Product Bulk Density

Pai+icle size enlargement equipment can be classified into several groups, with advantages, disadvantages, and applications summarized in Table 20-36. Comparisons of bed-agitation intensity, compaction pressures, and product bulk density for selected agglomeration processes are highlighted above in Fig. 20-71. 

All scales reqmre continuous monitoring to assure that the desired set weight is maintained and does not drift off because of changes in product bulk-density or flow characteristics. Microprocessors can perform this task automatically. 

In scale-up from laboratory quantities (up to 10 kg) to production batches (300 kg and up), bed depth increases significantly. The most notable consequence is an increase in finished product bulk density, typically in the range of 15% to 20%. In some instances, this is a disadvantage (if product is packed by volume and a low density is desired). However, granule strength is usually greater as a result of the decreased interstitial void space. 

The capacity of a pneumatic-conveying system depends on (1) product bulk density (and particle size and shape to some extent), (2) energy content of the conveying air over the entire system, (3) diameter of conveying line, and (4) equivalent length of conveying line. 

This is an important consideration for designing the fryer. For example, tortilla chips show some increase in specific volume after frying. However, the pellets expand tremendously in volume during frying. The internal design of the fryer must accommodate for this increase in volume. Product bulk density also impacts the size of packaging. 

In order to reduce the volume stream and to optimize the efficiency of the following processing units the plastics have to be compacted mechanically before heat/pressure treatment starts. Bales of compacted wet plastics reach bulk densities of about 450 kg/ m3, they are put into moulds which will be transported into autoclaves. During the autoclave process plastics are heated and plastified under saturated steam conditions. Autoclave process is within a wide range independent from changing compositions of the plastics. The process temperature (about 170°C) does not provoke decomposition of plastics, used for household packaging materials. Hydrothermal autoclave conditions lead to further compaction and a stable product (bulk density up to 700 kg/m3) of the mixed different kinds of plastics. Fig. 1 shows a compacted plastic block after finishing the autoclave process. 

Polypivalolactone (PPL) is insoluble in most solvents at temperatures below 100°C. We therefore envisaged conducting the polymerization in an inert diluent from which the polymer precipitates, and in which the lactone monomer and initiator may or may not be soluble. The diluent should be capable of dissipating the heat of polymerization, and the morphology of the product (bulk density, powder flow, etc.) should be as good as possible. In addition, the reaction rates should be practical, and the polymer should fulfill product requirements such as thermal stability. 

Oosimetry Dose delivery in industrial-scale cobalt-60 gamma irradiators is achieved through controlling the time of exposure of the product to the source. The initial relationship between source strength, product bulk density, time of exposure, and absorbed dose has to be determined empirically by dosimetry. 

Vanderpool (430) to recover fine, pure silica from the aqueous hydr ysis of ethyl silicate with ammonia. The product bulk density was about 0.1 g cm . 

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