HAZARDS ASSOCIATED WITH GASIFIER OPERATION
Unfortunately, gas generator operation involves certain problems, such as toxic hazards and fire hazards. These hazards should not be treated lightly; their inclusion here, at the end of this report, does not mean that these hazards are unimportant. The reader should not underestimate the dangerous nature of these hazards.
Many deaths in Europe during World War II were attributed to poisoning from wood gas generators. The danger of “generator gas poisoning” was one of the reasons that such gasifiers were readily abandoned at the end of World War II. It is important to emphasize that “generator gas poisoning” is carbon monoxide (CO) poisoning. Acute “generator gas poisoning” is identical with the symptoms that may develop if a heating stove damper is closed too early, or if a gasoline vehicle is allowed to idle in a poorly ventilated garage.
Table 3-2 shows how poisoning symptoms develop according to the concentration of carbon monoxide in breathable air. It is important to note that rather brief exposures to very small concentrations of carbon monoxide result in undesirable physiological effects.
In case of carbon monoxide poisoning, first aid should consist of the following procedures:
1. Move the victim quickly out into the open air or to a room with fresh air and good ventilation. All physical exertion on the part of the victim must be avoided.
2. If the victim is unconscious, every second is valuable. Loosen any tight clothing around the neck. If breathing has stopped, remove foreign objects from the mouth (false teeth, chewing gum, etc.) and immediately give artificial respiration.
3. Keep the victim warm.
4. Always call a physician.
5. In case of mild carbon monoxide poisoning without unconsciousness, the victim should be given oxygen if possible.
TECHNICAL ASPECTS OF “GENERATOR GAS POISONING”
Generator gas poisoning is often caused by technical defects in the functioning of the gas generator unit. When the engine is running, independent of the starting blower, the entire system is under negative pressure created by the engine’s pistons; the risk of poisoning through leakage is therefore minimal. However, when the engine is shut off, formation of wood gas continues, causing an increase of pressure inside the generator unit. This pressure increase lasts for approximately 20 minutes after the engine is shut off. For this reason, it is not advisable to stay in the vehicle during this period. Also, the gas generator unit should be allowed to cool for at least 20 minutes before the vehicle is placed in an enclosed garage connected with living quarters. It should be emphasized that the gas formed during the shutdown period has a carbon monoxide content of 23 to 27% and is thus very toxic.
The outside of a gas generator housing drum may reach the same temperature as a catalytic converter on today’s automobiles. Care should be taken when operating in areas where dry grass or combustible material can come into contact with the housing drum of the gas generator unit. If a gas generator unti is mounted on a personal car, bus, van or truck, a minimum 6-in. clearance must be maintained around the unit. Disposal of ashes must only be attempted after the unit has cooled down (to below 150°F). Such residue must be placed away from any combustible material and preferably be hosed down with water for absolute safety.