1. QUARRIES
PROCESS DESCRIPTION

2. Quarries PROCESS DESCRIPTIONS
SUMMARY
Primary
Vibrating feeder
Crusher or primary mill
Secondary
Vibrating machines
Transport bands
Gravel bins
Secondary mills
Third Part
Sander mills
Output transport bands
Criteria of use for Power Electronics equipments

3. General Process PRIMARY1

4. Quarries – Process Description SAND AND GRAVEL PITS
A. VIBRATING FEEDER
ENTRANCE: The biggest stones are transported directly to the main feeder using lorries.
The main vibrating feeder is the responsible of regulating the material entrance flow to the next stage. The motors used have powers around 40-75HP approximate.
» Primary material entrance
» Material at primary crusher

5. Quarries – Process Description SAND AND GRAVEL PITS
B. CRUSHER OR PRIMARY MILL
From the main feeder, the material goes to the crusher or Primary Mill, where the biggest stones start to be crushed. Those mill could be:
Crusher Jaw  VSD.
Crusher of Bars Rotor.
In these cases, power is around 340HP.
» Motor of primary mill
» Primary mill

6. General Process SECONDARY2

7. Quarries – Process Description SAND AND GRAVEL PITS
A. VIBRATING MACHINES
In the secondary, the vibrating machine starts the vibrating screen according to the grain size (granulometry), and this material is dosed to the corresponding transport bands.
In this stage power around 75HP are used and its common the use of variable speed drives to keep constant the production flow.
» Vibrating machine – Coarse screen 01
» Vibrating machine – Coarse screen 02

8. Quarries – Process Description SAND AND GRAVEL PITS
B. TRANSPORT BANDS
The transport bands lead the material to the gravel bins. The material which is out of range (gravel size) is not transported to those bins but it is lead back to the previous crushing stage. These are called feedback transport band.
Now we should consider motors around 10 and 30HP. The drives controlling these transport band is able of regulating the speed to warranty the correct level in the bins.
» Transport bands 01
» Transport bands 02

9. Quarries – Process Description SAND AND GRAVEL PITS
C. GRAVEL BINS
Normally the end of the transport band is directly placed on the top of the bins, where the material is stocked, although this depends on the quarry distribution. In some cases, the end of the transport band is in the open air. The vibrating machine placed afterwards will allow to dose the correct quantity to the mills.
Bins
Bins
» Stock bins 01
» Stock bins 02

10. Quarries – Process Description SAND AND GRAVEL PITS
D. SECONDARY MILL
The secondary mills will realize a second milling.
The granulometry is directly linked to the speed. So that, the variable speed drive will increase the mill speed up if a smaller gravel is required. The relation between the gravel size and the speed is inversely proportional.
Those mills are provided with motors with a approximate power of 340HP.
Two different kind of mills can be implemented in this stage:
Hammer mills  VSD.
Bars Rotor mills  Non VSD.
» Secondary mill

11. General Process THIRD PART3

12. Quarries – Process Description SAND AND GRAVEL PITS
A. TRANSPORT BANDS
These transport bands have the same functionality than the described for the secondary stage. The difference is the gravel size of the material transported.
Some times, they are closed to avoid the fallen of material and objects (safety reasons).
» Transport bands on third stage 01
» Transport bands on third stage 02

13. Quarries – Process Description SAND AND GRAVEL PITS
B. SANDER MILLS
The sander mills are hammer mills. They are managed with motor of 75 and 200HP power.
In addition to the previously reason described for using VSD, it should be considered that in that kind of mills it is possible to change the running direction (FORWARD – REVERSE) to prevent the hammer wearing.
» Sander mill

14. Quarries – Process Description SAND AND GRAVEL PITS
C. OUTPUT TRANSPORT BANDS
Now again there are some transport band, in the last stage, to transport the final products to the loading area for the lorries. It could be in open air stoke piles or in loading docks.
Bins
Loading docks
Open air stoke piles
» Output conveyors 01
» Output conveyors 02

15. Criteria of use for Power Electronics Equipments VARIABLE SPEED DRIVES & SOFTSTARTERS4

16. Quarries CRITERIA OF USE FOR POWER ELECTRONICS EQUIPMENTS

17. Quarries CRITERIA OF USE FOR POWER ELECTRONICS EQUIPMENTS
PRIMARY – ACTUATORS FOR VIBRATING FEEDER
PRIMARY FEEDERS: Variable Speed Drives
Power around 40 – 75HP approximately
Recommended equipments:
SD700 Series - Frame 4
SD450 Series - Frames 5 and 6
[ POWER ELECTRONICS EQUIPMENTS USE JUSTIFICATION ]
To keep a correct dosage to the crusher input.
By mean of this control, we try to obtain the maximum efficiency of the crusher motor.
The VSD allows controlling the speed to control in this way the production process.

18. Quarries CRITERIA OF USE FOR POWER ELECTRONICS EQUIPMENTS
PRIMARY – ACTUATORS OF THE CRUSHER
Primary crushers are classified according to:
JAW CRUSHER: Variable Speed Drives (power around 340HP approximately)
BARS ROTOR CRUSHER
Recommended equipments:
SD700 Series
[ POWER ELECTRONICS EQUIPMENTS USE JUSTIFICATION ]
The VSD is used as softstarter. Changing the speed it is possible to modify the size of the crushed stones. If the speed is increased up, the gravel size is smaller. If the speed is decreased, then the gravel size increases.
This avoid the grid changing each time a different gravel size is required. If we consider that each grid changing means around 1 hour, we are talking about a considerable saving in production costs.
When the crusher should start with load normally appears problem due to the high resistant torque, but the drive can perfectly control this situation by setting the starting parameters. Power supply lost means no additional problems then.

19. Quarries CRITERIA OF USE FOR POWER ELECTRONICS EQUIPMENTS
PRIMARY – ACTUATORS OF THE CRUSHER
Primary crushers are classified according to:
JAW CRUSHER: Variable Speed Drives (power around 340HP approximately)
BARS ROTOR CRUSHER
Recommended equipments:
SD700 Series
[ POWER ELECTRONICS EQUIPMENTS USE JUSTIFICATION ]
Additionally is possible to prevent blocking problems, since it is possible to crush gradually.
Important savings are getting since the machine do not need to be download due to a stone blocking (times higher than 1 working day).
Damage for the workers that should realize the un-blocking is avoided.

20. Quarries CRITERIA OF USE FOR POWER ELECTRONICS EQUIPMENTS
SECONDARY – ACTUATORS FOR VIBRATING MACHINE
SECONDARY VIBRATING MACHINES: Variable Speed Drives
Motor power is around 75HP approximately
Recommended equipments:
SD700 Series – Frame 5.
SD450 Series – Frame 7.
[ POWER ELECTRONICS EQUIPMENTS USE JUSTIFICATION ]
The objective is to control the material arriving to the mills, in order to not saturate them.
Production optimizing in order to get the mills operating at maximum efficiency but avoiding breakings.

21. Quarries CRITERIA OF USE FOR POWER ELECTRONICS EQUIPMENTS
ACTUATOR FOR GENERAL TRANSPORT BANDS
TRANSPORT BANDS: Variable Speed Drives
Motor power is around 10 – 30HP approximately
Recommended equipments:
SD700 Series.
SD450 Series.
[ POWER ELECTRONICS EQUIPMENTS USE JUSTIFICATION ]
The objective is to control the material arriving to the stocked bins to keep the level under control. To avoid start and stop.
In some cases, there are open bins where the level is visually controlled. In those cases softstarters are commonly used, so V2 and V5 series use is recommended according to different power.

22. Quarries CRITERIA OF USE FOR POWER ELECTRONICS EQUIPMENTS
ACTUATORS FOR VIBRATING MACHINES IN SECOND AND THIRD STAGES
SECOND AND THIRD STAGES VIBRATING MACHINES: Variable Speed Drives
Motor power is around 15 – 20HP and 2 – 10HP approximately.
Recommended equipments:
SD700 Series (small power).
SD450 Series (small power).
SD250 Series.
[ POWER ELECTRONICS EQUIPMENTS USE JUSTIFICATION ]
The objective is to control the material arriving to the mills, in order to not saturate them.
Production optimizing in order to get the mills operating at maximum efficiency but avoiding breakings.

23. Quarries CRITERIA OF USE FOR POWER ELECTRONICS EQUIPMENTS
ACTUATORS FOR SECONDARY MILLS
SECONDARY MILLS: Variable Speed Drives
Power are around 300 – 350HP approximately.
Recommended equipments:
SD700 Series (small power).
[ POWER ELECTRONICS EQUIPMENTS USE JUSTIFICATION ]
To modify the speed to control the granulometry.
Production optimizing because the grids changing does not exist any longer and the lines must not be stopped.
The starting is controlled in the same way as described for the primary crusher.

24. Quarries CRITERIA OF USE FOR POWER ELECTRONICS EQUIPMENTS
ACTUATORS FOR SANDER MILLS
SANDER MILLS: Variable Speed Drives
Motor power is around 75 – 200HP approximately
Recommended equipments:
SD700 Series (small power).
SD450 Series.
[ POWER ELECTRONICS EQUIPMENTS USE JUSTIFICATION ]
To modify the speed to control the granulometry.
Production optimizing because the grids changing does not exist any longer and the lines must not be stopped.
The starting is controlled in the same way as described for primary crusher.
This mills are hammer mills, so that it is possible to make them operate in reverse mode to avoid and prevent the wearing of the hammers (instead of crushing using only one face, it will be possible to crush using both faces of the hammers – maintenance saving).
Note: Some manufactures are: COFANCO, MAGOTEAUX, LARON.

25. Quarries PROCESS DESCRIPTION
COMPLETE LINE: ACTUATORS SUMMARY
SD700 SERIES - FRAME 4
SD450 SERIES - FRAME 7
SD700 SERIES - FRAMES 6 AND 7
SD700 SERIES
SD450 SERIES
SD700 SERIES - FRAME 5
SD450 SERIES - FRAME 7
SD700 SERIES
SD450 SERIES
SD250 SERIES
SD700 SERIES
SD700 SERIES
SD450 SERIES

26. Thanks for your attention
Presentation
QUARRIES: Process description
Realized
Pilar Navarro
Organized
Marketing Department
©2006 Power Electronics, S.L.