APPLIED FLUID MECHANICS
C3 MKII Multi-Pump Test Rig - Issue 2
The Armfield Multi-pump Test Rig has been designed to demonstrate the operating characteristics (headflow curves and efficiency) of a series of different types of pumps, each having a broadly similar input power.
The rig can accommodate both rotodynamic and positive displacement pumps, and is supplied with the most common example of each type as standard (ie a centrifugal pump and a gear pump). A range of other pump types are available as accessories, (including axial, turbine, flexible impeller, diaphragm and plunger, plus a second centrifugal pump for series/parallel demonstrations). Up to four pumps can be accommodated simultaneously within the rig for use within a single laboratory period, and each can be run without disconnecting any pipework or connections. Further pumps can also be easily interchanged.
This new system benefits from electronic instrumentation, control and data logging using a PC (not supplied) and the use of a sensorless vector drive to accurately determine the torque provided by the drive motors.
As an option, the unit can be fitted with two identical centrifugal pumps to enable simple series/parallel pump configurations to be demonstrated.
- A mobile self-contained Multi-Pump Test Rig, containing all the services and instrumentation for determining the characteristic curves of eight different pumps at different speeds
- For rotodynamic pumps:
> Pressure head vs flow
> Power absorbed vs flow
> Pump efficiency vs flow
- For positive displacement pumps:
> Flow vs pressure head
> Power absorbed vs pressure head
> Volumetric efficiency vs pressure head
- Contains five different pump positions (four active at the same time). Digital readout enables mounting of selected pump
- Centrifugal pump and gear pump supplied as standard
- Axial pump, flexible impeller pump, turbine pump, diaphragm pump, plunger pump and a second centrifugal pump are all available as accessories
- Series/parallel pump demonstrations can be performed with the second centrifugal pump option
- Control valve incorporated upstream of each pump (except axial pump) to demonstrate the effect of suction loss on performance
- A PC (not supplied) is used to set the required speed of the pump(s) on test. A separate mimic diagram for the selected pump(s) on test displays the important measured and calculated variables
- Electronic measurement of flow, pressure head, suction head and motor torque
- Optional volumetric flow measurement system for reciprocating pumps
- Data logging and educational software included
- Determining the performance of different types of pumps at constant speed by producing a set of characteristic curves:
> For rotodynamic pumps:
– Pressure head vs flow
– Power absorbed vs flow
– Pump efficiency vs flow
> For positive displacement pumps:
– Flow vs pressure head
– Power absorbed vs pressure head
– Volumetric efficiency vs pressure head
- Determining the effect of speed on the performance of pumps
- Understanding the difference between rotodynamic pumps and positive displacement pumps
- Understanding the effect of system resistance
- Investigating the effect of suction losses on a centrifugal pump
- Demonstration of the effect of running two centrifugal pumps in series and parallel (requires C3-MkII-20SP)
- Understanding the characteristics of a reciprocating pump (requires C3-MkII-25 or C3-MkII-26 and C3-MKII-40)
The equipment comprises a water reservoir, and five pump positions (four active).
Each pump position uses pipework and sensors optimised to the type of pumps it is intended for.
Positions 1, 2a and 2b are optimised for high flows at low heads, such as the rotodynamic pumps, whereas positions 3 and 4 are suitable for lower flows but higher pressures, as obtained from the positive displacement pumps. Positions 2a and 2b are mutually exclusive as they share the same motor drive.
Switching between any of the four installed active pumps, (or series/parallel configuration) is simple, requiring only isolating valve changes and control panel selection.
Changing over an installed pump for one of the other options is still straightforward, but requires plumbing changes (easy-release fastenings), topping up the tank with water (to replace any lost) and reprogramming some inverter settings. Additional pumps and options can be purchased at any time, and fitted by the user.
A PC (not supplied) is used to set the required speed of the pump(s) on test. A separate mimic diagram for the selected pump(s) on test displays the important measured and calculated variables.
The following table defines which types of pumps are available for each position.
|Position||Instrumented Flow Capability||Instrumented Pressure Capability||Pump Options|
|1||300 l/min||20m||- Centrifugal (C3-MkII-20)
(included as standard)
|2a||300 l/min||20m||- Flexible Impellor (C3-MkII-23) or
- Second Centrifugal (C3-MkII-20SP)
for series/parallel operation
|2b||300 l/min||3.4m||- Axial (C3-MkII-22)|
|3||75 l/min||70m||- Gear (C3-MkII-21)
(included as standard)
|4||75 l/min||70m||- Turbine (C3-MkII-24) or
- Diaphragm (C3-MkII-25) or
- Plunger (C3-MkII-26)
Technical Details - Pumps
C3-MkII-20 Centrifugal Pump (included in standard supply)
A brass-bodied centrifugal pump with plastic impeller and stainless steel shaft. Maximum flow 137 l/min and maximum head 9m.
C3-MkII-20SP Second Centrifugal Pump (optional)
A second centrifugal pump, identical to C3-MkII-20, includes the additional valves required to perform a series/parallel pump demonstration.
C3-MkII-21 Gear Pump (included in standard supply)
A corrosion-resistant bronze-bodied gear pump, with stainless steel shafts and bronze helical gears for quiet operation. Maximum flow 13.7 l/min and maximum head 60m (limited by system relief valve).
C3-MkII-22 Axial Flow Pump (optional)
A purpose-designed axial flow pump, housed in a clear acrylic casing. Maximum flow 100 l/min and maximum head 1.8m.
C3-MkII-23 Flexible Impeller Pump (optional)
A bronze pump head with stainless steel shaft and flexible impeller. Maximum flow 120 l/min at 3m head.
C3-MkII-24 Turbine Pump (optional)
A straight-bladed bronze turbine impellor with a bronze pump body and stainless steel shaft. Maximum flow 24 l/min and maximum head 30m.
C3-MkII-25 Diaphragm Pump (optional, also requires C3-MkII-40 Volumetric Measurement System)
A diaphragm pump with uPVC wetted parts, with a diaphragm 150mm diameter and a 25mm stroke. Maximum flow 5.8 l/min at a maximum head of 60m (limited by system relief valve).
C3-MkII-26 Plunger Pump (optional, also requires C3-MkII-40 Volumetric Measurement System)
A plunger pump with stainless steel wetted parts, with a bore of 34mm and a stroke of 25mm. Maximum flow 5.3 l/min at maximum head of 60m (limited by system relief valve).
Each pump accessory comes on its own baseplate, assembled complete with all pipes, valves and fittings to enable it to be easily fitted to the C3-MkII. Different types of fitting are used for different positions in order to help prevent incorrect fitting.
Volumetric Measurement System (essential for C3-MkII-25 and C3-MkII-26)
The reciprocating pumps (C3-MkII-25 and C3-MkII-26) are not suitable for electronic flow measurement due to the pulsating nature of the flow. To accurately measure the flow rate from these pumps requires a Volumetric Measurement System, where the volume of water flowing over a period of time can be measured.
The C3-MkII-40 is an eight-litre water column with a vertical scale. The bottom of this column is connected to the input of the reciprocating pump, and the time taken for the water level to change between two points is measured.
G version has optional 1.5kVA transformer available to accommodate 120V/1ph/60Hz supply.
A PC running Windows 98 or above with a spare USB port (not supplied by Armfield).
120 litres (initial fill only, no permanent connection required)