The Big Dutchman air scrubber PURO for strawless pig housing efficiently reduces ammonia, odour and dust emissions, as demonstrated by a recent usability test performed by the German Agricultural Society (DLG). “All values are above those of the DLG’s already challenging requirements,” says Big Dutchman product sales manager Roland Tapken, who is happy about the two-stage air scrubber’s excellent test results. PURO is now certified to carry the renowned “DLG Approved Full Test” quality seal.

The air cleaning system with chemical and biological filters has additional benefits. For example, the biological filter is extremely successful at reducing even very high odour concentrations, compared to standard single-stage systems.

The innovative chemical filter, on the other hand, helps farmers save money. “The pH value and conductivity of the wash water have a significant effect on the separation rates. For both values, PURO’s results are better than those of standard filters,” explains Tapken. In numbers: 80 % less desludge water is produced, thus clearly reducing the amount of residues. Costs incurred by spreading and storage are therefore lower.

The DLG has set a high bar. Air cleaning systems must be able to separate at least 70 % of ammonia and dust emissions to pass the DLG test. According to the test report, PURO achieved ammonia separation rates of 84.4 % in the summer and 77.4 % in the winter, and separates 92.4 % and 70.2 % (winter) of fine dust PM2.5 and PM10. The air scrubber’s separation rates for odours were also very impressive. Even for exhaust air with a concentration of odorous substances, measurements always indicated values below 300 OU/m3, and there was no smell of untreated gas perceptible in the clean gas.

How PURO works

The first cleaning stage is a plastic filter bank that is permanently sprayed with water from above. The main purpose of chemical cleaning is the separation of ammonia as well as total and fine dust. The cleaned air then flows through a droplet separator and into a biological filter. The second cleaning stage is a biological filter bank with brushwood filling, which filters odorous substances from the air.

PURO: also available as a module ready for connection

Farmers can decide whether they want to install PURO in a separate building annexe, or whether they prefer the modular design, where the air scrubber is supplied ready to be connected in a plastic housing, including a pre-installed technical room. The manufacturer performs a function test before delivery. “Even if some tasks still need to be done, commissioning of the modular air scrubber is very similar to what would be called ‘plug & play’ on a computer: we connect the system and the farmer is ready to go,” says Tapken.

The advantages of the modular version are thus quite obvious:

• lower construction costs;
• lower installation requirements;
• single-part plastic housing for reliable and long-term impermeability;
• high resistance to acids, alkalis and process water.