Isothermal heating

Austempering. Lower bainite is generally as strong as and somewhat more ductile than tempered martensite. Austempering, which is an isothermal heat treatment that results in lower bainite, offers an alternative heat treatment for obtaining optimum strength and ductility if the specimens are sufficiently small. 

Coil-in-Tank or Jacketed Vessel Isothermal Heating Medium... 

BATCH HEATING INTERNAL COIL, ISOTHERMAL HEATING MEDIUM... 

When heating a batch with an internal coil with an isothermal heating medium, the following equation applies ... 

Equation 7-101 ean also he used to ealeulate the heat-up time for non-isothermal heating (e.g., hy hot-water jaeketing), provided that the differenee between the outlet and inlet jaeket temperatures is not greater than 10% of the differenee between the hateh and average water temperature [47]. 

Batch heating internal coil isothermal heating... 

The non-isothermal heating medium has a eonstant flowrate Wj, speeifie heat Cj, and inlet temperature Tj, but a variable outlet temperature. Eor an unsteady state operation ... 

Fig ure 7-28. Batch heating through an external heat exchanger, isothermal heating medium. 

Alternatively, for bateh heating with a non-isothermal heating medium, the log mean temperature differenee AUj p is determined by... 

S. Olive, U. Grafe, I. Steinbach. The modelling of Ostwald-ripening during non-isothermal heat treatments resulting in temperature dependent matrix solubihty of the precipitate forming elements a further development of the LSW-theory. Comput Mater Sci 7. 94, 1996. 

The kinetic rate constant may be computed from the adiabatic temperature rise [38] or the isothermal heat release [37]. For a second order reaction ... 

In a J-T multistage heat exchanger, the mixture is cooled by the colder vapours coming out from the still (see Fig. 6.12). This type of exchanger can be seen as a series of isothermal heat exchangers connected in series by low thermal conductivity capillaries. 

Rate of Isothermal Heat Evolution of Lignocellulosic Sheet Materials in an Air Stream... 

The rate of isothermal heat evolution in lignocellulosic sheet material was studied at temperatures between 150 and 230°C using a labyrinth air flow calorimeter and commercial hardboards, medium density boards and laboratory hardboards of holocellulose, bleached kraft and groundwood, the latter with and without fire retardants. 

For all boards of mechanical or "therraomechanical pulp, the rate of isothermal heat evolution after an initiation period was maximum and then decreased with reaction time. For boards of delignified pulp, i.e. of holocellulose and bleached kraft, this rate reached an intial plateau and then increased with time at temperatures above 200°C whereas it remained almost constant at lower temperatures. The following parameters are evaluated as a function of temperature ... 

Figure 3. The rate of isothermal heat release versus reaction time for a 3.3 mm hardboard of groundwood. Above, on a linear scale below, on a logarithmic scale. Released heat 1.0 kcal equal to 4.19 kJ. (Reproduced with permission from ref. 10. Copyright 1989 De Gruyter.)...

In all the ligno-celluloslc boards, the logarithm of the rate of Isothermal heat evolution decreased approximately linearly with reaction time. A formal representation according to a first order reaction type is ... 

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