The Detergent Drawer Never Empties and Softener Cakes in the Pipe? NL-WDB-4 Dispenser Metering and Siphon Bench (washing machine test equipment)

The detergent dispenser is the part every user touches on every wash, and a frequent landing point for wash-performance complaints. It works two ways: the main compartment is flushed by the inlet jet, while the softener compartment relies on a siphon — the inlet fills the chamber, negative pressure forms, and the whole dose is pulled out. Problems live in the detail. If inlet pressure is low or the siphon cap gap is blocked by crystallised detergent, vacuum is insufficient, the softener is not fully drawn, a sticky film stays in the drawer and turns black within weeks. If the siphon tube seal leaks, the siphon trips early, the softener is flushed during prewash and there is none left for the rinse. Highly concentrated detergent is viscous, the venturi cannot lift it, and the user finds an undissolved blob in the drawer. The line check is usually “fit it, push the drawer in and out”. Metering error, siphon trigger timing and residue have no number at all.

What the NL-WDB-4 metering and siphon bench measures

• Four stations with inlet pressure swept from 0.05 to 0.6 MPa, low-pressure siphon failure reproduced directly (a dedicated station in our washing machine test equipment detergent range)
• Metering accuracy: each compartment dose weighed per cycle at 0.1 g resolution, setpoint against measured error tabulated for powder, liquid and pod media
• Siphon trigger timing: inlet time-segmented with outlet weighing in step, so whether softener leaves during prewash, main wash or rinse is decided on the spot and early siphoning caught
• Residue mass and location: chamber wall film, siphon cap gap and tube bend recovered and weighed separately, total residue tied to its location
• Viscosity coverage: liquid, concentrated liquid, softener and gel proportioned to real viscosities, so “cannot lift” and “will not empty” are separated
• Crystallisation reproduced with hard-water cycling, blockage at the cap and tube mouth trended as a flow-decay curve with cleaning recovery compared
• Mechanism endurance: drawer push-pull, lid cycling, clips and seals run until sticking or leakage
• Supply regulation on a pump performance test basis, identical pressure at every station
• Level and flow signals cross-checked on the level sensor life test acquisition chain, so dose sequencing under abnormal inlet conditions can be judged
• Barcode binding, metering error, siphon timing and residue exported per unit for drawer and detergent lot comparison

Applicable standards

Performance and detergent-feed clauses to GB/T 4288 (household electric washing machines); structure and safety to GB 4706.1 and GB 4706.24 on the same basis as IEC 60335-2-7; inlet conditions to the customer appliance specification. Metering limits, siphon timing windows and residue criteria can follow the customer standard, sampling to GB/T 2828.

Stations and throughput

Four stations, a full pressure sweep and rotating media complete a dispenser's dosing record across high and low pressure and several detergents in one day. “Push it in and out” becomes data on metering error, siphon timing and residue location. Incoming drawers, appliance inlet matching and after-sales softener and mould complaints share one bench.

Manufacturer

Guangdong Endurance Electronic Equipment Co., Ltd. — a non-standard testing equipment manufacturer of washing-machine dispenser metering and siphon benches, washing machine test equipment, pump test bench ranges, pump performance test systems, level sensor life test machines and dishwasher test equipment.

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