Abstract: Method and apparatus for recovery of waste heat from thermomechanical pulping systems and the like in which waste heat in the form of steam exhausted from the mechanical pulper and latency chest portions of the thermomechanical pulping system are respectively passed through first and second evaporators which increase the enthalpy of the working liquid. The working fluid outputted from the first evaporator passes through a first compressor to significantly increase both pressure and temperature and further increase enthalpy. The working fluid at the outlet of the first compressor then undergoes desuperheating within an intercooling tank. The liquid phase of the working fluid is passed from said tank to the inputs of both evaporators, while the vapor phase merges with the working fluid outputted from the second evaporator and enters a second compressor to undergo further increases in pressure and temperature.

Abstract: A flame intensity controller for controlling the air/gas mixture introduced into a conveying and/or mixing tube. Plural heating arrays are transversely aligned to the direction of movement to dry the moving web. The controller selectively controls the heating intensity of each section of the heating arrays to thereby control the amount of drying experienced by each longitudinal section of the web. The controller may be a countercurrent air controller or a mechanical restrictor. The energy output of each section is controlled between adjustable upper and lower energy levels. However, the lower energy level is chosen to be sufficient to sustain combustion. The independent control of the dryer sections provides dramatic improvement in uniformity of the moisture "profile" across the web.