Circulating air dryer

Claim 1

A circulating air dryer including a chamber for holding materials to be dried; a reversible power-operated air mover for selectively circulating air through said chamber in either of opposite direction; exhaust means communicating with the chamber for exhausting a portion of the air being circulated, said exhaust means withdrawing air at a location disposed upstream of the air mover and in a region under negative pressure with respect to the air mover with the air mover operating in either of opposite directions, means for introducing heat to the circulating air disposed downstream of the exhaust means with the air mover operating in either of opposite directions; and means for introducing makeup air into the chamber downstream of the exhaust means with the air mover operating in either of the opposite directions.

Claim 3

A system for circulating air within a space comprising a reversible air mover in said space for selectively forcing air along a course through the space in either of opposite directions, heating means disposed proximate said air mover for selectively introducing heat to air forced through the air mover, first air transfer means communicating between the atmosphere and a region of said space disposed on one side of the air mover which region is at a negative pressure with respect to the air mover with the air mover forcing air in one direction, said air transfer means including an inlet for admitting fresh air to said space for heating and an exhaust including means for exhausting cooled air at the region of negative pressure relative to said air mover from said space, and second air transfer means communicating between the atmosphere and a region of said space disposed on the other side of said air mover which region is at a negative pressure with respect to the air mover with said air mover forcing air in the other direction, said air transfer means including an inlet for admitting fresh air to said space for heating and an exhaust including means for exhausting cooled air at the region of negative pressure relative to said air mover from said space.

Claim 4

A system for circulating air within a space comprising a reversible air mover in said space for selectively forcing air along a course through the space in either of opposite directions, heating means disposed proximate said air mover for selectively introducing heat to air forced through the air mover, first air transfer means communicating between the atmosphere and a region of said space disposed on one side of the air mover which region is at a negative pressure with respect to the air mover with the air mover forcing air in one direction, said air transfer means including an inlet for admitting fresh air to said space for heating and an exhaust including means for exhausting cooled air at the region of negative pressure relative to said air mover from said space, and second air transfer means communicating between the atmosphere and a region of said space disposed on the other side of said air mover which region is at a negative pressure with respect to the air mover with said air mover forcing air in the other direction, said air transfer means including an inlet for admitting fresh air to said space for heating and an exhaust including means for exhausting cooled air at the region of negative pressure relative to said air mover from said space.

Claim 11

A system for circulating heated air within a closed lumber kiln comprising a reversible circulating fan in said kiln for selectively forcing air forwardly of the fan And rearwardly of the fan along a course surrounding a stack of lumber within the kiln, a heater disposed proximate said circulating fan for adding heat to the air forced through the circulating fan, air inlet means for admitting air from the atmosphere to said kiln, including a first inlet duct located in a region of said kiln rearward of said circulating fan and a second inlet duct located in a region forward of said circulating fan, louver means in each inlet duct for opening and closing the duct, and motor means associated with each louver means for positioning said louver means, and air exhaust means for exhausting air from said kiln to the atmosphere with said air being at substantially the lowest dry-bulb temperature and the highest relative humidity within the kiln, including a first exhaust duct located in a region of said kiln rearward of said circulating fan and a second exhaust duct located in a region of said kiln forward of said circulating fan, louver means in each exhaust duct for opening and closing the duct, motor means associated with each louver means for positioning said louver means, and exhaust fan means for selectively exhausting air from a region of negative pressure in said kiln relative to said circulating fan through said first exhaust duct and said second exhaust duct, when opened.

Claim 12

A system for circulating heated air within a closed lumber kiln comprising a reversible circulating fan in said kiln for selectively forcing air forwardly of the fan And rearwardly of the fan along a course surrounding a stack of lumber within the kiln, a heater disposed proximate said circulating fan for adding heat to the air forced through the circulating fan, air inlet means for admitting air from the atmosphere to said kiln, including a first inlet duct located in a region of said kiln rearward of said circulating fan and a second inlet duct located in a region forward of said circulating fan, louver means in each inlet duct for opening and closing the duct, and motor means associated with each louver means for positioning said louver means, and air exhaust means for exhausting air from said kiln to the atmosphere with said air being at substantially the lowest dry-bulb temperature and the highest relative humidity within the kiln, including a first exhaust duct located in a region of said kiln rearward of said circulating fan and a second exhaust duct located in a region of said kiln forward of said circulating fan, louver means in each exhaust duct for opening and closing the duct, motor means associated with each louver means for positioning said louver means, and exhaust fan means for selectively exhausting air from a region of negative pressure in said kiln relative to said circulating fan through said first exhaust duct and said second exhaust duct, when opened.