28/40kHz Switchable Dual-Frequency Ultrasonic Cleaner 30L with Heating for Motor Housings and Large Parts Degreasing

Frequency determines cavitation bubble size, impact force, and penetration depth. Lower frequencies produce violent impact for heavy dirt, while higher frequencies provide dense, gentle cleaning for sub-micron microstructures:

Based on Granbo multi-frequency switchable configurations (Single/Dual/Triple/Quad), we recommend:

To resist cavitation erosion, Granbo customizes tank thickness and welding based on operating frequency:

*Material Safety Tip: Soft metals (aluminum, brass, gold) and delicate glass/ceramics may scratch or fracture at 28kHz. We recommend 40kHz to 80kHz or pre-testing for delicate substrates.

When a workpiece has both stubborn contaminants and sub-micron precision requirements, use a multi-stage approach:

1. Stage 1 (Pre-cleaning / 28kHz or 40kHz): Strips heavy grease, rust, polishing paste, scale, or coarse metal particles.
2. Stage 2 (Fine Cleaning / 68kHz or 80kHz): Removes fine particles (5–10μm) from blind holes, threads, and complex internal geometry.
3. Stage 3 (Ultra-Precision Rinse / 120kHz or 200kHz): Eliminates sub-micron (<1μm) residues without damaging fragile surfaces or thin films.

• Sweep Mode: Automatically sweeps ±1kHz around the center frequency to eliminate standing waves, ensuring uniform cavitation across the bath.
• Degas Mode: Uses pulsed ultrasound intervals (e.g., 5s on / 5s off) to purge dissolved air/gas from liquids—crucial for HPLC sample prep and max cavitation efficiency.
• Pulse Mode: Rapidly cycles power from 100% to 0% to produce a "blasting" impact that removes tough or baked-on residues.

Granbo units utilize Full-Bridge Separately Excited PCB Driver Boards rather than cheap self-excited circuits:

1. Visualized Real-time Data: Displays live Power, Frequency, and Current for strict laboratory protocol logging.
2. High Power Density: Guarantees a standard ≥ 0.3W/cm² for thorough cleaning. Power Density = Ultrasonic Power (W) / Radiating Area (cm²)
3. Low Noise Operation: While 28kHz operation naturally produces more audible mechanical noise, Granbo's multi-layer noise-reduction design enables high-frequency units (≥68kHz) to operate at noise levels below 80dB.

Ultrasonic frequency determines sound wavelength and cavitation bubble collapse intensity:

• 20kHz (λ ≈ 72.5mm): Large bubbles, high collapse force. Best for heavy rust, sludge, and thick scale.
• 40kHz (λ ≈ 36.2mm): Medium bubbles. Ideal balance between cleaning power and component safety.
• 120kHz (λ ≈ 12.0mm): Micro bubbles. High penetration depth for sub-micron cracks and fragile silicon/semiconductor parts.

Beaker Size Matching:
• Beaker ≤ 500mL → 3.2L to 6.5L Tank.
• Beaker ≥ 800mL → 10L to 30L Tank (10L is the most popular size for general lab applications).

Temperature Management:
Ultrasonic activity inherently raises liquid temperature. Although Granbo heating goes up to 80°C, cavitation effectiveness drops significantly above 72°C–80°C due to increased vapor pressure. For temperature-sensitive or low-temp processes, use cooling coils or ice packs in the bath.

Standard production lead times for out-of-stock or customized Granbo models:

• 28kHz - 200kHz Models (Single, Dual, Triple, Quad Frequency): 3 - 5 business days for shipping.
• Ultra-Low Frequency (17kHz, 20kHz, 25kHz): 14 - 20 business days for shipping.

*Note: Customizations like RS-485 communication or PLC integration may slightly adjust delivery timelines. Contact us for precise scheduling.