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Concrete Chimneys

Inspections

IMPORTANCE OF STACK & CHIMNEY INSPECTIONS

Chimney inspections and maintenance are critical to maintaining the health of your structures and equipment as well as the safety of your plant personnel, as neglect may lead to severe deterioration and equipment failure. Bygging’s experienced team of engineers and skilled construction experts have developed detailed inspection programs for all types of stacks and chimneys. We’re able to evaluate the current condition of the structure to determine if the life of the stack or chimney can be extended, modified and utilized for another purpose, or if it needs to be demolished.

INSPECTION CLASSIFICATIONS

Class - I Inspections: Primarily a visual inspection and can be carried out when the chimney is on-line if needed.

Class – II Inspections: These inspections should be performed at regular intervals in the range of 2 – 5 years, and alternated with Class 1 inspections. A Class II inspection includes:

  • Non-destructive assessment of thickness and weld condition on steel chimneys and flue liners
  • Non-destructive assessment of FRP liners
  • Installation of crack monitoring equipment on concrete or brick chimneys
  • Full height inspection of chimney exterior, with focus on providing direct access to inspect areas that are usually inaccessible, using multiple drops as necessary
Concrete Chimney Inspections
Concrete Chimney Inspections

Class – III Inspections: Performed only when significant degradation of any structural component has occurred, as indicated by the results of a Class 1 or Class 2 inspection, or when the chimney has experienced an unusual event, such as:

  • Earthquake
  • Hurricane/tornado strength winds
  • Explosion, implosion, or significant impact
  • Flooding through failure or leakage of wet precipitator or scrubber systems
  • Local modifications that may change air flow & vortex shedding by a new neighbouring chimney

INSPECTION METHODS

  • Rope access – A cost effective way to access work locations safely and effectively with minimal site impact and downtime.
    • Bolt tension checks using calibrated torque wrench
    • Ultrasonic checks to measure and record stack shell thickness
    • Protective coatings check
    • Ladders and platforms
    • Electrical and grounding system
  • Hot Camera system - This method allows internal inspections to be completed while a unit is online, or when conditions are too hazardous or dangerous for personnel. The system is comprised of digital cameras which are enclosed and protected inside a thermally balanced housing which can take still photographs and HD quality video.
  • Suspended Camera - This method allows internal inspections to be completed when conditions are too hazardous or dangerous for personnel
  • Thermographic Inspection - Thermal imaging works by detecting the heat signature being radiated by objects and requires absolutely zero light. Since thermal imagers only look at heat, they are totally unaffected by light sources. Thermography is beneficial by reducing unscheduled outages, detecting problem areas more quickly without interrupting service, and allowing facilities to assess priorities for corrective action. Thermography does not intrude upon or affect the structure
  • Unmanned Aircraft system (UAS) - UAS technology allows for the ability to manually control a flight mission to follow and film at the same time. The advantages of using this technology are reduction in service costs, safety factors involved with high rope activity, faster turn-around time, and a more thorough and comprehensive system. UAS systems can capture areas of concern or general conditions in HD video or high resolution digital images.