Pumps, Fans, and Compressors
By:
Lauryn Emmitte
William Foy
David Harris
Bryce Machleit
Marissa Malinoski
Samantha Mero
Micah Thoms
Morgan Williams
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http://www.greenheck.com/products/detail/18
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http://www.propellerpumps.in/pages/products/axial-flow-pump/
http://www.cofimco.com/en/the-company/axial-fans-application-field.html
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http://www.hartzellairmovement.com/products/process-ventilation-equipment/vaneaxial-fans.html
http://www.cti.org/whatis/coolingtowerdetail.shtml
http://en.wikipedia.org/wiki/Ceiling_fan
http://en.wikipedia.org/wiki/Industrial_fan
http://en.wikipedia.org/wiki/Radiator_%28engine_cooling%29
http://www.doityourself.com/stry/ceiling-fans-how-do-they-work#b#ixzz3LYEv73bx
http://en.wikipedia.org/wiki/Centrifugal_fan
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http://www.tcf.com/products/radial-bladed-fans/rbr---industrial-radial-blade-fan-paddle-wheel
http://www.processbarron.com/industrial-fans/centrifugal-fans/forward-curved-fans
http://www.tcf.com/products/centrifugal-fans/bc-dw---flat-blade-backward-inclined-centrifugal-fan-dwdi
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http://petrowiki.org/Rotary_positive_displacement_compressors
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http://www.awcompressor.com/rotary-screw-vs-reciprocating-compressor.html
Reciprocating Compressors
Axial and Centrifugal Fans
Centrifugal Compressors
Blow Dryer
Leaf Blowers
- A blow dryer or hair dryer is a household device designed to blow cool or hot air over damp hair, in order to dry hair quicker than what a towel can do.
- A blow dryer uses a forward curved blade.
- Forward-curved blades curve in the direction of the fan wheel's rotation. Forward-curved blades are for high flow, low pressure applications.
- A leaf blower is a gardening tool that propels air out of a nozzle to move yard debris such as leaves.
- This type of fan is called a Radial Blade Fan.
- While the efficiency of this fan is usually low, it is designed to withstand high speeds, low volumes, and high pressures, making it great for pneumatic conveyances.
Centrifugal/Radial Fans
Air Conditioning System
- Air conditioners use refrigeration to chill indoor air and a fan is used to move the air around the home.
- The fan that is used is a Backward Inclined Fan.
- The Backward Inclined fans have simple flat blades, backwardly inclined to match the velocity pattern of the air passing through the fan wheel for high-efficiency operation. These fans are typically used in high-volume, relatively low-pressure, clean air applications.
- Unlike an Axial Flow Fan by comparison, a centrifugal or radial flow fan moves air perpendicular to the axis of rotation.
- The terms "blower" and "squirrel cage fan“ are a couple of the names it has been given (because it looks like a hamster wheel).
- Centrifugal fans may be classified into three basic types according to blade configuration, Forward curve, Backward inclined and Radial or straight blade.
Ceiling Fans
- A ceiling fan is a mechanical fan, usually electrically powered, suspended from the ceiling of a room, that uses hub-mounted rotating paddles to circulate air.
- A ceiling fan is a propeller, one of the three types of axial fans.
- The main function of a ceiling fan is to move air around in an enclosed environment. This movement both creates a breeze and mixes the warm air at the top of the room with the air at the bottom to achieve a more balanced temperature.
Car Engine Cooling Fans
- Centrifugal compressors are a type of dynamic compressor.
- The end result of this compression is to move material along pipes and machinery, to inject gas or material into a system, and to meet pressure requirements.
- Centrifugal compressors are machines in which velocity and pressure given to air or gas in a radial direction by one or more impellor diffuser combinations.
- In short a radiator, are heat exchanger used for cool internal combustion engines, mainly in automobiles but also in piston-engined aircraft, railway locomotives, motorcycles, stationary generating plant or any similar use of such an engine.
- This types of fan is called a Tubeaxial fan.
- Tubeaxial fans are machines whose primary function is to provide a large flow of air or gas to various processes of many industries. This is achieved by rotating a number of blades, connected to a hub and shaft, and driven by a motor or turbine.
Cooling Towers
- A cooling tower is a heat rejection device, which extracts waste heat to the atmosphere though the cooling of a water stream to a lower temperature.
- Cooling towers use a type of fan called a vaneaxial fan.
- Vaneaxial fans are highly efficient axial flow fans designed for static pressures up to 12”.
- Common applications for cooling towers are providing cooled water for air-conditioning, manufacturing and electric power generation.
Reciprocating Pumps
Centrifugal Compressors
Simple Flow Diagram
Axial Flow Fans
Applications
- This figure shows a simple centrifugal compressor.
- Air enters the eye of the impeller “D” from the inlet nozzle.
- The impeller rotates. This rotation causes air to be flung towards the ends of the impellers and into the casing due to centripetal forces. This flinging action causes the air to compress.
- The compressed air is pushed along the “A, B, C” path towards the discharge nozzle at “C”.
- Offshore Platforms
- Petroleum fields
- Ships
- Hair dryers
- Vacuum cleaners
Axial Compressors
- An axial flow fan moves air or gas parallel to the axis of rotation. Axial flow fans come in many variations that all have one thing in common.
- Axial flow fans are mainly applied in equipment dedicated to exchange heat through environmental air. Cooling Towers, Air-Cooled Condensers and Air Cooled Heat Exchangers are typical applications.
- Axial flow fans are not as efficient as centrifugal fans.
Diaphragm Reciprocating Compressor
- Similar to the single acting reciprocating compressor
- The compression of gas occurs by the movement of a flexible membrane, instead of an intake element.
- The back and forth movement of the membrane is driven by a rod and a crankshaft mechanism.
Centrifugal Compressors
Pump Classifications
- Direct Acting
- Power
- Crank and Flywheel
- Diaphragm
-Simplex
-Duplex
-Triplex
-Quadruplex
-Quintuplex etc.
- Vane
- Cam and Piston
- Screw
- Lobe
- Shuttle Block
- Volute
- Diffuser
- Regenerative turbine
- Vertical turbine
- Mixed Flow
- Axial Flow (Propeller)
-Single Stage
-Multi Stage
Breakdown
- Direct Acting – Plunger is directly driven by the pump rod
- Power – Drives plunger through reciprocating motion by use of a crank and slider mechanism or camshaft
Hand Pump
- Manually operated pumps
- Utilizes human power and mechanical advantage
- Widely used for a variety of industrial, marine, and irrigation purposes
- Direct acting pump
Radial Piston Pump
PUMPS
- Pistons extend radially around the driveshaft
- Extremely efficient
- High pressure (up to 1000 bar reliably)
- Supplies fluid to hydraulic cylinders
- Basis for hydraulically actuated vehicle suspension
- Power pump
- Pumps move a medium (usually liquid, sometimes gas) by mechanical means
- One of man’s oldest aids, first used to move water from low ground to high ground, and to supply irrigation canals
- Employed in every day use, be it the air pump for your bicycle tires, or the water pump in your car
Double Acting Reciprocating Compressor
Compliments of Archimedes
Reciprocating Pumps
- Useful when a small quantity of liquid is handled and must be delivered at high pressure
- Liquid is trapped inside a stationary chamber or cylinder containing a piston or plunger
- Liquid becomes pressurized in the chamber, and exits through an outlet valve
- Positive displacement (can produce the same flow at a given speed, regardless of discharge pressure) – unlike rotary or centrifugal pumps
- Compared to the Single Acting Reciprocating Compressor the cylinder has inlet and outlet ports at each end of the cylinder.
- As the piston moves forward, liquid is being drawn into the cylinder at the back end while, at the front end, liquid is being discharged.
Breakdown
- Crank and Flywheel – Plunger is fitted to a flywheel via connecting rod(s) which spins about its axis to create reciprocating motion
- Diaphragm – Utilizes the reciprocating action of a diaphragm and suitable valves on either side to pump a medium
Parts of an Axial Compressor
Axial Piston Pump
- Traps a fixed amount of liquid and forces it into a discharge valve
- Number of cylinders (usually odd) arranged circularly
- Can be used as a hydraulic motor, or automotive air conditioning compressor
- Power pump
- There are four main parts of an axial compressor: the Inlet Guide Vane (IGV), rotors, stators, and Exit Guide Vane (EGV).
- The diagram below shows the velocity, pressure, and temperature change throught the compressor.
Single Acting Reciprocating Compressor
- Only one side of the piston is used to compress air
- Gas is drawn into the cylinder through one or more, open intake valves on the pistons down stroke. It is then compressed on the upstroke, with all valves closed and at a certain pressure; the exhaust valve will open and release the compressed air.
Axial Compressor
- An axial compressor is a system which compresses a gas as it travels through a single or multistage process.
- Due to its low pressure increases over each stage, high efficiencies can be obtained.
Reciprocating Compressors
Positive Displacement
- They are typically low-speed devices that are direct, or belt driven by an electric motor and may or may not have a variable speed
- Create pressure up to 5000 atm
- Isentropic efficiency of about 80%
- low mechanical efficiency.
Four Principal Types of Compressors
Blade Nomenclature
- Reciprocating Compressors: Positive displacement
- Rotary Compressors: Positive displacement
- Centrifugal Compressors: Dynamic (radial flow)
- Axial Compressors: Dynamic (axial flow)
Compressors
- Airfoils are both concave which is the pressure side of the blade, and convex which is the suction side of the blade.
- The angle of attack in which the air deflects the airfoils, is what allows for the pressure and velocity to change.
Rotary Compressors
- Compressors function to increase the pressure of the air to provide conditions favorable for combustion and expansion of the hot gases through a turbine
- Can be: dynamic (continuous flow)
positive displacement (intermittent flow, increase pressure by decreasing volume)
Centrifugal Pumps
- Rotary compressors are produced in sizes that range from 10 cubic feet per minute to several thousand CFM.
- Rotary compressors are typically used in applications requiring more airflow than is produced by small reciprocating compressors but less than is produced by centrifugal compressors.
Scroll Compressor
This uses two interlocking scrolls to compress a gas. These scrolls come in many different shapes such as the Archimedean Spiral, etc. Generally, one of the scrolls is fixed, while the other orbits eccentrically without rotating. The gas is then trapped and compressed between the scrolls.
Liquid Ring compressor
Compresses gas by rotating an impeller located eccentrically within a cylindrical casing. Liquid (usually water) is fed into the compressor and by centrifugal acceleration, forms a moving cylindrical ring against the inside of the casing. This liquid ring creates a series of seals in the space between the impeller vanes, which form compression chambers. A gas is drawn into the pump through an inlet valve and is trapped in the compression chambers formed by the impeller and the liquid ring. This in turn, compresses the gas by a reduction of volume in the casing.
Rotary Pumps
Rotary Lobe
Pressurized gas using two inter-locking gear-type rotors called impellers or blowers. One lobe is driven by an external power source while the lobe is driven by a pair of equal ratio gears. Both lobes rotate at same speed but in opposite directions. As the rotors rotate, air is drawn into inlet side of the cylinder and forced out of the outlet side against the system pressure. With each revolution, a certain volume is displaced.
- Instead of using an impeller to move a medium, rotary pumps use rotating vane, screw, or gear systems in order to trap the medium on the suction side and then force it out with pressure out the discharge side of the casing
- Rotary pumps work very similar to a rotary or Wankel engine
- These engines and pumps are most known for their efficiency, but rotary pumps are limited by there size and need for constant lubrication
Helical Screw
Contains two helical screws that compress a gas, coming from the inlet, by reducing the volume of the gap between the screws as it flows to the outlet. Generally small and compact and have variable speed.
Centrifugal Pumps
- Centrifugal pumps are used to induce flow or create pressure on a medium (water, oil, air, etc.) using centripetal force.
- An impeller is at the heart of these pumps; it is mounted on a shaft which is connected to the motor and can rotate at high RPM’s.
- The medium is pulled into the inlet by a low pressure drop in the “eye” or center of the pump casting, then slung down the impellers to the pumps outer housing and out the discharge nozzle.
- This type of pump was believed to be invented in the late 17th century by Denis Papin, however his impellers were straight veined and the curved more efficient impellers were created by British inventor John Appold in 1851.
- Typically used in industrial applications such as construction sites, that need a larger air-flow with a lower pressure. They are generally easy to maintain and operate.
- There are 5 subcategories of rotary compressors.
- Sliding Vane
- Liquid Ring
- Rotary Lobe
- Helical Screw
- Scroll
Sliding Vane Compressor
A slotted cylinder is fitted with nonmetallic vanes and placed eccentric inside a tube. As the slotted cylinder is turned, the vanes slide along the inner wall of the tube forming regions of changing volume.
Axial (CF) Flow Pumps
- An axial flow pump has a propeller-type of impeller running in a casing. The pressure in an Axial Flow Pump is developed by the flow of liquid over the blades of the impeller.
Volute/Diffuser (CF) Pumps
Vertical (CF) Turbine Pumps
Regenerative (CF) Turbine Pumps
- Volute pumps do not require inlet and outlet check valves.
- Diffuser pumps are similar to Volute pumps, except they have a set of fixed veins, which minimizes turbulence
- The name “Volute” was inspired by the resemblance of a scroll-like fossil called a volute
Rotary Compressors are a type of positive displacement compressor.
- Vertical turbine pumps or submersible waterwell pumps work when water enters the bottom of the pump, or suction bell
- The motor and shaft windings are located right below the suction bell supplying electric power
- The motor gets hot while running and is cooled by the 72.6 degrees ̊F ground water that rushes past it
- From the suction bell the water moves into the first stage impeller, which raises the water’s velocity.
- The water then enters the diffuser bowl which directs the fluid into the next impeller located immediately above the bowl
- This process continues through all of the stages of the pump.
- Regenerative Turbine Pumps work like Volute/diffuser pumps
- They have a double row of veins cut in the impellers rim
- Low capacity but high head type, which means they have a huge efficiency for their volume
- The medium is only in the impellers for one rotation
Mixed Flow Fans, Cross Flow Fans, and the Fan Laws
Mixed Flow Fans
- The air flows in both axial and radial direction relative to the shaft
- Although they develop higher pressures than axial fans, their wheels resemble axial fans
- Quieter than axial fans
- Usage: they are ideal for variable resistance applications and cooling air in small enclosures
- Filters
- Computers
- Electrical equipment
- Supply, exhaust, or return installations
Fan Curves
- Fan curves demonstrate the relationship between pressure generated at various air quantities and the quantity of air that a fan will deliver
Cross Flow Fans
- In a cross flow fan, the air flows in an inward direction and then in an outward radial direction.
- The air enters through an elongated propeller
- As the wheel turns, the blades compress the air
- The air is then discharged out of a volute-like chamber
- It is compact in size, has high pressure capabilities, and low sound emission
- They keep components of a machine from overheating by producing an even laminar airflow
Flow Fans
Fan Law #1
The very first fan law states that the fan air flow rate is directly proportional to the rotational speed of the fan.
CFM2 = (RPM2 / RPM1) x CFM1
Fan Law #2
- What is a flow fan?
- Flow fans are designed to save the user cost, both in terms of energy consumption and a long trouble-free life.
- 2 Types:
- Mixed flow fans
- Cross-flow fans
The second fan law states that pressure output, whether it be static, velocity, or total, is directly proportional to the square of the rotational speed of the fan.
SP1 = (RPM2 / RPM1)2 x SP1
Fan Law #3
The third and final fan law states that the brake horsepower required to power a fan is proportional to the cube of its rotary speed.
BHP1 = (RPM2 / RPM1)3 x BHP1
Performance Tables
- An important reason to be able to read the tables relates to the case that there might need to be conversions for fans operating in non-standard conditions
- This standard is dry air at sea level, at 70 degrees Fahrenheit, and with a density of 0.075 lb/ft3
- When a fan is not in standard conditions, it must first be converted in order to read the performance tables
- After conversion, the proper performance tables can be used