PCB Exhaust Gas Treatment and Pump Selection: Comprehensive Analysis and QEEHUA Solutions

1. Challenges of Exhaust Gas Treatment in the PCB Industry

Printed Circuit Boards (PCBs), as a core component in electronics manufacturing, are widely used across telecommunications, computing, consumer electronics, and automotive electronics. However, PCB production involves multiple complex wet chemical processes that release significant volumes of harmful gases, making it one of the most pollutive industries.

Particularly during electroplating processes—such as chromium, copper, or nickel plating—various acidic or heavy metal-laden exhaust gases are emitted, for example:

• Chromium-containing exhaust: Originating from chromium plating, contains highly toxic chromium acid mist (CrO₃).

• Cyanide-containing exhaust: Mostly from traditional gold plating; usage is decreasing but still exists in some facilities.

• Acid mist: Includes sulfuric, hydrochloric, and nitric acid vapors, commonly found in etching and cleaning steps.

These exhaust gases pose serious health risks to workers, corrode equipment, and harm the environment, necessitating the deployment of reliable and efficient exhaust treatment systems.

2. Scrubbers and Pump Systems: Core to Acid-Base Neutralization

Scrubbers are the central equipment for treating PCB exhaust, typically utilizing a counterflow gas-liquid contact design. Polluted gases enter from the bottom, interacting with neutralizing liquids (acid or alkali) sprayed from the top, chemically removing harmful substances. The process relies on high-performance pumps to circulate these neutralizing liquids between spray nozzles, storage tanks, and recovery units.

Pumps used in this environment must offer excellent corrosion resistance, support frequent start-stop cycles, enable continuous operation, and tolerate dry runs.

As a long-term partner in the PCB industry, QEEHUA chemical pumps, purpose-built for corrosive liquid handling, have become a trusted choice for exhaust gas treatment systems.

3. QEEHUA Pump Applications in the PCB Industry

A PCB scrubber system typically includes three key pump configurations: horizontal magnetic drive pumps, vertical pumps outside tanks, and vertical pumps inside tanks, each selected based on placement, operation mode, and fluid characteristics.

1. Horizontal Magnetic Drive Pumps: The Main Circulation Engine

Magnetic centrifugal pumps, featuring a seal-less design and magnetic coupling for power transmission, eliminate leakage risks—making them ideal for corrosive fluid handling.

QEEHUA Horizontal Magnetic Pump Highlights:

• Versatile Materials: Options include GFRPP, CFRPP, PVDF, and CFRETFE, offering superior acid/base and high-temperature resistance.

• Optimized Hydraulics: Internal flow paths reduce losses and enhance efficiency.

• Reinforced Bearings: Made of 99% alumina ceramic or SSIC for wear resistance and longevity.

• One-Piece Injection-Molded Motor Connection: Prevents acid mist corrosion and leaks.

• Low Noise Operation: Dynamically balanced drive magnets keep vibration under 2.0 mm/s.

Application Scenarios:

• Neutralizing liquid circulation

• Acid/base solution replenishment

• Waste fluid collection and recovery

2. Vertical Pumps Outside the Tank: Dedicated for Scrubbers

These dry motor vertical pumps are mounted externally, with the pump body submerged below liquid level, ideal for layouts where horizontal pumps are unsuitable.

QEEHUA External Vertical Pump Highlights:

• Customizable Length: Tailored to tank depth and scrubber structure.

• Durable Materials: GFRPP, CFRPP, and PVDF offer excellent chemical and aging resistance.

• Dry Run Tolerance: Short-duration dry running is safe—perfect for scrubber circulation.

• Filtration Compatibility: Seamlessly integrates with QEEHUA filters for improved treatment precision.

Application Scenarios:

• Acid mist scrubber return pumps

• Neutralizing solution refill systems

• Exhaust tower drainage

3. Vertical Pumps Inside the Tank: Built-In Circulation Solutions

Designed for use in chemical storage or processing tanks, these pumps provide short-distance transport of acidic and alkaline liquids.

QEEHUA Internal Vertical Pump Highlights:

• High Corrosion Resistance: Molded in one piece using GFRPP or PVDF plastics.

• Leak-Proof Design: Isolated shaft seal prevents fluid backflow or vapor-induced corrosion.

• High Temp/Pressure Resistance: Reliable under extreme chemical conditions.

• Ease of Maintenance: Compact and easy to replace, reducing operational downtime.

Application Scenarios:

• Acid/alkali tank recirculation

• Corrosive chemical transport

• Closed-loop processing units

4. Chromium Acid Filter Systems: Specialized for Toxic Liquids

QEEHUA also developed advanced chromium acid filtration systems for hazardous wastewater applications.

QEEHUA Chromium Filter System Highlights:

• Highly Corrosion-Resistant Tanks: PVC injection molded for long-lasting acid/base resistance.

• Flexible Pump Options: Compatible with self-priming or magnetic pumps for process versatility.

• Zero Metal Contact: All internal components are non-metallic to avoid contamination.

• Efficient Filtration Design: Screw-cap filter cartridges are easy to install, tightly sealed, and offer large surface areas.

Application Scenarios:

• Chrome bath fluid purification

• Recovery tank solution reuse

• Electroplating wastewater recycling