1. General concept about machines and equipment.
Lecture 2
General concept about machines and equipment.
Comminution (milling, grinding), sifting, mixing.

2. Plan General definition about machines and equipment.
Processes of comminution. Characteristics.
Equipment for milling.
Processes of sifting. Equipment for sifting.
Processes of mixing. Equipment for mixing.

3. increase specific surface of substances,
Comminution – is a process of reduction of particle size of substance by mechanical influence.
Motivation for particle size reduction:
increase specific surface of substances,
increase the free surface energy of crushed substances,
significantly increase the speed of chemical and diffusion processes,
strengthen the pharmacological activity of substances.

4. Comminution is characterized by the symbol index –”i” - the degree of comminution of substances. “I” equal ratio of the diameter of pieces of material to the milling (D) to particles diameter after ones (d).
i = D / d

5. Types of milling in depend on degree of comminution (in haw much times the particles size was reduced):
Great (large) – in 2-6 times;
Medium - up times;
Fine - at times;
Micro fine - in times;
Super fine - thin (colloidal) – in times.

6. Classification equipment for milling:
By the way of milling:
Cutting machine
Attrition machine
Compression machine
Impact machine
Impact - Centrifugal machine

7. Classification equipment for milling:
By the degree of comminution: 1. crushers:
for great, medium, fine milling; 2. mills:
for micro fine, superfine (colloid) milling.

8. Classification equipment for milling:
By the mechanism used to break the particles:
Disc
Boll
Rotor
Hammer
Rollers and others

9. Requirements for the milling process:
Substances must has initial its composition and pharmacological properties during the milling process;
Periodically to remove enough milled particles from the sphere of comminution;
Prevent formation of dust (sealed enclosures);
Appropriate moisture of material;
The use of sequence connected crushing-milling machines.

10. Parameters for choosing optimal type of machines:
Initial size of the material and desirable size of final product
The total amount of material for milling
Physical and chemical properties of material for milling

11. Cutting machine are used to comminution herbal drug that has a fibers structure.
Grass cutting and straw cutting (grass, stalks).
Root cutting with the guillotine knife - for grinding roots, bark.
Drum straw cutting - for grinding dry medicines.
Knife mill - for milling volume materials, containing cellulose
Motorized soft meat grinder - for fresh herbal drugs, animal raw materials

12. Crushes machines which are used for milling solid materials:
Cheek and jaw mill
Rollers mill
Cone mill
Hammer mill
Disk mill (Excelsior)

13. Jaw mill type shock

14. Grasscutting

15. Grasscutting

16. Cutting mill

17. Rollers mill
1,2 - rolls
3 - spring

18. Rollers mill

19. Disk mill (Excelsior)

20. IMPACT - CENTRIFUGAL MILLS:
Hammer mill
Dysmembrator
Disintegrator

21. Hammer mill
1 - rotor;
2 - hammer ;
3 - corps;
4 - plates.

22. Hammer mill

23. Hammer mill

24. Disintegrator

25. Machines for fine milling:
Drum mills:
Ball mills
Rod mills
Mills, in which material are milled by acting of own weight:
Mills Continuous action
Mills periodic action

26. Ball mill

27. Ball mill

28. Work of Ball mill

29. Machines for Superfine milling :
Vibration mills
Jet mills
Colloidal mills:
Rotor - Pulsating apparatus (RPA)

30. Work of Jet mills

31. Jet mills

32. Equipment for Colloidal milling (vibration-cavitation mill, Conical mill )

33. Sifting (Sorting, Screens) - is process department more large or more small particles of primary mass separation loose materials on separate fraction that differ form and size.

34. Factors what affect on process of Sifting :
Shape and size of sieves
Thickness of material layer on sieve
Humidity of material
Movement speed of materials on the sieve
Nature of movement and length of way material
Work Speed of sifting

35. Classification sieves depend on way of make:
Wicker sieve - by binding thin filaments or wires, with silk, steel and others. Filaments are easily extracted and not strong, although cheap.
Stamped sieve - by punching metal plate with the formation of frequent round, oval or square holes. They are very strong and widely used in industry, but have rather large holes, so are not suitable for small particles.
Combination – by combination metal plates. They are very strong, but have low productivity.

36. Classification sieves depend on nature of movement
Sieves, rotary - a cylindrical drum sieve, which is set at an angle. It consists of sections of sieves with different size holes that can differentiate between material in size.
Sieve that swing - is installed on the box spring rests at an angle to the horizontal 7-14.
Vibration sieve - the structure is the same as in sieve that swing , but have a great frequency vibrations - vibrations.

37. Vibration sieve

38. Classification of mixers:
Mixing is process which ia used for achievement uniformity of mixtures.
Classification of mixers:
Mixers with rotating blades
Mixers with rotating corps
Circulation mixers which contains cone that rotates on a vertical axis
Mixers with fluidized layer (material is thrown up by the air pressure).

39. Mixer with rotating corps Patterson-Kelley

40. Mixer with rotating corps Patterson-Kelley

41. Mixer with rotating corps Ambica Boiler & Fabricators

42. Mixer with rotating blades Ambica Boiler & Fabricators

43. Mixer with continuous action

44. Mixer - "Drunk barrel"

45. Thank you for your attention