A flash boiler has a water jacket and a vertically oriented interior passage which includes water tubes or superheating tubes, or both. The interior passage is a hyperboloid surface to induce draft. Water tubes and superheating tubes can be staggered so as to create a helical path for flue gas passing through the boiler. Water tubes and superheating tubes may include, internally or externally or both, heat transfer aids such as pins, fins or vanes, which may also be helicies.

A flash boiler has a water jacket and a vertically oriented interior passage which includes water tubes or superheating tubes, or both. The interior passage is a hyperboloid surface to induce draft. Water tubes and superheating tubes can be staggered so as to create a helical path for flue gas passing through the boiler. Water tubes and superheating tubes may include, internally or externally or both, heat transfer aids such as pins, fins or vanes, which may also be helicies.

A gas-fired atmospheric pressure steam humidifier having high efficiency and ultra-low NOx(3) emissions is disclosed. In some examples, the gas-fired humidifier can have an efficiency of greater than 90 percent and a NOx(3) output of less than 20 parts per million (ppm). In one aspect, the humidifier includes a secondary heat exchanger having a first heat exchange section for pre-heating combustion air and a separate second heat exchange section for pre-heating make-up water, wherein the first and second heat exchange sections are in heat transfer communication with exhaust gases generated by the gas-fired burner and combustion blower assembly. In some examples, the first heat exchange section includes orifices for enabling flue gas recirculation.

A gas-fired atmospheric pressure steam humidifier having high efficiency and ultra-low NOx(3) emissions is disclosed. In some examples, the gas-fired humidifier can have an efficiency of greater than 90 percent and a NOx(3) output of less than 20 parts per million (ppm). In one aspect, the humidifier includes a secondary heat exchanger having a first heat exchange section for pre-heating combustion air and a separate second heat exchange section for pre-heating make-up water, wherein the first and second heat exchange sections are in heat transfer communication with exhaust gases generated by the gas-fired burner and combustion blower assembly. In some examples, the first heat exchange section includes orifices for enabling flue gas recirculation.

The present invention provides an economizer 70 including a plurality of cylindrical heat transfer tubes 71a-71d extending along a crossing direction crossing a flowing direction of combustion gas and disposed at a predetermined disposition interval P along the flowing direction, the combustion gas and fluid flowing in the plurality of heat transfer tubes performing heat exchange, and a swirl preventing section 75 disposed in contact with a downstream side outer circumferential surface 71Aa-71Ad in the flowing direction of each of the plurality of heat transfer tubes 71a-71d and configured to prevent a swirl of the combustion gas from occurring near the downstream side outer circumferential surface 71Aa-71Ad.

A combustion system and process of operating the combustion system incorporating an electrostatic precipitator, an optional flue gas desulfurizer, and a temperature swing adsorptive gas separator, for post-combustion emission abatement is provided. A very low pressure steam stream may be employed as a first regeneration stream for the temperature swing adsorptive gas separator where the very low pressure steam stream may optionally be recovered from, a very low pressure steam turbine or an auxiliary boiler. A fluid stream at a suitable temperature for regeneration of at least one adsorbent material in the temperature swing adsorptive gas separator may be employed as a second regeneration stream where the fluid stream may optionally be recovered from an electrostatic precipitator, an oxidant preheater, or an auxiliary heater.

A combustion system and process of operating the combustion system incorporating an electrostatic precipitator, an optional flue gas desulfurizer, and a temperature swing adsorptive gas separator, for post-combustion emission abatement is provided. A very low pressure steam stream may be employed as a first regeneration stream for the temperature swing adsorptive gas separator where the very low pressure steam stream may optionally be recovered from, a very low pressure steam turbine or an auxiliary boiler. A fluid stream at a suitable temperature for regeneration of at least one adsorbent material in the temperature swing adsorptive gas separator may be employed as a second regeneration stream where the fluid stream may optionally be recovered from an electrostatic precipitator, an oxidant preheater, or an auxiliary heater.

In a clean boiler with steam conversion and hydrogen/oxygen pre-blending, the clean boiler comprises two identical boiler bodies integrated to form a single entity. The clean boiler comprises two slim cavities, four water-containing chambers and four combustors, which is heated at wide faces and generates steams rapidly. The boiler comprises an integrate body containing two independent boiler bodies (1), and each of the independent boiler bodies (1) contains an independent boiler chamber (19). A steam conversion and transformation system is simultaneously provided for introducing a part of steam into the independent boiler chamber (19). High temperature of the boiler chamber (19) is utilized to promote a decomposition of the steam into H.sub.2 and O.sub.2. Water formed by H.sub.2 and O.sub.2 is utilized as a fuel to provide a self-sustaining combustion and heating, thus reducing a dependence on a primary energy source, reducing carbon emissions and protecting the environment.

In a clean boiler with steam conversion and hydrogen/oxygen pre-blending, the clean boiler comprises two identical boiler bodies integrated to form a single entity. The clean boiler comprises two slim cavities, four water-containing chambers and four combustors, which is heated at wide faces and generates steams rapidly. The boiler comprises an integrate body containing two independent boiler bodies (1), and each of the independent boiler bodies (1) contains an independent boiler chamber (19). A steam conversion and transformation system is simultaneously provided for introducing a part of steam into the independent boiler chamber (19). High temperature of the boiler chamber (19) is utilized to promote a decomposition of the steam into H.sub.2 and O.sub.2. Water formed by H.sub.2 and O.sub.2 is utilized as a fuel to provide a self-sustaining combustion and heating, thus reducing a dependence on a primary energy source, reducing carbon emissions and protecting the environment.

A gas-fired steam-injection boiler has a flue and a water supply pipeline. The flue is provided with a radiation section and a convection section. The water supply pipeline has, in the flue gas flow direction, a first pipe section located at an upstream portion of the convection section, a second pipe section is located at a downstream portion of the convection section, and a third pipe section arranged between the first pipe section and the second pipe section. In a water flow direction of the water supply pipeline, the second pipe section, the first pipe section and the third pipe section are arranged in sequence. By using a flue gas condenser, the temperature of flue gas can be further reduced, and the latent heat of vaporization of steam in the flue gas is absorbed to form condensate water.