Humanity has milled materials like salt and seeds for millennia, but large-scale grinding became possible in the last century due to technological advancements. Industrial machines, like the hammer mill, have evolved to improve material processing efficiency, making them vital in various sectors.

Hammer Mills in Industry

Due to its relatively straightforward layout and operating mechanisms, hammer mill applications are many and extraordinarily varied. Almost any substance – from recycled plastic and glass to ancient grains and plant proteins – can be processed with the help of a hammer mill. The versatile and robust hammer mill can be tailored for various uses, offering customizations for specific applications. Its design and manufacturing capabilities enable it to process a wide range of materials easily.

Some basic hammer mill uses in industry involve:  

  • Activating ingredients: Active ingredients are especially important in the pharmaceutical industry, where medicines are milled to increase particle surface area, which speeds a medicine’s absorption within the body and encourages a more homogeneous mix that helps ensure proper dosages; similar hammer mill uses are found in food processing to enhance the taste of food and cosmetics to augment consistency.
  • Facilitating mixing: One of a hammer mill’s uses that’s particularly important to the food processing and pharmaceutical sectors involves mixing ingredients while breaking them down; multiple fibrous and dry solid substances can be reduced together, allowing for a more even distribution of ingredients in baking mixes or medicines.
  • Grinding product: The cosmetics, food processing, and pharmaceutical industries often require that materials be ground to produce products like body lotions, prepared foods, and medications.
  • Producing powders: The chemical, cosmetics, food processing, and pharmaceutical industries depend on hammer mills to produce intermediate powder grades from dry material to produce powdered chemicals, makeup, granulated sugar, and powders for pills or capsules.
  • Recycling: The impact force a hammer mill uses to break down; this same impact force can also be used for breaking down and recycling other materials like wood, plastics, paper or glass. 

Particle size reduction is a key goal for material-handling equipment like the hammer mill. Hammer mills are versatile, efficiently resizing anything from dry fibrous materials to slurries with their crushing force.

Foundations of Hammer Mill Operation

There are numerous designs for a hammer mill. The number of hammers attached to the shaft might fluctuate as it rotates between a set of plates. The direction they strike might be vertical or horizontal, but any machine that features freely swinging hammers around a shaft is still a hammer mill. Uses may also vary, but normally, hammer mills receive material from above, feeding it into a grinding chamber. Crushing occurs progressively between the milling components before the material drops from the chamber, where it’s packaged or continues to the next processing phase.

The stages a hammer mill uses to break down product generally work as follows:

  • Material is first fed through a chute, usually by gravity, above the grinding chamber.
  • Once within the grinding chamber, hammers crush the material with recurrent strikes, while impact with walls and other particles further reduces the product.
  • Screens or bar grates made from metals or alloys classify material once it reaches the preferred size range.
  • Coarser materials that can’t fit through the screen or bar grates return for further grinding, while those that are the proper size pass through.
  • Free-flowing and denser materials get discharged via gravity, normally directly below the machine.

The classified material that passes through the grates or screens ensures consistent and uniformly sized particles. Particle size can be altered by varying the hammer configuration, changing the driveshaft’s speed, or modifying the screen size. More hammers moving more quickly around the shaft with smaller screens result in a finer product, while fewer hammers moving slowly around the shaft with a larger screen produce a coarser product.

Other design variations can also factor into the finished product after going through a hammer mill. The use of these milling machines can vary depending on the grate or screen type, housing size, speed at which the hammers rotate, and type of rotor. The higher the rotations per minute, the more centrifugal force is applied, resulting in the desired particle size range in the final product.

Applications for Prater Hammer Mills

The elegant design of the hammer mills made by Prater Industries allows manufacturers to customize them to suit their purpose exactly. Prater hammer mill uses include but are not limited to processing chemicals, corn meal, flour, food, granulated sugar, livestock feed, minerals, powdered pharmaceuticals, spices, and various other products. Prater hammer mills are particularly effective at reducing raw materials from mid-sized to ultrafine particles.

Applications in which Prater hammer mills excel include: 

  • Agricultural industry: In an industrial capacity, one of the original hammer mill uses for Prater equipment was within the agriculture industry – initially for processing grains like wheat, rye, rice, corn, or barley – though chia, flax, pumpkin, sunflower, and other seeds have become more popular in recent years.
  • Animal feed processing: Hammer mills are used in the feed industry and include around-the-clock operations to reliably mill various feeds for different animals, from large livestock to small pets, which Prater equipment readily supports.
  • Bakery industry: Due to the type of hammer mill common in bakeries of all sizes, the industry requires durable and easily cleaned equipment, for which Prater offers ideal solutions.
  • Bakery premixes: Whether it’s premixed ingredients for an industrial bakery or a box of cake mix on a grocery store shelf, Prater’s hammer mills aid the mixing of dry ingredients, reducing the time it takes to make baked products for commercial bakeries and consumers.
  • Chemical processing: As part of the chemical processing equipment, Prater hammer mills are used by prominent chemical companies and other leaders in the industry to handle some of the most toxic chemicals.
  • Food processing: Prater hammer mill uses for processing food and beverages are many and varied, offering food processors a reliable way to break down an array of materials to make products like bran flakes, granola, pasta, and powdered cocoa.
  • Hemp processing: When processing hemp with a Prater hammer mill, its uses depend on whether the raw material being processed is fiber, flowers, oils, or combinations of any plant parts.
  • Pharmaceuticals and nutraceuticals: Through its ability to create compact powders that can fit into small capsules, the impact energy Prater’s hammer mill uses allows companies in the pharmaceutical industry and its sister, the nutraceutical sector, to make products with better bioavailability.
  • Spice processing: To preserve taste and nutrition, spices are ground by Prater’s hammer mills in a manner that preserves essential oils that enhance flavor and nutrition.
  • Wood processing: Plant material from trees and other woody plants can be made into a wide variety of products, with Prater hammer mill uses including bedding for animals, biofuels, briquettes, compost, fire starters, paneling, plywood, and other wood-based products.

Other hammer mill uses include processing of bulk materials that don’t quite fit into the above applications. The engineering team at Prater is skilled at designing specially built machinery to achieve each customer’s distinct processing goals.  

Case Study: Soybean Processing 

Processing soybeans is done primarily for the meal, with oil from the beans being an ancillary product. The hulls of the beans need to be cracked, which involves removing the hull and then rolling the beans into flakes containing high amounts of fat. This rolling process facilitates oil extraction, after which the solvent used to extract the oil is removed, and the flakes sans fat are dried.

Most of the defatted soy flakes are made into meal and animal feed. These soy flakes can be processed into flour, grits, or textured vegetable protein (TVP) through grinding. Further processing results in products like soy protein isolate and soy protein concentrate, which are used as ingredients for various bakery, dairy, and meat products, as well as formulas for infants and other soy foods.

A prime concern with soybean processing involves the two different uses for soybeans: for oil or food. Since most soy meals are used for animal feed, most soybeans are first made into meals. As soy meals contain significant fat, the equipment that handles them must be cleaned and maintained regularly. Other products from the soy meal need to be ground into a fine powder to produce them. However, shear is difficult to achieve due to the high fiber content in soy flakes.

Prater’s Solution

The first part of Prater’s solution involved Prater’s Mega Mill. This hammer mill uses tried and tested particle reduction methods to reduce the soy meal to under 40 mesh (400 microns). It’s an ideal answer for grinding the meal, as Prater’s Mega Mill Hammermill uses a system designed so that the rotor can be completely disconnected from the housing. This allows operators or maintenance personnel to clean it to prepare it for processing in less than twenty minutes.

This significantly reduces the time it takes to clean a conventional hammer mill. Used for applications like soybean processing that require stoppages for regular cleaning, the Mega Mill presents a much better option than a full-screen hammer mill, which often requires several hours of downtime to scrub down, with each hammer and pin requiring individual cleaning. The Prater-designed system for processing after the hammer mill uses one of Prater’s M-series fine grinders that grinds meal down to 200 mesh (74 microns) with very tight particle distribution.

Hammer Mills by Prater Industries

Thanks to their versatile and robust design, discover the endless possibilities and efficiency of hammer mills in various industries, from agriculture to pharmaceuticals. With Prater's customized solutions tailored to specific needs, manufacturers can streamline their processes and achieve optimal particle size reduction. Utilize the power of innovation with Prater's hammer mills for unrivaled productivity and quality in material processing.