Caustic Soda Dissolving Package

Overview

TiERMAX supplied a complete caustic soda dissolving package to an industrial customer to prepare 20 wt% sodium hydroxide (NaOH) solution safely and consistently from solid caustic flakes.

The turnkey package combines bulk bag unloading, controlled solids feeding, dissolving, instrumentation and dosing in one system. The goals were to reduce manual handling of caustic, improve operator safety, make solution strength consistent and simplify daily operation. It was customized to the site, including a 1,320-gallon (5,000 L) dissolving tank, automated flake feeding, process instruments and electrical equipment rated for a humid environment.

The Challenge

Dissolving caustic soda in water is strongly exothermic, so both the rate of addition and the solution temperature must be controlled. The customer needed a consistent 20 wt% solution with minimal operator contact with flakes.

The system also had to accept bulk bags of up to about 4,400 lb (2,000 kg), meter flakes into the tank, monitor key process values and offer a manual feeding option when needed.

The Solution

Bags are lifted into the bulk bag discharger with a hoist. Paddle bag massagers break up compacted flakes, and a manual butterfly valve isolates the discharger from the conveyor.

A screw conveyor with VFD speed control meters flakes into the dissolving tank, so the feed rate can be matched to the process. An agitator circulates the solution and speeds dissolution, while level and temperature transmitters report continuously to the control system.

An optional manual feed hopper provides a backup way to add flakes. Once the solution reaches the target concentration, a dosing unit delivers it to the customer’s process.

Equipment Supplied

• Hoist-loaded bulk bag discharger for bags up to 4,400 lb
• Manual butterfly isolation valve
• Screw conveyor with VFD speed control
• 1,320-gallon (5,000 L) dissolving tank with agitator and process instruments
• Optional manual feed hopper
• Dosing unit
• Integrated control panel for the complete system
• IP65-rated motors for the humid site conditions

Integrated Controls

The TiERMAX control panel brings the screw conveyor VFD, agitator, level and temperature signals and dosing equipment into one system, with operating sequences, interlocks and alarms. Instead of running each machine separately, operators run the whole package as one coordinated process, from flake handling and feeding through dissolving and final dosing.

For U.S. plants buying liquid caustic by truck, a similar package can turn lower-cost solid NaOH into on-demand solution at the strength the process needs.