Pumps & Compressors

Leveling the base Stainless pump click twice to inlarge pictures fish-deversion-pump-install-046.jpg click to inlarge Lay out click to inlage Pooring grout setting the pump click to inlarge Stoning the feet Industrial contractors Harelson Mechanical                    long day Leveling the base Millwrights at work fish-deversion-pump-install-201.jpg

HARELSON MECHANICAL Excels in pumps and Compressors
Reciprocating Compressors

Crank Deflection, Cross heads, Connecting rods, Valves, Packing box,Piston end gap.

Pumps

 

Boiler Feed pumps, Slurry Quench Pumps, Main Air Blower, FD Fans/ ID Fans

Alignment

Pipe strain, Magnetic Center

As Found & As Left, Hot & Cold alignment, Soft foot.

TWIST & TILT BEARING Readings.

Gempo valves/Over speed trip. If you need assistance in your shut down Give us a call, 916-386-2586

 

 


 


INDUSTRIAL LIFE, IS THE ONLY LIFE WE KNOW.

Pump

 

 

 

A two-lobe pump (multiple rotor, positive displacement type)

Pumps fall into two major groups: rotodynamic pumps and positive displacement pumps. Their names describe the method for moving a fluid. Rotodynamic pumps are based on bladed impellers which rotate within the fluid to impart a tangential acceleration to the fluid and a consequent increase in the energy of the fluid. The purpose of the pump is to convert this energy into pressure energy of the fluid to be used in the associated piping system.

Positive displacement pumps

 

 

 


 


Mechanism of a scroll pump

A positive displacement pump causes a liquid or gas to move by trapping a fixed amount of fluid or gas and then forcing (displacing) that trapped volume into the discharge pipe. A positive displacement pump can be further classified as either a rotary-type (for example the rotary vane) or lobe pump similar to oil pumps used in car engines. Another common type is the Wendelkolben pump or the helical twisted Roots pump. The low pulsation rate and gentle performance of this Roots-type positive displacement pump is achieved due to a combination of its two 90° helical twisted rotors, and a triangular shaped sealing line configuration, both at the point of suction and at the point of discharge. This design produces a continuous and non-vorticuless flow with equal volume. High capacity industrial “air compressors” have been designed to employ this principle as well as most “superchargers” used on internal combustion engines.

Reciprocating-type pumps use a piston and cylinder arrangement with suction and discharge valves integrated into the pump. Pumps in this category range from having “simplex” one cylinder, to in some cases “quad” four cylinders or more. Most reciprocating-type pumps are “duplex” (two) or “triplex” (three) cylinder. Furthermore, they are either “single acting” independent suction and discharge strokes or “double acting” suction and discharge in both directions. The pumps can be powered by air, steam or through a belt drive from an engine or motor. This type of pump was used extensively in the early days of steam propulsion (19th century) as boiler feed water pumps. Though still used today, reciprocating pumps are typically used for pumping highly viscous fluids including concrete and heavy oils.

Another modern application of positive displacement pumps are compressed air-powered double-diaphragm pumps, commonly called SandPiper or Wilden Pumps after their major manufacturers. They are relatively inexpensive, and are used extensively for pumping water out of bunds, or pumping low volumes of reactants out of storage drums.

Centrifugal Pumps

Centrifugal Pumps are rotodynamic pumps which convert Mechanical energy into Hydraulic energy by centripetal force on the liquid. Typically, a rotating impeller increases the velocity of the fluid. The casing, or volute, of the pump then acts to convert this increased velocity into an increase in pressure. So if the mechanical energy is converted into a pressure head by centripetal force, the pump is classified as centrifugal. Such pumps are found in virtually every industry, and in domestic service in developed countries for washing machines, dishwashers, swimming pools, and water supply.

A wide range of designs are available, with constant and variable speed drives. Horizontal shafts are the most common. Single-stage pumps are usual in the smaller ratings. Pumps with up to 11 stages are in service. A demanding duty is boiler feed, and today’s designs are typically 3 - 4 stage, with speeds of up to 6000 revolutions per minute.

After motors, centrifugal pumps are arguably the most common machine, and they are a significant user of energy. Given design margins, it is not unusual for a pump to be found to be over-sized, having been selected poorly for its intended duty. Running a constant speed pump throttled causes energy waste. A condition monitoring test can detect this condition and help size a smaller impeller, either new, or by machining the initial one, to achieve great energy reduction.

Pumps also wear internally, at a rate varying with the liquid pumped, materials of construction and operating regime. Again, condition monitoring can be applied to detect and quantify the extent and rate of wear and also help decide when overhaul is justified on an energy-saving basis.

Kinetic Pumps

  1. Continuous energy addition
  2. Conversion of added energy to increase in kinetic energy (increase in velocity)
  3. Conversion of increased velocity to increase in pressure
  4. Conversion of Kinetic head to Pressure Head.
  5. Meet all heads like Kinetic , Potential, and Pressure

Positive Displacement

  1. Periodic energy addition
  2. Added energy forces displacement of fluid in an enclosed volume
  3. Fluid displacement results in direct increase in pressure