Dr E. Ramanathan PhD
Degreasing plants — whether batch-type, conveyorized, or fully automated — face several engineering problems that can affect productivity, safety, cleaning quality , and compliance . Below is a structured list of common engineering issues along with causes and remedies , tailored for plants handling metal cleaning with aqueous (alkaline or neutral) degreasers .
🔧 Common Engineering Problems in Degreasing Plants
1. Inadequate Cleaning Performance
Cause Engineering Issue Remedy Poor spray impact Incorrect nozzle type or pressure Optimize spray angle, increase pressure, replace worn nozzles Poor chemical mixing Lack of circulation or agitation Add in-tank pumps or recirculation loops Wrong process timing Conveyor speed too fast Adjust line speed or increase dwell time Overloaded system Parts packed too tightly Improve part spacing for uniform exposure
2. Redeposition of Dirt/Oil (Recontamination)
Cause Engineering Issue Remedy Dirty rinse water No counterflow or overflow Implement fresh water rinse or cascade rinsing Insufficient filtration No particulate removal Install bag or cartridge filters in circulation line Poor bath maintenance Sludge not removed regularly Add sludge traps, set maintenance schedule
3. Aluminum or Zinc Etching or Staining
Cause Chemical too aggressive Engineering Fix Overheating of solution No bath temperature control Install thermostats or PID temperature controllers High concentration or pH Lack of dosing control Add chemical dosing pumps with pH/EC feedback loop
4. Nozzle Clogging or Spray Imbalance
Cause Hard water, particulates, sludge Remedy Scale formation No water softening or filtration Use DI/RO water or inline descalers Solids in bath No inline strainer or filter Use 100–200 micron pre-filters Chemical precipitation Improper formulation mixing Maintain order of addition, control temperature
5. Foaming Problems in Spray Tanks
Cause High surfactant load or turbulence Engineering Solution High agitation Use low-shear pumps, baffles Reduce turbulence, use airless spraying Lack of anti-foam system No dosing or physical control Add defoamer injectors, mechanical foam breakers
6. Corrosion of Components or Machine
Cause Improper materials of construction Fix Incompatible piping/tank metals Mild steel in alkaline zone Use SS316, PP, or PVDF depending on chemistry Steam coil corrosion No coating or galvanic issues Use titanium coils or protective liners
7. High Energy and Water Usage
Issue Cause Remedy High water consumption No reuse or recovery Install counterflow rinse or reclaim tanks Heat losses Poor tank insulation Use thermal insulation on tanks and pipes Constant pump operation No VFD or automation Add VFDs, timers, and level sensors to control usage
8. Operator Safety and Ventilation
Risk Engineering Concern Solution Slippery floors, vapors Poor drainage or exhaust Install floor slopes, fume extraction units Chemical burns or spills Poor ergonomics Use drip-free spray wands, chemical-resistant trays Hot tank access No guarding or alarms Add thermal cutoffs, safety interlocks on tank lids
🧰 Engineering Recommendations Summary:
Use automated chemical dosing and temperature controllers
Ensure proper nozzle type, layout, and spray angle
Install filtration and bath recirculation systems
Design for easy sludge removal and drainability
Provide thermal insulation , ventilation , and operator safety features
Engineering Audit Checklist
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