D2 Multifunctional Sprayer & D7-5 Hot Water Pressure Washer: Chemical Application Systems for Duct Cleaning (2026)
By Gaolijie Technical Support
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Mechanical + Chemical: The Complete Cleaning System
While Gaolijie robots handle 90-95% of duct cleaning through mechanical brush agitation, certain situations demand supplementary chemical application: carbonized grease deposits that have hardened beyond mechanical removal, sanitization requirements in healthcare facilities, and pre-treatment of heavy buildup to reduce brush wear. The D2 and D7-5 are purpose-built for these scenarios.
D2 Multifunctional Sprayer: Precision Chemical Application
Specification
D2 Value
Spray Pressure
0-50 bar adjustable
Flow Rate
2-8 L/min adjustable
Chemical Tank
25 liters (separate from water)
Nozzle Types
Fan (wide coverage), pencil (targeted), fog (sanitizing mist)
Power
110V/220V electric pump
Weight
22 kg (portable cart design)
Chemical Compatibility
Acid, alkaline, solvent, enzyme — all wetted parts are stainless steel or chemical-resistant polymer
The D2's key advantage is its separate water and chemical tanks with adjustable mixing ratio. This lets you switch from degreasing to rinsing without changing equipment or manually remixing.
D7-5 Hot Water High-Pressure Washer: For the Toughest Deposits
Specification
D7-5 Value
Pressure
150 bar (2,175 PSI)
Water Temperature
Up to 100 degree C (212 degree F) / steam mode optional
Flow Rate
15 L/min
Heating Method
Diesel-fired boiler
Power
220V electric pump + diesel heater
Weight
120 kg (trailer or van-mounted)
The D7-5 is reserved for extreme cases: carbonized grease in 10+ year un-cleaned ducts, industrial exhaust with baked-on particulate, and post-fire restoration cleaning. The combination of 150 bar pressure plus 100 degree C water dissolves deposits that mechanical brushing alone cannot remove.
When to Use Which System
Situation
Recommended System
Routine kitchen exhaust (quarterly)
CR360 robot only (mechanical)
Heavy grease buildup (6+ months)
D2 pre-treatment + CR360
Carbonized deposits (years of neglect)
D7-5 hot water + D2 chemical + CR360
HVAC sanitization (healthcare)
D2 with EPA-registered sanitizer (fog nozzle)
Post-construction duct cleaning
D2 rinse + K7S with HEPA vacuum (K8)
Industrial exhaust restoration
D7-5 steam mode + E200 heavy brush
Safety and Chemical Handling
PPE required: Chemical-resistant gloves, splash goggles, respirator if using fog application in enclosed spaces
Ventilation: Ensure adequate airflow when applying chemicals in confined ducts; use K8 HEPA system for negative air
SDS documentation: Maintain Safety Data Sheets for all chemicals used; provide copies to facility managers upon request
Wastewater management: Grease-laden wastewater must be collected, not discharged to sanitary sewer without pretreatment. Check local regulations.
