A method for reducing pollution in a cement kiln environment and a system for treating cement kiln exhaust gas are provided. The method includes the steps of: treating a cement kiln exhaust gas stream with a treating fluid, such as a water soluble alkaline-earth metal sulfide. In one application, the treating fluid is injected by spraying droplets into the cement kiln exhaust gas stream. A system for treating cement kiln exhaust gas includes a reagent containing a water soluble alkaline-earth metal sulfide in water, and a nozzle to spray the reagent into the cement kiln exhaust gas stream.

To provide a cement production apparatus in which heat-exchanging efficiency can be improved by even pre-heating by supplying material equally to cyclones above a duct and which can perform an operation with low pressure loss and small energy consumption. A cement production apparatus includes: a duct 21 provided between upper cyclones 13A and a lower cyclone 13B being provided below the upper cyclones 13A, the duct 21 in which the exhaust gas drained from the lower cyclone 13B flows upward, distributing and introducing the exhaust gas to the upper cyclones 13A; a plurality of material-supplying pipes 22 for supplying cement raw material provided on the duct 21 below a distribution part 23 to the plurality of the upper cyclones 13A with a same number of distribution outlets 21a among the upper cyclones 13A; and connection ports 22a of the material-supplying pipes 22 to the duct 21 each provided at each of positions corresponding to swirl flows of the exhaust gas poured into the distribution outlets 21a.

A combustion gas bleeding probe includes a gas pipe for bleeding a part of a combustion gas from a kiln, and a plurality of discharge ports each of which is provided penetrating through the gas pipe and each of which discharges a low-temperature gas in a direction that is perpendicular to a direction of flow of a bleed gas bled by the gas pipe and that is directed toward a center of the flow of the bleed gas. The discharge ports discharge the low-temperature gas such that a ratio of a momentum of the low-temperature gas per discharge port to a momentum of the bleed gas satisfies 1.2 to 4.0, and a value (m1) obtained by dividing a ratio of a wind speed of the low-temperature gas to a wind speed of the bleed gas by an inner diameter of the gas pipe satisfies 1.5 to 3.5.

A combustion gas bleeding probe includes a gas pipe for bleeding a part of a combustion gas from a kiln, and a plurality of discharge ports each of which is provided penetrating through the gas pipe and each of which discharges a low-temperature gas in a direction that is perpendicular to a direction of flow of a bleed gas bled by the gas pipe and that is directed toward a center of the flow of the bleed gas. The discharge ports discharge the low-temperature gas such that a ratio of a momentum of the low-temperature gas per discharge port to a momentum of the bleed gas satisfies 1.2 to 4.0, and a value (m1) obtained by dividing a ratio of a wind speed of the low-temperature gas to a wind speed of the bleed gas by an inner diameter of the gas pipe satisfies 1.5 to 3.5.

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.

An electrically controlled valve which can be operated using a programable controller. A cooperating pair of the electrically controlled valves can be used in a Regenerative Thermal Oxidizer (RTO). The electrically controlled valve has two seats, and a blade which can move between a first position contacting the first seat and a second position contacting the second seat. The blade is moved by an actuator which is controlled by a variable frequency drive (VFD). A control computer continuously monitors the operation of both valves and halts operation of the system upon detecting a fault (error). The motion of the blade is programmed such that force of impact on the seat is reduced. Once the blade is seated, a brake is engaged which maintains the stationary position while utilizing relatively low power.

A method for calcination of a carbon dioxide rich sorbent (containing CaCO.sub.3) includes combusting in a furnace a fuel with an oxidizer, supplying heat transfer (HT) solids into the furnace and heating them, transferring the HT solid particles from the furnace to a reactor having a rotatable container, supplying a carbon dioxide rich solid sorbent (containing CaCO.sub.3) into the rotatable container, rotating the rotatable container for mixing the solid particles and the carbon dioxide rich solid sorbent for transferring heat from the solid particles to the carbon dioxide rich solid sorbent and generating carbon dioxide and carbon dioxide lean solid sorbent (mainly CaO), discharging the carbon dioxide and the carbon dioxide lean solid sorbent from the rotatable container and the subsequent classification of the HT solids from the lean sorbent.

A method for denitrification of flue gases and a system, wherein flue gases generated in a rotary kiln are conveyed to a calcining zone for the deacidification of raw cement meal. Aqueous ammonia solution, ammonia, or ammonia-releasing substances for denitrifying the flue gases injected into the calcining zone according to the method of selective non-catalytic reduction (SNCR), and the flue gas stream, together with an ammonia slip generated during the denitrification, is passed through a heat exchanger and through at least one dedusting device. The flue gas is guided through a exhaust gas line via a catalyst for the decomposition of excess ammonia with residues of nitrogen oxide in accordance with a method of selective catalytic reduction (SCR), wherein the catalyst is arranged in a reactor provided in the exhaust line, and is no larger than is required for a sufficient decomposition of the ammonia.

Methods and apparatus for reducing the content of controlled acidic pollutants in clinker kiln emissions are disclosed. The methods and apparatus include introducing bypass dust produced during production of clinker into one or more locations between the preheater exhaust and the inlet to a dust filter including into a gas conditioning tower. Total bypass dust separated from the kiln exhaust gas may be used. The bypass dust can be separated into a fine and coarse portions. Fine or total bypass dust can be mixed with water to form a bypass dust slurry that can be introduced into the gas conditioning tower. Bypass dust can be used to reduce the content of acidic pollutants such as hydrogen chloride HCl and sulfur oxides SO.sub.x from clinker kiln emissions.

A combustion gas bleeding probe includes a gas pipe for bleeding a part of a combustion gas from a kiln, and a plurality of discharge ports each of which is provided penetrating through the gas pipe and each of which discharges a low-temperature gas in a direction that is perpendicular to a direction of flow of a bleed gas bled by the gas pipe and that is directed toward a center of the flow of the bleed gas. The discharge ports discharge the low temperature gas such that a ratio of a momentum of the low-temperature gas per discharge port to a momentum of the bleed gas satisfies 1.2 to 4.0, and a value (m-1) obtained by dividing a ratio of a wind speed of the low-temperature gas to a wind speed of the bleed gas by an inner diameter of the gas pipe satisfies 1.5 to 3.5.