Abstract: Fouling of the convection section of a steam generator by ash or other solid deposit from the product gas stream is monitored using radiation pyrometers which determine the temperature drop across a bank of heat exchanger tubes and calculation therefrom of a fouling factor related to the degree of fouling. Soot blowers are actuated, in manual response or automatic response, to the fouling factor, to effect cleaning of the heat exchanger tubes. Heat flux meters also may be provided to determine variations in the degree of fouling transverse to the flow of the gas stream and the determinations may be used to actuate selective cleaning of parts of the tube bank.

Abstract: A heat flux meter for measuring heat flux in a hot environment, such as, a coal-fired boiler, includes a cup-shaped body member of one-piece construction having an internal cavity in which is mounted an annular thermoelectrically-dissimilar member from that of the body member and in heat and electrically conducting contact with the body member. Electrically conducting wires of the same metal as the annular member enter the cavity and are connected to the center of the circular portion of the body member and to the annular member. An e.m.f. is induced by the difference in temperature between the center of the disc portion and the annular member. Since the body member is of one piece construction and the heat flux meter is sealed to the walls of the boiler, gases from the hot environment cannot enter the cavity and cause failure of the meter.

Abstract: Fouling of the convection section of a steam generator by ash or other solid deposit from the product gas stream is monitored using radiation pyrometers which determine the temperature drop across a bank of heat exchanger tubes and calculation therefrom of a fouling factor related to the degree of fouling. Soot blowers are actuated, in manual response or automatic response, to the fouling factor, to effect cleaning of the heat exchanger tubes. Heat flux meters also may be provided to determine variations in the degree of fouling transverse to the flow of the gas stream and the determinations may be used to actuate selective cleaning of parts of the tube bank.

Abstract: The build up of ash in a pulverized coal-fired boiler and other similar ash producing combustion operations is achieved by comparing the heat flux simultaneously detected by a first flux detector which is maintained free of deposits and a second flux detector on which deposits are permitted to form. The net values from the heat flux comparison is proportional to the heat flux which is not reaching the boiler walls as a result of the ash deposits.

Abstract: Fouling of the convection section of a steam generator by ash or other solid deposit from the product gas stream is monitored using radiation pyrometers which determine the temperature drop across a bank of heat exchanger tubes and calculation therefrom of a fouling factor related to the degree of fouling. Soot blowers are actuated, in manual response or automatic response, to the fouling factor, to effect cleaning of the heat exchanger tubes. Heat flux meters also may be provided to determine variations in the degree of fouling transverse to the flow of the gas stream and the determinations may be used to actuate selective cleaning of parts of the tube bank.

Abstract: Fouling of the convection section of a steam generator by ash or other solid deposit from the product gas stream is monitored using radiation pyrometers which determine the temperature drop across a bank of heat exchanger tubes and calculation therefrom of a fouling factor related to the degree of fouling. Soot blowers are actuated, in manual response or automatic response, to the fouling factor, to effect cleaning of the heat exchanger tubes. Heat flux meters also may be provided to determine variations in the degree of fouling transverse to the flow of the gas stream and the determinations may be used to actuate selective cleaning of parts of the tube bank.

Abstract: Magnesium metal is formed by the silicothermic method in a manner which is a substantial improvement over prior art processes. Magnesium oxide, calcium oxide and silicon are reacted in a heated flowing inert gas stream, for example, hydrogen, argon or helium, which maintains the reaction temperature and removes gaseous magnesium from the reaction zone. Magnesium is recovered from the inert gas stream in liquid or solid form by cooling. Heat recovery is effected to preserve thermal efficiency and the inert gas stream is recycled to the reaction zone. Continuous production of magnesium can be effected.

Abstract: The build up of ash in a pulverized coal-fired boiler is achieved by comparing the heat flux simultaneously detected by a first flux detector which is maintained free of deposits and a second flux detector on which deposits are permitted to form. The net values from the heat flux comparison is proportional to the heat flux which is not reaching the boiler walls as a result of the ash deposits.

Abstract: The build up of ash in a pulverized coal-fired boiler is achieved by comparing the heat flux simultaneously detected by a first flux detector which is maintained free of deposits and a second flux detector on which deposits are permitted to form. The net values from the heat flux comparison is proportional to the heat flux which is not reaching the boiler walls as a result of the ash deposits.