On the Evolution and Application of Hammer Mill Hammer Heads

As one of the primary components of hammer mills, hammer heads play a crucial role in the crushing process. During operation, driven by the high-speed rotation of the crusher rotor, the hammer heads violently strike the feed material entering the crusher, breaking it down for further processing. As one of the primary components for crushing materials, hammer heads are also the most heavily worn and consumed parts of hammer crushers. This is particularly true in industries like sand and gravel plants or brick factories, where the hardness of crushed materials exceeds that of cement plants, leading to more severe wear on hammer heads. Consequently, users are most concerned about the hammer heads' wear resistance, service life, quality stability, and susceptibility to breakage. Let's first explore the development of hammer crusher hammer heads:

Before the 1970s: Primarily made of ordinary white cast iron and wear-resistant ductile iron;

Post-1970s: With the development of multiple new dry-process production lines in the cement industry, high-chromium cast iron—known for its reliability and excellent wear resistance—gained popularity;

The 1980s saw breakthroughs in high-chromium hammers, with low-chromium, medium-chromium, and high-chromium cast irons emerging and entering mass production. Dual-metal cast irons combining high-chromium cast iron with steel were also adopted.

In recent years, high-chromium hammerhead technology has seen continuous innovation, with the successive development of martensitic matrix, austenitic-pearlitic matrix, and martensitic-pearlitic matrix ductile iron. We have independently developed manganese white cast iron, boron white cast iron, and tungsten white cast iron for wear resistance.

The primary hammer types currently available on the market include forged hammers, high-manganese steel hammers, high-chromium alloy hammers, and cemented carbide hammers. The most widely used are high-manganese steel hammers and high-chromium composite hammers.

Among these, high-manganese steel hammers demonstrate poor wear resistance in actual operation, with a short service life. Hammer heads used for crushing limestone typically last 2-3 months, and under certain operating conditions, they may fail within a week. The lack of wear resistance in high-manganese steel hammer heads stems from two factors: primarily abrasive wear and insufficient impact force during operation, which limits the work-hardening effect of the high-manganese steel. High-chromium composite hammerheads employ advanced composite casting technology. The hammer head utilizes wear-resistant high-chromium cast iron, while the handle incorporates tough alloy steel. This integration of toughness and wear resistance ensures the product is both wear-resistant and fracture-resistant. It represents the perfect combination of steel and iron, endowing the product with excellent comprehensive properties including wear resistance, impact resistance, and safety reliability. The service life of high-chromium composite hammers is four times that of forged or high-manganese steel hammers, while costing only twice as much.

The hammer crusher developed by OCP Heavy Industry, also known as the composite hammer crusher, utilizes high-chromium composite hammers. These hammers integrate toughness and wear resistance, ensuring the product is both wear-resistant and fracture-resistant with a long service life. Full hammer rotation reduces rotor pressure; high-chromium composite hammers ensure extended service life; wear-resistant protective rings on hammer discs simplify maintenance; spiral-shaped design with reinforced backing enhances strength and impact resistance; straight-through crushing chamber without grate bars facilitates high throughput and prevents material blockage.

During operation, feed material enters the crushing chamber through the inlet. The high-speed rotating rotor drives the hammers to deliver the initial impact, fracturing the material. The accelerated material then collides with the impact plate or collides with other particles for secondary fragmentation. During collisions, the material gradually moves toward the movable impact plate at the bottom of the crushing chamber. When the particle size becomes smaller than the gap between the hammers and the movable impact plate, the material exits the crushing chamber under its own weight or through compression by other materials. After undergoing multiple crushing processes—iron-on-stone, stone-on-stone, and stone-on-iron—within the crushing chamber, the material is discharged through the outlet.

(Technical parameters and other data mentioned herein are subject to updates with product upgrades. Click website customer service to obtain the latest equipment parameter sheet.)

OCP specializes in the research, development, and production of complete sets of equipment for crushing, screening, grinding, washing, feeding, conveying, environmental protection, dust removal, as well as steel, metallurgy, and steel slag processing and recycling. Our products are widely used in the crushing and processing of metals, non-metallic minerals, energy raw materials, and metallurgical waste residues within the steel and metallurgical sectors. Click on the website customer service for a free consultation now. Available 24/7.