Dubai pumping stations

Project:

Pumping Stations C,E,G&S Odor Control System

  • Location: Dubai-UAE
  • Client: Dubai Municipality
  • Contractor: Al Ahmadia Aktor
  • Consultant: MWH
  • Capacity: 8,500~11000 m3/hr
  • Design: 1 Vertical Bio Scrubber followed by modified existing chemical scrubber
  • Performance: - 50~250 ppm 99.5% /99.99% Bio/Total Removal Efficiency
  • Year: Installation/Commissioning:2012/2012

AmerAir International, AAI, is a leading supplier of Odor Control Systems in the Gulf Area for the last 7 years. Dubai Pumping Stations C, E, G and S Odor Control System are being presented as samples of our supplied systems. AAI scope of work included the initial conceptual design, detailed engineering and design, equipment supply, installation supervision, commissioning, testing, training and follows up support to the completion of defect liability period and final hand over of the projects.

Background

In 2010, AmerAir International was approached by the main contractor (Al Ahmadia Aktor) to re-evaluate the specification and design of the planned odor control systems at several Dubai Municipality Pumping Stations. Dubai Municipality had planned the extension of the existing pumping stations to include new inlet chambers and screen building. The extension of the pumping stations specified a new two stage odor control system that included a first stage Bio Trickling Scrubber followed by a new Chemical Scrubber.

These pumping stations are located in the most sensitive areas of Dubai (Deira City Center, Health Care City and Burj Khalifa Area). The design was based on the performance and design of previously supplied Bio Trickling Scrubber in front of the existing Chemical Scrubber by AAI in 2009 for pumping station S. The specification for the new extension would provide for two separate odor control systems at all sites while the exiting Chemical Scrubbers at Pumping Stations C, E and G would be left as a Chemical Scrubbers only operation for the ventilation of the wet wells and therefore continued use of chemicals on these sites.

Consequently, AAI presented an optimal design that employed a single vessel Bio Trickling Scrubber installed in front of the existing Chemical Scrubber system (20 years old system). The existing Chemical Scrubber capacity was increased from about 3,000 to more than 8,500 m3/hr by changing the internal design of the scrubber (i.e. packing, supports, wash header and mist eliminator) to the proprietary AAI design. This design eliminated the need for the new 2nd stage Chemical Scrubber that was specified for the new screen building by utilizing the increased capacity of the existing Chemical Scrubber. A larger capacity BTS vessel capable of covering both old and new structures was therefore the only equipment s needed. The reduced capital cost CAPEX) of the odor control system was achieved while the operational cost (OPEX) was also reduced drastically while achieving the highest levels of odor removal efficiencies and reliability for all pumping stations and minimizing the operation cost to the lowest level possible. Additionally, the AAI designed odor control systems provided for 40-50% more ventilation capacity form the original specification. This higher capacity ventilation has made a drastic positive effect during the routine maintenance flushing of the wet wells.

AAI design was later approved by Dubai Municipality and MWH (consultant Engineers). These systems have been in operation since August of 2012 and have achieved all specification requirements. The BTS and OCU performance are being monitored separately on routine basis (every two hours) by Dubai Municipality operators with on line H2S analyzers. Zero outlet concentrations out of the BTS are continuously achieved.

Design Key Point

This system consists of a Bio Trickling Scrubber, Fans and a Modified Chemical Scrubber. The flow is passed through Bio Trickling Scrubber as the main treatment stage by two Fans (duty/stand-by). Then the treated air is pushed to a polishing stage of Chemical Scrubber. The clean air is discharged through the stack installed on top of the polishing stage.

The Bio Scrubber is equipped with all internals and irrigation line and pump. The TSE water is used as make-up water of scrubbing solution to remove the H2S.

The Chemical Scrubber is equipped with all internals, and recirculation line and two pumps (duty/stand-by). The water softener and chemical dosing system including two/two dosing pumps for NaOH 50% and H2O2 30%, are supplied.

The system is equipped with necessary instrumentation to control and monitor the operation. A H2S monitoring system is provided to check the performance of odor control unit.

Service conditions

Ambient Temperature: +1~ +55°C

Relative Humidity: 20~100%

Our design is based on following design data:

Pos.Parameter 
1Exhaust flow rate, wet, operation conditions8500~11000 m³/h
2H2S-inlet concentration100~250 ppm
3Minimum H2S-removal efficiency at average load99.95%

 

System Performance

These systems have been in operation since August of 2012 and have achieved all specification requirements. The BTS and OCU performance are being monitored separately on routine basis (every two hours) by Dubai Municipality operators with on line H2S analyzers. Zero outlet concentrations out of the BTS are continuously achieved.