Experimental electrostatic Precipitator - WIP

thingiverse

###/!\ WARNING :\r\n This device is experimental, use at high voltage and can generate a strong electrostatic field if improperly shielded. \r\nThis is NOT a finalized and safe product Do not try if you do not know exactly what you are doing. If you are under age, ask for adult supervision. Doing wrong manipulation can hurt you, kill you, burn your house or fry nearby electronic devices. \r\nThe share is only to allow people to test and improve it\r\n###/!\ USE THIS AT YOUR OWN RISK WITH THE UPMOST CAUTION\r\n\r\nDoes that sound scary enough for you ? Good, that's the spirit ;)\r\n\r\nHowever, here is the thing:\r\n\r\n3D printing produces variable amounts of ultra-fine particles that can be a concern for health, especially if your printer operates in a small and enclosed area.\r\n\r\nThere are various approaches to reduce these particles, based on HEPA filters or activated carbon, but these methods are not perfects. HEPA is not so good at filtering particles below 0.3 µm, and can host various bacteria after some time. Activated carbon can be efficient but tends to saturate over time.\r\n\r\nAn electrostatic precipitator (ESP) is a filtration device that removes fine particles, like dust and smoke, from a flowing gas using the force of an induced electrostatic charge minimally impeding the flow of gases through the unit. (Cf https://en.wikipedia.org/wiki/Electrostatic_precipitator) ESPs are known to be efficient and widely used in industry.\r\n\r\nThe goal of this prototype is to create an ESP suitable for inclusion inside an enclosure, filtering air in a closed circuit.\r\n\r\nThis ESP prototype uses cylindrical charging and collecting plates and utilizes a central opposite charge for improved \r\nI decided to use a cylindrical shape with insulated edges to limit ozone production, based on the study: http://www.isesp.org/ISESP/ICESP%20X%20PAPERS/PDFS/Paper%203C1.pdf\r\n\r\n###BOM:\r\n* 80mm diameter PVC tube (from 35 to 40 cm is fine)\r\n* 80 mm fan (12 V)\r\n* 2 small 16mm diameter copper tubes (8 cm long)\r\n* Some coaxial cable.\r\n* A high voltage static generator (do not use pulsing one) with 12V power supply. I use a 20kV generator, but this is probably overkill. Starting with 1 kV should be fine. Example: http://www.ebay.fr/itm/DC-12V-to-20000V-High-voltage-electrostatic-generator-negative-ion-generator-/171961910986?hash=item2809ba86ca\r\n* 2 aluminum soda cans (the standard ones)\r\n* Some screws, bolts, zip ties ...\r\n\r\nSoda cans must be uncoated (inner and outer faces) and cut. The most effective method I found was to use a Dremel with a round grinding stone. The cut should be clean so that the can can be properly inserted inside the holders. A can holder is provided in the STL file to ease manipulation and reduce the risk of cutting your hands. Please use gloves during these manipulations! \r\n\r\nFor now, I'm not happy with the result, mainly because of the impact of the electrostatic field on surrounding electronic devices. During my early tests, the particle detector encountered strange instability and unwanted resets. A proper shielding must be defined to make it usable in a printing enclosure; that's where I'm stuck for now, before I can continue evaluating the particulate capture rate.