A positive-displacement pump with vanes mounted on a rotor spinning inside a hollow is known as a rotary vane pump. These vanes can be variable in length and/or tension in some circumstances to keep in touch with the walls while the pump spins. In its most basic form, a rotary vane pump is a type of pump that uses air compression inside the pump chamber to provide suction for the removal of air molecules from a vessel or region.
The Rotary vane pump operates on the basis of positive displacement pumping. A rotor is positioned eccentrically inside a cylindrical housing or stator in this configuration. The blades inside the rotor rotate in and out due to centrifugal force as they follow the inner surface of the housing.
Rotary-vane pumps can handle lubricating and other low-viscosity fluids in low to medium quantities at moderate pressures, as well as relatively viscous fluids in some applications. The design has typically been utilized in automotive applications and is sometimes referred to as carbonator pumps because of its use in manufacturing carbonated soft beverages. They can create a strong vacuum and are frequently used to transport LNG and various chemicals.
Their numerous permutations, as well as their operation and popular applications, are discussed below. A rotor is positioned within a stator or housing in rotary vane vacuum pumps. The rotor’s blades move farther apart as a result of the centrifugal force, capturing the incoming air and expanding it in the chamber to produce a vacuum. While rotary vane vacuum pumps are available in a number of sizes and configurations, there are fundamentally two types lubricated and dry operating.
The Rotary Vane Pump is an oil-sealed vacuum pump, which means the evacuation chamber is filled with specially formulated mineral oil that serves as a sealant and lubricant between the vanes and the vacuum pump chamber housing. One-stage and two-stage Rotary Vane Pumps are available. Volumetric flow rates typically range from 2 to 20 cubic feet per minute.
A Rotary Vane Pump can produce a vacuum of roughly 1 milli Torr, which is why it is used as a roughing pump in a variety of vacuum applications. The housing, eccentrically placed rotor vanes that move radially under centrifugal and resilient forces, and the intake and outlet make up the rotary vane pump system. If one is available, the intake valve is intended as a vacuum safety valve that remains open at all times during operation. The stator, rotor, and vanes enclose the working chamber, which is placed inside the housing. The rotor and vanes, which are positioned eccentrically, split the working chamber into two independent compartments with varying volumes. Gas pours into the expanding suction chamber as the rotor rotates until the second vane seals it off. The compressed gas is subsequently released through the exit valve, which opens against air pressure.
WORKING OF ROTARY VANE PUMP
The functioning of a rotary vane pump is based on the idea of increasing pressure by reducing volume. The blades revolve inside the cylinder, and there is almost no wear due to a thin coating of oil within the cylinder. Oil lubrication is created by differential pressure within the housing. Pipes between the housings aid in this endeavour. Inside the housing, the rotor is eccentrically positioned.
Centrifugal force presses the blades against the housing wall, resulting in three chambers that collect the air. Air enters the compressor chamber through the suction flange when the first chamber opens. The following blade shuts the first chamber and opens the second as the rotor rotates.
This is the position at which the blades are the farthest apart, allowing for the most airflow. In Rotary vane pump designs, outlet valves are utilized to prevent air backflow once maximum pressure is reached or the pump is turned off. Oil and gas are separated from one another in the oil separator housing by a procedure. The oil is sent to the oil sump. This technique may remove 95-98 percent of the oil content from the air. To eliminate any leftover oil particles, the remaining oil and gas combination is passed through fine filter components. Through a float valve, these particles will be reintroduced into the pump’s oil circuit. The gas may now be expelled by the air exit or through pipes or hoses because it is practically oil-free.
In the Rotary van pump, The gas enters the suction chamber and is compressed immediately by the rotor’s vane. As the rotor spins, the gas molecules are pushed around the pump chamber and out the exhaust, where they are released into the atmosphere. The spring-loaded vanes establish an airtight seal between the rotor and the pump chamber housing. These vanes and rotor housing, on the other hand, are sealed with a specially designed, low vapor pressure oil that serves as a vacuum pump sealant, lubricant, and coolant.
The vacuum pump rotor is powered by numerous different types of drives. The first is a direct drive, which uses a crankshaft and coupling to connect to a spinning power source, usually an electric motor. The Belt Drive pump, which is coupled to the spinning power source through a pulley and belt, is the second drive type. Belt-driven vacuum pumps have a lower working temperature than direct-drive vacuum pumps, ranging from 10 to 20 degrees Celsius.
The rotation speed, the viscosity of the vacuum pump oil, the oil quality, the age of the vacuum pump, the quality of the gas being pumped out, and the quality and type of the vacuum pump all impact the operating temperature of each pump type.
PARTS OF ROTARY VANE PUMP
The rotary vane pump’s casing is the outermost portion. It ensures the safety of the pump’s internal components. It protects the internal components, such as the rotor, shaft, and sliding vanes, from external harm.
Through the input port, the fluid is pulled into the rotary vane pump. It has the same function as a one-way valve.
The inside wall of the rotary vane pump housing has a cam ring mounted on it.
The fluid is discharged through the exit port once the pump has pressurized it. It serves as a one-way valve as well.
The rotor is where the rotary vane pump’s vanes are placed. The primary goal of the vanes is to transform the fluid’s kinetic energy into speed. The form of these vanes is rectangular. Sliding Vanes may be found in the rotor’s slots. The sliding vanes slide within the slots of the sliding vanes.
It is the most crucial component of the rotary vane pump since it is responsible for fluid suction and pressurization. It attaches to the shaft. The shaft revolves, and the rotor rotates with it. It has a number of vanes. The rotor generates a vacuum inside the pump, which causes the pump to suction fluid.
An electric motor is linked to a shaft of the rotary vane pump. This motor rotates the shaft while delivering electricity to it. The rotor is connected to this shaft.
TYPES OF ROTARY VANE PUMP
BALANCED ROTARY VANE PUMP
The elliptical housing of the balanced rotary vane pump. The rotor and the elliptical shell share the same center. There is no offset in this case. The design of these vane pumps is adaptable, and they’re most commonly employed in mobile and industrial applications. Because this pump has two inlets and output, there is no pressure differential between the inlets and outlets. Both intake ports are on opposing ends of the building. In the same way, the outlet ports are on opposing sides.
The input and outlet port assembly balances equal and opposing thrust forces, ensuring that the rotor shaft is not subjected to lateral thrust forces. In many applications, this type of pump has a long service life. The balancing vane pumps have a service life of over 24,000 hours in industrial applications. From the entrance to the exit, the cavity size between the two vanes shrinks. The pump draws fluid in via the input port and discharges it through the output port. The rotor is under a lot of pressure in the exit area, and the forces in the two outlet zones are equal but in different directions. As a result, there is no net load on the shaft’s bearings.
UNBALANCED ROTARY VANE PUMP
The most popular form of rotary vane pump is this one. The lateral push on the pump shaft is caused by the pressure differential between the suction and discharge valves. The bearing life is shortened due to the lateral force on the shaft. Because of the pressure differential between the input and exit valves, this type of vane pump is known as an unbalanced vane pump. The rotor shaft of the balanced vane pump does not have lateral thrust. A cylindrical rotor is positioned on the offset of a circular housing in an unbalanced vane pump.
This signifies that the cylindrical rotor’s center does not line up with the housing’s center. The rotor’s center and the housing’s center are separated by a specified distance. A radial groove in the rotor corresponds to a groove in the driving shaft. The cam ring moves the rotor. By centrifugal force, each radial groove contains a vane that may freely move in and out of the groove. The vanes are built such that when the rotor rotates, they make contact with the cam ring surface. Between the housing and the vane tip, there is no leakage.
VARIABLE DISPLACEMENT ROTARY VANE PUMP
The pocket size may be adjusted using the variable displacement rotary vane pump. The delivery rate varies according to the varying diameters of the pump pocket. The vanes of this pump are not in direct contact with the pump housing. Between the vane and the casing of this rotary vane pump is a ring. The response ring is the name for this ring.
The spring is connected to one end of this ring, and the adjustment screw is connected to the other. The adjustment screws vary the size of the pump pocket. The response ring slides up and down with the rotation of the adjustment screw. The offset between the rotor center and the response ring center changes as the reaction ring travels up and down.
Kiron Hydraulic Needs, in association with Procon Pumps, provides a comprehensive Rotary vane pump system solution. For more than fifty years, Procon Pumps has been producing high-quality, trustworthy pumps. Their precise, hand-crafted pumps have set the standard for performance and value in the industries they serve since 1950.