Catalytic hot-water bottle - a chemical hot-water bottle designed for individual heating of a person due to flameless oxidation of vapors of highly refined gasoline, for example, Nefras C2 80/120 or 95–97% alcohol in the presence of a catalyst. Often a catalytic heating pad is incorrectly called an infrared heater .
Content
History
During World War I , millions of soldiers froze in the trenches, and over the course of four war years, the inventors of the United States , Japan, and England patented several options for pocket-sized liquid warmers. The principle of their action was simple: the catalytic flameless oxidation of alcohol or gasoline. The catalyst in all cases was platinum. The Japanese hot-water bottle looked like a cigarette case, inside of which there was a tank filled with cotton and a platinum pad. Holes were drilled in the housing for supplying air to the catalyst and for removing gaseous combustion products. To start the heating pad, alcohol was poured into the tank, which was absorbed into the cotton. Then the catalyst was heated by the flame of a match, and a catalytic reaction began.
Currently, warmers for individual heating a person on a camping trip , fishing , hunting , in conditions associated with working outdoors, in winter sports, and so on, are quite popular. The Soviet industry produced a catalytic gas heater GK-1, which, when fully charged, could generate heat for 8-14 hours with temperatures up to 60 ° C, that is, at the level of a pain threshold .
Device and principle of operation
The heating pad consists of a tank filled with cotton wool , a nozzle with a mesh cartridge in which the catalyst is placed, and a lid with ventilation holes.
The principle of operation of a heating pad is based on heat generation during flameless oxidation of gasoline vapors in the presence of a catalyst . Gasoline vapors from the reservoir pass through a catalytic cartridge , where they are oxidized by atmospheric oxygen (burn without flame) on the surface of a heated catalyst . Oxidation products enter the vents of the lid. At the same time, air containing oxygen enters the catalyst surface through the ventilation openings of the lid. The catalytic grid ( catalyst ) has the form of a wick and is located inside the steel mesh cartridge, made of platinum - this is the most important part of the heating pad. To start the grid in a catalytic cartridge is heated for 10-15 seconds, using a flame that does not give soot (for example, a lighter ).
Fuel for a heating pad - gasoline of the highest degree of purification. Gasoline for lighters or some grades of nefras are well suited for these purposes: C2-80 / 120 (Kalosha) or C3-80 / 120. The use of other types of fuel can lead to rapid damage to the catalytic network (a phenomenon called “catalyst poisoning”), which will affect its effectiveness. It is often possible to increase the efficiency of a clogged catalyst by calcining a mesh cartridge with a catalyst inside on a non-smoking (gas) flame or in a muffle furnace.
Using individual catalytic heating pads in enclosed spaces can be hazardous to health, as gasoline oxidation products are toxic!
Notes
See also
- Salt water heater