Disclosed is a combustion heat generator with a recirculation region for forming uniform temperature distribution in a combustion chamber by forming a gas recirculation region around a central part of a combustion space in a housing and injecting fuel into the gas recirculation region to generate space combustion based on the recirculation region.

A method for the manufacture of a high alumina hydraulic binder comprising hydrating a source of aluminium ions with a source of calcium ions in the presence of water to form mineral hydrates and subsequently heating said mineral hydrates to form said high alumina hydraulic binder.

A bypass system may be utilized in installations and methods for producing cement clinker. A portion of a kiln offgas produced in a kiln may be branched off as bypass gas via a bypass line connected between the kiln and a calciner. In some cases 3 to 15% of the kiln offgas is branched off as the bypass gas. The bypass gas may be cooled to a temperature in a range from 300 to 550° C. and dedusted in a temperature range from 300 to 550° C. The dedusted bypass gas may then be recirculated to the calciner and/or into a tertiary air line arranged between the cooler and the calciner and/or into a region between the kiln and the calciner.

A bypass system may be utilized in installations and methods for producing cement clinker. A portion of a kiln offgas produced in a kiln may be branched off as bypass gas via a bypass line connected between the kiln and a calciner. In some cases 3 to 15% of the kiln offgas is branched off as the bypass gas. The bypass gas may be cooled to a temperature in a range from 300 to 550° C. and dedusted in a temperature range from 300 to 550° C. The dedusted bypass gas may then be recirculated to the calciner and/or into a tertiary air line arranged between the cooler and the calciner and/or into a region between the kiln and the calciner.

A rotary kiln capable of segmented temperature control includes a kiln body, a kiln head cover, a kiln tail cover, and a bottom base. A drive device is disposed between the bottom base and the kiln body. The kiln further includes a first fuel supply pipe having a supply segment, a connecting segment, and a rotating segment. The supply segment is fixedly disposed on an outer side wall of the kiln body. The rotating segment is disposed coaxially with the kiln body and connected to a fuel supply source through a rotatory joint. The supply segment communicates with the rotating segment through the connecting segment. Multiple groups of combustion components are disposed on the outer side wall of the kiln body, and a fuel inlet of each combustion component is connected to the supply segment of the first fuel supply pipe through a branch pipe.

A rotary kiln capable of segmented temperature control includes a kiln body, a kiln head cover, a kiln tail cover, and a bottom base. A drive device is disposed between the bottom base and the kiln body. The kiln further includes a first fuel supply pipe having a supply segment, a connecting segment, and a rotating segment. The supply segment is fixedly disposed on an outer side wall of the kiln body. The rotating segment is disposed coaxially with the kiln body and connected to a fuel supply source through a rotatory joint. The supply segment communicates with the rotating segment through the connecting segment. Multiple groups of combustion components are disposed on the outer side wall of the kiln body, and a fuel inlet of each combustion component is connected to the supply segment of the first fuel supply pipe through a branch pipe.

The present application discloses a pellet flue gas circulation and waste heat utilization process and a system thereof, which relates to the technical field of flue gas treatment. The system includes a grate, a rotary kiln, an annular cooler, and ducts connecting each part. On the basis of not changing the existing process a flue gas circulation unit and intelligent control equipment are arranged additionally in the present application. The process is simple, and not only can ensure the parameter stability of the production system such as temperature, gas flow or gas pressure, but also can make full use of the low and medium temperature flue gas components and the waste heat, so as to achieve net zero waste gas discharging, energy saving and emission reduction.

A cement production plant may include a preheater for preheating raw meal, a calciner for calcining the preheated raw meal, and a furnace with a furnace burner for firing the raw meal to form cement clinker. The furnace has a combustion gas inlet for admitting a combustion gas with an oxygen content of 30% to 75% into the furnace. The cement production plant may also include a cooler for cooling the cement clinker. The calciner and the furnace each have at least one respective fuel inlet for admitting at least one fuel into the calciner and the furnace. The calciner and the furnace each have at least one respective inert gas inlet for respectively admitting inert gas into the calciner and the furnace.

A cement production plant may include a preheater for preheating raw meal, a calciner for calcining the preheated raw meal, and a furnace with a furnace burner for firing the raw meal to form cement clinker. The furnace has a combustion gas inlet for admitting a combustion gas with an oxygen content of 30% to 75% into the furnace. The cement production plant may also include a cooler for cooling the cement clinker. The calciner and the furnace each have at least one respective fuel inlet for admitting at least one fuel into the calciner and the furnace. The calciner and the furnace each have at least one respective inert gas inlet for respectively admitting inert gas into the calciner and the furnace.

The invention relates to a method of producing a binder comprising the steps of preparing (20) a residual material comprising amorphous alumina-rich and/or aluminium hydroxide-rich constituents, heating (30) the residual material to produce a fired material, the heating (30) of the residual material being at a temperature of >800° C.