The self-heating of wet wool

Abstract

A study has been made of the tendencies for various grades of wet wool to self-heat under aerated adiabatic conditions, and comparisons made with the behaviour of wet wool in bales. Whereas 76°c is the highest temperature recorded for wet baled wool, it is demonstrated that adequately 8crated wet wool can attain temperatures ranging up to 102°c under adiabatic conditions. An automatic apparatus capable of producing these conditions is described. The self-heating of wet wool up to 76°c is normally caused by bacterial metabolism, and it is shewn that some thermophilic bacteria appear to be able to produce temperatures up to at least 79.4°c.Although al'l these bacteria utilise the wool fibre itself, their metabolic activity is greatly stimulated by the presence of grease, suint, scud, and other materials.When wet wool is kept hot (say 80°c or above) it degrades, and will then react chemically to cause further heating. This chemical heating reaction does not occur when the wool is completely dried. Aerated wool containing water in insufficient amount to saturate the interstitial atmosphere can also heat, probably because of the growth of moulds. All these effects are discussed in relation to the self-heating of other wet organic materials and to the known action of microbiological agencies on wool. The relation of this wet heating to the spontaneous ignition of wool is also discussed.

Aerogel insulation materials for industrial installation: properties and structure of new factory-made products

“…half of the maximum temperature value of the sample. A similar effect was observed with mineral wool products [34,35,37,38] and the effect is called internal self-heating. Its source in mineral wool products is due to exothermic reactions occurring in the binder (phenol formaldehyde resin) [35].…”

Composting Process Control Based on Interaction Between Microbial Heat Output and Temperature

“…Two suitable experimental designs have been followed. The first used the adiabatic apparatus to give free rein to the interplay between heat output and temperature (2,3,14,18,22). The second fixed the temperature in test chambers at selected levels (12,17,20,23,24).…”

An Investigation of the Ignition and Combustion of Loosely Compacted Commercial Steel Wool

“…It has been reported by Walker et al [5,6,7] that bales of raw wool burst into flames when opened after about 60 days. They suggested that slow decomposition of raw wool by bacterial activity produces flammable pyrolytic products.…”