Abstract: In an exhaust gas treatment system including a denitration device that removes nitrogen oxide in exhaust gas from a heavy fuel-fired boiler, an air preheater that recovers heat in the gas after the nitrogen oxide is removed, an electric precipitator that removes dust while adding ammonia into the gas after heat recovery, a desulfurization device that removes sulfur oxide in the gas after dust removal, and a stack that exhausts the gas after desulfurization to the outside, an ash-shear-force measuring instrument is provided to measure an ash shear force, which is ash flowability, on the downstream side of the electric precipitator, so that a feed rate of an air supply unit that supplies air to the boiler is reduced according to ash shear-force information.

Abstract: Disclosed is a sieve including a mixing space, a sieving space, and a mixture transport space formed therein. A mesh for holding an active material in the mixing space is arranged in the undermost part of the mixing space. A gas containing a powder of a conductive material is supplied from a lower part of the mesh toward an upper part of the mesh to float the active material placed on the mesh and cause the collision between floating particles of the active material and particles of the conductive material, thereby producing particles of a mixture. Among the particles of the mixture, particles having particle sizes equal to or smaller than a desired particle size range rise up from the mixing space to the mixture transport space through the sieving space, while particles having relatively large particle sizes do not reach the mixture transport space.

Abstract: In an exhaust gas treatment system including a denitration device that removes nitrogen oxide in exhaust gas from a heavy fuel-fired boiler, an air preheater that recovers heat in the gas after the nitrogen oxide is removed, an electric precipitator that removes dust while adding ammonia into the gas after heat recovery, a desulfurization device that removes sulfur oxide in the gas after dust removal, and a stack that exhausts the gas after desulfurization to the outside, an ash-shear-force measuring instrument is provided to measure an ash shear force, which is ash flowability, on the downstream side of the electric precipitator, so that a feed rate of an air supply unit that supplies air to the boiler is reduced according to ash shear-force information.