Case Study 2 - Blowing bedding directly into the poultry shed

This broiler farm uses wood shreds produced from soft-wood pallets as bedding, which is dust extracted at source and supplied in bulk. However the litter still contains some dust which is needed to absorb moisture and increase insulation.

The poultry houses on the farm are fitted with axial fans in the roof and ventilation openings in the side walls.

The delivery lorry, which has a purpose built discharge port at the rear, is positioned near to the open shed doors. A rigid discharge pipe (approx 6ins diameter x 10ft long) is connected to the port and supported on a trestle, pointed upwards and into the open shed.

The lorry driver controls the discharge from the rear of the lorry, with a control box on a wander lead that means he can stand well back from the shed entrance. He wears a disposable respirator (FFP3 Standard) and ear defenders. It takes about 20 minutes to transfer the required amount of litter into the shed. Nobody is allowed inside the shed during the transfer period.

The blowing of the litter into the shed creates a lot of airborne dust. The atmosphere inside the shed quickly becomes very dusty once the transfer from the lorry to the shed has started. However, this is not a problem as nobody is allowed inside the shed during this period.

Without the shed's extraction fans in operation, some dust can be seen escaping from the entrance to the shed.

When two roof fans are operating, an inward airflow is induced through the shed doorway which prevents  the escape of dust to the outside. The ventilation openings down the sides of the house remain closed. In this case the lorry driver no longer needs to wear the dust mask.

The atmosphere inside the shed was very dusty at the end of the transfer period so the ventilation fans are operated to clear the air. All fans need to be operated and vents opened for maximum effect. The air was visually clear after about 5 minutes, although the company instruct staff not to enter for 10 minutes.