Processes and systems for improvements on the efficiencies of convection ovens utilizing exhaust heat recuperation in the form of heat exchangers and premixed combustion systems, and a combination thereof. The heat exchangers and premixed combustion systems allow for increased efficiency of use of fuel and gaseous mixtures within convection oven cavities for improved heating capabilities and decreased efficiency losses.

Processes and systems for improvements on the efficiencies of convection ovens utilizing exhaust heat recuperation in the form of heat exchangers and premixed combustion systems, and a combination thereof. The heat exchangers and premixed combustion systems allow for increased efficiency of use of fuel and gaseous mixtures within convection oven cavities for improved heating capabilities and decreased efficiency losses.

A scroll heating device includes a base, a reaction region, and a first and a second channel. The reaction region is at the center of the base. The two channels are located on the base and extend spirally from the reaction region toward the periphery of the base. The width of each channel is gradually reduced as the channel extends from adjacent to the center of the base toward the periphery of the base. The first channel allows a gas that flows into the first channel through the periphery of the base toward the center of the base to flow toward the reaction region at a progressively slower rate, enter the reaction region slowly through the gradually widening first channel, and therefore stay in the reaction region for longer. The combusted exhaust enters the second channel from adjacent to the center of the base and exits through the periphery of the base.

A process for manufacturing a cast metal heat exchanger housing (12) for a vehicle heater having a pot-shape housing wall (14) extending in a direction of a housing longitudinal axis (L) and having a plurality of heat transfer ribs (22) extending on an outer side of the housing wall (14) in the area of a circumferential wall (16) and in the area of a bottom wall (18) of the housing wall (14) in the direction of the housing longitudinal axis (L). The process includes metal casting wherein a sprue cross-sectional area including at least some of the heat transfer ribs (22). The cast metal heat exchanger housing has an axial end face formed upon cutting off metallic material that is essentially at right angles to the housing longitudinal axis and extends into an area of at least some of the heat transfer ribs.

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.

A monolithic engine assembly may include an engine body that includes a regenerator body. The engine body and the regenerator body may respectively define at least a portion of a monolithic body, or the engine body may define at least a portion of a first monolithic body-segment and the regenerator body may define at least a portion of a second monolithic body-segment operably coupled or operably couplable to the first monolithic body-segment. The regenerator body may include a regenerator conduit, and a plurality of fin arrays adjacently disposed within the regenerator conduit and respectively supported by the regenerator conduit in spaced relation to one another. The spaced relation of the plurality of fin arrays may define a gap longitudinally separating adjacent ones of the plurality of fin arrays.

Systems and processes provide for a thermal process to transform sludge (and a variety of other natural waste materials) into electricity. Dewatered sludge and other materials containing a high amount of latent energy are dried into a powdered biofuel using a drying gas produced in the system. The drying gas is recirculated and is heated by the biofuel produced in the system, waste heat (from turbines or internal combustion engines), gas (including natural gas or digester gas) and/or oil. The biofuel is combusted in a boiler system that utilizes a burner operable to burn biofuel and produce heat utilized in a series of heat exchangers that heat the recirculating drying air and steam that powers the turbines for electricity production.

Systems and processes provide for a thermal process to transform sludge (and a variety of other natural waste materials) into electricity. Dewatered sludge and other materials containing a high amount of latent energy are dried into a powdered biofuel using a drying gas produced in the system. The drying gas is recirculated and is heated by the biofuel produced in the system, waste heat (from turbines or internal combustion engines), gas (including natural gas or digester gas) and/or oil. The biofuel is combusted in a boiler system that utilizes a burner operable to burn biofuel and produce heat utilized in a series of heat exchangers that heat the recirculating drying air and steam that powers the turbines for electricity production.

A heat exchanger including a shell extending in a longitudinal direction D from a first end to a second end and including a mantle extending from the first end to the second end, and a solid inner core made of a core material and located inside the shell, the core extending in direction D from a first extremity towards the first end to a second extremity towards the second end. Whereby, at least one first flow path is provided inside the core, each first flow path extending from the first extremity to the second extremity of the core, n circuitous second flow paths extend through the core and/or between the core and the mantle, so that the at least one first flow path is surrounded by the n second flow paths over a non-zero rectilinear distance ΔL in direction D, n being an integer greater than 1.