Home > Encyclopedia

Impact Crusher

Impact Crusher

Impact Crushers(Impactors) comprise a lined chamber within which revolves a rotor on a horizontal axis. The rotor is fitted either with swing hammers located by pins or blow-bars of alloy steel located by mechanical or hydraulic clamps. The hammers or blow bars impart impact to the rock resulting in comminution that is energy efficient and a typically cubical product shape. Impact with the rotor, the chamber liners (breaker plates) and interparticulate collision all contribute to comminution. Reduction ratios of 20:1 are achievable in a single stage and even 40:1 for double rotor impactors. The impactor thus offers several potential advantages of high reduction ratio, low capital and operating cost, ease of installation and low head room requirement and good product shape. Product size can be varied within limits by changing rotor speed and the clearances between  rotor and liners.

The major limitation to the application of impactots is abrasive wear. Abrasive wear necessitates the costly replacement of hammers or blow-bars but, more importantly, results in loss of operating time, and low availability. Therefore, impactors tend to be restricted to crushing of non-abrasive rocks e.g. non-siliceous limestones and dolomites and to nonaggregate minerals e.g. coal, gypsum, salt. It has been stated that impactors are not suitable for rocks containing more than 5% free silica. Swing-hammer type impactors are generally applied to the production of the finer sizes of aggregate but impact becomes  ineffective at a particle size less than about 3 mm.

Impactors in Factory

The recent developments have mainly concerned the fixed blow-bar type which is now available as a primary crusher that can reduce very large lumps by a combination of impact and 'nibbling' actions. The use of a few large blow-bars forged from special alloys in place of many hammers and the design of the crushing chamber to permit very rapid access for maintenance, e.g. hydraulically actuated mechanisms for opening the casing and clamping wearing items, has overcome to some extent the principal disadvantage of impactors. They are now applied to the crushing of mineral ores, slags and siliceous limestones. Abrasive gritstones, quartzites and even basalt may also be crushed at the final stage by impactors when the value of the cubical shape produced justifies the cost, e.g. surface chippings  for roads or decoration.

In most cases the impactor operates in open circuit with no control upon product size other than clearances between rotor and liners, speed of rotation and feed rate. Caged hammer mills are available which include a discharge grating but the problems of wear and blockage can be severe and their use is usually restricted to soft minerals such as clays, coal, etc.

>>Previous: Gyratory Crushers, gyratory crusher working principle

>>Next: Vertical shaft impactors, What is Vertical shaft impactors?

Get Support & Quotation

Please fill in the form below(* are required), and we will get in touch with you as soon as possible.

Batching Plant Concrete Mixer Crusher Other

Solution

  • Ready Mix Concrete Plant, Ready Mix Concrete Production EquipmentReady Mix Concrete Plant

    Ready-mix concrete or ready mixed concrete (RMC) is produced at a central concrete plant withbatching system, and then it will be delivered to the customer’s c...

  • Concrete Aggregates Processing Plant,Sand and Gravel Processing PlantSand and Gravel Processing Plant

    A cone crusher is depicted as most suitable to crush very coarse rejects into the desirable size range of concrete aggregates. A ZS vertical shaft impactor may be used to increase the yield of sand....

  • Mason Sand Making Solution, Plaster Sand Making Plant, Sand Crushing PlantMason Sand Making Solution

    Mason Sand is also called as Plaster Sand, one type of important building material in construction industry. Mason sand has a maximum particle size of 9.5 mm, a...

  • Hard rock Crushing Plant, Roadstone Processing PlantHard rock Crushing Plant

    The following figure depicts the flowsheet for a plant producing various forms of dry (uncoated) roadstone including high PSV (+60) surface chippings. The produ...

  • Aggregate Production,River Pebble or Cobblestone Sand Manufacturing LineRiver Pebble or Cobblestone Sand Manufacturing Line

    The manufactured sand made of river pebble materials has a wide applications in cement concrete, asphalt concrete and various soil cement (stabilized soil) materials and other road, tunnel, bridge and culvert engineering projects....

Contact Us

Tel: 008637165861518

Fax: 008637165861528

E-mail:info@camelway.com

Mobile: 008618838109566

WhatsApp: 008618838109566

Skype: Camelway1983