A fire tube with three hollow tube sections, two of which are parallel to each other and one of which is perpendicular to and connects the ends of the first two tube sections. The bottom-most tube section, which contains the burner, has an inner ceramic liner that is made up of one or more separate ceramic tubular sections. An upper set of cooling funs surrounds the top part of the bottom-most tube section, and a lower set of cooling fins surrounds the bottom part of the bottom-most tube section.

A fire tube with three hollow tube sections, two of which are parallel to each other and one of which is perpendicular to and connects the ends of the first two tube sections. The bottom-most tube section, which contains the burner, has an inner ceramic liner that is made up of one or more separate ceramic tubular sections. An upper set of cooling funs surrounds the top part of the bottom-most tube section, and a lower set of cooling fins surrounds the bottom part of the bottom-most tube section.

An integrated steam generator/steam superheater apparatus is disclosed. The disclosed apparatus can be used in a process, such as an ammonia synthesis process, to cool an ammonia converter effluent process gas and to generate superheated steam. The integrated apparatus includes a steam superheater portion wherein hot process gas is used to generate superheated steam by heat transfer to saturated steam. The apparatus also includes a steam generator portion wherein the process gas is used to generate saturated steam by heat transfer to water. Both the superheater and the steam generator are integrated into a single unit, without intervening pluming, etc., thereby saving space and equipment.

A waste heat boiler system for cooling a process gas, including a first shell-and-tube heat exchanger for cooling relatively hot gas down to relatively warm gas, an intermediate chamber for receiving gas, cooled down to relatively warm gas, coming out of tubes of the first heat exchanger, and a second shell-and-tube heat exchanger for cooling relatively warm gas further down to relatively cool gas. The intermediate chamber is provided with an outlet fluidly connected to a bypass channel for allowing a part of the relatively warm gas to bypass tubes of the second heat exchanger. The bypass channel and tubes of the second heat exchanger are both fluidly connected with a mixing chamber for mixing together relatively warm gas flowed from the intermediate chamber into the mixing chamber via the bypass channel and relatively cool gas come out of the tubes of the second heat exchanger.

A waste heat boiler system for cooling a process gas, including a first shell-and-tube heat exchanger for cooling relatively hot gas down to relatively warm gas, an intermediate chamber for receiving gas, cooled down to relatively warm gas, coming out of tubes of the first heat exchanger, and a second shell-and-tube heat exchanger for cooling relatively warm gas further down to relatively cool gas. The intermediate chamber is provided with an outlet fluidly connected to a bypass channel for allowing a part of the relatively warm gas to bypass tubes of the second heat exchanger. The bypass channel and tubes of the second heat exchanger are both fluidly connected with a mixing chamber for mixing together relatively warm gas flowed from the intermediate chamber into the mixing chamber via the bypass channel and relatively cool gas come out of the tubes of the second heat exchanger.

A fire tube with three hollow tube sections, two of which are parallel to each other and one of which is perpendicular to and connects the ends of the first two tube sections. The bottom-most tube section, which contains the burner, has an inner ceramic liner that is made up of one or more separate ceramic tubular sections. An upper set of cooling funs surrounds the top part of the bottom-most tube section, and a lower set of cooling fins surrounds the bottom part of the bottom-most tube section.

A fire tube with three hollow tube sections, two of which are parallel to each other and one of which is perpendicular to and connects the ends of the first two tube sections. The bottom-most tube section, which contains the burner, has an inner ceramic liner that is made up of one or more separate ceramic tubular sections. An upper set of cooling funs surrounds the top part of the bottom-most tube section, and a lower set of cooling fins surrounds the bottom part of the bottom-most tube section.

A fire tube boiler includes a perforated flame holder configured to hold a combustion reaction that produces very low oxides of nitrogen (NOx).

A fire tube boiler system including a plurality of oxygen transport reactors that heats a working fluid. Each oxygen transport reactor has a first inner tube with an ion transport membrane that receives air from a first supply line, extracts oxygen from the air, and evacuate oxygen depleted air through a first exhaust line, a second inner tube that surrounds the first inner tube that receives the oxygen from the ion transport membrane and a mixture of fuel and carbon dioxide from a second supply line and produces a oxy-combustion, and an peripheral tube that surrounds the second inner tube and evacuates the exhaust gases produced by the oxy-combustion and transfer heat from exhaust gases to the working fluid and the ion transport membrane.

A fire tube boiler system including a plurality of oxygen transport reactors that heats a working fluid. Each oxygen transport reactor has a first inner tube with an ion transport membrane that receives air from a first supply line, extracts oxygen from the air, and evacuate oxygen depleted air through a first exhaust line, a second inner tube that surrounds the first inner tube that receives the oxygen from the ion transport membrane and a mixture of fuel and carbon dioxide from a second supply line and produces a oxy-combustion, and an peripheral tube that surrounds the second inner tube and evacuates the exhaust gases produced by the oxy-combustion and transfer heat from exhaust gases to the working fluid and the ion transport membrane.