Oil smoke generators

Smoke produced by the combustion of chemical mixtures was not the perfect answer to screening because mixtures were expensive, the smoke nauseated the troops, pots burned out in a short time, and many men were needed to maintain a large screen. On the other hand, it was easy and cheap to produce smoke by burning oil, and in 1941 the CWS stand- 

Mechanical smoke generators came into existence through the co-operative efforts of industry, the National Defense Research Committee, and the CWS. The principle behind the device was simple. It vaporized a mixture of water and oil (the CWS used a special oil commonly referred to as fog oil), and then discharged the mixed vapors into the air. When the hot vapor hit the cool air it condensed back into tiny liquid droplets. 

Mechanical generators had many advantages over oil burning generators. They produced smoke more rapidly and in larger quantity so that fewer men could screen a larger area. Their smoke was very persistent. By way of comparison, smoke from HC pots was seldom effective for more than 500 to 800 yards downwind, while smoke from mechanical generators extended for several miles. 

Development of the first mechanical generators took more than a year. In 1941 the CWS received reports from the British of the Haslar genera- 

Mechanical Smoke Generator Ml (100-Gallon) pouring out smoke screen to conceal Fifth Army operations from the Germans, Anzio area, Italy, March 1944- 

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CWTC Item 357, Standardization of Generator, Oil, Smoke, Ml, 22 Jul 41. (2) CWTC Item 403, same title, 14 Oct 41. (3) Brooks F. Smith, Engineering Test of Kincaid Oil Smoke Generators. TDMR 265, Jan 41. 

V) Capt T. L. Hurst, Capt Winton Brown, and H. E. Norton, Development of a Lightweight Portable Oil Smoke Generator of Fifty Gallon Pet Hour Capacity. TDMR 810, 1 Mar 44, (2) TM 3-381, 14 Jun 44. (3) CWTC Item 8(34, Standardization of Generator, Smoke, Mechanical, M2 (50 Gallon), 3 Dec 43. 

The life persistency of a smoke cloud is deterrnined chiefly by wind and convection currents in the air. Ambient temperature also plays a part in the continuance or disappearance of fog oil smokes. Water vapor in the air has an important role in the formation of most chemically generated smokes, and high relative humidity improves the performance of these smokes. The water vapor not only exerts effects through hydrolysis, but it also assists the growth of hygroscopic (deliquescent) smoke particles to an effective size by a process of hydration. Smoke may be generated by mechanical, thermal, or chemical means, or by a combination of these processes (7). 

Smoke generator A device that electri cally heats oil-producing smoke. The smoke is liberated from a nozzle by either thermal forces or by means of a fan and used to observe airflow patterns within a space or to observe leakage from ductwork, etc. 

The following are pyrotechnic methods for smoke generation as opposed to mechanical methods such as atomization of fog oil, of Ti tetrachloride (FM smoke) or of S trioxide. This discussion is drawn from Ref 134, which should also be consulted for earlier references ... 

Of the approximately 15 aluminum forging plants, three use wet scrubbers to control particulates and smoke generated from the partial combustion of oil-based lubricants in the forging process. 

Smoke flavoring, 12 48 Smoke generation tests, 19 588 Smoke point, of fats and oils, 10 822 Smoke retardants, molybdenum compounds in, 17 39 Smoke suppression, by ethylene-acrylic elastomers, 10 700 Smoking, age-related macular degeneration and, 17 659 Smoky quartz color, 7 337... 

Various chemicals and their crude mixtures were used in the wars in many parts of the world all throughout history. In the fifth century BC Spartan used toxic smoke generated from burning wood dipped in a mixture of sulfur and tar against Athens. Early Chinese manuscripts in the fourth century BC indicate the use of toxic smokes from cacodyl (arsenic trioxide). Chemicals of incendiary compositions, such as, sulfur, pitch and sawdust and oil-based incendiaries slowly attained wider applications in the latter wars. 

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