compressor handbook principles and practice

[...]... (controllers, valves, pressure and temperature transmitters, etc ) available and 6 Compressor Handbook: Principles and Practice which are most suitable in controlling surge Destructive modes of other compressors are also addressed A few algorithms are presented, primarily in Chapters 4 and 7, to help demonstrate interactions of pressure, temperature and quantify results, but their understanding is not essential... speed and flow, the angle of attack relative to the blades is optimum 18 Compressor Handbook: Principles and Practice Figure 3-4 Compression System Curve Figure 3-5 Compressor Performance Curve and the compressor operates at peek efficiency If flow is reduced at a constant speed, the angle of attack increases until the compressor airfoil goes into stall As flow is increased at a constant speed the compressor. .. the differential pressure and density, and referring to feet of head 20 Compressor Handbook: Principles and Practice Figure 3-6 Velocity Diagrams for an Axial Flow Compressor µ ∆P Head = —— x ∆C = —— gC ρ (3-2) where ∆P/ρ is the pressure rise across the stage and head is the pressure rise of the stage measured in feet head of the fluid flowing The standard equation for compressor head is given below... the turbo-expander, the axial compressor, and the axial turbine (Figure 1-5 and 1-6) In 1808 John Dumball envisioned a multi-stage axial compressor Unfortunately his idea consisted only of moving blades without stationary airfoils to turn the flow into each succeeding stage.4,5,6 Not until 1872 did Dr Franz Stolze combine the ideas of John Bar- 4 Compressor Handbook: Principles and Practice Figure... intentionally blank.” Chapter 3 Compressor Types DYNAMIC COMPRESSORS Two types of dynamic compressors are in use today—they are the axial compressor and the centrifugal compressor The axial compressor is used primarily for medium and high horsepower applications, while the centrifugal compressor is utilized in low horsepower applications Both the axial and centrifugal compressors are limited in their... of Alexandria (also noted for describing the principles of expanding steam to convert steam power to shaft power) 1 2 Compressor Handbook: Principles and Practice The water organ consisted of a water pump, a chamber partly filled with air and water, a row of pipes on top (organ pipes) of various diameters and lengths plus connecting tubing and valves By pumping water into the water/air chamber the air... provides a practical introduction to dynamic and positive displacement compressors, including compressor performance, operation and problem awareness In reading this book the reader will learn what is needed to select, operate and troubleshoot compressors and to communicate with peers, sales personnel and manufacturers in the field of dynamic and positive displacement compressor applications In addition to... compressor represents an equal and opposite rearward force on the gas—causing an increase in pressure; 2 a component in the plane of rotation represents the torque required to drive the compressor 15 16 Compressor Handbook: Principles and Practice Figure 3-1 Forces Acting on the Blades From the aerodynamic point of view there are two limiting factors to the successful operation of the compressor They are the... motion machines are not possible ∆s ≥ 0 (2-17) 12 Compressor Handbook: Principles and Practice Horse Power Calculations The brake horsepower (BHP) required to drive the compressor can be determined by calculating the gas horsepower (GHP) and then correcting for mechanical losses Hd × Wg GHP = ——————— 60 × 33,000 × Ep Where BHP Hd Wg E p = = = = and SCFD × MW Wg = ——————— 24 × 379.5 (2-18) Brake... compressibility 10 Compressor Handbook: Principles and Practice factor “Z.” Therefore, the ideal gas equation becomes and Pv = ZRT (2-7) PQ = ZWRT (2-8) Compressor performance is generally shown as pressure ratio plotted against flow (Note: it is more accurate to use head instead of pressure ratio, because head takes into account the compressibility factor of the gas, molecular weight, temperature, and the .