Project TW – CleanNOx SNCR System

AT A GLANCE:

• SNCR System
• 10,000 litre Water bunded storage tank
• 6,000 litre Urea/Adblue bunded storage tank
• 3 x Ceramic coated Stainless Steel injection lances
• 3 x 4-20mA peristaltic dosing pumps

• 4kW high pressure lance cooling air fan
• 880L Stainless Steel bunded mixing tank
• 1.2m³/hr duplex water softener
• Comms over ethernet control panel with HMI

PROJECT MANAGERS REPORT:

In the constant pursuit of a cleaner, greener environment for all EU and UK Legislation gets ever stricter.  Legislation changes introduced in December 2023 require reduced quantities of NOx to be emitted.  FD were able to respond quickly to the customers enquiry to follow up an initial trial with a single water injection lance with our in-house built ad-blue/Urea based skid (article here Trial SNCR Skid - Filter Designs).  After NOx abatement trial success using a dilute-mix, in October 2023 we were subsequently awarded a contract to provide a CleanNOx SNCR (Selective Non-Catalytic Reduction) system to ensure the site remained compliant when the new legislation came into force on 3^rd December 2023.  Because of the short time frame we organised the supply to ensure that the operatives on site had a system that they could manage NOx within the new limits, albeit in a more labour intensive manner initially than with a fully complete and commissioned system.

This CleanNOx system starts with a pair of fully bunded solution storage tanks, one a 10,000 litre water tank, the other a 6,000 litre AdBlue/Urea tank. Both tanks were specified with an upgraded submersible pump. The adblue storage tank is designed to be filled by a tanker. The water tank holds towns water that has been through a duplex softener as part of our supply.  These two tanks hold the fluids which are required to fill a bespoke stainless steel mixing tank which was positioned inside the main building, closer to the injection points in the combustion chamber. All the EPDM pipework carrying fluids  is run neatly on specific cable containment, all the outside pipework is also insulated with tailer made jackets to add winter resilience.

Inside, the mixing tank sits on load cells and allows for full flexibility of solution concentration. The mixing tank sits over a powder coated mild steel bund tank.

A bespoke panel housing three peristaltic dosing pumps, each connected to an injection lance allows variation of dosing rate via a 4-20mA input, this means that when provided with a NOx level via an ethernet connection from the site CEMS (Constant Emissions Monitoring System) the system can ramp up or down as required to ensure legislative compliance.

The client installed 3 injection ports, we provided lances with a swivel joint to angle the nozzle head according to a CFD study the client commissioned along with a quick release universal design lance per injection port.  Lance cooling is via a high-pressure fan to a 3-way header, reducing compressed air consumption to a minimum.

A stainless-steel cabinet houses the control system which is positioned close to the mixing skid but linked to the sites control room.  The panel has a protective dust covered touch-screen HMI on the door of the cabinet.  

A powder coated mild steel cabinet houses the three peristaltic pumps, supplied via a common header tank below.

Each pump runs at the required rate via a 4-20mA input (although the pump can be operated in manual mode at any rate via the LCD screen on top of the pump if required).

The system has been in use 24hours a day, 7 days a week since the start of 2024.