Embodiments of the present disclosure include a system, method, and apparatus comprising a direct steam generator configured to generate saturated steam and combustion exhaust constituents.

A boiler has a shell surrounding a vertical centerline. The shell defines an inner surface having an inner diameter and an inner length extending between an upper upstream end and a lower downstream end. The inner surface defines a hollow interior, the boiler having a pre-combustion zone, a combustion zone downstream from the pre-combustion zone, and a post-combustion zone downstream from the combustion zone. The shell is tapered outward along its length in at least a portion of the combustion zone. An oxidizer inlet is in fluid communication with the pre-combustion zone, and a fuel nozzle introduces fuel into the combustion zone. A tube assembly is mounted in the hollow interior of the shell for transferring heat to fluid flowing through the tube assembly. A flue duct is in fluid communication with the post-combustion zone for transporting flue gases from the hollow interior.

A boiler has a shell surrounding a vertical centerline. The shell defines an inner surface having an inner diameter and an inner length extending between an upper upstream end and a lower downstream end. The inner surface defines a hollow interior, the boiler having a pre-combustion zone, a combustion zone downstream from the pre-combustion zone, and a post-combustion zone downstream from the combustion zone. The shell is tapered outward along its length in at least a portion of the combustion zone. An oxidizer inlet is in fluid communication with the pre-combustion zone, and a fuel nozzle introduces fuel into the combustion zone. A tube assembly is mounted in the hollow interior of the shell for transferring heat to fluid flowing through the tube assembly. A flue duct is in fluid communication with the post-combustion zone for transporting flue gases from the hollow interior.

Embodiments of the present disclosure can include a system for generating steam. The system can include a direct steam generator configured to generate saturated steam and combustion exhaust constituents. A close coupled heat exchanger can be fluidly coupled to the direct steam generator, the close coupled heat exchanger can be configured to route the saturated or superheated steam and combustion exhaust constituents through an exhaust constituent removal system. The system can include an energy recovery system that reclaims the energy from the exhaust constituents.

Hydrogen boilers with no measurable NOx emissions. In some versions the fuel is a ratio of already mixed hydrogen and oxygen, ratio of pre-mixed hydrogen and oxygen, or the fuel comprises hydrogen and the burner also contains a separate nozzle for introducing a ratio of oxygen. In some versions, these ratios are stoichiometric between hydrogen oxygen. Some versions show burner systems that monitor the combustion process, which is a condensing process, and have hydrogen oxygen pilots and ultraviolet flame detectors. These hydrogen boilers can supply all the process steam needed by a system or can supply part of the process steam needed by a system.

Hydrogen boilers with no measurable NOx emissions. In some versions the fuel is a ratio of already mixed hydrogen and oxygen, ratio of pre-mixed hydrogen and oxygen, or the fuel comprises hydrogen and the burner also contains a separate nozzle for introducing a ratio of oxygen. In some versions, these ratios are stoichiometric between hydrogen oxygen. Some versions show burner systems that monitor the combustion process, which is a condensing process, and have hydrogen oxygen pilots and ultraviolet flame detectors. These hydrogen boilers can supply all the process steam needed by a system or can supply part of the process steam needed by a system.

The present invention relates to a method of combusting a fuel gas with a stoichiometric or near stoichiometric amount of molecular oxygen in the presence of a controlled amount of a diluent to enhance the extent of combustion reactions in high heat transfer environment. The energy released is utilized to heat a fluid by direct contact with the flame. The diluent can be different from the fluid to be heated with respect to composition, temperature or pressure. The diluent can be same as or derived from the fluid to be heated.

The present invention relates to a method of combusting a fuel gas with a stoichiometric or near stoichiometric amount of molecular oxygen in the presence of a controlled amount of a diluent to enhance the extent of combustion reactions in high heat transfer environment. The energy released is utilized to heat a fluid by direct contact with the flame. The diluent can be different from the fluid to be heated with respect to composition, temperature or pressure. The diluent can be same as or derived from the fluid to be heated.

A method and apparatus for direct contact steam generation for a variety of industrial processes including heavy oil recovery, power generation and pulp and paper applications. The steam generation system consists of a combustor and steam generator and is constructed to be operable at elevated pressures. The fuel, at least one oxidant and a fluid supply including water are supplied at pressure to the combustor. Flue gas from the combustor is delivered to the direct contact steam generator at pressure, and upon direct contact with water produces a flue gas stream consisting primarily of steam. This product stream can then be cleansed and used for industrial application. The combustor can be operated with low grade fuel and low quality water with high solids and hydrocarbon contents. The apparatus and method reduce the environmental footprint by reducing air emission, concentrating CO.sub.2 to enable capture and reducing clean water requirements.

A method and apparatus for direct contact steam generation for a variety of industrial processes including heavy oil recovery, power generation and pulp and paper applications. The steam generation system consists of a combustor and steam generator and is constructed to be operable at elevated pressures. The fuel, at least one oxidant and a fluid supply including water are supplied at pressure to the combustor. Flue gas from the combustor is delivered to the direct contact steam generator at pressure, and upon direct contact with water produces a flue gas stream consisting primarily of steam. This product stream can then be cleansed and used for industrial application. The combustor can be operated with low grade fuel and low quality water with high solids and hydrocarbon contents. The apparatus and method reduce the environmental footprint by reducing air emission, concentrating CO.sub.2 to enable capture and reducing clean water requirements.