Heat Pump Dryer Stops Mid-Cycle With a Scorched Smell? NL-LNT-4 Duct Lint and Outlet Temperature Bench, Four Stations (washing machine test equipment)

Heat pump dryers that stop mid-cycle with the laundry still damp, a scorched smell at the door and a filter matted with a thick layer of lint. Lint passes the first filter, packs into the evaporator fins and the duct work, airflow falls away and compressor discharge temperature climbs until the thermal cut-out trips; households clean that filter once a year at best, so the layer only thickens. Reliability testing on the line usually runs a standard load with no lint feed and no simulation of a neglected filter, so how much airflow is lost and at what temperature the machine cuts out are unknown before shipment — and the after-sales visit is a strip-down and a clean.

What the NL-LNT-4 duct lint and outlet temperature bench measures

• Four stations in parallel feeding standard lint into the duct at a set rate, reproducing a season to two years of accumulation within days (the drying branch of our washing machine test equipment)
• Airflow decay curve: outlet airflow and static pressure re-measured at intervals to plot lint load against airflow loss
• Outlet and discharge temperature rise: multi-channel logging tracks each point as lint builds up, locating the cut-out point and the safety margin
• Filter penetration: primary and secondary filters weighed separately to quantify the share of lint reaching the evaporator fins
• Cycle time and energy before and after lint loading on the same load, quantifying the efficiency loss
• Clogging limit and protection: lint added until airflow falls to a set threshold, recording whether the cut-out and reset behave reliably
• Barcode and batch binding, with raw data exported per unit for filter and duct revisions compared side by side

Applicable standards

GB 4706.1 (household appliances – general safety), GB 4706.30 (tumble dryers – particular requirements), IEC 60335-2-11 (tumble dryers – particular requirements), GB/T 20292 (household tumble dryers – methods for measuring performance) and GB/T 2828 sampling; criteria can follow the customer’s standard and the duct construction.

Stations and throughput

Four stations running continuously turn a judgement by experience — the filter needs cleaning — into lint mass, airflow and temperature rise data, with airflow decay and temperature margin rechecked round by round — so filter and duct revisions, and end-of-line machines, can both be sampled batch by batch, stopping damp laundry, odour and thermal cut-outs before shipment.

Manufacturer

Guangdong Endurance Electronic Equipment Co., Ltd. — a non-standard testing equipment manufacturer of duct lint and outlet temperature benches, washing machine test equipment for washers and dryers, dishwasher test equipment, pump test bench and pump performance test systems and level sensor life test machines.

Keywords: pump test bench, pump performance test, level sensor life test, dishwasher test equipment, washing machine test equipment.