Abstract
(1) For the amount of natural ventilation caused by density difference of dust air of the farm structore, considering the dust source existed inside of structure and perfect diffusion was held; the author obtained:
V=VrlogeV(c1-c0)-nxΔZ/V(c2-c0)-nxΔZ
denoting by V the amount of ventilation; w: the volume of room; c1: the density of inside dust air at the first time Z1; c2: the density of inside dust air at the later time Z2; c: the density of outside dust air; x: the amount of splashed dust per unit; and n: the number of dust sources.
It may be seen that c2 decreases in reference to Nr, times of ventilations, as follows:
c2=V(c1-c0)+eNr(nxΔZ+Vc0)-nxΔZ/eNrV
As for the dust source existed outside of srtucture, the above is simplified by denoting x=0.
(2) Sufficient exclusion of inside dust air can not be performed so long ass the effeciency of ventilaton reduces in as much as the amount of ventilation increases.
Efficiency of ventilation can be denoted by ηp and ηr, named respectively by author efficiency of purity and efficiency of residual. In this occasion, carried out ηp, and ηr resembling volumetric effeciency and scavenging efficiency in case of 2 cycle Internal Combustion Engineering.
Then ηp=c1-c2/c1-c0 ηr=1/N(c1-c2/c1-c0)
(3) Accounts are also given of he deducted amount of insufficient diffusion compared to sufficient diffusion taking consideration of ηp and ηr.
