Caustic Soda Dissolving Package

Overview

TIERMAX supplied a complete Caustic Soda Dissolving Package to an industrial customer for the safe and efficient preparation of 20 wt.% sodium hydroxide (NaOH) solution from solid caustic soda flakes.

The turnkey system was engineered to integrate bulk bag unloading, controlled solids feeding, mixing, instrumentation, and dosing into one complete process package. The objective was to reduce manual handling of caustic soda, improve operator safety, provide consistent solution preparation, and simplify day-to-day operation.

The package was customized around the customer’s process requirements and site conditions, including a 5,000-liter mixing tank, automated caustic flake feeding, process instrumentation, and electrical components suitable for the humid operating environment.

The Challenge

Preparing sodium hydroxide solution from solid caustic soda requires careful control of both material addition and temperature. Dissolving caustic soda in water is strongly exothermic, meaning that significant heat is generated as the flakes dissolve.

The customer required a system capable of preparing a consistent 20 wt.% NaOH solution while minimizing direct operator contact with the caustic flakes.

The system also needed to accommodate large bulk bags of up to 2,000 kg, provide controlled transfer of flakes to the dissolving tank, monitor critical process parameters, and provide an alternative manual feeding method when required.

The Solution

TIERMAX engineered the package as a fully integrated process system, beginning with bulk bag handling and controlled solids feeding and continuing through dissolution, process monitoring, solution dosing, and centralized control.

Bulk bags are positioned in the discharger using a hoist loading system. The bulk bag discharger incorporates paddle massage to assist material discharge and reduce problems caused by compacted caustic flakes. A manual butterfly valve provides isolation between the bulk bag discharge section and the downstream conveying equipment.

The caustic flakes are transferred to the 5,000-liter mixing tank by a screw conveyor equipped with VFD speed control, allowing the feed rate to be adjusted according to process requirements.

Inside the mixing tank, an agitator provides effective circulation and promotes dissolution. Integrated level and temperature transmitters provide continuous process information for monitoring and control.

An optional manual feeding hopper provides an alternative method of introducing caustic flakes when required. Once the required solution concentration is achieved, the downstream dosing unit transfers the prepared solution to the customer’s process.

The complete package is operated through a TIERMAX integrated control panel, bringing the major equipment, instrumentation, alarms, and operating functions together within a centralized control system. This allows the unloading, conveying, mixing, monitoring, and dosing stages to operate as one coordinated package.

Equipment Supplied

The complete TIERMAX package includes:

• Hoist-loading bulk bag discharger for bulk bags up to 2,000 kg
• Manual butterfly isolation valve
• Screw conveyor with VFD speed control
• 5,000-liter caustic dissolving/mixing tank with Required process instrumentation and agitator
• Optional manual feeding hopper
• Dosing unit
• Integrated control panel for the complete system
• Customized IP65 motors suitable for the site’s humid operating conditions

Integrated Control & Automation

A key part of the package is the integrated control panel supplied by TIERMAX, which provides centralized operation and monitoring of the complete caustic dissolving system.

The control system integrates the main process equipment and field instrumentation, including the screw conveyor VFD, mixing tank agitator, level and temperature signals, and dosing equipment. Appropriate operating sequences, interlocks, and alarms can be incorporated to help maintain controlled and reliable operation.

Rather than operating each component independently, the integrated controls allow the complete package to function as a coordinated process – from caustic flake handling and controlled feeding through dissolution and final solution dosing.