Energy saving on the FD fan at Indo Gulf.

The problem

Indo Gulf Fertilizer at Jagdishpur runs a critical FD fan in its ammonia plant, rated 1090 KW at 980 RPM. The fan had a twin drive — a steam turbine on one end and a 1250 KW / 990 RPM electric motor as standby on the other — with hydraulic clutches to decouple whichever drive was not in use.

Driven by the turbine at 983 RPM, the fan was simply too large for the duty: it ran with the damper 70–75% closed to meet process flow, which caused high vibration and made gas-flow regulation erratic — adversely affecting other plant parameters. Worse, the hydraulic clutches broke down frequently, repeatedly stopping production.

The brief

Indo Gulf set out to solve the problem for good: drive the fan reliably by motor, save energy, and work within severe space and layout constraints. Fluidomat was invited to study the drive and propose a solution.

The Fluidomat solution

Fluidomat offered a custom-built scoop-control variable-speed coupling, model CBSC-14, engineered to fit the available space. The oil tank, cooler, pump and filter were placed at a lower level to overcome the space constraint, and a duplex oil system (pump, cooler, filter) was provided for reliability. A pneumatic actuator with automatic control gave stepless speed variation from 1000 down to 250 RPM. The coupling was installed in July 2003, replacing the clutch on the motor side.

The outcome

Fluidomat advised Indo Gulf to open the damper fully and reduce fan speed for substantial energy saving. The plant found it could meet flow by running the fan at just 400–600 RPM with the damper fully open under automatic speed control.

• 400 KW of power saved — about ₹1.5 crore per year at 7,500 hrs and ₹5/unit.
• Improved fan life, bearing life and noise levels at low-speed operation.
• Vibration and gas-flow-rate control problems fully solved.

The project added one more proven drive solution to Fluidomat’s record — and underlined how variable-speed scoop control turns a process problem into an energy win.