Pulverizers

Just a few of the many examples of pulverizers include grinding mills, jaw crushers, impact crushers, hammermills and ball mills. Some of the industries in which crushers and impactors are used include pharmaceutical products development, for grinding of various medicines into powder form for encapsulation and other applications; construction, in which stone crushers and concrete crushers are popular for use in the reduction of building materials; industrial manufacturing, for material processing applications; agricultural, as size reduction equipment for grain and other produce for use in food products; printing, to create pulp and other pastes used in the creation of paper; and power generation, in which coal mills are used to process coal in advance of its use in power plants. Similar to a shredder in function, a pulverizer differs from a shredder in that it can reduce material to tiny particles and can be exact with reduction sizes.

Pulverizers are generally sorted into three main categories: crushers, impactors and grinding mills. Crushers are designed to reduce the size of large, dense materials such as rock and stone to gravel or dust. Primarily, crushers are used for size reduction, easy disposal or recycling and to simplify differentiation of materials. One of the most common crusher designs is the jaw crusher, which has two jaws, one that is stationary and one that is mobile. Impactors, also referred to as impact crushers, are very similar to crushers but differ in the manner of size reduction. Impaction is force that is transmitted through a collision or by striking one body against another, whereas crushing is the use of pressure created by two opposing forces. Crushing and impacting utilize pressure and collision-wrought force. Grinding mills use friction to break down materials. The friction in grinding mills is brought about as a result of grinding media, which can refer to many different coarse materials such as non-sparking lead, ceramics, brass, bronze and flint. Two common types of grinding mills are ball mills and hammermills. A ball mill is constructed from a rotating cylinder that is mounted horizontally. They use grinding media such as steel balls or rods, which, as the cylinder turns, are tossed around the cylinder, smashing into the material to be grinded as they do so. Hammermills utilize numerous hammers encased in steel that rapidly revolve in a vertical plane.

In addition to the common types of pulverizers, there are many that are more custom-fitted to specific applications. For example, a MPS mill is a type of mill known as an applied force mill, meaning that the force used in this type of mill has both magnitude and direction. MPS mills utilize large tires as their grinding media and are primarily used for the pulverizing of coal. Bowl mills are very similar to MPS mills and come in two main designs: deep bowls and shallow bowls. Another example of a more application-specific pulverizer is a gyratory crusher. This type of crusher is very similar to a jaw crusher, but it utilizes a different motion to crush materials in that it does not rotate. Instead, its motion is eccentric, or off-center. Gyratory crushers are most commonly used in mine or ore processing plants for either primary or secondary crushing. Another very similar crusher to gyratory crushers is a cone crusher. A cone crusher is more commonly used for secondary crushing of ore and rocks than primary, and it functions by squeezing the materials between its mantle and bowl liner, where they fall lower and lower until they are small enough to fall through a narrow opening at the bottom of the crusher.

Some pulverizers are capable of processing materials continuously, while other pulverizers process materials in batches. Single-batch pulverizers shut off once the desired time duration has transpired in order to achieve appropriate particle size. Usually more dense materials such as plastic or wood are processed in single batch pulverizers, whereas concrete or coal can be continuously fed into a pulverizer via a conveyer or other automated system. Pulverizers are available in carbon, stainless steel and other materials depending on their intended use, since certain materials may be more suited for use in different applications and industries such as in food or other industries that require sanitary materials. As a result, it is important to explore the safety regulations associated with the material being reduced. Because of the immense force and pressure used in industrial pulverizers, the risk of employee injury can be high if proper safety precautions are not taken. Safety items such as guard rails, shields, sensors and auto shut-off controls decrease the likelihood of accidents. When properly installed, maintained and operated by trained professionals, pulverizers are invaluable assets to many operations.

Images Provided by Stedman Machine Company

Pulverizers Types

• Ball mills are cylinders partially filled with a spherical grinding medium used to grind material.
• Coal mills grind coal into powder using heavy rollers.  The rollers crush the coal into a powder.
• Concrete crushers are pulverization equipment used in the crushing or breaking of concrete into concrete aggregate.
• Crushers are machines designed to reduce the size of materials in a wide variety of industrial processes.
• Grinders are size reduction tools that abrade away a material's surface until it has taken the appropriate shape.
  
• Grinding mills are machines designed to crush solid material into small pieces. They can take on many different forms, including ball mills, hammermills, jaw crushers and roll crushers.
  
• Hammermills are high-speed rotor equipped machines with large hammers for crushing material into reduced sizes.
• Impact crushers utilize impaction to reduce the size of a range of materials. Impaction enables size reduction because it is as a force that is transmitted through the striking of one body against another.
• Impactors press and crush materials together. They are used often as a pre-pulverizing machine in a larger process.
  
• Jaw crushers macerate feed materials when they pass through two plates to turn out coarse particle.
  
• Jet mills uses a combination of air and fluid pressure to pulverize material in a sanitary environment at a low energy cost.
• Pulverizer manufacturers are industrial companies that produce various machines used for breaking up solid material.
• Rotary feeders are devices that move material or objects along in a process by a main rotating plate that picks up the items and moves them.
  
• Size reduction equipment is equipment that crushes, shreds, compacts or in some way decreases the size of an object or material.
• Stone crushers are pulverizers that are used to compress or break apart very hard materials. These materials can include any kind of hard, solid, nonmetallic mineral.

Pulverizers Terms

Aggregate - A coarse material, such as gravel, broken stone or sand, with which cement and water are mixed to form concrete.
 
Centrifuges - Centrifuges are devices that separate materials or components through centrifugal force or rapid rotation. 
 
Crush - To break into very fine particles; this is the main job of a pulverizer.
 
Feedstock - Stock from which material is taken to be fed into a processing unit.
 
Ferrous - Iron-based metals like steel.

Friable - Term used to describe a substance that is easily crumbled or powdered.

Hydraulic - Involving, moved by or operated by a fluid under pressure.
 
Industrial Balers - Industrial balers compress and bind materials.

Industrial Mixers - Industrial mixers are used to combine materials.

Industrial Shredders - Industrial shredders are equipment for the processing and size reduction of a wide range of materials.
 
Mechanical Pulp - Lignin-containing pulp produced from mechanically grinding logs or wood chips in refineries and pulverizers. It is used mainly for the production of newsprint and other paper.
 
Mesh - The class of particle size based on its passing through a sieve. Often used with powders and fine grains.
 
Particle - A small piece of matter having negligible dimensions or volume.  
 
Polytetrafluoroethylene (PTFE) - Resin is a class of polymer that has some or all of the hydrogen replaced by fluoride.
 
Powder - A solid substance in the form of many tiny particles; a solid that has been pulverized.
 
Pulp - The raw material used for the production of paper made mechanically via a pulverizer or chemically by separating cellulose fibers from the other structures in wood or other materials such as used/recycled rags, recycled paper, bagasse and straw.
 
Rotor - The rotating or moving component of a motor or drive, can include the shaft or fan.  
 
Sheave - Often used in drive systems, it is a wheel with a groove around it that guides or supports a rope, cable or belt.
 
Sieve - Acts as a strainer for separating chunks from material or for establishing the grade of particles.
 
Slurry - A liquid based mixture or suspension of solids.
 
Teeth - Jagged protrusions that are part of the plates that grind and crush in a pulverizer unit.
 
Waste Capacity - Measured in gallons, it is the volume of paper that the waste bag or other waste bin can hold.