Gujarat Narmada Valley Fertilizers & Chemicals Ltd. (GNVFC)

Date: 2012-2016
Acoustic Cleaner Model: PAS120
Year: 2012 – 2016
Location: Gujarat State (India)
Application: Coal-fired boilers
Problem: Erosion of boiler tubes

GNVFC has a fertilizer plant located in Bharuch District of Gujarat state. It has a captive power plant of 3 x 15 MW which uses coal as a fuel for its boilers. All the 3 boilers in this power plant are fitted with long retractable steam soot blowers. GNVFC was facing a typical problem of tube erosion due to steam injection done for cleaning of the tubes through LRSBs & they need to replace a considerable no. of tubes during their annual shutdowns.

The Approach

GNVFC approached Primasonics for a possible Acoustic Cleaning Solution to solve this problem in the Bank Tube Zones & Superheater Zones of their boilers. Indian representative Mr Abhijit Bakshi of Ambiz Group visited GNVFC plant for a detailed presentation & collection of data on bank tube & superheater zone. Primasonics proposed the following acoustic horns:

  • Bank tube zone: One acoustic horn of 120 Hz in SS 316
  • Platen Superheater – One acoustic horn of 120 Hz in Inconel 625
  • Final Superheater – One acoustic horn of 120 Hz in Inconel 625

Before finalization, GNVFC team also visited M/S. Indian Rayon & Chemicals Ltd. to study the performance of the acoustic cleaners supplied by Primasonics on their coal and lignite-fired boilers.


GNVFC placed first on order for PAS 120 for bank tube zone in year 2012. Considering the operating temperature of 600ºC, the PAS 120 was supplied in SS 316 construction. It was installed with a mounting tube arrangement under the supervision of Ambiz Group’s representative. The use of the existing LRSB’s was stopped completely. After one year, the diameters of the tubes in bank tube zone were inspected during a shutdown. The readings showed that the diameters of majority of the tubes were intact which proved that the tube erosion was considerably reduced after stopping the steam injection from LRSBs completely. This was possible because of the effectiveness of the “Low Frequency High Power” sound waves generated by the PAS 120 acoustic horn which prevented the depositions of soot particles on tube surfaces

In the year 2013, GNVFC ordered one PAS 120 for the bank tube zone of the 2nd boiler.

Since the bank tube zone performance was firmly established on 2 boilers, GNVFC decided to buy PAS 120 in Inconel 625 for Platen & Final superheaters. The Inconel 625 material was selected based on the operating temp. of +1000ºC in the superheater zones. The subsequent order was released on Primasonics & installation was completed in May 2015.

The inspection of the tubes conducted in May 2016 once again endorsed the performance of PAS 120 acoustic cleaners & the final order for PAS 120s for Platen & Final supeheaters of 2nd boiler was placed in May 2016.


  1. The superheated steam injected by steam soot blowers caused erosion of tubes in GNVFC’s coal-fired boilers.
  2. Primasonics acoustic cleaners helped GNVFC to stop the steam injection completely & eliminated the tube erosion.
  3. With a successful running operation since the year 2012, Primasonics acoustic cleaners proved to be the most effective solution for cleaning the boiler tubes in GNVFC’s coal-fired boilers.