Paraformaldehyde decreases required enclosed compartment disinfectant time and temperature by vaporizing powdered material from water slurry. Fire and explosion hazard at lower temperature is reduced. Total mixture evaporation occurs at plate temperature of approximately 167 deg K below that required to vaporize powdered material

Milner, J. F.

English

NASA Technical Reports Server

May 1971	 Brief 71-10096 
NASA TECH BRIEF 
_4V Manned Spacecraft Center 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the. Tech Brief program may 
be directed to the Technology. Utilization Office, NASA, Code KT, Washington, D. f. 20546. 
Improved Method of Using Paraformaldehyde as a Disinfectant 
The time and temperature required to disinfect 
enclosel compartments using paraformaldehyde (a 
solid polymer of formaldehyde) can be decreased 
by vaporizing the powdered material from a water 
slurry. In conventional practice, a plate holding dry, 
powdered paraform aide hyde is heated to approxi -
mately 533°K (500°F) to vaporize appreciable 
amounts of the material 4 which decomposes to release 
gaseous formaldehyde. This relatively high temperature 
is required because of the low heat transfer rate 
through the dry powder granules and across the 
voids that form between the granules as vaporiza-
tion proceeds. 
In a water slurry of the paraformaldehyde, the 
heat transfer rate is greater, and total evaporation 
of the mixture (with decomposition of the parafor-
maldehyde) occus at a plate temperature that is 
approximately 167°K (300°F) below that required to 
vaporize the dry, powdered material. In addition, 
the fire and explosion hazard at this lower tem-
perature is substantially reduced; in the event of an 
accidental spill, the slurry will present less of a 
personnel hazard and can be cleaned up more 
readily than the powdered material. 
Note: 
No additional documentation is available. Specific 
questions, however, may be directed to: 
Technology Utilization Officer 
Manned Spacecraft Center, Code JM7 
Houston, Texas 77058 
Reference: B71-10096 
Patent status: 
No patent action is contemplated by NASA. 
Source: James F. Milner of

North American Rockwell Corp.
under contract to 
Manned Spacecraft Center
(MSC-15887) 
Category 05 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this docUment, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19710000095 2020-03-17T02:22:04+00:00Z


Improved method of using paraformaldehyde as a disinfectant

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server