IDS - Engineering Subcontractor to Foster Wheeler Energy Services, Inc, for the retrofit of the Larkspur Units 100 & 200. Both units are Simple Cycle Gas Fired Units each nominally rated at 45 MWe. Each unit had an existing SCR Reactor installed, however, the internal duct insulation in both units failed. As a result, insulation particles clogged the catalyst baskets and subsequently the units were unable to meet the required NOx levels

The retrofit focused on installing a new Ammonia Injection Grid, Air Preheater, and SCR panels. Several existing systems were also modified to accommodate the new equipment. In addition, the Ductwork and SCR housing were exposed to extreme temperatures and as a result were damaged by thermal expansion. In order to alleviate future damage, the duct and SCR housing were insulated, Re-lined with stainless steel and structurally strengthened. The primary challenges were schedule and several unknown operating conditions regarding the existing systems.

IDS provided Foster Wheeler with Plant Design, Engineering, Design/Drafting, and Outage Site Support Services for the installation of the main systems related to the SCR Retrofit

IDS’s Scope of Work included the following systems and components for each unit:

• External Reactor Casing & Housing Modifications
• Internal Liner & Casing Modifications
• Ammonia Storage & Handling System Modifications
• Ammonia Piping System Modifications
• Air Preheater System Modifications
  
• Structural Supports Modifications

IDS’s responsibilities included developing the SCR Field, Assembly & Installation Drawings and all Shop Fabrication Detail drawings. IDS also provided on site (around the clock) construction supervision during the Outage/Retrofit period

IDS performed all the required Structural Engineering, Piping Stress Analysis and Code Calculations for all the modified systems in accordance with the applicable ASME Boiler Code and Standards including determining all SCR load calculations, thermal expansion movements, structural steel & platform loads, and developing all required pipe & duct support design details.