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Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan

Citation:  Pp. 048-055 in Swine Housings II Proceedings of the 12-15 October 2003 Conference (Research Triangle Park, North Carolina USA), Publication Date 12 October 2003.  701P1303.(doi:10.13031/2013.15468)
Authors:   G. Zhang; S. Morsing; J.S. Strøm; B. Bjerg; K. Svidt
Keywords:   airflow pattern, floor air velocity, CO2 distribution, non-isothermal ventilation

Air velocity fields and their effect on CO2 distribution in the near floor region were investigated in a full-scale ventilated room with pig simulators and a partition wall. The room was 10 m wide, 3 m high and 8.5 m long. The solid partition wall was 0.8 m high and 10 m wide spanning across the room 5 m from the ventilation inlet wall. Two rows each with 8 standing pig simulators and a row with 8 lying pig simulators were placed along the partition wall.

Four rectangular inlets with an elliptic profile in the contraction section were symmetrically installed in the inlet wall 0.5 m beneath the ceiling. The elliptic profile followed the ISO standard for a long-radius nozzle. The geometric opening of each inlet was 0.525 m wide by 0.05 m high pointing upwards 20° above horizontal towards the ceiling in order to provide an initial inclination of the jet.

During the experiments, a pressure difference of 10 Pa between the test room and the surrounding laboratory was maintained. This resulted in an inlet flow rate of 1480 m3/h equivalent to 5.8 air changes per hour. CO2 was injected into the room through a point source on the floor in the symmetric position 5.5 m from the inlet wall. The investigation covered both isothermal conditions with no heat for the pig simulators and non-isothermal conditions with heated pig simulators. In the isothermal conditions the pig simulators were maintained in the room with power off. In the non-isothermal experiments, the surface temperature of the pig simulators were kept at 39±1.5 °C with a power consumption of 5.8 kW. The room temperature was kept at 20±0.5 °C and the supply air temperature was about 10 °C lower than the room air temperature.

Measurements showed that the airflow patterns under isothermal and non-isothermal conditions were different due to the buoyancy created by the heated pig simulators. CO2 distribution was strongly related to the air motion and highly correlated to the airflow (Download PDF)    (Export to EndNotes)