Abstract: In a preferred embodiment, the invention relates to a steam turbine having a speed-loop droop governor with two load-frequency error gains (droops). The first gain (fast change) may be a conventional high gain that is used for power loads that have a constant frequency. When using only the first gain, the high rate of the first gain causes the droop governor to shut off steam to the turbine if the speed of the turbine drifts above a narrow speed range centered on the rated speed set-point. The second gain (slow change) is a low gain that causes the droop governor to tolerate a wide range of turbine speeds about the rated speed set-point.

Abstract: A method and apparatus for determining turbine rotor stresses in real time enables increased operation efficiency and more accurate stress determinations. The system calculates rotor bore and surface temperatures based on the time response of the rotor. The rotor surface temperature is measured using a sensor such as a thermocouple, and the measured rotor surface temperature is used to calculate rotor bore temperature and rotor average temperature based on time constants determined as a function of rotor geometry and material. The rotor surface thermal stress and the rotor bore thermal stress can be determined based on the measured and calculated temperatures.

Abstract: A method and apparatus for determining turbine rotor stresses in real time enables increased operation efficiency and more accurate stress determinations. The system calculates rotor bore and surface temperatures based on the time response of the rotor. The rotor surface temperature is measured using a sensor such as a thermocouple, and the measured rotor surface temperature is used to calculate rotor bore temperature and rotor average temperature based on time constants determined as a function of rotor geometry and material. The rotor surface thermal stress and the rotor bore thermal stress can be determined based on the measured and calculated temperatures.

Abstract: A process for the purification of phenol-containing waters, in particular waste waters from phenolic resin production, where the term "phenol" is taken to mean all steam-volatile benzene derivatives according to DIN 38,409 H 16, by reaction of the phenol with formaldehyde in an alkaline environment at 50.degree. to 100.degree. C. to form those phenolformaldehyde condensates which, by subsequent acidification of the waste water, precipitate in filterable, granular and no longer sticky form and can be separated.