Gas heater

About: Gas heater is a research topic. Over the lifetime, 1799 publications have been published within this topic receiving 6169 citations.

Start-up method for a direct reduction process without an external reformer

Abstract: Start-up method for an iron ore direct reduction process, where in the steady-state process the reducing gases are produced by steam reformation of natural gas catalyzed within the reducing zone of the reduction vessel by the reduced ore present therein. During established steady-state operation, a process gas stream is circulated in a reducing gas loop comprising the reduction vessel, a gas heater, and units to remove H 2 O and CO from the gas circulating in said loop. Natural gas and water are fed directly to the reducing gas loop as make-up reactants for the reformation. At plant start-up there is a complete absence of metallic iron to catalyze the reformation reaction at any temperature, and a complete absence of H 2 or CO so no effective reduction is possible to produce the needed metallic iron. In a multi-stage start-up, the reduction vessel is first charged with iron ore and pressurized by introducing natural gas to said loop. Simultaneously, the temperature is raised to the range of 400° to 600° C. The natural gas cracks, producing a small amount of H 2 and some carbon soot. Second, the temperature is further increased, and injection of water is begun to prevent further carbon deposition, to promote the production of H 2 , and to avoid H 2 consumption; until 3% to 8% by volume of H 2 accumulates. Third, at about 750°-820° C., water injection is interrupted favoring the accumulation of hydrogen until a concentration of about 65% is achieved while the temperature of the process gas stream reaches its steady-state value of about 950° C. Fourth, water is again injected to promote the reforming of make-up natural gas within the reduction vessel and all process feeds are adjusted to their steady-state values.

Pilot regulator operated main valve

Abstract: A control for a gas heater or the like including a regulator for the pilot burner gas supply, and a control valve connecting the regulator output to a main line gas shutoff valve. The main line valve is a diaphragm valve.

Clothes dryer gas heater assembly

Abstract: An automatic clothes dryer having a gas heater assembly for heating the air includes a gas control valve and a gas nozzle in gas flow communication with the valve. The gas nozzle has an exit orifice having spaced therefrom a plate member such that gas will impinge the plate member. A combustion chamber having a truncated cone shaped upper portion and with an opening at the top and bottom thereof surrounds and is spaced outwardly of both the plate member and the nozzle. The bottom opening of the combustion chamber is arranged to allow air into the combustion chamber for mixing with the gas exiting the nozzle orifice. A hood member is spaced outwardly and below the opening at the top of the combustion chamber to allow ambient air into the hood member for mixing with the heated air. There is also provided an igniter for igniting the gas and air mixture.

Metal spray apparatus with a U-shaped electric inlet gas heater and a one-piece electric heater surrounding a nozzle

Abstract: An electrically heated metal spray apparatus is provided with a supersonic nozzle. Molten metal is injected into a gas stream flowing through the nozzle under pressure. By varying the pressure of the injected metal, the droplet can be made in various selected sizes with each selected size having a high degree of size uniformity. A unique one piece graphite heater provides easily controlled uniformity of temperature in the nozzle and an attached tundish which holds the pressurized molten metal. A unique U-shaped gas heater provides extremely hot inlet gas temperatures to the nozzle. A particularly useful application of the spray apparatus is coating of threads of a fastener with a shape memory alloy. This permits a fastener to be easily inserted and removed but provides for a secure locking of the fastener in high temperature environments.

Cold spray equipments and technologies

Abstract: This chapter provides an overview of cold spray equipments and technologies The main elements of the cold spray setup are: the spraying unit consisting of a prechamber and a supersonic nozzle, a powder feeder, a gas heater, a source of a compressed gas, a spraying chamber with a motion system, and a system for monitoring and controlling spray parameters The two technologies presented are—spraying electro-conductive corrosion-resistant coatings, and spraying metal-polymer coatings The Institute of Theoretical and Applied Mechanics of Siberian Branch of the Russian Academy of Sciences (ITAM SB RAS) has developed the technological process and equipment, which allows applying a thin (005–02 mm) but strong layer of copper, nickel, or zinc onto the operating surface of the tip by cold spraying, which eliminates conditions that favor electrochemical corrosion