Fine particles combination

On a chute, higher drag results in lower particle velocity which can be accentuated by stratification on the chute surface because of the sifting mechanism. Concentrations of smaller particles close to the chute surface and larger particles at the top of the bed of material, combined with the typically higher frictional drag of finer particles, often result in a concentration of fine particles close to the end of the chute, and coarse particles farther away. This can be particulady detrimental if portions of the pile go to different processing points, as is often the case with multiple outiet bins or bins with vertical partitions. 

ESPs), and some of the previously discussed novel devices. Series combinations of control devices may be necessary to achieve the required level of particulate matter emission. A commonly used system is a multiple cyclone followed by a fine-particle control system, such as a baghouse, scrubber, or ESP. 

Situation There are two vendors for a particular bulk chemical who meet all written specifications. The products are equally useful for the intended reaction as far as the chemical parameters are concerned both comply in terms of one physical parameter, the size distribution of the crystals, but on the shop floor the feeling prevails that there is a difference. Because the speed of dissolution might become critical under certain combinations of process variables, the chemical engineers would favor a more finely divided raw material. On the other hand, too many fine particles could also cause problems (dust, static charging). 

This process, according to the manufacturer,54 has been developed in such a way that space requirements are kept to a minimum. A BIOPAQ IC reactor is used as the initial step in the treatment process. The name of this anaerobic reactor is derived from the gas-lift driven internal circulation that is generated within a tall, cylindrical vessel. These reactors have been operational in the paper industry since 1996. The second step in the purification process is a mechanically mixed and aerated tank. The aerating injectors can be cleaned in a simple way without the need to empty the aeration tank. Potential scaling materials are combined into removable fine particles. At the same time, the materials that may cause an odor nuisance are oxidized into odorless components. The process can be completed by a third and a fourth step. The third step focuses on suspended solids recovery and removal. The fourth step is an additional water-softening step with lamella separation and continuous sand filters in order to produce fresh water substitute. The benefits claimed by the manufacturer are as follows54 ... 

The stronger and more economical types with fine particle sizes are also found in transparent paints. If it is to be used in two-coat metallics, however, the application of the pigment must be combined with UV absorbants in topcoats to render it weatherfast enough to be applied in original automotive finishes. 

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