roller crusher 250t jam

Roller Crusher 250t/h: An Overview of High-Capacity Crushing

The specification "Roller Crusher 250t/h" refers to a class of crushing equipment designed to process up to 250 tonnes of material per hour. This high-capacity machine is typically a double-roll crusher, utilizing two counter-rotating cylinders to crush raw materials through compression and shear forces. It is a cornerstone in industries requiring the intermediate crushing of medium-hard to hard materials such as coal, limestone, ore, and construction aggregates. The 250-tonnes-per-hour capacity marks it as a solution for medium to large-scale mining, quarrying, and cement production operations, balancing robust throughput with controlled product size reduction.

Key Features and Comparative Advantages

A Roller Crusher rated at 250t/h is engineered for reliability and efficiency. Its primary features include a sturdy frame, manganese steel wear segments for long service life, adjustable crushing gap for product size control, and often a hydraulic or spring-based overload protection system to safeguard against uncrushable material. To understand its positioning in the crushing circuit, it's useful to compare it with other primary crusher types at a similar capacity range.

Feature	Double Roller Crusher (~250t/h)	Jaw Crusher (~250t/h)	Impact Crusher (~250t/h)
Crushing Mechanism	Compression & Shear	Compression (Eccentric)	Impact & Blow Bars
Product Shape	Cubical, minimal fines	Slabby, elongated particles	Highly cubical, can be friable
Feed Size	Medium (relative to roll diameter)	Very Large (high reduction ratio)	Medium
Wear & Maintenance	Wear on roll surfaces; predictable	High wear on jaw plates; periodic replacement	High wear on blow bars; frequent replacement
Best For	Secondary/Tertiary crushing of abrasive materials; precise size control in coal/salt.	Primary crushing of very hard, abrasive materials (e.g., granite).	Primary/Secondary for non-abrasive, medium-hard rock where shape is critical.

As the table indicates, the 250t/h roller crusher excels in applications where a consistent product size with fewer fines is required from materials that are abrasive but not extremely hard.

Real-World Application Case Study: Limestone Processing for Cement Production

A cement plant in Southeast Asia faced challenges with its existing secondary crushing circuit for limestone. The goal was to achieve a stable feed of 0-25mm material for the raw mill at a rate of 230-250 tonnes per hour. The previous hammer crusher produced excessive fines (<3mm) beyond specification, leading to packing issues in the mill and higher energy consumption.

The solution was the installation of a heavy-duty double-roll crusher (model spec: 2PGC-1500×2000) with a designed capacity of 250-300t/h. Key implementation steps included:

1. Feeding System Modification: A grizzly feeder was installed upstream to scalp off already sub-25mm material, directing only oversize to the rolls.
2. Crusher Configuration: The roll speed and gap were precisely set to maximize throughput while ensuring the top-size product did not exceed 25mm.
3. Wear Management: Automatic welding systems were used for in-situ rebuilding of manganese steel roll shells.

The results were documented in the plant's operational reports:

• Throughput: Consistently achieved 245-255 t/h.
• Product Yield: Over 85% of output within the desired 3-25mm range—a significant improvement.
• Operational Cost: Reduced power consumption by ~15% compared to the previous system and extended wear part life from ~800 hours to over 1,200 hours.
• Mill Efficiency: The optimized feed size distribution improved raw mill stability and output.

This case demonstrates how selecting a correctly sized roller crusher directly addresses specific production bottlenecks.

Frequently Asked Questions (FAQ)

Q1: What is the typical maximum feed size for a roller crusher with a 250t/h capacity?
A: The maximum feed size depends on the roll diameter. For a crusher rated at ~250t/h with common roll diameters (e.g., 1500mm), the maximum feed lump size is typically in the range of 300mm to 500mm. It is crucial to consult manufacturer specifications like those from FLSmidth or Metso Outotec for exact models.

Q2: Can this crusher handle wet or sticky materials?
A: Double-roll crushers can struggle with clay-rich or highly sticky materials due to packing and clogging between the rolls. For such applications (e.g., certain iron ores), specialized "toothed" or "cleated" roll designs are available from suppliers like McLanahan or TerraSource Global to aid in grabbing and pulling material through.

Q3: How is the product size controlled?
A: Product size is primarily controlled by adjusting the gap between the two rolls using mechanical shims or hydraulic adjustment systems. A smaller gap produces finer product but reduces throughput potential; a larger gap increases capacity but yields coarser output.

Q4: What are common maintenance points?
A: Key maintenance focuses on wear parts:

• Roll Shells/Segments: Regular inspection for wear profile and thickness.
• Bearings: Monitoring temperature and vibration.
• Drive Components: Checking gear couplings or V-belts for alignment and tension.
• Overload protection systems should also be tested periodically as per OEM manuals.

Q5: Is this suitable as a primary crusher for run-of-mine (ROM) ore?
A: Generally not recommended unless specifically designed as a primary sizer/roll crusher with very large rolls and robust construction (e.g., mineral sizers). For most hard ROM ores (>200 MPa compressive strength), jaw or gyratory crushers are preferred due to their higher reduction ratio and ability to accept larger lumps without bridging problems