WHY RETROFLO?

At Retroflo we recognise that every pumping system is different, not only in physical parameters but also in its operating requirements for flows, storage, type of medium and its position within a network. The Retroflo RPC_2000 has been developed to calculate these variables and automate processes, using the system's interactive control screens for greater flexibility and overall ease-of-use.

Retroflo technology has been extensively trialled at pumping stations in the UK. The success of these installations is clearly demonstrated by improved energy efficiencies and carbon management, results that satisfy the growing need in industry for energy savings and reduced OPEX.

It is generally accepted that the different methods of pumping have associated drawbacks. Fixed-speed pumping, whilst generally accepted as the most reliable means of pumping, is not efficient in terms of energy costs. The solid handling capability of a pump is generally greater when operated at its maximum speed.

In contrast, utilizing VSDs to operate pumps at lower speeds will reduce both energy consumption and COČ emissions. For example: 80 percent speed is equal to 50 percent consumption. Historically however, running pumps at a lower speed has the potential to increase the amount of blockages with many end-users opting to forego the significant energy-saving benefits offered by VSDs in favour of the increased reliability provided by fixed speed pumping.

The RPC_2000 now enables customers to benefit from the reduced energy costs offered by variable speed pumping, combined with the improved reliability of a fixed speed system.

Retroflo systems currently in operation have a proven track-record of delivering:
A minimum of 12 percent reduction in power consumption
Little or no operator or maintenance intervention call-outs
Cleaner wells, enhancing the life cycle of pumps and requiring less frequent well cleansing

EASE OF IMPLEMENTATION AND USE

The RPC_2000's ease of implementation is a key benefit to pumping station operators. The initial set up menu uses "prompts" to gather the necessary operating data. A help menu is available at each screen to provide further guidance. In addition, direct access to the operating parameters is provided for commissioning and optimisation of the system for particular site conditions.

Access to the parameters is password protected with accessibility for Operator, Engineer and Supervisor. These factory set passwords may be altered at site to suit customer preferences. Facility is also provided to reset access passwords to factory default in the event that details are mislaid.

Upon initialisation the system will enter the set-up wizard. The desired pump configuration is input, following which the necessary well levels are requested. Drive, pump and instrumentation information may also be stored for maintenance records and re-ordering purposes. These include manufacturer, model, serial number and date of installation.

During the set-up stage the optimum operating characteristics are logged (Pump Self-Analysis and Initial Efficiency Test). The data is used to determine equipment and system performance deterioration and informs the customer of impending maintenance requirements. Easy to use trend mimics enable interrogation of the system to determine historic operating conditions, particularly useful for fault-finding purposes.

OPERATOR SELECTED BATCH PUMPING OF CONSTANT PUMPING

The RPC-2000 allows the system operator to select the pumping system used, either Batch or Constant Level. Operators with concerns about the risk of increased blockages from use of VSDs can opt for traditional (Batch) operation.

To realise the energy-saving benefits of Constant Level, the operator is able to switch the pumping as confidence in the system is gained through usage.

PRE-BLOCKAGE DETECTION

Pre-Blockage Detection is a unique patented function of the RPC_2000. By comparing real-time data against benchmarked data collected during the Self-Analysis routine, the system can pre-empt a blockage situation and implement automated corrective action.

Any solid build-up on the pump impeller is immediately detected by the RPC_2000 and a Self-Cleansing sequence is initiated. This ensures that the impeller remains debris free, hence maintaining optimum performance.

Without Pre-Blockage Detection small deposits of debris on an impeller would lead to a much larger build-up and eventually a blockage condition. In the period between the initial deposit and eventual blockage the pumps performance will be compromised, resulting in increased energy costs.

Typical blockage detection would initiate only after a significant build-up of debris. This build-up could take a considerable period of time during which the pump will operating inefficiently. Due to this increased build-up the success rate of any automated corrective action is potentially reduced, in many cases leading to a reactive call out.

The RPC_2000 is fully programmable to allow the operator to determine the criteria of the self cleansing sequence, i.e. reverse direction, its speed and duration.

CONSENT MAINTAINED/SECURITY OF CONSENT

Dependent on the specific requirements of a system, the RPC_2000 allows a selection to be made for either controlling level or flow rate. Control via level ensures that pumped flow matches inflow, thereby maximising efficiencies. Alternatively, control can be linked to flow, ensuring that in all circumstances only the correct flow rates are passed forward. These operating preferences are manually selected.

If the system is selected for maximum efficiencies (level control), the system has the ability to detect a change in conditions and intuitively switch to flow control in order to protect the process. This key feature of the RPC_2000 ensures Consent Security for "at risk" stations.

INTELLIGENT FLUSHING CYCLE

Retroflo's new approach means the RPC_2000 incorporates an intelligent flushing cycle. The cycle works on a real-time clock and is fully programmable.

Prior to the selected time RPC_2000 allows the well to fill to a pre-set level; selected to ensure there is sufficient liquid present to properly dilute the settled solids, and that the fat/solids build-up level is exceeded.

When initiated, the well is emptied rapidly using the maximum number of available pumps. A further benefit of the cycle is that rapid emptying of the wells usually ensures self-cleansing velocities are generated in the rising main, thereby alleviating solids settlement and septicity problems.

PERIODIC PUMP EFFICIENCY TESTING

Over time impellers and other pump parts suffer wear, which leads to a progressive drop-off in performance. The RPC_2000 includes an automated Efficiency Test function.

The system allows the operator to determine the frequency of the test. Upon selection and initialisation of the Efficiency Test facility, the system will request an initial test be implemented for all pumps. The pumps are operated over a pre-determined level, calculated by the system. The results are automatically stored for benchmark purposes, when the equipment is at optimum performance.

The results are referenced against the pump's benchmarked performance. Should the results fall outside the operator's predetermined criteria a fault signal is generated, which can be passed through telemetry if required.

INBUILT DIAGNOSTIC TOOLS

The RPC_2000's onboard trends facility constantly monitors and plots real-time data, such as level and flow and pump particular operating data such as speed, current, power and torque. This data can be viewed in real-time or alternatively in retrospect.

These trends, when used in combination with the alarm history facility, provide a comprehensive diagnostic tool, particularly valuable for interrogation of events occurring at times when sites are un-manned.

ENERGY SAVING AND REDUCED CARBON FOOTPRINT

Industry worldwide faces the challenge set out in the Kyoto Protocol to reduce emissions through the management of energy. This coupled with rising energy costs has increased the impetus to reduce operational expenditure alongside carbon management. The RPC_2000 has been designed with these criteria at the fore.

A recent study by the US Department of Energy concluded that pumping systems account for around 25 percent of the world's electric motor energy demand, with this sector now offering the largest opportunity for energy efficiencies improvements in industry. As an estimated 75 percent of pumps are oversized by at least 20 percent, the use of variable speed operation is making a valuable contribution to carbon emission reduction.

Through continuous dynamic monitoring of the pump characteristics, over a range of wet well levels and pump speeds the RPC_2000 is able to realise the energy-saving potential of variable speed drives (VSDs). Use of VSDs aligned with Retroflo's optimised control system also contributes to sustainable construction through improved asset life of equipment, reduced health and safety risks to maintenance personnel, and reduced environmental risks.

PUMP SELF-ANALYSIS

Upon selection and initialisation of the Pre-Blockage Detection facility, the RPC_2000 will request a self-analysis run be implemented for all pumps. The pumps are operated at a range of necessary levels and operating speeds, as calculated by the system.

The operating data is automatically stored for benchmark purposes, when the equipment is at optimum performance. The real time operating data is then constantly compared to the benchmark data for implementing remedial action. All this is done at the touch of a button.

RETRO-FIT FLEXIBILITY

Retroflo's new approach offers a control system that is applicable to a wide range of manufacturers' equipment (pumps and drives) and may be installed in new control panels, or integrated into existing systems.

The retro-fit capability provides opportunities for dealing with historically problematic sites. The success of installations in problematic site has been demonstrated by improved energy efficiencies and reduced maintenance costs.
See Case Studies for more information.

OPERATION AND MAINTENANCE SAVINGS

The operational and maintenance savings associated with the implementation of the RPC_2000 are substantial. Extensive trials on systems in operation have shown that in most cases the RPC_2000 will pays for itself within two years.

The operational savings are mainly derived from lower energy costs, but there are also savings from fewer call-outs and a lower incidence of operator interventions for clearing blockages. There are maintenance benefits from improved asset life of pumps, automated efficiency tests, simplicity of installation, and generally heightened operator confidence for meeting consents.

A reduction in pump speed also potentially reduces operating temperatures, thus reducing wear on pump components such as bearing and seals, increasing maintenance intervals and prolonging asset life.

Click here to view the RPC_2000 Efficiencies Chart