A molten metal rotor receives and retains an end of a molten metal rotor shaft. The rotor shaft has one or more projections at the end received in the rotor. The rotor has an inner cavity, a top surface with an opening leading to the inner cavity, and at least one abutment. The opening includes one or more portions for allowing each projection to pass through the opening and into the inner cavity. The rotor and/or shaft are then rotated so at least one of the outwardly-extending projections is under the top surface of the rotor and is against an abutment. A molten metal pump, rotary degasser scrap melter or other device used in molten metal may utilize a rotor/shaft combination as disclosed herein.

Furnace operation includes consecutive cycles of a heating step, a stopping step and a restarting step. The fuel and/or the oxidizing agent is preheated upstream of the furnace by indirect exchange with the discharged fumes through a medium passing through a chamber. A first wall separates the fumes from the medium in the chamber. The fuel and/or oxidizing agent is separated from the medium in the chamber by a second wall. During restarting, the medium's flow rate Dm is regulated to limit the heating rate of the first wall until it reaches the operational temperature at an end thereof.

A cooperative emission reduction method for sintering using an energy-carrying composite gas is disclosed. A surface of a sintered material is divided into an ignition section, a heat preservation section, a middle section, a flue gas heating section, and a machine tail section from a machine head to a machine tail of a sintering machine; according to flue gas components, temperature characteristics, and heat requirements of different sections, a hot exhaust gas is introduced to the ignition section for ignition, a hot exhaust gas is introduced to the heat preservation section and a hydrogen-rich gas is cascadingly sprayed synchronously, cascaded spraying of water vapor is coupled based on spraying of a hydrogen-rich gas in the middle section, and the high-temperature flue gas in the machine tail section and the flue gas in the ignition section and/or the heat preservation section are circulated to the heating section.

A cooperative emission reduction method for sintering using an energy-carrying composite gas is disclosed. A surface of a sintered material is divided into an ignition section, a heat preservation section, a middle section, a flue gas heating section, and a machine tail section from a machine head to a machine tail of a sintering machine; according to flue gas components, temperature characteristics, and heat requirements of different sections, a hot exhaust gas is introduced to the ignition section for ignition, a hot exhaust gas is introduced to the heat preservation section and a hydrogen-rich gas is cascadingly sprayed synchronously, cascaded spraying of water vapor is coupled based on spraying of a hydrogen-rich gas in the middle section, and the high-temperature flue gas in the machine tail section and the flue gas in the ignition section and/or the heat preservation section are circulated to the heating section.

A cooling system is configured to cool exhaust gases exiting a furnace of a steel production system through an exhaust hood, a dropout box, and a hot gas duct of the steel production system. The cooling system includes an inlet configured to receive water from a water pump for cooling the exhaust gases, and an outlet configured to exhaust the water from the cooling system. The cooling system further includes a first water line configured to supply the water to the exhaust hood of the steel production system for cooling the exhaust gas received therein, and a second water line configured to supply the water to the dropout box of the steel production system for cooling the exhaust gas received therein. The cooling system also includes a third water line configured to supply the water to the hot gas duct of the steel production system for cooling the exhaust gas received therein, and each of the first water line, the second water line, and the third water line are operably coupled between the inlet and the outlet of the cooling system. The cooling system also includes a controller configured to control and maintain a defined temperature of the water circulating within the cooling system.

This disclosure provides a method of recycling heat during operation of a plant in which equipment for processing at least two different materials is co-located. The method comprises a first process for processing a first material and a second process for processing a second material. The second material has a melting point that is less than a melting point of the first material. During the first process, the first material is subjected to a first melting process and then subjected to a first cooling process that includes solidification of the first material. During the second process, the second material is subjected to a second melting process and then subjected to a second cooling process that includes solidification of the second material. The method comprises recovering heat from the first cooling process and using at least some of the heat as a heat source for the second melting process.

A furnace for a heating, ventilation, and/or air conditioning (HVAC) system includes a heat exchanger tube including a tube inlet and a tube outlet, such that the heat exchanger tube is configured to receive combustion products via the tube inlet, circulate the combustion products through the heat exchanger tube, and discharge the combustion products via the tube outlet. Additionally, the furnace includes a collector box coupled to the heat exchanger tube and having a cavity configured to receive the combustion products via the tube outlet. The furnace includes a diverter plate disposed within the cavity, where the diverter plate overlaps the tube outlet to disperse the combustion products received via the tube outlet throughout the collector box.

A method for reducing pollution in exhaust gases and a system for treating exhaust gas are provided. The method includes the step of treating an exhaust gas stream with a treating fluid. In one application, the treating fluid is injected by spraying droplets into the exhaust gas stream. A system for treating exhaust gas includes a reagent, and a nozzle to spray the reagent into the exhaust gas stream.

A molten metal rotor receives and retains an end of a molten metal rotor shaft. The rotor shaft has one or more projections at the end received in the rotor. The rotor has an inner cavity, a top surface with an opening leading to the inner cavity, and at least one abutment. The opening includes one or more portions for allowing each projection to pass through the opening and into the inner cavity. The rotor and/or shaft are then rotated so at least one of the outwardly-extending projections is under the top surface of the rotor and is against an abutment. A molten metal pump, rotary degasser scrap melter or other device used in molten metal may utilize a rotor/shaft combination as disclosed herein.

A process for the production of potassium sulphate by conversion of potassium chloride and sulphuric acid using a muffle furnace, said furnace comprising a reaction chamber and a combustion chamber, wherein in the reaction chamber potassium chloride (KCI) and potassium hydrogen sulfate (KHSO.sub.4) are reacted to form potassium sulphate while supplying heat to the reaction chamber from the combustion chamber, wherein the combustion chamber has at least a pair of regenerative burners and wherein the process comprises the steps of alternatingly causing one of the regenerative burners to perform a combustion operation in the combustion chamber to heat the reaction chamber and another of the regenerative burners to perform a heat-regenerating operation in a regenerator, wherein the pressure in the combustion chamber is kept at a pressure of between 0.2 and 3 mbarg.