In an industrial incinerator, suppression of ash emission is of great importance from a viewpoint of environment preservation. In some of the incinerators, a control plate is equipped to suppress the ashes, where it is designed based on engineers’ experience. The control plate is assumed to recoil the ash particles. On the other hand, effect of the control plate has not been examined sufficiently, and besides behavior of ash particles has not been figured out in the incinerator. This is because the incinerator scale is so large that validation tests cannot be performed. In the present study, a numerical technology is applied to an industrial incinerator to examine the effect of the control plate and to analyze the ash particle behavior. In the numerical simulations modeling of an arbitrary shape wall boundary and large-scale simulation technique are required. In this study, advanced DEM-CFD method is employed, where coarse grain model of the DEM is used as scaling law modeling and signed distance function and immersed boundary method are applied to arbitrary shape wall boundary in the DEM-CFD method. The numerical simulations illustrate that the control plate works effectively, whereas, against all expectations, the ash particles are shown to remain in the incinerator not by collision to wall but by settling on the plate due to vortex.

The choking prevention effect on dense-phase pneumatic conveying has been investigated experimentally while moisture and particle diameter are changed. Consequently, the adhesion force between particles and pipe wall has been increased drastically with increasing of moisture content. However, it has been reduced with ultrasonic in spite of experimental condition. This means the possibility of choking can be removed with ultrasonic vibration. Additionally particle motion on the ultrasonic vibration plate was analyzed. This result showed that particle velocity increases along with particle diameter and moisture content influences on only large-sized particle. This cause was considered that heavy particle which includes a lot of water cannot jump in long distance and water makes the meniscus between particle and wall.

To understand the detail structure of the pulverized coal flame, it is necessary to apply the carefully controlled optical diagnostics because the significant signal disturbance from the fuel particles would reduce the accuracy of data. In this paper, the highlight results obtained by applying shadow Doppler particle analyzer (SDPA) and laser induced incandescence (LII) and time-resolved LII (TiRe-LII) to the pulverized coal flame were summarized.

This study aims to evaluate granules and tablets properties prepared by twin-screw continuous granulation (TSG) by comparing with those by fluidized-bed granulation (FBG) and high shear granulation (HSG). During FBG, mass median diameter increased in proportional to moisture content of wet granules. In HSG and TSG, granules growth was observed with an increase in mass ratio of liquid to solid. The mass median diameter was affected by the blade rotation speed at higher level of water content in HSG. By contrast, granule growth was less affected by the screw rotation speed in TSG. Friability and density of granules prepared by TSG remained between FBG and HSG. Scanning electron microscopy and cross-sectional 3D X-ray tomography images suggested that granules prepared by TSG did not receive high shear force as HSG during the granulation. The tablet strength and the percentage of dissolution were similar with those by FBG. It was because granules prepared by TSG had relatively porous structure as FBG. Under practical operation conditions, the tablet properties were comparable with those by FBG and HSG.

The method to improve the properties of dry granules was investigated by introducing pre-coating process with an active pharmaceutical ingredient (API) and a submicron-sized binder prior to conventional roller compaction. Hydroxypropylcellulose (HPC) and acetaminophen (APAP) were used as models of a binder and a low-compactible API, respectively. The submicron-sized HPC (HPC-subMP) was obtained by a lab-scale spray dryer. The APAP particles were pre-coated with 5–10% of the HPC-subMP by a high shear mixer, formed into granules using a lab-scale roller compactor, mixed with other excipients and then compressed to make them tablets containing 50% APAP. The tablets prepared with the HPC-subMP showed a high tensile strength without significant retardation of the disintegration time in comparison to those with a raw HPC particle, indicating that the use of API particles pre-coated with submicron-sized binder particles in roller compaction was effective to prepare granules suitable for tableting without any fundamental changes of materials and manufacturing processes.