1. PNEUMATICS Chapter 3 ROTARY COMPRESSORS
RBTC

2. Objectives Classification Vane Compressors – Rotary Screw
Positive Displacement
Dynamic
Vane Compressors –
Rotary Screw
Low Pressure High Volume
Diaphragm
Centrifugal

3. Objectives Continued Axial Flow Selection of Compressor Capacity
System
Compressor
Checking
Accessories
Packaged

4. Introduction There are 2 types of compressors: Positive Displacement
Rotary Compressors with mechanically separated inlet and discharge ports are PD
Include Sliding Vane, dry and wet screw, liquid-ring, impeller (lobe) types
Dynamic
No method of separating inlet and discharge ports
Centrifugal and axial flow

5. Vane Compressors The Sliding vane is a rotary, PD
Compact, less efficient than piston but more efficient than other rotary compressors
Resemble vane pumps but are larger
Consists of a rotor mounted off center in a round casing
The rotor has rectangular slots
Negative pressure draws in suction
Space becomes continuously smaller as it turns
Single vanes max p = 50 psig – 2 stage = 125 psig

6. Compressor Valves

7. COMPRESSOR SKID

8. Compressors

9. THEORY

10. COMPRESSION
Means increasing gas pressure from a low pressure to a high pressure
Most common type – Gas engine driven reciprocal
From 50 to 15,000 HP
Also driven by electricity
Also driven by turbines

11. COMPRESSOR PARTS

12. RECIPROCATING COMPRESSION

13. VALVES

14. INTEGRAL COMPRESSOR

15. CROSSHEAD

16. INTERNALS

17. MOVEMENT

18. VALVES

19. TURBO EXPANDER

20. NGL PLANT – Low Temp – 40°F

21. CENTRIFUGAL COMPRESSORS
Multi stage
Dynamic
Inlet
Impellers vary in size
In the eye
Low suction pressure
Outlet – higher kinetic energy
Impeller housing
150,000 cfm, 150 psi – 3000 to 12,000 rpm
Higher HP Motor required

22. Centrifugal Controling
Throttling