PST Scraper Bridge

case study details

Inlet Works

case study description

Screening Conveyors and Megawashers

other case studies

 
Hartshill STW - Inlet Works
Severn Trent Region

Client
Severn Trent Water

Location 
Hartshill, UK

Project Type
Turnkey Wastewater Treatment Plant

Project Duration
10 mths

Project Value
£1.3 M
 

Completion Date
September 2006

Project Summary:

The scheme comprised replacing the existing inlet screens and screenings Handling equipment while retaining the existing civil channel and providing  access steelwork to new equipment.

A new washwater ring main was installed connecting to the existing ring main system.

The three primary settlement tank half bridge scrapers and associated scum removal equipment and electrical control equipment were all replaced.

All redundant assets were then demolished. 

Project Scope

  • New inlet screens and screenings handling equipment, retaining the existing civil channel
  • New inlet washwater ring main to connect onto existing ring main system.
  • Replace three primary settlement tank (PST) half bridge scrapers, scum boards, traps and weirs and associated electrical control equipment.
  • Replace three PST feed penstocks incorporating stoplogs to provide better maintenance access to chamber.
  • Flooring and hand railing was modified to match the new layout.
  • Demolition of redundant assets
  • Construction of a new 1.4 m diameter bypass around the screens into the grit removal plant
  • Installation of a pilot plant

Added Value/Benefits

Detailed liaison with all parties during the design phase resulted in very good access to all motors and drives and a lifting beam was incorporated into the access steelwork arrangement to enable the removal of drives.

Aco drains were provided to avoid liquors spilling from the inlet works skips and creating a hazard in freezing temperatures.

Health and safety modifications were made by way of new handrailing and footpaths around the primary settlement tanks.

The new primary tank scrapers were designed with removable scraper blade assemblies so that they can be removed from the tank for maintenance purposes

Additional lighting was provided in the screenings area for better visibility and operational access.

The existing inlet works is adjacent to the existing road system. The access track was made wider to enable better access with a small maintenance vehicle

The success of the scheme relied on a well integrated team relationship with Pick Everard and Severn Trent operations throughout, enabling a number of value engineering solutions.

All commissioning, turn of flow and substantial completion dates were met.

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