Minimum drop height

On the basis of the results obtained, the impact sensitivity can be expressed as the drop height at 4lich 50% initiations occurred (//50), the minimum drop height at which 100 initiations occurred (//loo), and the maximum drop height at which lack of initiation is observed (Ho). 

Some impact testing methods take the minimum drop height at which at least one of ten consecutive trials results in initiation of the sample as a measure of the impact sensitivity. 

The nature of the area for dropping the catalyst must be prescribed. The ideal condition is that the area has the same hardness as that of the catalyst it can be harder than that of the catalyst and not softer. For tablets, the minimum drop height for particle fracture is related to the diameter/height ratio and the tablet s utmost tensile strength (UTS). A rough approximation of the relationship is as follows The drop height for particle fracture (m) = 0.075 x d/Lx(UTS), UTS is expressed in kg Cm . ... 

It can be seen from the above equation, the strength of tablets that are thin but long is poorer than that of tablets that are thick but short. The value of the d/L is usually one, and the design value of minimum drop height for the tablet is 3 m or the UTS is 40 kg-cm. ... 

The strength of a spherical catalyst for ammonia synthesis can be expressed by the minimum drop height, with a design value above 10 m. 

It can be seen from this that the driving difference in content drop is starkly reduced. The J minimum required height of the fluidised bed is accordingly very small. 

ONE ELBOW IN PIPING GIVES MINIMUM PRESSURE DROP UP TO THE CONTROL VALVE AND MINIMUM EQUIPMENT HEIGHT. 

It can be verified that for a droplet having a reduced drop height of H, its maximum possible inflection angle a ax is equal to its maximum possible contact angle under the fulfillment of Eq. (29) and its minimum possible inflection angle occurs at 0 = 0 ... 

A bed height of 10 ft is recommended for general use greater depth results in bed compaction and increased pressure drop unless tray or grid supports are provided. Maddox (1974) recommends a minimum bed height of 4 to 10 ft. Anerousis and Whitman (1984) recommend 10 ft minimum for H2S and 20 ft if mercaptans are present. 

The pressure drop of these trays is usually quite low. They can be operated at an effective bubbling condition wnth acceptable efficiencies and low pressure drops. For more efficient operation the clear liquid height on the tray appears to be. similar to the sieve tray, i.e., 1.5-2-in. minimum. This is peculiar to each system, and some operate at 1 in. with as good an efficiency as when a 2-in. is used. When data is not available, 2 in. is recommended as a median design point. 

Calculate the total wet tray pressure drop, using an assumed height of clear liquid on the tray of 0.5-in. minimum to 4-in. maximum (1 to 2-in. are usual values). 

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