Smoke generators mechanical

Smoke extraction A mechanical ot natu-tal means by which smoke generated during a process or a fire is removed from the space to outdoors. 

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 ... 

Due to the low cost, the excellent physico-mechanical properties of the resulting urethane - isocyanuric foams, thermal and fire resistance and low level of smoke generation, the most important applications of aromatic polyester polyols are for rigid PU/PIR foams in the boardstock market (continuous rigid foam lamination) and for building insulation. 

Relatively low smoke generation. One high-performance additive and one high-performance reactive formulation used. Paraffins have low heat stability and are plasticizing. Flame retardant mechanism similar to bromine. 

Crosslinked phenolics combine high strength, excellent thermal and mechanical stress, very good electrical and thermal insulation, fire resistance, veiy low smoke generation with a good compatibility with fillers and fibers. Phenolics are not expensive. 

The current discussions across the plastics sector show a steady upwards trend in demand for reduced flammability, minimum smoke generation and low toxicity, yet with optical, mechanical or electrical properties still being retained. This can be quite difficult to master in technical terms, since these demands are contradictory in some measure and also because the matrix polymers display greatly dissimilar behaviour in the event of a fire, with PVC and polyethylene being good examples. 

Fillers can modify the properties of the cured polymer in a wide variety of ways. Some examples of properties readily modified by incorporation of fillers are mechanical properties such as stiffness, hardness, strength and toughness, and thermal properties such as expansion, conductivity or thermal decomposition. The latter can have a considerable effect on flammability and smoke generation. Fillers are also an important way of varying and enhancing aesthetics. 

I) For development of the mechanical smoke generator see Brophy Miles, and Cochrane, from Laboratory to Field, Chapter IX. (2) For smoke generator operations in North Africa, see bdow Chapter VIII. 

In this particular instance Major Wilson was probably right. But, in retrospect, this incident and the supply operations which it represents assume more significance than the immediate problems imply, for this operation marks the bifurcation of the chemical supply system. Henceforth, one element of the chemical supply system was oriented, despite doctrine to the contrary, to an impetus from the front. This element of the system was primarily devoted to meeting the demands and special requirements of the combat forces, especially for new equipment, such as the lightweight mechanical smoke generator, or equipment used in new missions, such as the 4.2-inch chemical mortar. ... 

The 76 officers and 373 enlisted men of the CWS in North Africa by the end of December 194a knew their mission—to prepare for the eventuality of gas warfare, to provide artificial smoke concealment, and to support combat troops with chemical weapons and equipment— but few of these men could have had much conception of what the mission involved or how they were to accomplish it. They had no toxics and no means to use them. The mechanical smoke generator was a new... 

---