The structural types of double-roll crushers (also known as twin-roll crushers) can be classified into various categories based on dimensions such as the number of rolls, roll surface shape, adjustment method, transmission form, and application scenarios. The specific classifications and technical characteristics are as follows:
1、 Classification by number of rolls
1. Double-roll crusher (standard type)
Structural features: Consists of two parallel rollers, one fixed roller and one movable roller. The movable roller is supported by springs or a hydraulic system and can move horizontally to adjust the gap and provide overload protection.
Application scenarios: Medium and fine crushing operations, processing medium to low hardness materials such as coal, limestone, and coke (compressive strength ≤ 300 MPa), with adjustable output particle size ranging from 1–20 mm.
Representative models: 2PG—400×250, 2PG—750×500 (processing capacity 5–55 t/h).
2. Four-roll crusher
Structural features: Composed of two sets of rollers in series to achieve two-stage crushing. Features hydraulic gap adjustment and a centralized lubrication system, with optimized tooth design to enhance crushing efficiency.
Application scenarios: Fuel preparation for circulating fluidized bed boilers (e.g., coal gangue), capable of replacing a secondary crushing system to reduce equipment investment.
Advantages: High crushing ratio (10–15), low over-crushing rate, suitable for crushing large pieces of raw coal or medium-sized coal.
3. Single-roll crusher
Structural Features: Consists of a rotating roller and a fixed jaw plate, crushing materials through compression and shearing forces.
Application Scenarios: Coarse crushing of medium-hardness, sticky materials (e.g., clay, coal), handling larger particle sizes (feed size ≤500 mm).
2. Classification by roller surface structure
| Type | Roller surface characteristics | Applicable materials | Crushing mechanism | Typical applications |
| Smooth roller | Smooth surface | Medium-hard materials (limestone, quartz stone) | Compression + grinding, uniform particle size (0.3–20 mm) | Artificial sand production, coke fine crushing |
| Toothed roller | Toothed or raised surface | Hard or sticky materials (coal gangue, coke) | Splitting + shearing, good anti-blocking effect | Coal preparation plants, metallurgical industry |
| Welded roller | Surface overlay welded with wear-resistant alloy layer | Highly abrasive materials (cement clinker, steel slag) | Compression-based, wear resistance life extended by 50% | Cement plant pre-crushing, steel slag treatment |
Tooth roller classification:
Double tooth roller: Designed for handling sticky materials (such as fibrous biomass), using tooth teeth to tear and reduce blockages.
Four-tooth roller: Two-stage crushing design, suitable for large-sized raw coal (feed size ≤1050mm).
3. Classification by adjustment and overload protection mechanisms
1. Spring-adjustable type
Principle: Adjust the roller gap (1–20 mm) by adding or removing shims or adjusting bolts to compress the spring.
Advantages: Simple structure, low cost; however, adjustment accuracy is low, and shutdown is required for operation.
Representative models: Traditional spring-type double roll crushers (e.g., 2PGT series).
2. Hydraulic adjustment type
Principle: Hydraulic cylinders replace springs to automatically adjust the roller gap in real time, providing instant protection against hard objects.
Advantages: High adjustment precision (±0.5 mm), supports remote control, and faster overload response.
Representative models: 2PGY series (e.g., 2PGY1000×800, processing capacity 25–35 t/h).
4、 Classification by transmission method
| Type | Transmission structure | Features | Applicable machine types |
| Dual motor drive | Independent motor drives each roller, V-belt + long-tooth gear synchronization | Uniform torque, avoiding gear interference | Large gear rollers (such as 2PGC1200×1500) |
| Single motor drive | One motor drives two rollers through belt + gear linkage | Compact structure, low cost; gears require high tooth design | Small smooth rollers (≤30kW) |
Special transmission: A hydraulic coupling is used between the motor and the reducer to prevent overload (e.g., in cement industry models).
5. Classification by application scenario
1 Mining and metallurgy type
Features: Roller surface made of high-manganese steel/chromium alloy for strong impact resistance; equipped with a centralized lubrication system.
Case: Crushing iron ore and manganese ore (feed size ≤110mm, discharge size 3–30mm).
2. Construction Materials and Environmental Protection Type
Features: Sealed dust-proof design, noise level ≤85dB; processes construction waste and limestone, with output used for brick making or cement production.
Innovation: Intelligent control system optimizes speed and clearance, achieving 20% energy savings.
3. Chemical Industry Specialized Type
Features: Corrosion-resistant roll body suitable for acidic or alkaline environments; equipped with scrapers to prevent blockages when processing sticky materials.
Summary: Selection Recommendations
For medium-fine crushing with uniform discharge: choose smooth rollers + hydraulic adjustment (e.g., 2PGY series).
For sticky/fibrous materials: choose toothed rollers (double-toothed or four-toothed rollers).
For high-hardness materials: welded roller surfaces + hydraulic overload protection (e.g., metallurgy industry).
For cost-sensitive applications: spring-adjusted double-roller machines (small sand plants).
