I was out googling for home-built food dehydrators. Found several sites offering plans for purchase, and a few sketchy descriptions. Several references to a plan from a guy at OSU as well, but mostly in out-of-print books from Amazon.
Then I found what I was after --
<broken link removed>
"The majority of the text and plans provided here were originally obtained from the Oregon State University Extension Service Circular 855, and were last revised in 1984 by Dale E. Kirk, professor emeritus of agricultural engineering at Oregon State University..."
It looks like a typical up-draft unit, but he deals with the usual problem of the last tray getting wet air (and working more slowly) by tapering the depth of the lower trays to allow more bypass air. This does mean you have to make your own trays, but maybe that's not a bad thing if you'd like to replace them periodically. Also means you can't shuffle the tray positions to balance out drying rates, but perhaps the bypass works as designed.
The other hot set-up, I gather, is buying the loose trays from the Excaliber folks and building your own box around 'em.
MrB
Then I found what I was after --
<broken link removed>
"The majority of the text and plans provided here were originally obtained from the Oregon State University Extension Service Circular 855, and were last revised in 1984 by Dale E. Kirk, professor emeritus of agricultural engineering at Oregon State University..."
It looks like a typical up-draft unit, but he deals with the usual problem of the last tray getting wet air (and working more slowly) by tapering the depth of the lower trays to allow more bypass air. This does mean you have to make your own trays, but maybe that's not a bad thing if you'd like to replace them periodically. Also means you can't shuffle the tray positions to balance out drying rates, but perhaps the bypass works as designed.
The other hot set-up, I gather, is buying the loose trays from the Excaliber folks and building your own box around 'em.
MrB