:
- Bulk material is evenly fed onto the dynamic screeningsurface
- Through shaft rotate , material moving forward as smaller particles drop through screen openings
- Scraper beneath every shaft removing materials stuck on the screen disc and shaft
- The interaction of shaft rotating and scraper action maintains clean screeningapertures throughout the operation cycle.
As a arguably critical and universally adopted self-clean mechanism of roller screen, here are some detail:
The combs are installed beneath the screening deck, aligned near perpendicularly to the rotating shafts. Positioned that the tip of comb teeth are within millimeters of the screen disc surfaces , make sure effective contact without block shaft rotation.
Commonly used wear-resistant and abrasive-standing steel.
Designed for easy access, fast inspection and replacement.
So self-cleaning device came to solve those problems once and for all. The design of a self-cleaning device are multiple comb-tooth shaped wear-resistant metal sheets with sharp edge , inclined installed just below every shaft, so whether threadlike or solid debris can be scoop down while shafts rotate, thus prevent material attached to each other causing clogging or blinding.
Benefits brought by self-cleaning devices
So self-cleaning device came to solve those problems once and for all. The design of a self-cleaning device are multiple comb-tooth shaped wear-resistant metal sheets with sharp edge , inclined installed just below every shaft, so whether threadlike or solid debris can be scoop down while shafts rotate, thus prevent material attached to each other causing clogging or blinding, keeping roller screen function normally.
Environmental Compliance : Through fully enclosed self-cleaning systems will help dust emission controlling.
High efficiency : Special designed shape with sharp edge, can clean the disc surface effortless
Thus reduce downtime to save repairment and maintenance hour, provide a stable and safe operation system.
Low-maintenance costs: Reduce wear of shafts and discs, thus lowering downtime and maintenance costs.
Lowering manual cleaning requirements: By adopted self-cleaning advice, manually cleaning needs is reduced, also enhance worker safety.
Simple and low profile : With great performance while keeping a compact and smaller profile without enlarge the size of whole roller screen.
After a brief description of what is self-cleaning device and what it do, we can see the self-cleaning device of roller screen isn’t just an auxiliary feature, but an inseparable element that can defines the roller screen’s capability to function effectively in industries where high moisture content, clay or fine particulate adhesion are prevalent, like coal-fired power plants, lignite mining ,mineral processing, and aggregate production-the risk of clogging and blinding in traditional screening equipment is a persistent operational challenge.
To any bulk material handling system facing this kind of challenge, investing on self-cleaning device is not just a technical preference , it’s a necessity which ensure process stability and operational efficiency.
