Abstract: A water level control system for enhancing the controllability of the level of water retained in a steam drum. A water level control section of the system determines the volume of retained water in a steam-water separator from a detected steam flow rate signal by using a function operator and a first order lag circuit, determines a signal representing the mass flow rate balance of water in the steam-water separator by differentiating the volume of retained water with respect to time with a differentiator, generates a compensated signal by adding the signal to the difference between a detected feed water flow rate signal and the detected steam flow rate signal, and properly compensates a valve area demand for a feed water flow control valve.

Abstract: A trigger mechanism is provided for a water heater fail safe valve assembly which automatically shuts off the flow of water to a water heater when leakage of water from the water heater is detected in an underlying catch tray. The trigger mechanism includes a vertical housing having a drive rod which is upwardly urged by a spring and holds a resilient valve closing component. A cam member holds the drive rod down, representing the open state of the valve. An accumulation of water in the catch tray causes the cam member to release the drive rod to an upper position which closes the valve.

Abstract: A method of controlling the operation of a pressurised steam boiler (50) heated by a burner (20), which includes the steps of a) monitoring the level of water in the boiler (50), b) monitoring the pressure of steam in the boiler (50), c) monitoring the firing rate of the burner (20), and d) controlling the flow rate of water into the boiler (50) having regard to the signals resulting from a) and b) and, at least for some signal conditions, also having regard to signals resulting from c). The level of water is detected by a pair of capacitance probe assemblies (58A and 58B).

Abstract: A heating system for heating liquids, stored in a tank at low ambient temperature, has a heating chamber with an inlet and an outlet for convectively flowing liquid past a flameless heater. Cold liquid is drawn through an inlet line, from the tank near its base and into a heating chamber, absorbs radiant energy from the heater as it travels therethrough. Heated liquid is circulated into the tank through an upper outlet from the heating chamber and back into the tank. Preferably, the heated liquid reenters the tank through a floating discharge flexibly connected to the upper outlet so as to remain dynamically in contact with the liquid at all times, thus avoiding airlocks which would interrupt the convective flow of liquid through the heating system.

Abstract: Apparatus and method is disclosed for monitoring black liquor recovery boilers to detect the presence of water leakage into the combustion chamber (furnace) of a black liquor recovery boiler, or extinguishing of flame at the black liquor spray nozzles, to release into the furnace at a relatively high rate of speed an absorption agent to collect the water in the furnace and thereby isolate the water from the smelt, and further to provide a medium from which the water may be evaporated to expedite cooling within the furnace without risk of a water/smelt explosive reaction. The apparatus includes propulsion devices for distributing the absorption agent over the furnace smelt, which propulsion devices are controlled by sensors respectively detecting boiler steam pressure, water pressure, and combustion flame. Manual actuation of the propulsion devices is also contemplated by the invention.