Granite Pickling Tanks

Pickling process: Hydro surge, hydrochloric acid pickling process, which utilises acid injection through specially machined ports in the side V-shaped granite blocks in the pickling tank. This high-velocity injection attacks scale where it is heaviest on the edges, then with turbulent action cleans the entire coil surface uniformly.

The acid tanks are made of granite blocks, which are contained in a mild steel trough (tank) and sealed with a special sealing compound. The cross section of the tank is “VEE” shaped as shown in the view. This provides a small bowing across the width of the leading end of the strip, thus stiffening it for the “PUSH” operation.

Further, the “VEE” shape facilitates the centring of the strip during threading. The granite blocks are specially cut and chamfered adequately to ensure smooth movement of the leading end of the strip.

In the rinse section, the rinse spray pipes are well protected by placing them in recesses provided in the granite blocks, which are again chamfered to facilitate smooth movement of the lead end.