A1 WG - Experiment Flashcards
Learn about the parameter in a TSG HSG- effect of L/S of torque measurement FBG, granules size (108 cards)
Name equiment with which granulation is possible
Twin screw Granulator
High shear Granulator
Fluid-bed granulator
Name the processes which leads to granules in TSG
Nucleation, layering growth
agglomeration and breakge
Name the elements of a TSG and their functions
Coneveying elements important for transportation
Kneading elements important for compaction and distribution
the feeding system in a TSG
powder feeding and the liquid feeding system
how can you describe the screw?
they are coroating, having temperature jacket for coolin for heating
What is the importance of composition of the screw?
the screws elements determines the process characteristics
what’s the different between the longer and shoter pitch in the conveying element?
longer pitch, faster transportation, material is evenly distributed
shorte pitch length, smaller volume in the length, unevenly distribtion
How does the pitch length affects the granuales porosity?
the porosity of the granules decreases with increase pitch length, due to higher densification
what’s the disadvantges of the shoter pitch?
it leads to oversized granules and fines
What’S the advantage of TSG?
it can be used for continues manufacuring
What are the properites of the wet mass for TSG
The wet mass should be self-lubricanting, fluidity ad rigidit properties and not adhesive
lower angles of the kneading element in TSG
they have a forward flow propeties, more a conveying element
less shear fore, better distribution
higher angles of the kneading element in TSG
reversing kneading, higher pressure and compaction
How does the angle of the kneading element influence the granules properties?
they do not have any significant impact on the PSD of the granules. Nevertheless, increasing kneading elements will produced granules with high density and longer dissolution time
Which parameter were investiged in the A1 experiment?
L/S, feeding rate and srew speed
What is the most siginicant paramter in granulation
L/S ratio, because it affects the mean PSD of the granules.
Low L/S: non-homogeneous weeting of the powder mass. (bimodal granules size distribution
Low L/S affect on the PSD
Low L/S: non-homogeneous wetting of the powder mass. (bimodal granules size distribution
moderate high L/S affect on the PSD
more liquid available for distribution, more wetted and deformation of granules with monomodal size distribution
What’s the affect of the binding viscosity?
too high binder viscosity leads to poor distribution of the liquid, increase of fines
But the viscoity should be high enough to decrease the porosity of the granues, increase stickness
how does the FR and SS affect the granules?
Both impact the barrel fill that can change the shear and compaction forces , theryb influencing the granules size, density and structure
How the MRT affected by the FR and SS
the increasee if the SS leads to descreas of the MRT
why do the MRT reduces by high SS
increasing the SS increase the axial transport rate of the powder, thereby reducing the time the powder spedns in the granulator
Relation between the high MRT and throughput forces?
the decrease of the SS and the FR, leads to an increase of the MRT, due to low throughput force. therefore, the powder stays longer in the barrel
On what does the powder rfeed rate depends?
it depends on the fill level and the throughput force