Bitumen and pipeline enamel:
Albany have extensive experience in the pumping of Bitumen with heated pumps. The heating is by hot oil, electricity or steam.
A special leaflet (b1) for this application is available.
Immersed bitumen pumps for use in horizontal or vertical tanks are supplied. Liquid sulphur, wax and Rosin pumps follow similar principles. |
Branches:
The pump inlet and outlet connections threaded or flanged. |
Cavitation:
The formation of bubbles of vapour in the fluid due to locally reduced pressure below the liquid vapour pressure. |
Centrifugal Pumps:
Depend on the rotation of an impeller at speed and the action of the centrifugal force for their effect. |
Corrosive Materials:
Albany pumps have been used for concentrated acids, caustics and chlorides for many years. Vertical, immersed or horizontal designs are available for most applications. |
Flammable Materials:
Solvent are present in many pump applications in paint, ink and chemicals. These often have a low flashpoint. Safety standards are becoming stricter, so it is advisable to anticipate problems and install a suitable leak proof pump and flameproof motor, even for materials not yet covered by legislation. Air motors are available.
Vertical immersed centrifugal pumps are often used with sealed top flanges for this service. |
Flooded Suction:
The pump is positioned such that liquid will flow freely into the pump due to gravity or supply from a pressurised supply |
Gear Pumps:
The Albany gear pump is a type of positive displacement pump. |
Gland:
The point where the shaft driving the pump is sealed to keep in the pumping pressure or keep out ingress of air. Glands can either be packed or sealed by mechanical face seals in rotary pump according to application. |
Head:
The height or pressure to which the pump raises the fluid, measured at the delivery branch. |
Metering Pumps:
Variable output Albany gear pumps are supplied for metering viscous materials. The principle is to count the number of revolutions of the pump for batching purposes or to automatically vary the speed of the pump in continuous process. |
NPSH (available):
Important where the likelihood of cavitation occurs. It is the difference between the pressure at the pump suction and vapour pressure of the liquid at the pumping temperature, expressed in metres or feet. |
Pelton Wheel:
A device for converting the energy in a jet of liquid into rotational motion. Albany supply foam injection pumps for fire fighting which are powered by Pelton wheels. These represent the ultimate in safe solutions for dangerous atmospheres. |
Pressure psig:
Is the pressure measured on the pressure gauge, eg. at 0 p.s.i.g. the pressure is atmospheric, approximately 14.7 p.s.i abs (1 barA).
Albany gear pumps are in use on resins at up to 400 psig pressure (35 bars). |
Relief Valve:
A valve which opens to allow the output of the pump to return to the inlet in the event that pressure exceeds a set level. This might be due to a blockage in the pipe such as a valve being turned off. The relief valve protects the pump and motor from damage. Many Albany Pumps can be supplied with built in relief valves. |
Rotary Positive Displacement Pumps:
Depend on the creation of vacuum by the rotation of elements which seal the pressure side of the pump from the suction side displacing a fixed volume of liquid during each revolution of the driving member. |
Screw Pump:
A screw pump is a large positive displacement pump with good vapour handling and a smooth relatively pulse free output. Albany make our own range of screw pumps and also supply pumps to the designs developed by Stothert and Pitt. |
Suction Lift:
The distance the liquid level is below the pump suction branch, expressed in feet or metres of liquid. |
Viscosity:
The resistance of a liquid to flow. Kinematic viscosity is used by pump makers, expressed in centistokes (c/S).
The viscosity of the material involved is important as it affects both the size and speed of the pump. This is particularly relevant where for some reason or other the material cannot be heated. Slower running geared pumps are resorted to with possibly a jacketed pump (oil or steam). These points apply in particular to such materials as bitumen, alkyd resins non viscous solutions or 100° solvent free. Some general points are given herewith, clearly they are not exhaustive, but are a good guide. - The suction should be flooded. The higher viscosity, the greater the head needed to force the liquid into the pump and overcome pipe friction. (Albany pumps will also draw viscous materials from underground tanks. Albany need to be advised of this at the enquiry stage).
- The suction pipe should be as large a diameter and as short as possible.
- Pumps can be supplied with extra large suction branches to cater for high viscosity and can be mounted with suction branch vertical for feeding from a hopper.
- Filters should be of as coarse a mesh as possible and only be used on the suction side of the pump if absolutely necessary. It is advantageous to fit such filters on the delivery side of the pump enabling a higher pressure drop across the filter to be accommodated.
- Power- provided the pump is run at a sufficiently low speed, which should decreased as the viscosity increases, no increase in power requirements will be observed over that needed for liquids of normal viscosity.
- Relief valves can be supplied to prevent the motor overloading should the discharge pipe become blocked.
|
