Air OPerated Pump
An air operated diaphragm pump (AODD) is also known as a membrane pump is a type of positive displacement pump that uses compressed air as a power source. Air operated double diaphragm (AODD) pumps are used in facilities of all sizes, and in a variety of different industries From petrochemical to food and beverage, these pumps are popular and versatile.
Air OPerated Pump
An air operated diaphragm pumps (AODD) Applications
- Oil & Gas
- Paint and Varnish
- Waste treament / Wastewater
- Food Processing
- Sludge / Slurry
- Metal Fabrication
- Agriculture and Manufacturing
The internal mechanisms of a double diaphragm pump can vary subtly between brands, however there is a common working principle applicable to all models.
An air operated double diaphragm pump has two diaphragms. These diaphragms are connected by a shaft in the center section. The diaphragms are working as separation wall between the air and the liquid. The air valve is located In the center section of the diaphragm pump.
The air valve directs the compressed air to the back of diaphragm number one. This way, diaphragm number one moves away from the center section. This diaphragm causes a press stroke moving liquid out of the pump. At the same time diaphragm number two is performing a suction stroke. The air behind diaphragm number two is being pushed out to the atmosphere. Atmospheric pressure pushes the liquid to the suction side. The suction ball valve is being pushed away off its seat. This allows the fluid to flow along the ball valve into the liquid chamber.
When the pressurized diaphragm number one has reached the end of its stroke, the movement of the air is switched from diaphragm number one to the back of diaphragm number two by the air valve. The compressed air pushes diaphragm number two away from the center block. Doing so, diaphragm number one is pulled toward the center block. In pump chamber number two the discharge ball valve is pushed off its seat. In pump chamber number one the opposite occurs. Upon completion of the stroke the air valve leads the air again to the back of diaphragm number one and restarts the cycle.
Centrifugal pumps are the most commonly used kinetic-energy pump. Centrifugal force pushes the liquid outward from the eye of the impeller where it enters the casing. Centrifugal pumps are used to transport fluids by the conversion of rotational kinetic energy to the hydrodynamic energy of the fluid flow. The rotational energy typically comes from an engine or electric motor. The fluid enters the pump impeller along or near to the rotating axis and is accelerated by the impeller, flowing radially outward into a diffuser or volute chamber , from where it exits.
Centrifugal Pumps Applications
- Food and beverage production
- sugar refining
- drainage and irrigation
- air conditioning systems
- wastewater management
- flood protection
Centrifugal Pumps Specification
Flow rate : describes the rate at which the pump can move fluid through the system, typically expressed in gallons per minute. The rated capacity of a pump must be matched to the flow rate required by the application or system.
Pressure : is a measure of the force per unit area of resistance the pump can handle or overcome, expressed in bar or psi (pounds per square inch). As in all centrifugal pumps, the pressure in axial flow pumps varies based on the pumped fluid’s specific gravity. For this reason, head is more commonly used to define pump energy in this way.
Head : is the height above the suction inlet that a pump can lift a fluid. It is a shortcut measurement of system resistance (pressure) which is independent of the fluid’s specific gravity, expressed as a column height of water given in feet or meters.
Net positive suction head : (NPSH) is the difference between the pump’s inlet stagnation pressure head and the vapor pressure head. The required NPSH is an important parameter in preventing pump cavitation.
Output power : also called water horsepower, is the power actually delivered to the fluid by the pump, measured in horsepower.
Input power : also called brake horsepower, is the power that must be supplied to the pump, measured in horsepower (hp).
Efficiency : is the ratio between the input power and output power. It accounts for energy losses in the pump (friction and slip) to describes how much of the input power does useful work.
Normally, a centrifugal pump comprises of a fluid-filled casing. This fluid can be anything, but in most cases water. A component within the casing (impeller) rotates at a fast speed thereby subjecting the fluid to centrifugal force. Because of this force, the fluid goes to the discharge opening.
As the water is discharged, a vacuum is created leading to the formation of atmospheric pressure, which forces more fluid from the casing. Part of the reason this movement is flawless is because the blades on the impeller are curved.
Fluid Movement inside a Centrifugal Pump
The idea of a centrifugal pump is to convert centrifugal force into kinetic energy. The rotation of the impeller gives the liquid at the tip a centrifugal force that is proportional to velocity at the vane tip. As the liquid comes out, it has kinetic energy. This kinetic energy further converts into pressure energy because of the resistances in the discharge nozzle and pump volute.
Positive Displacement Pump
A positive displacement pump makes a fluid move by trapping a fixed amount and forcing (displacing) that trapped volume into the discharge pipe.
Some positive displacement pumps use an expanding cavity on the suction side and a decreasing cavity on the discharge side. Liquid flows into the pump as the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. The volume is constant through each cycle of operation.
The positive displacement pumps can be divided in two main classes
- reciprocating pumps
- rotary pumps
Reciprocating Pumps : Reciprocating Pumps move the fluid using one or more oscillating pistons, plungers, or membranes (diaphragms), while valves restrict fluid motion to the desired direction. In order for suction to take place, the pump must first pull the plunger in an outward motion to decrease pressure in the chamber. Once the plunger pushes back, it will increase the pressure chamber and the inward pressure of the plunger will then open the discharge valve and release the fluid into the delivery pipe at a high velocity.
Rotary Pumps : These pumps move fluid using a rotating mechanism that creates a vacuum that captures and draws in the liquid.
positive displacement pump Applications
- Marine Industry
- Liquids and Compress gas
- Oil production
- Reverse Osmosis
- Pressure Washing
- Concrete and Other Aggregate Applications
- Fuel Transfer
A submersible pump, also called an electric submersible pump. A submersible pump is a pump which has a hermetically sealed motor close-coupled to the pump body. The whole assembly is submerged in the fluid to be pumped. The main advantage of this type of pump is that it prevents pump cavitation, a problem associated with a high elevation difference between pump and the fluid surface. Submersible pumps push fluid to the surface as opposed to jet pumps having to pull fluids. Submersibles are more efficient than jet pumps.
One style of submersible pump
Electric submersible pumps are multistage centrifugal pumps operating in a vertical position. Liquids, accelerated by the impeller, lose their kinetic energy in the diffuser where a conversion of kinetic to pressure energy takes place. This is the main operational mechanism of radial and mixed flow pumps.
The pump shaft is connected to the gas separator or the protector by a mechanical coupling at the bottom of the pump. Fluids enter the pump through an intake screen and are lifted by the pump stages. Other parts include the radial bearings (bushings) distributed along the length of the shaft providing radial support to the pump shaft. An optional thrust bearing takes up part of the axial forces arising in the pump but most of those forces are absorbed by the protector’s thrust bearing.
Submersible Pump Applications
Deep well drilling
Offshore drilling rigs
Mine dewatering and Irrigation systems.
Drum and Barrel Pumps
Drum and barrel pumps include siphon pump, rotary pump, hand pump and piston pump models. All can be helpful in handling lightweight oils and soap solutions typically used in automotive and cleaning applications. A barrel pump can add speed, convenience and control to dispensing low-viscosity fluids, while an air drum pump uses compressed air for helping dispense heavier-weight liquids. Barrel accessories, like a barrel liner, barrel adapter or barrel seal, help minimize slippery spills from leakage and keep workers safe around drum and barrel pump stations.
Drum and Barrel Pumps
Drum Pump applications
- flammable liquids
A gear pump uses the meshing of gears to pump fluid by displacement. They are ideal for transferring high viscosity fluids such as automotive oils, plastics, paint, adhesives, and soaps with a steady and pulseless flow and offer self-priming capabilities. Th
Gear Pump Operation
They operate by creating suction at the inlet with a rotating assembly of two gears –a drive gear and an idler. Pump flow is determined by the size of the cavity (volume) between gear teeth, the amount of slippage (reverse flow), and the speed of rotation (rpm) of the gears.
Gear pumps can be either external or internal and vary in design and operation.
Gear Pump Operation
As the gears rotate they separate on the intake side of the pump, creating a void and suction which is filled by fluid. The fluid is carried by the gears to the discharge side of the pump, where the meshing of the gears displaces the fluid. The mechanical clearances are small— in the order of 10 μm. The tight clearances, along with the speed of rotation, effectively prevent the fluid from leaking backwards.
A dosing pump is a small, positive displacement pump. It is designed to pump a very precise flow rate of a chemical or substance into either a water, steam or gas flow. A dosing pump will deliver this precise flow rate of chemical or other product by a number of different methods but it generally involves drawing a measured amount into a chamber and then injecting this volume of chemical into the pipe or tank being dosed. Dosing pumps are used in a variety of applications from agriculture, industry, manufacturing to medicine.
Dosing pumps have a large range of applications across a number of industries. Generally dosing pumps are set up to inject a product into a water or fluid stream to cause a chemical or physical reaction.
Doosing pump Applications