Hardgrove Grindability Index Tester Coal Grindability Determination Instrument

Product Overview

This precision laboratory instrument is engineered to determine the relative ease of pulverization for bituminous coal and anthracite in strict compliance with GB/T 2565 standard test methods. Based fundamentally on Rittinger's classical grinding law—which establishes that the mechanical energy expended during pulverization is directly proportional to the new surface area generated—the apparatus grinds, sieves, and weighs prepared coal specimens under tightly regulated laboratory conditions. The resulting grindability index provides essential empirical data, enabling engineers to predict pulverizer capacity, minimize grinding energy consumption, and optimize overall solid fuel processing circuits.

Widely adopted across thermal power generation stations, metallurgical coking plants, coal preparation facilities, and technical research institutions, the equipment acts as a vital tool for quality assurance and operational planning. Precise grindability metrics allow operators to assess raw coal blend variations, forecast mill throughput, and schedule preventive maintenance on grinding elements before excessive wear reduces combustion performance. The data derived from testing serves as a foundational baseline for both plant-scale equipment procurement and day-to-day combustion efficiency optimization.

Manufactured with a rugged cast-iron chassis, heavy-duty worm reduction gearing, and a stabilized vertical loading assembly, this system provides uncompromising mechanical reliability under high-frequency testing schedules. The integration of advanced digital revolution counting and an ergonomic mechanical bowl lift mechanism removes common points of operator error and physical strain, ensuring high test reproducibility and long service life across demanding industrial environments.

Detail & Parts

Key Features

• Ergonomic Push-Up Bowl Loading Mechanism: Designed with a bottom-mounted mechanical lift assembly that smoothly elevates and positions the heavy grinding bowl, completely eliminating manual lifting strain and ensuring perfect axial alignment with the grinding spindle.
• Precision Microcomputer Revolution Controller: Features an intelligent digital counter that accurately monitors rotational cycles, automatically cutting motor power at precisely 60 revolutions to deliver reproducible test cycles in strict adherence to national testing standards.
• Calibrated Vertical Grinding Load: Delivers a constant, certified downward force of 284 N ± 2 N across the eight grinding balls, guaranteeing uniform crushing pressure throughout the milling cycle without variation caused by mechanical drift.
• Heavy-Duty Worm-Gear Transmission: Powered by an industrial-grade speed reducer paired with a 90 W drive motor, achieving a stable reduction ratio of 1:72 to maintain an exact spindle rotational speed of 20 rpm under varying coal hardness profiles.
• Failsafe Memory and Emergency Stop Functionality: Equipped with an instantaneous mechanical emergency cutoff switch that safely halts operation during anomalies, while the microcomputer retains revolution counts in non-volatile memory to allow seamless cumulative restarts without ruining the sample.
• Comprehensive Sieve Classification Suite: Supplied complete with precision-woven brass/stainless test sieves (0.071 mm, 0.63 mm, and 1.25 mm) and a heavy-duty protective screen (Φ16 mm) ensuring end-to-end sample fractioning from raw pre-screening to fine analytical separation.
• Vibration-Dampened Rigid Architecture: Built with a reinforced low-clearance chassis and machined dynamic components that absorb rotational chatter, protecting internal mechanical bearings and preserving dimensional calibration over thousands of sample runs.

Applications

Technical Specifications

Analytical Testing Procedure Summary

To ensure complete methodological fidelity using the equipment, prepared sample material must follow standard processing protocols:

1. Sample Preparation: Air-dry representative coal samples, crush via gentle stages, and sieve through the included 1.25 mm and 0.63 mm screens to isolate the 0.63 mm to 1.25 mm analytical fraction.
2. Grinding Cycle: Exactly 50.0 g of prepared sample is distributed evenly within the grinding bowl track with the eight steel balls. The push-up mechanism secures the bowl under the vertical spindle to apply the certified 284 N ± 2 N load.
3. Automated Milling: The unit operates at 20 rpm for precisely 60 revolutions via the digital microcomputer counter, halting automatically upon cycle completion.
4. Analytical Sieving: The pulverized contents are collected and agitated through the 0.071 mm analytical sieve using standard sieving protocols. The mass passing through the screen is weighed to calculate the Hardgrove Grindability Index using the calibrated reference equation.

Why Choose This Product

• Strict Adherence to Testing Standards: Built to meet rigorous GB/T 2565 specifications, this testing instrument guarantees reliable correlation with national and international standard coal calibration curves.
• Elimination of Operator Fatigue: The integrated mechanical push-up bowl design replaces outdated, physically demanding manual loading methods, creating a safer, faster, and more ergonomic laboratory environment.
• Uncompromising Mechanical Precision: Premium machined steel grinding elements, certified vertical weighting, and an industrial 1:72 speed reducer prevent mechanical deflection and deliver peerless cycle-to-cycle repeatability.
• Turnkey Analysis Package: Delivered with a full suite of analytical sieves, protective screens, and collection pans, the unit is immediately ready for deployment into power plant and commercial laboratory operations.

Contact our technical sales team today to receive a prompt quotation, discuss sample preparation requirements, or configure a complete solid fuel testing suite for your facility.

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