Explosion Proof HVAC: Mining and Drilling - Case Study
The Challenge: Air Innovations was asked to design a Class I Division I environmental control system (ECU) to cool an electrical cabinet that houses several variable frequency drives for a large centrifuge machine. These drives generate a significant amount of heat that needs to be removed from the cabinet. Centrifuges are typically used to remove slurry during drilling for oil and gas operations.
An explosion-proof system was designed to integrate inside the client’s custom purged electrical cabinet and was able to withstand the harsh environment in which these centrifuges typically operate. The unit was configured to provide once-thru air steady state air to a single LDCS-PRO coater. The ECU was designed for a Class I Division I explosion proof environment.
Key performance specifications for this custom explosion proof HVAC system were:
- Ambient (condenser inlet) range -40°F to +130°F
- Cabinet control point 85°F +/-5°F, non-condensing environment
- Airflow range 420-520 CFM
- Designed for near continuous (not ON/OFF control) operation to ensure a non-condensing environment and to provide thermal stability
- 2-ton nominal cooling capacity
- CE approved
Key design considerations for this custom explosion proof HVAC system were:
- Fit inside the customer’s custom cabinet without interfering with the frequency drives and while allowing appropriate access to service components
- Integrate and communicate with customer’s control system
- High reliability as these units are in very challenging environments to provide field service (offshore platforms for example)
- Class I, Division I ambient
- Integral phase monitoring and auto switchover
- Harsh environment; high salt and dust content
- All design specifications were met.
- An explosion-proof system was manufactured to integrate inside a custom purged electrical cabinet, withstanding very harsh environments of high salt and dust, normally encountered in the field.
- The system was designed as a Class 1 Division 1 explosion-proof air conditioner that communicates with customer’s control system and has integral phase monitoring and auto switchover.