Downdraft tables are used to capture dust, smoke and fumes of the plasma cutting process and then by means of a filter return filtered air back to the workshop.
The downdraft tables of Voortman have integrated suction canals which are divided into several sections. These sections are used for sectional extraction of the cutting fumes from the cutting zone. Electronically operated pneumatic valves control the sectional extraction, so that suction is only provided in the vicinity of the cutting torch. Not only will this result in a better suction performance on a smaller area but this will also reduce power consumption. On tables up to and including a width of 2.100 mm (7’), suction is provided on one side of the table. Wider tables are equipped with two or more canals, to ensure an optimal fume extraction.
|Sectional fume extraction|
In conventional downdraft tables dust and sparks rise up because of the dispersion during cutting. The integrated surface extraction system of the Voortman downdraft tables captures fine dust that rises which is then separated in the attached filter system. The tables are also designed in a manner that they pre-clean the extracted air.
Robust and flexible
The downdraft table is a robust welded construction suitable for material thicknesses up to 200 mm and it can even cope with a cutting performance in excess of 440 amperes. The downdraft tables are build with standard modules which allow a flexible table design with various widths and lengths. It is also possible to extend the table length afterwards.
The pneumatic valves are electronically operated. Not only does this result in less mechanical parts and thus less wear but it also significantly improves software diagnostics. The pneumatic valves are integrated at the side of the table, to avoid influence of the cutting process on the valves. All pneumatic actuators are positioned free from the airflow, so that wear on the parts is strongly reduced.
|Easy exchangeable deck||Large slag trays|
The machine is equipped with a strong and rigid plasma table. Straight support bars are placed at a distance of 100 mm (4”). Slots in the frame of the deck allow for the insert of additional support bars, at a distance of only 50 mm (2”). The deck is divided in multiple sections which enables easy replacement of a single deck or of an individual support bar.
Each section has his own slag tray which is easy removable by means of lifting chains. The slag trays are extra large to increase the cleaning intervals.
Slag removal table
The downdraft table can be equipped with a slag removal system to remove slag and small products from the cutting area and transport them to the end of the table. The slag removal system uses oscillating conveyors which are set precisely in the resonance area to reduce the power required. Slag removal has never been so easy. Time required for cleaning of the table is strongly reduced and immediate discharge of slag also reduces the build-up of waste material on the inside of the table, so that the cutting performance and fume extraction improve significantly.
Voortman can also provide a water table for their plate cutting machines which captures 98% to 100% of the smoke and thus eliminates the need for a filter. A water table is normally used for cutting mild steel or for cutting products where heat input can play a significant role. Cutting products with high height-width ratios can deform during cutting due to heat input when cutting dry. The parts are also heated up during the cutting process which can obstruct and/or lengthen the unloading process. Cutting underwater ensures immediate part handling after cutting which leads to less downtime.
The initial investment is also lower due to the fact that a filter system, to extract the fume and dust, isn’t necessary. This makes a water table more appealing for smaller workshops. Dust created by the cutting process is directly absorbed by the water. Because a fume extraction unit and thus ductwork is not required the footprint and the power costs of the whole installation are reduced.
|Slag removal system||Grid for small parts|
Under water plasma cutting also has some other major advantages above dry plasma cutting. For instance the water reduces the amount of noise created by the cutting process by at least 35 dB which will ensure a better working environment for the rest of the building. It also reduces the amount of arc glare.
Automatic water level management
The water table of Voortman regulates the water level automatically. Cutting above and below water level is possible. Marking for instance has to be done above water level while heat-sensitive parts are better to cut underwater to fully utilize the cooling abilities of the water. Thin stainless steel also shows less edge discoloration when it is cut underwater.
Water levels are raised and lowered by the use of air chambers. After the water level is set in the VACAM control software compressed air is pumped in the air chambers which force the water level in the table to rise. To lower the water level air is allowed to escape. In a matter of seconds the water is on the desired level. At low water levels, cutting can be done above water. By lowering the water level slag trays can also be easily removed.
Slag removal system
The water table can be equipped with a slag removal system which removes all small products and waste material with the use of a scrape conveyor which runs over the bottom of the table. The collected products are transported to the end of the table, and will be collected in a bin. This will significantly reduce cleaning time and thus downtime of the machine.
No aluminum underwater
Cutting aluminum underwater results in a chemical reaction which extracts Hydrogen out of the water. Hydrogen gas can cause a fire or an explosion. Explosion hazard due to hydrogen can also occur when cutting with H35 processes underwater. Because the water tables of Voortman automatically regulate the water level it is possible to cut aluminum or to cut with H35 processes above water level.