Vitelia Voeders in Venray had to meet the odour emission levels from the city council. The company also wanted to reduce its dust emissions. Both of these problems have been addressed by equipping one of their feed lines with a system that combines positive ionization with ozone injection. With success. Expansion to other feed lines is considered.

Until recently Vitelia Voeders in Venray never took any action on odour reduction. But following their increase on compressed feed production and the share of expanded feed, the factory’s odour emissions grew substantially. This was noticed also by the city council, which then imposed an 80% odour emission reduction to Vitelia Voeders. Enough reason for the company to began a search for a system than could ensure this. “We were not satisfied with the dust reduction achieved by the cyclones. Although there were no complaints, we found too much dust settled around the plant’s near surroundings”, says Ton Van Paassen, project manager at Vitelia Voeders. ENS installed its technology on one of the feed lines in order to combat both dust and odour emissions. With this adjustment, there are no more complaints from the area. The order to implement ENS’s technology on the other feed production lines has not yet been given by Vitelia, but is being considered.

Dust reduction with the Titan

“The dust is tackled by the Titan dedusting system” says Roel Gijsbers, technical project manager at ENS. “The Titan is installed on the roof where it is coupled with the exhaust gas pipe. The plant treats between 20.000 and 30,000 m3 of air per hour. This happens after a cyclone has first captured the coarse dust that is produced primarily by the coolers of Vitelia Voeders. The Titan captures the finer dust. The device is equipped with an automatic cleaning system. Once a week, the plate vibrates, so that the amalgamated substance falls on a conveyor belt and is discharged as waste; an amount of about half a wheelbarrow.”

Positive ionization

Gijsbers: “The fine dust collector from ENS works on the basis of ionization; a technology developed by TU Delft. Electrodes ensure that oxygen molecules in the air become electrically charged. The charged molecules attach themselves to dust particles, however small. Subsequently, these charged particles are drawn toward a grounded collector plate, on which the dust binds. ENS has patented this method of dedusting.”

Odor removal with ozone injection

The odour problem is solved by the injection of ozone. Gijsbers: “The ozone reacts with the odour components. The odour is not merely masked, it really disappears. The ozone is produced from compressed air using ozone generators, so it is not necessary to bring ozone containers. The combination of dust capture and odour reduction works well. It is easier to remove odour from clean air, free from particulate matter.” Van Paassen: “Depending on the type of feed, a 50% odour reduction is achieved at the normal extrusion process and 90% at the expansion process. On average, this means an odour reduction of 75 to 80 percent for us. And with dust emissions we go back to 2 mg/m³. Dust from a cyclone unit is considerably higher.” Independent measurements made by Buro Blauw show a emission reduction average of 81% on dust and 77% on odour.

Cost

Van Paassen likes ENS’s technology because of its low energy consumption and low investment costs compared to other systems. “The Titan’s maintenance is minimal. The electrodes need to be replaced only once a year, but this cost is negligible. Operating costs are therefore limited. The Titan is coupled to the gas outlet pipe, in which airflow is already present. The electrical power is thus low, 150 watts. The system is connected to the control room, so it can be checked remotely whether everything still works. The only downside might be that there is a large unit of 3 to 4 meters high on the roof, with plenty of piping.”

Indoor air purification

Gijsbers also foresees many other applications for this dust removal technology: “For example, it is possible to recirculate indoor air. That is very interesting for industrial sectors where air quality in the workplace doesn’t meet the requirements. Unfortunately, however, often there is still an attitude of ‘it costs money and does not yield anything for us directly’. That is because the health problems caused by poor air quality reveal themselves in the long term. The technique can be used to improve the environment in all kinds of buildings. Ionization is also effective against fine dust particulates, but is still an underestimated problem, although the World Health Organization has recently tightened standards for particulate matter. However, in practice the main applications of our technology currently exist in the field of dust and odour reduction, in particular to meet the current standards.”

By: Tessa Nederhoff  |  Bron: Bulk, volume 23, number 5 (September 2015)