Monorail Washers
Industrial mono-rail parts washers, a specialized type of conveyor washers, are used to pretreat metal parts prior to powder or liquid coating. The parts are hung on a continuous motorized conveyor, enclosed track or I-beam, which moves the parts through the washer. A continuous monorail parts washer has a higher production rate with less labor than a cabinet and batch washer.
Main Factors to Consider in Washer Design
- Part sizes, orientation, and materials of construction
- Conveyor line speed
- Process specification (typically provided by the customer’s chemical supplier.)
- Washer’s materials of construction
- Spray system design
- Heating system requirements
- Washer housing cross section and drain lengths
- Exhaust Fan requirements
- Solution tank size requirements and burner tube accommodation (if applicable)
- Serviceability and maintenance
The innovative, patented, Torrent Washer™ design, exclusively produced by Horizon, supersedes the older conventional design of washers, that uses multiple riser columns of many stationary nozzles.
Torrent Washers™ have riser bars with attached nozzles that move in a circular pattern as the riser bars rotate.
Fewer nozzles are required due to the circular motion, which results in less water flow. Less water flow means lower pump horsepower requirements, reduced electrical energy costs, and less chemical usage.
The rotating action creates a swirling spray pattern that provides excellent coverage, including difficult-to-reach areas of the parts. The rotational velocity increases spray impingement, improving cleaning effectiveness. Variable frequency drives (VFDs) control the pumps and rotating motors.
Multi-Stage Pretreatment Process
Multi-stage pretreatment washers are used by virtually every manufacturer that uses painted metal parts in their products, whether directly in their own in-house powder/paint line or indirectly through outsourcing.
The pretreatment process is typically a multi-stage process that cleans and applies a conversion coating to the parts prior to powder or liquid coating. The process improves the adhesion of the powder or liquid coating to the part surface and increases its effective longevity and corrosion protection.
In general, conversion coatings include iron phosphate, zinc phosphate, or the more environmentally friendly and versatile zirconium-based treatments.
Pretreatment washers have solution/water tanks for each stage of the multi-stage process. The liquid in these tanks is pumped through spray nozzles onto the parts inside the canopy of the washer. In continuous monorail washers, the conveyor moves parts through each processing stage, such as cleaning, rinsing, conversion coating, and final rinsing.
Electrical Energy Savings
Below is a comparison between a proposed Torrent Washer™ and an existing, conventional five-stage washer operating at a line speed of 12 ft./min.
Torrent Technology™
5-Stage Continuous Washer
| Stage | Flow Rate | Pump HP | Rotator HP |
|---|---|---|---|
| Stage 1 | 294 | 10 | 1.5 |
| Stage 2 | 98 | 5 | 0.5 |
| Stage 3 | 98 | 5 | 0.5 |
| Stage 4 | 198 | 7.5 | 1.0 |
| Stage 5 | 98 | 5 | 0.5 |
| Total 36.5 HP | |||
Traditional
5-Stage Continuous Washer
| Stage | Flow Rate | Pump HP | Rotator HP |
|---|---|---|---|
| Stage 1 | 1240 | 25 | N/A |
| Stage 2 | 450 | 15 | N/A |
| Stage 3 | 450 | 15 | N/A |
| Stage 4 | 840 | 20 | N/A |
| Stage 5 | 450 | 15 | N/A |
| Total 90 HP | |||
The HP required to operate the Torrent Washer™ is less than half that of the conventional washer which results in significant savings in both electrical usage and demand charges.
Monorail Washer Performance
The rotating nozzle bars/arms create a swirling spray pattern which excels at cleaning the leading and trailing ends of the parts, as well as hard to reach pockets.
Industrial Monorail Washer Construction and Features
Stainless Steel Construction
- Walls, roof, and drain boards are stainless steel
- Piping is stainless steel
- Wetted pumps are stainless steel
- Nozzles are stainless steel
- Stainless steel, welded, leak tested tanks
- Stainless steel tank covers with handles and latches
Advanced Pump and Spray Systems
- VFD controlled vertical pumps
- The rotating risers have adjustable speed drive mechanisms, and thus are not dependent on water pressure
- The rotating unions are ceramic coated stainless steel, and oversized gearboxes are used for years of trouble-free service
- Header pressure is continuously monitored
Heating Systems
- Stainless steel immersion heaters or plate-type heat exchangers
- Temperature is maintained via digital thermostats with feedback control
- Efficient insulation reduces heat loss and conserves energy
Process Control Systems
- PLC-based control panels with touchscreen HMIs
- Real-time monitoring of temperature, pressure, and chemical concentration
- Automatic alarms and shutdown features for safety and maintenance
- Data logging and system diagnostics
Maintenance and Safety Features
- Access doors
- Plank grating for internal walkways are stainless steel
- Screens in each tank located in the charge box areas, prior to the pumps
- Optional electronic liquid level sensing and control
- Optional internal lights
Continuous Monorail Washer Accessories
Filter System for Monorail Parts Washers – High-performance stainless steel bag filter housings designed to integrate seamlessly with monorail parts washers. Each unit features isolation valves for safe and efficient servicing without interrupting washer operation. Solids are captured within the internal bag or basket, protecting spray nozzles and pumps from clogging and wear. Integrated pressure monitoring enables proactive maintenance, ensuring consistent filtration and extended equipment life in high-throughput monorail washing systems.
Magnetic Filter for Monorail Parts Washers – Designed to enhance the performance and longevity of monorail parts washers, this magnetic filter system captures ferrous particles from the return water stream before recirculation. As used wash water flows over the integrated drain board, it passes across a high-strength magnetic surface that efficiently collects and retains fine magnetic debris such as machining fines or wear particles. This reduces system contamination, minimizes nozzle blockage, and improves overall wash quality in continuous, high-volume monorail operations.
Internal LED Lighting for Monorail Parts Washers – Enhance visibility and inspection capability inside your monorail parts washer with internal LED lighting, controlled directly from the operator interface terminal. The high-efficiency LED lights are mounted externally to avoid exposure to harsh wash environments and shine through a durable tempered glass window, providing clear illumination of the wash chamber without compromising system integrity. Ideal for maintenance checks, part monitoring, and ensuring consistent wash performance in continuous flow monorail systems.
Oil Coalescer for Monorail Parts Washers – Designed to improve fluid quality and reduce maintenance in monorail parts washer systems, the oil coalescer effectively removes floating oils and grease that accumulate during continuous washing operations. Wash solutions are first filtered, then passed through the coalescing unit where oil and grease are separated before the clean solution is returned to the main tank. Recovered contaminants are automatically routed to a dedicated disposal container, helping to extend solution life, reduce maintenance downtime, and prevent issues in downstream waste treatment systems.
Blow-Off System for Monorail Parts Washers – Positioned at the exit of the monorail parts washer, this high-efficiency blow-off system is engineered to remove excess moisture from parts before they continue down the production line. Equipped with a high-pressure blower and a VFD-controlled motor, the system provides adjustable airflow to accommodate varying part sizes and throughput rates. This helps reduce drying time, prevent water spotting or contamination, and prepare parts for downstream processes such as painting, assembly, or packaging.
Mist Eliminator for Monorail Parts Washers – The mist eliminator is designed to reduce airborne moisture and chemical carryover from the exhaust of monorail parts washers. Constructed with a durable stainless-steel framework, it effectively captures and separates fine liquid droplets from the vertical exhaust stream, preventing them from escaping into the facility environment. This improves air quality, protects downstream ventilation equipment, and supports compliance with air quality and safety standards in high-throughput monorail washing operations.
Water Treatment System for Monorail Parts Washers – Optimize performance and efficiency in your monorail parts washer with a complete water treatment system, including Reverse Osmosis (RO) technology. These systems help reduce overall water consumption, minimize chemical usage, and improve the consistency and quality of part finishes—especially critical in applications requiring a clean, residue-free surface. By supplying high-purity water to the washer, RO treatment helps extend solution life, reduce maintenance, and enhance downstream process reliability in high-volume monorail operations.
Post-Installation Service & Maintenance for Monorail Parts Washers
Horizon's commitment to your equipment doesn't end at installation. Our experienced service team provides ongoing technical support, preventative maintenance, troubleshooting, and repairs to help keep your monorail parts washer operating safely, efficiently, and reliably. From spray nozzles, circulation pumps, heating and filtration systems to conveyor components, variable frequency drives, and PLC controls, we offer the technical expertise to maintain consistent cleaning performance, minimize unplanned downtime, and extend equipment life. Our team can also assist with equipment modifications and process improvements to accommodate changing production requirements.
Learn more about Horizon's Service & Maintenance capabilities and how we can support your monorail washing system long after startup. You can also explore our Spare Parts Center for replacement components and ongoing equipment support.
Frequently Asked Questions
HOW DOES A MONORAIL PARTS WASHER WORK?
Answer: Parts are suspended from hooks or fixtures attached to a continuously moving overhead conveyor. As they travel through the washer, spray systems apply cleaning solutions, rinses, and surface treatments according to the required process specifications. Horizon's patented Torrent Technology™ uses rotating spray risers to provide thorough coverage while reducing the water and energy required compared to conventional stationary-nozzle designs.
WHAT ARE THE ADVANTAGES OF A MONORAIL WASHER COMPARED TO A BATCH WASHER?
Answer: Monorail washers provide continuous processing, making them ideal for high-volume operations where parts move directly from washing to coating or other manufacturing stages. Unlike batch washers, which require separate loading and unloading cycles, monorail systems integrate into conveyorized production lines, reducing material handling, labor requirements, and interruptions in production.
CAN A MONORAIL PARTS WASHER BE INTEGRATED INTO AN EXISTING CONVEYOR SYSTEM?
Answer: Yes. Horizon custom engineers monorail parts washers to accommodate existing overhead conveyor systems or new production lines. Design considerations include conveyor configuration, line speed, part dimensions, available floor space, and required pretreatment stages. This flexibility allows manufacturers to incorporate automated washing into their production workflow.
HOW MANY PRETREATMENT STAGES CAN A MONORAIL WASHER HAVE?
Answer: Monorail parts washers can be configured with multiple pretreatment stages depending on the application. Common stages include alkaline cleaning, rinsing, conversion coating, and final rinsing. Some systems also incorporate additional rinses or specialized treatments. Horizon engineers each system according to the customer's process specifications, coating requirements, and production needs.
ARE INDUSTRIAL MONORAIL WASHERS ENERGY EFFICIENT?
Answer: Horizon designs monorail washers with energy efficiency in mind. Torrent Technology™ reduces the water flow required for effective cleaning, allowing the use of smaller circulation pumps compared with many conventional systems. Variable frequency drives (VFDs), efficient heating systems, and insulated construction further support reduced energy consumption and lower operating costs.
Ready to Optimize Your Manufacturing Process?
At Horizon, we’re not just building industrial monorail washers—we’re creating engineered cleaning solutions that move your business forward in a cost-saving, efficient, and reliable way. Contact us today to discuss your application and discover how a custom Horizon monorail washer with Torrent Technology™ can improve your manufacturing process.
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