News article, 21. May 2024

Wire-type cleaner system for finisher units

A study carried out by SEGES Innovation indicates that the wire-type cleaner system will reduce methane emissions from slurry in finisher units.

The wire-type cleaner system enables manure and urine to be mechanically transported from the slurry channel to the collection pit or other outlet. The system offers a number of benefits when it comes to manure handling. It is likely to result in methane emissions from manure being largely eliminated provided the manure is scraped away on a daily basis or once or twice per week. Based on SEGES Innovation’s calculations, the cleaner system is expected to remove around 100-120 kg CO2 equivalents per m2 of finisher unit per year compared to the vacuum system where discharge is carried out twice during the growth period. It is also expected to reduce odour. Moreover, slurry discharge will be automated, labour costs will be reduced. The system, however, is not without its challenges.

Economic perspectives

As it requires ongoing maintenance, the wire-type cleaner system will be more expensive to set up and operate than the traditional vacuum system, i.e. DKK 2.2-DKK 18 more in annual costs per finisher compared to the vacuum system, depending on the layout and size of the housing unit and whether the time saved on weekly slurry discharge is included. However, in the long-term, the wire-type cleaner is expected to prove to be a relatively inexpensive piece of odour and methane-reducing technology as it is likely to be on the Technology List (a list of environmental technology which is reliable in service and has a documented positive environmental effect). The system will also allow for the use of more straw as enrichment material.

Less odour from housing units

In finisher units with several sections positioned next to each other, there is a risk of drawing air between the sections in the unit if a common cross-channel is used. The wire-type cleaner system consists of slurry channels with scraper blades which move the slurry to a cross-channel. From the cross-channel, the slurry is moved to a reception tank and a storage tank. It is at the transition between the cross-channel and the channels from the individual sections that the risk of air interchange occurs.

There are several options for establishing cross-channels that can prevent air interchange between sections in finisher units. The simplest is a square “slurry pit” at the end of the wire-type cleaner system instead of a cross-channel with sloping sides. The “slurry pit” is equipped a traditional slurry pipe outlet with drainage to the reception tank via an automatic valve or plug. This ensures that no air can be drawn between the sections.