Dry raw materials

The spray-dried flavours or powder blends are processed by a roller compactor into lumps (Fig. 21.12). These lumps are crushed into granules. This process cannot be categorised as a direct encapsulating technique, since the flavour-encapsulating effect of compacted flavours is based on the use of spray-dried raw material. 

In general, volatile components can be extracted from the dried raw materials under conditions close to the critical point of carbon dioxide. Temperatures should be within the range of 32 to 60°C. However, some heat-sensitive components may decompose, even below this range. Extraction pressures should be between 74 and 120 bar, since at higher pressures the increased solvent power of CO2 also increases the solubility of unwanted components. The yields obtained by SFE are very similar to those found by steam distillation. However, even under mild extraction conditions, some small amount of cuticular waxes is co-extracted with the volatiles. The major constituents of the waxes are -paraffins, ranging from C25 to... 

An example of an actual physical activation procedure is as follows [176] the dried raw material is crushed, and sieved then the furnace temperature is increased at a rate of 10 [°C/min] up to 600°C for about 3 h, under inert purge gas flow. The resulting chars are then activated at 500°C-900°C for 10-60 min under purified C02 flush. In Figure 3.16 [175], a flow chart of the physical activation method is shown. 

The standard chemical activation procedure is similar to the physical method of activation. That is, the dried raw material is crushed and sieved to the desired size fraction. Afterward, the obtained powdered material is mixed with a concentrated solution of a dehydrating compound subsequently, this blend is dried and heated under inert... 

Method of preparing inulin-pectin concentrate powder for medicinal and food aims from dried raw materials. 

The typical process steps for formulating a laundry or auto-dish detergent usually are defined in the laboratory prior to continuous plant processing however, they generally follow the scheme shown in Fig. 36.40. Frequently the dry raw materials are premixed and then metered into the agglomeration equipment. In... 

Vertical mixers have become more commonly used due to low space requirements and high efficiency of operations. The vertical mixer shown in Fig. 36.42 utilizes high speed agitation to intimately mix and uniformly blend liquids and dry raw materials prior to discharge. The contact time is reduced to less than five seconds. The rotary drum units generally contain baffles that roll or lift the product... 

The enormous advantage of the STAKE feeder lies in the fact that it can handle almost dry raw material. For the manufacture of furfural, water is required only to the extent as it is needed for hydrolyzing pentosan to pentose, and for dissolving this pentose. The subsequent conversion of pentose to furfural actually creates water. Thus, any excess input water is undesirable as it dilutes the acid catalyst and reduces the caloric combustion benefit of the residue. Against this background, a furfural process using the STAKE feeder has inherent advantages. 

Mixed tocopherols can be added dispersed in dry raw materials or suspended in water or mixed with ethanol as a carrier (O Brien and Robertson, 1993 Six, 1994). Typical usage levels are 150-450 pg/g. Partly, this large range of different addition levels is due to the large range of tocopherol and tocotrienol contents of the raw materials (Cort et al., 1983) and their susceptibility to oxidation. Often, tocopherols and tocotrienols are added mixed with other compounds such as ascorbic acid or chelating agents that enhance the effect of tocopherols as natural antioxidants (Six, 1994). 

This enzyme oxidizes linoleic and linolenic acids rapidly in whole flour or milling products containing wheat germ or bran mixed with water. The initial hydroperoxides formed by lipoxygenases in stored wheat bran are converted to secondary products, mono- and trihydroxy fatty acids. These oxidation products causing bitter and rancid flavors are formed in higher concentrations in hydrated products than in dry raw materials. Rancid flavors develop rapidly on hydration. 

The required quantity of dry raw material (i.e., without its inherent natural moisture) for the production of Portland cement clinker can be computed as... 

Over dried raw material Reduce drying time/temperature. 

It should be pointed out that none negative effects were observed at the stage of mixing raw materials and preparation of plastic masses. Processes of drying raw materials and burning of semi-products proceeded properly and the obtained final products, apart from the mentioned defects, exhibited the similar external appearance and comparable technical parameters in relation to the products from the normal production line. 

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