Loose bulk density

When determining bulk density, a distinction should be made between loose bulk density and tap density, eg, ASTM B527-81. The latter is a measure of the influence of settling on filler volume at constant mass. 

The plate dryer may vary in size from 5-35 vertically stacked plates with a heat-exchange area between 3.8-175 m". The largest unit available has overall dimensions of 3 m (w) by 4 m (1) by 10 m (h). Depending upon the loose-bulk density of the material and the overall retention time, the plate dryer can process up to 5,000 kg/hr of wet product. 

The loose bulk density of indinavir sulfate is typically 0.2 g/cc, while the tapped bulk density is typically 0.2 and 0.4 g/cc [8]. 

Powder flow requirements vary with equipment design. To maintain a low weight variation, optimum values of Carr s index (CI) is in the 25 to 35 range for Zanasi and 18 < CI < 30 for H K. Note Carr s Index is calculated from the loose bulk density (LED) and tapped bulk density (TED) of powders. CI = 100[(TED LED)/TED]... 

Example 1—Dry 100 lbs. ofwetcake with an/ /fto/ volatiles content ofl5%(wetbasis) dovmXodiflnalvolatilescontent of less than 1 %. This will be achieved in a batch operation for lot identification, GMP and high quality standards. The loose bulk density of the wet cake is 45 lbs../ft. and the loose bulk density of the diy powder is 12 Ibs./ft. The temperature limit of the product is 145°F and the feed material is wet with ethanol. The product is a pharmaceutical which will be a finished product. The solvent is to be recovered for reuse, and its physical properties can be found in a handbook of hydrocarbons. The product is freeflowing in the dry state, but very tacky and pasty in the wet state. 

In general terms, compressibility refers to the variation in bulk density with respect to consolidating confined pressure acting on a powder bed. Bulk density (in terms of apparent, compact, or tap density) and normal stress have been associated in empirical logarithmic or semilogarithmic relationships, from which a constant slope value is defined as mechanical compressibility. Simultaneous decrease in a powder s loose bulk density and increase in compressibility indicate greater attractive and cohesive interactions among powders. 

Generally, ATH is considered to be thermally stable at around 180-200°C (360-400°F), and—with some reservations—until 216°C (420°F). Some data indicate the decomposition of ATH in the temperature range of 180-240°C (360-460°F). ATH is usually cream-colored, free-flowing powder with specific gravity of 2.42 g/cm loose bulk density of 70 Ib/ft (1.12 g/cm ), and the so-called packed bulk density of 55 Ib/ft (1.36 g/cm ). A typical commercial grade of ATH (for example, product of Alcan Chemicals, Cleveland, OH), contains up to 15% of powder with mesh size of 100 and larger particles, 67-87% with mesh size 200-200, and between 1 and 12% of mesh size 325. 

Part 3 Determination of loose bulk density and voids... 

Loose bulk density and voids Durability against freeze/thaw, weathering and thermal shock CEN EN 1097-3 (1998) Yes ... 

Loose bulk density is the mass of dry aggregates that fills a container of a particular volume without any compaction divided by the volume of the container. 

The loose bulk density (pi,) is calculated by the following formula ... 

Source Reproduced from CEN EN 1097-3, Tests for mechanical and physical properties of aggregates - Part 3 Determination of loose bulk density and voids, Brussels CEN, 1998.With permission ( CEN). 

The representative loose bulk density is the mean of three test values and is expressed in 0.01 Mg/m. ... 

To convert the aggregate spread rate expressed in square metres per cubic metre to units of kilograms per square metre, the loose bulk density of the aggregate is divided by the value of the spread rate determined from the above tables the loose bulk density of aggregates is determined by CEN EN 1097-3 (1998), ASTM C 29 (2009), AASHTO T 19 (2009), AS 1141.4 (2000) or any other specification. 

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