1. Vacuum system

2. Principal scheme

4. Vacuum parameters 1 Preliminary vacuum 1*10-2 Pa 2 Melt storage3
Crystal annealing
5*10-5 Pa

5. Mechanical pump. Construction and principle of operation.

6. Two Stage Rotary Vane Vacuum Pump
Inlet and outlet
Oil level
3 phase engine
Oil removal

7. Gas flow in rotary pump
1, 7 –stages, 2,3 – valve, 4 – gas outlet, 5- gas channel, 6 – gas inlet

8. Vacuum characteristic

9. Diffusion pump

10. Structure of diffusion pump
1 – body;
2, 10 – covers;
3, 11 – washer;
4 – oil reflector;
5 – earth;
6 – vapor path;
7 – spiral way;
8 – heater;

11. Oil reflector
Stage
Cooling water

12. Vacuum characteristic
Speed l/sec
Input pressure, torr

13. Electromagnetic valve. Solenoid principle of operation.

14. Vacuum lock. Construction and principle of operation.
Cover
Engine
Manual close ring

15. Structure of lock

16. Vacuum meter APG. Principle of operation.
1- electric cable, 2- socket,
3 – spring ring, 4-vacuum flange, 5-filter

17. Principle of operation Pirani
TO MEASURE VACUUM BY MEASURING HEAT CONDUCTIVITY OF GAS
Heater wire
Thermocouple

18. Vacuum meter WRG. Principle of operation.
WRG – combination of inverse magnetron sensor and Pirani
Way of measuring is chosen automatically

19. Principle of operation
Dependence of ionized gas current on pressure
Crossed magnetic field make longer path of ions before reach anode E H - +

20. Plant assembly

21. Vacuum line is fixed to the frame by
Joining crystallizer with 3 bolts
Joining right angle tube with 2 bolts
Vacuum devices and parts are mutually fixed with clamps and rings

22. To set the crystallizer on the frame and to fix it with the bolts

23. To join the vacuum tube to crystallizer and frame by means of the bolts and the studs

24. To join the lock and diffusion pump by means of the studs

25. To set the side shields and to fix them with the screws

26. To set up vacuum devices

27. To set up water tube with water collector
Pressure meter

28. Water collector

29. Water piping 1-Valve 2-Pressure meter 3-12 –Valves of the grower parts
13- Diffusion pump
14-Thyristor
15 – Chamber
16 –Bottom
17- Small cover
18- Big cover
19 -Rod
20-Cutter
21- Current lead 1
22- Current lead 2
23-34 –Thermal sensor of the elements
35- Funnel

30. To set and fix with the bolts the column to the frame

31. To set and to fix the computer control board

32. To set the supports and to adjust them in order to provide for horizontal orientation of the grower

33. Assembly of hot zone inside the crystallizer
Bottom
Support
Side shield
W Tube

34. Checking the center of W-tube and the gap

35. Mo shield and W-tube
Bottom shield
Shield to the current lead

36. Bottom shield
Support
Granules
Bottom shield

37. Al2O3 loading

38. To put on and to fix the big cover with the nuts

39. Heater

40. Small cover
Window
Lobe

41. To set and to fix bus bars with the bolts

42. To set and fix the side shields on the frame

43. To set the transformer unit

44. To set the mechanical vacuum pump

45. Maintenance Checking for vacuum seals and junctions
Checking of water cooling system
Checking for thermal screens and hot zone elements wear
Correction of crucible position

46. Safety measures Electrical safety
There are the following sources of electric safety: chains of power supply of the component parts of the grower,panels and blocks with electric apparatus and electric equipment, located on the control panel, crystallizer, power cabinet.
Protection of maintenance staff against electrical shock is provided by the doors which can be opened by special key and by protective grounding.
There are grounding bolts with special marks on the doors of the power cabinet and control unit.

47. Danger of thermal burns.
There are the following sources of thermal burns: the heater, screens and the melt surface at monitoring of crystallization front through non-protected window, therefore after termination of technological process it is allowed to open the grower only after its complete cooling.
To protect the eye of process engineer from thermal irradiation at monitoring of seeding process it is necessary to use the light filter.