Upstream Investment Equals Downstream Saving By Alex Lloyd - - PowerPoint PPT Presentation

Upstream Investment Equals Downstream Saving

By Alex Lloyd Managing Director – Jacopa Ltd

Overview

‘The seismic shift towards Totex is putting the onus on delivering outcomes rather than outputs.’ We will argue, using grit as an example, that spending more at the preliminary stages of treatment will lower the overall Totex for the whole treatment system.

Primary Settlement Humus / Final Settlement Digester

Digested Sludge Gas for Power Generation Gas Waste

Primary Sludge Pump

Primary Sludge

Biological Treatment

Settled Effluent Partially treated

Recycle pump

Final Effluent FE

Secondary Sludge Pump Reception Sump

Raw Sewage

Grit Trap

Raw Sewage

Grit Clasifier

Screened Sewage Incoming Sewer Crude

Screens Storm Tanks

Storm Water Storm Return Pumps Storm Return Grit

Screenings Compactor

P-25 Returns Screenings

Totex – System Cost Impact

Asset Ownership Cost System Totex Capital costs Capital costs Efficiency / power costs to use Power costs Maintenance costs (spares & time) Maintenance costs (spares & time) Operational staff costs Income from sale of products (power to grid) Risk of consent failures (fines and bad PR) Ongoing monitoring costs Innovation cost benefit

▪ Product suppliers historically look at cost of

• wnership for their product
• E.g. Pump Capex and efficiency for given duty

▪ Suppliers need to ask ‘what else impacts our products?’ ▪ Difference between Totex and cost of ownership Cost of Ownership System Impact

Outcomes – Industry Challenges

“Outcomes must reflect what customers need, want and are willing to pay for” ▪ Re-use of existing assets in new configurations ▪ Maintenance of existing equipment ▪ Improved performance (e.g. pump efficiency) ▪ Longer life of assets with flexibility to upgrade and refurbish ▪ Reduced risk of service failure ▪ Compliance with environmental and drinking water standards ▪ Reduction in carbon emissions

Factors Impacting Totex & Outcomes

Primary Settlement Humus / Final Settlement Digester

Digested Sludge Gas for Power Generation Gas Waste

Primary Sludge Pump

Primary Sludge

Biological Treatment

Settled Effluent Partially treated

Recycle pump

Final Effluent FE

Secondary Sludge Pump Reception Sump

Raw Sewage

Grit Trap

Raw Sewage

Grit Clasifier

Screened Sewage Incoming Sewer Crude

Screens Storm Tanks

Storm Water Storm Return Pumps Storm Return Grit

Screenings Compactor

P-25 Returns Screenings

• Failure of Preliminary Treatment
• Maintenance Concerns
• Condition Monitoring
• Failure of Preliminary Treatment
• Maintenance Concerns
• Condition Monitoring
• Failure of Preliminary & Primary

Treatment

• Maintenance Concerns
• Condition Monitoring
• Failure of Preliminary, Primary &

Biological Treatment

• Maintenance Concerns
• Condition Monitoring
• Failure of Storm Treatment

(preliminary treatment can be used for storm treatment)

• Maintenance Concerns
• Condition Monitoring

Common theme! What happens upstream impacts on life and

• peration of pumps and other equipment

Typical Flow Diagram

What is Grit?

Grit Removal is defined by WIMES as

>200µm equivalent diameter (95% removal) Specific gravity 2.65kg/l Inorganic (sand, gravel, cinders, rock salt, egg shell) Also includes organics (coffee grinds, sweetcorn and seeds)

THICKNESS OF A 20p PIECE

Why Remove Grit

▪ Grit is highly abrasive and destructive

• In the network
• To mechanical equipment

▪ Why remove grit >200µm?

• To comply with WIMES
• Prevent further maintenance

costs downstream.

Does grit less than 200µm present any

• perational concerns?

Pump and System Performance

▪ Increased Power

• Removes efficiency coatings by abrasion
• Increased friction in pipework
• Settlement in pipework (reduced pipe area)

▪ Increased Maintenance

• Blockage in pipes
• Abrasion of pump castings, seals and

bearings

• Erosion of pipe material (too high velocity)
• Difficult identification and access to problem

▪ Departure from design parameters (e.g. pump system curves, digester throughput) ▪ Reduced life and early component replacement

How Does Grit Impact Totex?

▪ Screens – damage from wear and tear (early maintenance) ▪ Compactor – abrasion of any screw (early maintenance) ▪ Storm System – reduced life of storm return pumps, increased cleaning and odour ▪ Interstage Pumps – abrasion on impellor (inefficient pumping / increased power) ▪ Primary Settlement – Excessive scraper wear (inefficient desludging) ▪ Biological Treatment – Fouling of aeration diffusers (increased power consumption) ▪ Digester – reduced volume and increased digging out (reduced yield & increased maintenance.

Primary Settlement Humus / Final Settlement Digester

Digested Sludge Gas for Power Generation Gas Waste

Primary Sludge Pump

Primary Sludge

Biological Treatment

Settled Effluent Partially treated

Recycle pump

Final Effluent FE

Secondary Sludge Pump Reception Sump

Raw Sewage

Grit Trap

Raw Sewage

Grit Clasifier

Screened Sewage Incoming Sewer Crude

Screens Storm Tanks

Storm Water Storm Return Pumps Storm Return Grit

Screenings Compactor

P-25 Returns Screenings

Examples of Downstream Grit Deposition

Quantity and size of grit coming from the catchment is unknown (depends

• n individual catchment)

Detritor (not maintained) Pump wear Aeration Lane (diffusers fouled) Pipe failure Dug out of digester Digester reduced volume

Removing Grit

Rake Classifier Air Lift Ram Pump Recessed Impeller Grit Channel Vortex Cross Flow

Separation Transfer Cleaning

▪ Separation is done at settlement velocity. ▪ Transfer is done using equipment designed for grit ▪ Cleaning removes the organics and prevents odour ▪ Opex must include Maintenance ▪ Totex impact on system cost

▪ Regular and efficient removal from settlement zone ▪ Inspection of equipment for correct operation

• Wear strips checked and replaced
• Scrapers operating effectively
• Reciprocating rakes linkage operational
• Realignment / replacement of mechanical assemblies

▪ Greasing and other regular activities completed ▪ Cleaning off FOG (attracts grit forming a floating abrasive mixture) ▪ Address screen failures immediately ▪ Speak to the specialists

Operating and Maintenance Considerations

Upstream Investment vs Downstream Saving

Investment in Grit Removal

System Totex Grit Capex Grit Opex

▪ Totex is related to the complete system not an individual product

• Upstream process units affect the performance of

downstream equipment

• Include any investment (time, resources and capital)
• Re-use, re-configure, maintain or refurbishment of

assets may be a more cost effect solution

▪ Building new assets means maintaining new assets; a greater Totex ▪ Improved upstream treatment equates to an improved downstream life of pumps and equipment

‘Suppliers need to engage with end users and each other, working together to deliver a lower Totex solution to meet an Outcome and not just their own product in isolation.’

Thank You