How to Dry a Frozen Bookcicle - Fast

STANDING in a nondescript downtown warehouse, Don Hartsell, a law student-cum-entrepreneur, dipped his hand into a crate of frozen books - and pulled out one of the 700,000 volumes that were water damaged in the Los Angeles Public Library fire here three years ago. For the past eight months, his company had dried them with dehumidifying fans that extract the wetness by replacing the air in special, huge drying chambers every 23 seconds. The rock-hard bookcicles - frozen off-site in the aftermath of the fire with the aid of 10,000 local volunteers - went from ice-solid to completely dry in two to 12 days, depending on the initial saturation.

The process was completed last week, but the painstaking recataloging and stacking will continue for quite some time.

Four years ago when torrential rains poured in the open ceiling of a branch of the Houston Public Library - then undergoing roof repair - 100,000 volumes were threatened by mold and mildew. With power and air-conditioning units out, Mr. Hartsell's company, Solex Technologies, brought in special dehumidifiers and converted the entire library into a drying chamber.

In four days, the crisis was over. No books had to be removed, no freezing, transportation, or storage costs were incurred. Library patrons lost very little time.

``We were going to spend thousands [of dollars] having the books hauled off to [freezing chambers] across town at NASA,'' recalls library director David Hennington. ``But by then, most of them would've been ruined. Solex saved my books!''

This achievement marks a new age of document and book-drying technology. ``[They've] proved they can come in here with a minimum of dislocation and do everything that was done before without so much as taking a book from the shelf,'' says Mr. Hennington. Success at the Houston site led to another project and similar testimony from officials at the Southwestern University Library.

Although there are other high-tech methods to salvage books damaged by acts of firefighters and nature - most notably a vacuum technique that can turn ice into vapor without first changing it to the damaging state of water - the Solex method eliminates the need for freezing at all.

And because of a high-efficiency refrigerant that makes drying possible at more comfortable temperatures, library or office personnel can often go on working in the drying environment itself.