When engineers talk about inlet screening, Multi Rake Bar Screens usually come up first. And for a good reason. These screens sit at the very beginning of a sewage or effluent treatment plant, catching solids before they reach pumps, aeration equipment, clarifiers, and other core systems. If this first step fails, the entire plant feels it. Pumps choke. Channels overflow. Maintenance teams spend their nights clearing rags with iron rods. We’ve seen this happen many times in the field.
At Multitech Engineers, we work with many industries—municipal STPs, pharma ETPs, chemical plants, food processors, sugar mills, pulp mills, and more. No matter the sector, one thing stays the same: when the inlet screening is weak, the whole downstream process becomes unstable. And that’s why these screens matter.
If you want to explore the fundamentals of filtration systems, our earlier blogs on wedge wire screens and industrial filtration are also helpful. You can read about how industries meet modern wastewater norms here:
https://multitechengineer.com/how-wedge-wire-screens-help-indian-industries-meet-2025-wastewater-norms/
How Multi Rake Bar Screens Work
I often explain screening with a simple image: imagine standing at the entrance of a busy railway station holding a long metal comb. You drag the comb through the crowd, and the wider people cannot pass through the narrow gaps, so they stay behind. That’s how the bars of a screen work. Everything larger than the bar gap is stopped.
In our Multitech Defender Multi Rake Bar Screen, the stationary bar rack sits at a 75° incline. Wastewater flows through it, and solids get trapped. But unlike a manual screen, you do not need a person with a rake pulling out waste. This machine does it on its own.
A series of rakes with stainless-steel teeth move on both sides, driven by roller chains powered by a flange-mounted gear motor. These rakes pick up the trapped solids and lift them upwards. They release the debris at the discharge point, where it falls into a bin, conveyor, or compactor.
One important design detail makes this model more reliable in real wastewater conditions:
There is no submerged sprocket at the bottom.
Instead, we use a curved stainless-steel guide. This looks simple, but it solves a problem that most operators complain about—jamming. Submerged sprockets often get stuck with rags and plastic carry bags. Our guide system avoids this and reduces maintenance.
You can explore the product here:
https://multitechengineer.com/products/multi-rake-bar-screens/
Where Industries Use Multi Rake Bar Screens
And yes, these screens are not just for municipal sewage. Many of our installations come from industries with heavy solids loads.
Common applications include:
- Municipal STP inlets
- Industrial ETPs
- Pharma and chemical plants
- Textiles (high fiber load)
- Food and beverage
- Sugar and starch processing
- Pulp and paper mills
If you work in pulp or sugar, you may find our related blogs useful, such as:
- Fiber recovery in pulp mills: https://multitechengineer.com/sieve-bend-screens-for-paper-mills-improving-fiber-recovery-and-pulp-quality/
- Bagasse and sugar applications: https://multitechengineer.com/screens-for-bagasse-water-reuse-in-sugar-production/
Screening is not a one-size-fits-all issue. Different industries trap different types of solids. And that changes how the screen must be designed.
Multitech Defender Multi Rake Bar Screens – Technical Breakdown
When we design a screen, we focus on reliability. Because the inlet of a plant never sleeps. Flow can increase at midnight. A sudden storm can push debris into the channel. A shift worker may forget to check the bin. So the machine must handle pressure without failing.
Here’s a simple breakdown of the key specs of the Multitech Defender Multi Rake Bar Screen:
1. Bar Gap Size
- Starts at 6 mm (minimum)
- Fully customizable based on industry
Fine gaps help catch plastics and rags. Larger gaps work better for heavy fibrous loads.
2. Installation Angle
- Fixed at 75°
- This angle helps the rakes climb smoothly without slipping.
3. Rake Speed
- 6–8 m/min
- Fast enough to avoid buildup, slow enough to avoid wear.
4. Material of Construction (MOC)
- SS 304 for all parts
- Wastewater is corrosive. Mild steel fails quickly, so we avoid it.
5. Drive System
- Chain-driven
- Flange-mounted gear motor
This setup keeps the drive stable even under sudden load changes.
6. Bottom Guide (No Submerged Sprocket)
This is one of the screen’s strongest features. The stainless-steel lower guide prevents jamming and simplifies cleaning.
7. Automated Operation
- PLC/Control panel
- Level-based auto start
- The screen only runs when needed.
If you want to compare this style with other screening designs, you can check our blog on incline vs rotary screens:
https://multitechengineer.com/incline-vs-rotary-screens-how-to-choose-the-right-fit-for-your-process/
Why This Design Works in Real Plants
We’ve seen many screens fail simply because they were not built for messy, unpredictable wastewater. A submerged sprocket chokes. A mild-steel bottom bends. A chain slips because rags have wrapped around it.
But when the design stays simple, and the structure stays strong, the screen performs well for years.
A few advantages of this model include:
- Easy maintenance
- Lower cleaning frequency
- No underwater sprocket troubles
- High operating life with SS 304
- Single-panel replacement (no need to remove the full screen)
- Efficient solids lifting with stable chain movement
If you want more screening insights, you may like our blog on how screens protect pumps:
https://multitechengineer.com/how-multi-rake-bar-screens-safeguard-pumps-and-improve-plant-reliability/
How to Choose the Right Multi Rake Bar Screen for Your Plant
A screen is not chosen only by price or channel width. Here are the points we usually check during design:
- Inlet flow rate
- Type of solids expected
- Bar gap requirement
- Channel depth
- Incoming load variation
- Hydraulic conditions
- Preferred discharge method
- Electrical panel needs
- Site accessibility
Choosing the wrong bar gap, for example, may slow the plant. Choosing the wrong rake speed may overload the motor. And choosing a design with submerged sprockets may increase jamming.
If your plant also uses rotary drum filtration, here’s a helpful guide from our earlier posts:
https://multitechengineer.com/smart-maintenance-for-rotary-drum-filtration-tips-every-plant-should-know/
Performance You Can Measure
For engineers who like data more than description, here’s a direct view of what the screen delivers:
| Parameter | Specification |
|---|---|
| Bar Gap | 6 mm minimum (customizable) |
| Angle | 75° |
| Rake Speed | 6–8 m/min |
| MOC | SS 304 |
| Drive | Flange-mounted motor + chain drive |
| Bottom Design | No submerged sprocket |
| Cleaning | Automatic, level-based |
This simple table helps during vendor comparison or during procurement documentation.
If you’re exploring filtration options beyond screening, our guide on wedge wire screen performance is helpful:
https://multitechengineer.com/how-our-wedge-wire-screen-handles-extreme-conditions/
Conclusion
Multi Rake Bar Screens are a dependable way to protect pumps, pipelines, aeration systems, and downstream equipment. A strong screen at the inlet saves time, cuts maintenance hours, and keeps the plant running smoothly. And when the design is simple, the structure is stainless steel, and the components are built for tough wastewater, the screen becomes something you don’t have to think about every day.
If you want to see full technical details or need help selecting the right size, contact us.