The invention relates to multi-stage cement calcining plant suspension preheater of the kind mentioned in the introduction, wherein the preheater comprises a top separator comprising a central tube entering the top separator in a lowermost part of the separator housing whereas the central tubes of the bottom separators enters the separator housing in an upper part of the separator housing.

A dividing-wall rotary kiln device comprises a rotary kiln, an exhaust gas residual-heat power generation device, a gas recovery processing device, a cooler, a combustion fan, a feeding system and an exhaust emission system. A refractory brick unit of a kiln body is a hollow structure formed by a refractory inner cylinder and a refractory outer cylinder. A center of the refractory inner cylinder is a kiln chamber. A material channel is between the refractory inner cylinder and the refractory outer cylinder. The feeding system is connected to a feeding device via a raw material preheating compartment or a dividing-wall preheater. The feeding device is provided with a decomposition gas outlet connected to the gas recovery processing device via the raw material preheating compartment or the dividing-wall preheater. The kiln chamber is connected to the exhaust gas residual-heat power generation device via a kiln tail hood.

Disclosed is a bypass system for use with off gases that have exited a cement kiln utilized in a cement making process. The bypass system is adapted to remove both NOx and volatile components that are present in the off gases while the off gases are in the bypass duct.

It is described an integrated process for the production of clinker by dry process, with treatment in continuous of by-pass dusts produced by the kiln, wherein the solid matter to treat consists of bypass dusts of a clinker production process, containing compounds of chloride, sodium, potassium and sulphur, such a process comprising the following steps: a) extraction of the bypass dusts directly from the phase of quench, without intermediate storage, at a temperature comprised between 150 and 200 C., with a moisture content varying from 0.1 to 3% by weight, preferably from 0.1 to 0.5% by weight, and with a quantity of calcium carbonate lower than 55% by weight; b) mixing of said dusts coming from step a), within a maximum time comprised between 2 and 10 minutes, preferably lower than about 5 minutes, with water up to a water/dusts ratio varying from 2:1 to 4:1, preferably from 2.5:1 to 3.5:1, in a way to obtain a mixture with a moisture content comprised between 45 and 75% by weight, preferably between 50% and 55% by weight, even more preferably equal to about 50% by weight; c) mechanical stirring of the mixture diluted up to complete dissolution of the soluble salts; d) mechanical separation of the mixture so diluted in a liquid fraction containing water and soluble salts and in a solid fraction in form of cake or crust.

In methods of and/or plants for manufacturing cement clinker, the amount of chloride bypass exhaust gas 79 can be substantially decreased, when using previously cooled chloride bypass exhaust gas 81 and/or cooled kiln exhaust gas as coolant for the chloride bypass exhaust gas 39 prior to deducting the chloride bypass exhaust gas 39.

Disclosed is a bypass system for use with off gases that have exited a cement kiln utilized in a cement making process. The bypass system is adapted to remove both NOx and volatile components that are present in the off gases while the off gases are in the bypass duct.

A dividing-wall rotary kiln device comprises a rotary kiln, an exhaust gas residual-heat power generation device, a gas recovery processing device, a cooler, a combustion fan, a feeding system and an exhaust emission system. A refractory brick unit of a kiln body is a hollow structure formed by a refractory inner cylinder and a refractory outer cylinder. A center of the refractory inner cylinder is a kiln chamber. A material channel is between the refractory inner cylinder and the refractory outer cylinder. The feeding system is connected to a feeding device via a raw material preheating compartment or a dividing-wall preheater. The feeding device is provided with a decomposition gas outlet connected to the gas recovery processing device via the raw material preheating compartment or the dividing-wall preheater. The kiln chamber is connected to the exhaust gas residual-heat power generation device via a kiln tail hood.

A thimble assembly for a cyclone separator comprising a plurality of carrier brackets separately mountable on a shelf of the separator along the perimeter of a circular exhaust opening, a plurality of segments vertically successively suspended from the brackets, the segments of an upper row being joined to the brackets, the segments of each successive lower row being joined to the segments of a row immediately above, each bracket exclusively serving a chord of an arc concentric with the circular opening that is substantially the same in length as the chord of an arc that a segment spans, a center-to-center chordal spacing of adjacent brackets being the same as a center-to-center distance of an adjacent pair of segments.

A method for calcination includes providing a heated coarse solid particle stream with a carbon dioxide rich sorbent to a reactor having a rotatable container.

Providing a cement production apparatus in which raw material is supplied into a duct with being dispersed uniformly so that heat-exchanging efficiency is improved by even preheating and clogging and the like are prevented, so that stable operation can be carried out. Between cyclones at an upper stage and a cyclone at a lower stage disposed below cyclones at an upper stage, a duct 21 is provided to introduce exhaust gas to the cyclones at the upper stage with distributing after flowing upward from the cyclone at the lower stage; at a lower position than a distribution part 23 of the duct 21, a material-supplying pipe 22 is connected for supplying cement raw material; at a connected part of the material-supplying pipe 22 to the duct 21, a material-guiding chute 24 on which the cement raw material is supplied from the material-supplying pipe 22 and which drops it into the duct 21 is provided with protruding into the duct 21; and the material-guiding chute 24 is formed to have a flat upper surface and to be expandable by sliding so that insertion depth of a tip end 24a from an inner-wall surface 21b of the duct 21 is 0.15 to 0.5 times of an inner diameter of the duct 21.