Huakeyi HK-6010 Flue Gas Desulfurization (FGD) pH Monitoring System

Overview

The Huakeyi HK-6010 Flue Gas Desulfurization (FGD) pH Monitoring System is an industrial-grade online pH measurement and telemetry solution engineered specifically for wet limestone-gypsum FGD processes in coal-fired boiler exhaust treatment systems. It operates on the principle of potentiometric pH measurement using a robust, temperature-compensated glass electrode sensor (HK-328H), coupled with real-time data acquisition, local trend visualization, and secure remote transmission via GPRS/3G cellular networks. Unlike generic online pH meters, the HK-6010 is purpose-built to monitor the alkalinity of circulating scrubber slurry—where maintaining pH ≥9.0 is critical for efficient SO₂ absorption and particulate capture. Its architecture supports continuous, unattended operation under harsh industrial conditions, delivering high reproducibility in pH tracking across fluctuating load cycles and intermittent lime dosing events.

Key Features

• Real-time, 24/7 pH and temperature monitoring of FGD scrubber liquor with automatic temperature compensation (ATC) over 0.1–60 °C range
• Dedicated waveform-based operational diagnostics: sawtooth-shaped pH trend curves indicate normal cyclic alkali dosing and SO₂ consumption dynamics
• Triple-output analog current interface (0–10 mA, 0–20 mA, or 4–20 mA) compliant with standard PLC/DCS integration protocols
• Integrated industrial PC with local HMI display for on-site visualization of live pH trends, historical curves, and alarm status
• GPRS/3G-enabled secure data transmission to centralized environmental supervision servers—enabling remote compliance auditing by municipal or provincial EPA authorities
• Robust enclosure rated for ambient temperatures up to 50 °C and humidity ≤95% RH; meets IP65-equivalent ingress protection for field-mounted deployment
• Electrical isolation and dielectric strength of 1500 VAC/1 min ensure safety and noise immunity in electrically noisy power plant environments

Sample Compatibility & Compliance

The HK-6010 is validated for use with typical FGD process streams—including limestone slurry, sodium hydroxide wash solutions, and recycled scrubber liquor—within specified operating limits: sample temperature 5.0–50.0 °C and pressure <0.6 MPa. Its HK-328H pH sensor employs a low-drift reference system and chemically resistant glass membrane optimized for high-solids, high-chloride, and mildly abrasive media common in desulfurization applications. While not certified to ISO/IEC 17025 or accredited for metrological traceability, the system aligns with routine operational requirements defined in Chinese Environmental Protection Standards (e.g., HJ/T 75–2017 for CEMS auxiliary parameter monitoring) and supports data integrity practices consistent with basic GLP principles. Its analog outputs are compatible with industrial control systems adhering to IEC 61131-3 and ISA-50.00.01 signal standards.

Software & Data Management

The embedded industrial PC runs a deterministic Windows-based runtime environment hosting proprietary monitoring software that logs pH and temperature at user-configurable intervals (default: 10-second sampling, 1-minute averaging). All data are timestamped with local system clock and stored locally for ≥30 days. Historical trends are exportable in CSV format for offline analysis. Remote data transmission follows a lightweight TCP/IP protocol with configurable retry logic and packet-level checksum validation to ensure delivery integrity over public cellular networks. Although the system does not implement FDA 21 CFR Part 11-compliant electronic signatures or full audit trail functionality, it maintains a chronological event log—including calibration timestamps, sensor fault alerts, and communication status changes—to support internal QA reviews and regulatory inspection readiness.

Applications

• Continuous pH surveillance of circulating alkaline scrubbing solution in small- to medium-capacity coal-fired boiler FGD units (≤75 t/h steam output)
• Automated compliance verification for municipal environmental monitoring centers overseeing distributed boiler emissions sources
• Process optimization feedback for lime dosing control loops—reducing chemical overfeed while sustaining desulfurization efficiency >90%
• Early detection of scrubber performance degradation due to sensor fouling, reagent depletion, or pump failure
• Integration into enterprise-wide energy management systems (EnMS) for correlating pH stability with fuel sulfur content and flue gas flow rates

FAQ

Is the HK-6010 suitable for high-pressure scrubber recirculation lines?

No—it is designed for atmospheric or low-pressure (<0.6 MPa) sample streams, typically installed on bypass sidestreams or overflow lines.
Does the system support MODBUS RTU or Profibus DP communication?

No—the primary digital interface is GPRS/3G telemetry; analog current outputs serve as the sole standardized fieldbus-compatible interface.
Can the HK-328H sensor be replaced with third-party pH electrodes?

Yes, provided the replacement electrode delivers mV output compatible with the HK-6010’s input impedance (>10¹² Ω) and includes a built-in Pt1000 or similar temperature element for ATC.
What maintenance interval is recommended for field calibration?

Bi-weekly two-point calibration (pH 4.01 and 7.00 buffers at 25 °C) is advised under continuous operation; more frequent calibration may be required in high-fouling environments.
Is cybersecurity certification (e.g., IEC 62443) available for the GPRS module?

No—the GPRS firmware implements basic TLS 1.2 encryption for data payloads but lacks formal industrial cybersecurity certification.