Heat continued source considerations

Kach method suffers from one or more inherent sources of error. Method 1 is not readily adaptable to the determination of second explosion limits. If temperature equilibrium is reached very quickly by the gas flowing into the vessel, as the continued flow causes the pressure to increase, the system must first intersect the lower explosion limit. Method 2 can lead to large errors if explosion is preceded by an induction period. In the carbon monoxide-oxygen reaction, for example, it was found that the heating rate could considerably affect the results owing to the existence of a zone of slow reaction adjacent to the second limit and inhibition of the reaction by the product, carbon dioxide... 

Heat treatment furnaces are known to be continuous sources of well known non-air components. Emission levels are closely related to energy consumption, burner design and maintenance. Emission collection is trivial in annealing furnaces. The capture of the emissions in the different furnaces does not differ considerably, and emissions are expelled via the waste gas pipe. In general, no further waste gas treatment is applied. 

If this were not the case it would be possible to construct a device for making a heat transfer from a region of the earth at a uniform temperature and using it as a continual source of mechanical power. This has never been achieved, and there seems good reason from molecular and statistical considerations to believe that it never will be achieved. 

The other method. of conducting the evaporation of vat liqiiors is by means of iron pans, with the fire and, heated air applied beneath. These—named fishing pans —are of considerable size, and shaped somewhat similar to a boat. They may bo heatad by a fire used solely for the purpose in which case to prevent injury to the pan, the arch of the furnace should be continued for some distance beneath, or the pan may be placed at the end of the black-ash furnace farthest from the fire, just as with the salting pan, except that the heated air is mads to pass under instead of over the pan. The evaporation is rapidly conducted by this method and when the lie becomes concentrated to a certain strength, small crystals of mo nob yd rated carbonate of soda— Na 0, COa, HO—constantly fall to the bottom, and as quickly as thoy fall are raked together to tho end of the pan farthest from the source of heat, and then Scooped or fished out by moans of perforated iron shovels. After being allowed some time to draiD, the salta so obtained are washed with fresh vat liquor, and then removed a reverberatory furnace, and all worked about until sufficiently dry. The deep-red mother liquor is either applied to the production of caustic soda or evaporated, and the residue heated with sawdust as before directed. 

The nonlinearity of chemical processes received considerable attention in the chemical engineering literature. A large number of articles deal with stand-alone chemical reactors, as for example continuously stirred tank reactor (CSTR), tubular reactor with axial dispersion, and packed-bed reactor. The steady state and dynamic behaviour of these systems includes state multiplicity, isolated solutions, instability, sustained oscillations, and exotic phenomena as strange attractors and chaos. In all cases, the main source of nonlinearity is the positive feedback due to the recycle of heat, coupled with the dependence of the reaction rate versus temperature. 

---