Delfin CUBE 20 K2 PN ACD

ACD (Approved for Combustible Dust) is a certification category in IEC 60335-2-69 Annex AA -- a standard for vacuum cleaners handling combustible dust in non-ATEX classified areas. The difference from ATEX is that the ACD area is NOT classified as an explosion-hazardous zone (Zone 20/21/22), but the dust itself is so combustible that it still requires constructive safety measures: earth grounding, antistatic filters, internal temperature limitation and closed enclosure. ACD is the correct certification when your risk analysis demonstrates combustible dust but no explosive atmosphere -- typically because the concentration never reaches LEL (Lower Explosive Limit). If the area IS classified as Zone 22, an ATEX version should be chosen (CUBE 20 K2 PN Z22).

Pulse-jet (PN -- pneumatic counter-flow cleaning) is an automatic filter cleaning system using short compressed-air pulses to clean the cartridge filters while the deduster operates. The principle is simple: a valve opens for a fraction of a second and sends a short compressed-air pulse (typically 5-7 bar) into the cartridge interior, causing the filter cloth to flex outward and shake the dust layer off the outer surface. Dust falls into the collection container. The pulses alternate between the two cartridges with 10-30 second intervals, so only one cartridge is out of service at a time while the other continues to filter. The result is stable suction-point vacuum over time without manual cleaning -- crucial for continuous operation.

Consumption is modest because the pulses are short. Typical consumption is 50-150 nl/min at 5-7 bar -- in contrast to pneumatic venturi vacuums which draw 500-2,500 nl/min continuously. A standard industrial compressed-air installation at 6-8 bar with a 100-200 L buffer tank can easily supply it. Pulses are fired typically every 10-30 seconds depending on dust load -- the controller adjusts the interval automatically based on filter pressure drop. Important: compressed air must be clean (filter, water separator, cooler) to extend cartridge life -- oil and water in compressed air wear the cartridge coating and can permanently clog the filter cloth.

The CUBE 20 has two inlet options. Standard is a single 200 mm inlet (oe200) used when the deduster serves one suction circuit or one extraction arm at full flow. Alternatively, 2 x 150 mm (oe150) can be configured -- two separate inlets each accepting an extraction arm or suction circuit. Total airflow remains 2,500 m³/h, but is now distributed across two points at ca. 1,250 m³/h each. The difference is that the dual configuration allows two operators to work independently without one's start-up disturbing the other's suction-point vacuum -- good for parallel work at welding booths or grinding stations. Choose configuration based on installation architecture.

The CUBE chassis is built more heavily than the ZFR EV chassis for three reasons. (1) The cartridge filter housing is larger and requires thicker steel walls to be airtight under the pulse-jet cleaning's pressure variations. (2) The built-in forklift lifting points and frame-like sub-chassis require stronger steel beams. (3) The entire unit is built for continuous operation over many years without maintenance, which demands robust components. The higher weight is a feature, not a weakness -- the CUBE is built to operate uninterrupted for 10-15 years. If weight is an issue (low-ceiling installation, upper floors with limited load capacity), consider the ZFR EV range which is 50 % the CUBE's weight with the same airflow.

Classic ACD applications in Denmark include (1) the wood sector -- furniture factories, joinery workshops, MDF/OSB production -- where dust is combustible but normal-operation concentrations do not reach zone classification limits, (2) the bakery industry -- flour handling, sieve stations, rye-bread production -- where flour dust is combustible but the plant is ventilated enough to avoid zones, (3) coating and powder coating without gas zones -- where the powder is combustible but spraying happens in extraction booths, (4) feed plants with grain and oily powder -- typically classified as non-Zone in Denmark when the process is ventilated, and (5) lighter chemical industries with organic powders without categorised substances. The prerequisite is always a risk analysis demonstrating that LEL is not reached in normal operation -- if in doubt, the Zone 22 version should be chosen.