Acid Dosing Flow

Overview

A UK specialty-chemicals manufacturer required accurate mass flow measurement for automated dosing of hydrochloric acid (34–36% concentration) and methanesulfonic acid within an upgraded, ATEX Zone 2 process area.

The challenge

The dosing lines ran under initial vacuum with an automated valve sequence controlled by the site PLC, and the media demanded careful wetted-material selection.

• Confirm wetted materials suitable for 34–36% hydrochloric acid and methanesulfonic acid, including tantalum and high-nickel alloy options.
• Maintain measurement performance during vacuum-assisted transfer, from full vacuum to 2 bar g.
• Provide a usable output for end-of-dose valve control through the PLC.
• Limit pressure loss across the dosing lines.

Our solution

Quality Lab Solutions reviewed the customer's P&ID, safety data sheets and User Requirement Specification before specifying DN25 Coriolis mass flow meters covering 5–50 kg/min per line, with vacuum-rated diaphragm-seal pressure transmitters alongside.

• Sized separate DN25 instruments for the two acid duties across 5–50 kg/min.
• Verified wetted materials against the acid concentrations before purchase.
• Checked accuracy and pressure drop at both ends of each operating range.
• Supported the project through URS review, RAMS documentation and site attendance.

Results

A dosing measurement package specified end-to-end for corrosive, vacuum, PLC-controlled service in an ATEX Zone 2 area — from first enquiry through materials verification to on-site support.

Customer benefits

• Direct mass measurement for repeatable dosing.
• No dependence on density or temperature compensation between the two acids.
• Clear PLC integration path for end-of-dose control.
• Wetted materials verified before commitment.