The Problem: Severe Clogging & Low Sulfur Recovery Due to Over‑Crushing
Double Tooth Roll Crusher — A coal mine in northern China was dealing with raw coal moisture of 20–25%, along with a high content of fine slime. The hammer crusher originally used would have its grate bars and screen plates clogged with wet fines every few hours, forcing at least two cleaning stops per shift. The effective operating rate dropped to barely 60%. Worse, the high‑speed impact of the hammer crusher severely over‑crushed the coal – fines below 3 mm accounted for more than 35% of the output. This created heavy dust, reduced thermal efficiency in the downstream boiler, and made briquetting nearly impossible.
Double Tooth Roll Crusher production site。
Retrofit Solution
The mine finally replaced the hammer‑type machine with a Huashengming Double Tooth Roll Crusher. This machine works on a low‑speed, high‑torque shearing principle. The two toothed rolls rotate at differential speeds (around 70 RPM), tearing and squeezing the coal instead of smashing it. The specially arranged tooth profiles allow wet fines to fall off naturally by gravity, without sticking to the roll surfaces. As a result, even at 25% moisture, the crushing chamber never clogs. At the same time, the shear‑dominated action keeps the -3 mm fine fraction below 12%, significantly raising the proportion of usable lump coal (6–50 mm).
Operational Results
After commissioning, the machine runs continuously with no need for manual cleaning. The plant’s operating rate jumped from under 60% to over 92%. The yield of usable lump coal increased by more than 35%, while dust collection load dropped by 40%. Boiler combustion became more stable, and briquette strength met the required standard. The site manager commented: “With this double tooth roll, we no longer have to poke at the screens with iron bars all day long.”
Double tooth roll crusher tooth profile
The plant switched from a hammer‑type machine to our heavy‑duty Double Tooth Roll Crusher. Operating at a low speed (≈70 RPM) with high torque and differential roll rotation, it tears and shears the coal gangue rather than impacting it. The self‑cleaning geometry allows wet fines to fall away naturally, keeping the crushing cavity clear even at 30% moisture – no clogging. At the same time, the shear‑dominated action keeps -6 mm fine powder below 15%, preserving the integrity of pyrite particles and significantly improving downstream jigging and flotation recovery. After commissioning, the equipment runs continuously without manual cleaning, and the coal concentrate yield has increased by more than 40%.
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