The design principles of internal recirculating dry air filters for use in livestock buildings are discussed and several designs described. In one design for a flat-deck early-weaner room a centrifugal rotor draws air through a floor-standing pre-filter and discharges it through a fine filter at a velocity of about 0.4 m\/s. The fine filter constitutes the under-surface of a duct located above the pigs. The air throughput of the filter is equal to the max. ventilation rate of the room in order to achieve adequate dust reduction. When used in flat-deck rooms with early-weaner pigs, the filter unit reduced dust mass and bacterial colony-forming particle concn. by 50-60% and collected dust at daily rates of 100-500g per 100 piglets, depending on the design of the room and the age of the pigs. The pre-filter was periodically vacuum cleaned and the changes in pressure losses across the filters recorded for several weeks. The airborne dust concn. in a flat-deck room with a wire-mesh pen floor was only one-quarter of that in a room with similar stocking and ventilation rate with a solid floor. Measurements of dust deposition rate suggest that it is approx. proportional to the airborne dust concn. A theory is proposed which relates dust concn. to ventilation, filtration and deposition rates and accounts for the reductions in dust concn. achieved by the filtration described above. Calculations suggest that, under certain conditions, sedimentation can clear as much as 74% of the dust mass and of the number of particles generated and that this value is normally likely to exceed the percentage cleared by ventilation. It is probable that a floor of high voidage reduces dust because of the combined effects of a reduction in floor-generated dust and the voids providing a clearance path.<\/p>\n","protected":false},"excerpt":{"rendered":"
The design principles of internal recirculating dry air filters for use in livestock buildings are discussed and several designs described. In one design for a flat-deck early-weaner room a centrifugal rotor draws air through a floor-standing pre-filter and discharges it through a fine filter at a velocity of about 0.4 m\/s. The fine filter constitutes […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[18992,535,18498,20268,8882,372,6618,13816,2854,12251,1972,73,286,536,537,538,19315,171,531,20007,539,4951,14,505,126,89,33,16262,219,9159,20561,323,20911,4874,6053,274,6206],"class_list":["post-1042","post","type-post","status-publish","format-standard","hentry","category-environment","tag-air-filter-piggery","tag-air-filters","tag-air-filtration","tag-air-filtration-in-a-piggery-filter-design-and-dust-mass-balance","tag-al","tag-animal-housing","tag-articles","tag-ass","tag-bin","tag-born","tag-condition","tag-control","tag-dust","tag-dust-extractors","tag-extractors","tag-filtration","tag-flat-deck-piglets-weaners-publication","tag-floor","tag-floors","tag-gh","tag-grid-floors","tag-particle","tag-pig","tag-pig-housing","tag-piglet","tag-piglets","tag-pigs","tag-pl","tag-reduction","tag-swine-filter-ventilation","tag-swine-flu-filter","tag-swine-housing","tag-t","tag-tan","tag-use","tag-ventilation","tag-weaner-pigs"],"_links":{"self":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/1042","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/comments?post=1042"}],"version-history":[{"count":0,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/posts\/1042\/revisions"}],"wp:attachment":[{"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/media?parent=1042"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/categories?post=1042"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/prairieswine.com\/rsc\/wp-json\/wp\/v2\/tags?post=1042"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}