Our first trial was carried out in September, with as mentioned, limited data recording by the Kestral data loggers, that required the entry into the sheds and the down loading of the data via Bluetooth communications. Although it is possible to view the data on a hand-held device, it is easier to view the data on a PC. This is under taken by transfer the data via email to a PC, this was cumbersome, but proved very useful.
Previous experience had revealed a problem with dust in the sheds. Armed with this experience we set about trial 3 different air operated filter cleaning technologies.
This involved the installation of rotary air blowers, oscillating air blowers and an “air blade”. The air blade was a failure, the oscillating air blowers had some effect, in that were the air was most powerful the dust was effectively blown away, but was only about 25% of the filter area. The “air blade” was the most successful, but had drawn backs in how to get it to travel back and forth within the limited space of the filter housed, with a further draw back being the volume of air required to operate it. This highlighted a further issue, in that with any method of cleaning a backup would be required in case of a failure.
To assess the operation of the system, the filters were removed and clean spare filters fitted, each morning and late afternoon, they were then taken outside and cleaned whilst we were onsite carrying out the installation of the electronic logging, then on weekends cleaning was only carried once a day. This did provide a result of a 57% gas reduction on the farm.
For the next batch of birds, it was decided that a flat filter be used in lieu of the traditional corrugated filter and for a brush/broom to sweep over the filter to clean away the dust. Designs were quickly produced and components sources, resulting in a system that pushed a hard brush across the flat filter, this was driven by an electric actuator motor. This proved very successful with a 87% gas saving against one of the control sheds. In addition to the Kestrel loggers, we were able to record the data from the hard-wired logging devices, such as air temperature in & out, water temperature in & out and the pressure differential across the filter. This data had proved very useful in evaluating the issues and to create discussion in an endeavor to solve some of the issues with the circulation of heat within the structure and where the heat may be lost. Additionally, adjustments to this system have been highlighted and will be carried out if time permits between the next batches of birds.
This did highlight a further issue that requires investigation, this being that what was thought to be the heater that would use the most gas, used 0.2lts of liquid gas, the heater adjacent to it, used 218lts of liquid gas, and the heater next to the cold zone only used 17lts of gas. These figures are from the actual gas meters at each location.
The next batch of birds will be place around the 17th of January, at which tile we should have no problem obtaining a 100% gas elimination, provided we can find the source of the heat escape from the central area of the shed.
