July 24, 2021: Pharmaceutical Interview Questions and Answers
#PartsOfMultimill #MOCofMultimill #MechanismMultimill #SpeedsOfMultimill #SettingsOfMultimill
1. Explain parts of multimill?
Material Charging Hopper: To load the material to be milled
Milling chamber: Milling of material happens within the chamber with the help of Cutting blades and desired size of particles are passed through specific size screen
Discharge port: Milled material is discharged from this part
Castor wheels: To move the mill from one place to another place
Operating Panel: To operate the equipment
Screen: To produce desired particle size
Cutting blades: To mill the material
2. What is the Material Of Construction (MOC) of multimill parts?
Product contact parts are made up of SS 316 or SS316L
Non-product contact parts are made up of SS 304 Castor wheels are made up of Polyurethane
3. What is the mechanism of size reduction when using multimill?
a. Impact Milling: Particles are reduced in size by high-speed mechanical impact or impact with other particles; also known as milling, pulverizing, or comminuting.
b. Cutting: Particles are reduced in size by mechanical shearing.
c. Screening: Particles are reduced in size by mechanically induced attrition through a screen. This process commonly is referred to as milling or deagglomeration.
4. What are the typical speeds of multimill?
Fast speed: 2880
Medium fast speed: 2160
Medium speed: 1440
Low speed: 720
Note: Nowadays multimill are available with variable frequency drive where speed can be set as per the requirement (Custom speed).
5. What are the typical settings for milling operation using multimill?
Blade direction: Impact forward or Knife forward
Machine speed: Using V belt adjustment or using VFD as per machine design