Extraction Fan Assembly for an Animal Husbandry Barn

Abstract

An animal barn includes air inlets which are filtered to extract pathogens and a plurality of extraction fans for generating an air stream so as to draw replacement air into the containment area through the air inlets. Each fan has a housing mounted in a wall with an outlet duct extending through the wall to an outlet opening outside the wall. A damper flap is mounted on the fan suspended by a hinge at an upper edge so as to extend in a closed position across the opening in a mounting plate. The damper flap is movable to an open position under forward air flow from the fan and closes against a resilient deformable seal to seal the damper flap to prevent reverse flow of pathogen contaminated air through the fan housing when the fan is shut off. An adjustable abutment member can act to hold the flap partly open against opposing wind forces during low fan operation.

Description

[0001]This invention relates to a fan construction for use in an animal husbandry barn.[0002]Typically such barns comprise a containment area; a plurality of air inlets into the containment area and a plurality of extraction fan constructions for generating an air stream exiting the containment area so as to draw replacement air into the containment area through the air inlets. In many cases each air inlet has an air filter system for extraction from incoming air of pathogens so as to reduce transmission of disease to the animalsBACKGROUND OF THE INVENTION[0003]In recent years prevention of disease to animal husbandry barns has reached the extent where attempts are made to ensure that all air entering the barn is filtered of pathogens that can be airborne. For this reason a number of companies provide systems for filtering the air at the intakes. Typically the air intakes communicate with the roof space with the air entering into the containment area through the ceiling and also fro...

AI Technical Summary

Benefits of technology

[0010]a plurality of air inlets into the containment area where each air inlet has an air filter system for extraction from incoming air of pathogens so as to prevent transmission of disease to the animals;

[0048]In non-filtered swine and poultry barn, this feature allows a better minimum ventilation rate control during windy period. When the wind comes in the fan direction, this has a restriction effect on the fan's airflow. When a fan is running at its minimum speed, a strong wind can almost totally block the airflow and cause air quality problem inside the building because the contaminants are still in the barn. Then, this equipment will help to optimized the air quality control and the heating cost in the barns. Also, this concept can allow to reduce the number of fans on first and second ventilation stage by using larger fans and reduced energy consumption.

Problems solved by technology

However it is known that pathogens can still enter the containment area by the fans louvers and disease can still strike, often with very damaging results.

However it is known that pathogens can still enter the containment area through closed fans louvers, due to known negative air pressure (0.05 inch of water) inside the building.

It has been experimented that a 24″ fan that is not running even with the louvers closed, can allow in as much as 400 cfm of viral contaminated air into the building, and that 3×24″ fans can allow in as much viral contaminated air into a building as a 12″ running fan would do if it were used to push viral contaminated air into a building, which may cause airborne pathogen to strike, often with very damaging results.

Images