Pumps and power packs

Learning Outcomes

Look at Pumps:Type,Application,Choice,Operation.

Look at Hydraulic power packs:Type,Application,Choice,Operation.

Pump TypesRecovery capability.

Limitations with different pumps and maintenance required.

Common types: Centrifugal pumps, Diaphragm pumps.

Pump TypesPumps

Positive Displacement

Rotary

Flexible Impeller

Progressing Cavity

Peristaltic

VaneRoller

Gear

Lobe

Screw

Reciprocating

Piston

Diaphragm

Plunger

Kinetic

Turbine

Centrifugal

Positive Displacement Pumps

Liquid is allowed to flow into the pump as the cavity on the suction side expands and the liquid is forced out of the discharge as the cavity collapses.

This principle applies to all types of positive displacement pumps.

Lobe, Gear, Diaphragm, Screw, Vane, Peristaltic etc.

Lobe pumpLobe pumps can handle solids.

A gentle pumping action minimizes product emulsification.

Can operate dry for brief periods of time.

Can handle viscous products.

Screw pumpWCMRC use hydraulic drive screw pumps.

Typical is the Desmi opposite.

This can generate 10 bar discharge pressure.

Max. capacity 30 m³/h.

80 liters per minute @ 210 bar max.

Centrifugal PumpLiquid enters the pump at the center of a rotating impeller and gains energy as it moves to the outer diameter of the impeller. 

Liquid is forced out of the pump by the energy it obtains from the rotating impeller. 

Transfer large volumes of liquid.

Efficiency and flow decrease rapidly as pressure and/or viscosity increases.

Gear pumpsFor each revolution of an internal gear pump, (below) the gears have a fairly long time to come out of mesh allowing the spaces between gear teeth to completely fill and not cavitate.

External gear pumps (below) come in single or double configurations.Handle viscous and watery-type liquids.Reduced speeds with high-viscosity liquids results in greater efficiency. Two gears come into and out of mesh to produce flow. Uses two identical gears rotating against each other.

Peristaltic PumpA vacuum is created by the rollers compressing the hose and moving along

Liquid is drawn into vacuumRollers capture liquid between them and move liquid towards discharge 

Vane PumpsRotating eccentric cam principle

Not suitable for high viscosity productsUsed to move light products

FuelCrudeWaterdispersant

Diaphragm PumpUsing a diaphragm to push and pull the product through a chamber.Typical example at OSRL is the spate pump 75C.Capable of moving up to 30m3/hr.

Power Pack safety precautions

Know the limits of the equipment you connect.

Operate the power pack safely.

Use the correct PPE.

Familiarisation of operation.

HydraulicsUsing fluid movement to make things work.

Creating a pressure and flow to control hydraulic equipment.

Simple hydraulic circuitPump is driven by an engine in our power packs.

Flow and pressure can be controlled separately on most systems.

Direction is controlled by changing the flow.

Pressure relief systems

Other power packsMPPP:

34.7kW Lister air cooled engine.

80lpm@160bar on two circuits.

Combined 160lpm@90bar.

Aux circuit capable of 42lpm@160bar.

SAME PP:50kW SAME Air Cooled Engine.

160lpm@200bar max.

Load sensing circuits.

Air compressor.

Electric supply.

Integral airfan.

Other power packsGT185

Air cooled Lister TL3-12 engine producing .

30.6 Kw @ 2,500 RPM.

The maximum output of the hydraulic pump is 140 bar, 80 L/min. max.

Desmi 250Engine: Lister HR3. 34KW @ 2200 RPM, hydraulic start. 210 bar@140lpm.

Hydraulic power packsRemember some equipment requires more power than others.

Don’t just open a valve – Think first.

Make sure you know what you are connecting/operating

Ro-Boom Reel – approx 15lpm, Dop250 pump – 200lpm.

Use the correct circuit.

Power Pack safety precautionsDo you know how to turn it off?

Know the limits of the equipment you connect.

Operate the power pack safely.

Be aware of the pressures involved.

Use the correct PPE.

Use the correct offloading methods and equipment.

Read and follow the OWI.

The dangers of oil injection through the skin.

Caution Next Slides are a bit gruesome!

Hydraulic injectionHydraulic fluid in use was Mineral OilPressure of liquid: 630 Bar (~9510 psi)Equipment in use: scissor cutters used at Road Traffic Collisions to release vehicle occupantsLocation of accident: Fire Service Training GroundRisk assessments were in place and full PPE was worn

What happened nextMineral oil had already started to eat away fatty tissue in hand and began travelling up arm

5 operations to cut away oil depositsWound could not be sutured due to tissue damage so it was gradually closed over weeks