2026-10-31
A municipal district heating plant in Harbin circulates 1,100 m³/h of hot water (85°C) across a 15-kilometer closed-loop urban pipe network.
During winter operation, aging steel district piping releases significant amounts of iron rust flakes, pipe scale, and sand particles into the returning water.
These abrasive particulates damaged pump impellers and clogged electronic control valves inside residential heat exchange sub-stations.
Because the system operates at a high line pressure (1.0 MPa), traditional strainers required isolating main circulation pumps to clean strainer baskets—an unacceptable option during sub-zero winter months.
LEFILTER supplied a heavy-duty LF-SS-1100 Automatic Suction-Scanning Self-Cleaning Filter:
Suction Scanner Mechanism: The unit features an internal hollow shaft carrying multiple focused suction nozzles that sweep the inner 200 $\mu\text{m}$ screen face in a smooth spiral motion driven by an external motor.
High-Differential Hydraulic Vacuum: Opening the flush valve creates a localized high-velocity vacuum at the nozzle tips, pulling accumulated iron rust and scale off the screen screen without interrupting system pressure or main loop flow.
High-Temperature Build: Outfitted with high-temperature Viton seals, packing glands, and an IP65 rated control cabinet designed for humid 85°C boiler house ambient conditions.

Sub-Station Valve Failures Eliminated: Control valve jams across 24 regional heating sub-stations dropped by 95%, stabilizing urban heat distribution.
Pump Seal Protection: Main circulation pump impeller seal lifespans doubled from 1 heating season to over 3 seasons.
Uninterrupted Operation: Performed continuous online self-cleaning throughout the 5-month heating season without a single system shutdown.