One of the main agricultural operations is called grinding - grinding grains to a state of flour. The primary role in this process is played by crushers, among which hammer mills occupy a leading position. The variety of raw materials with different physicochemical properties requires the use of various types of similar equipment.
Principle of operation
The main working element of the equipment is an electric motor, which is connected to the rotor. Jackhammers are fixed on the shaft driven by the engine with the help of articulated links . The frame is supported by the elements, and the metal case is used as protection against external influences.
The work of mills is based on impact and abrasion. After starting and supplying the raw material, the rotor, rotating at a tremendous speed, creates an air stream that draws in and makes the grain and grain rotate. Impact hammers, freely moving through the loose grain mass, hit particles with working faces, thereby grinding them.
The presented process continues until the hammer mill can provide the user with a product of a given condition. Additional grinding of raw materials occurs due to friction on the sieve. The processed material, which is smaller than the size of the sieve mesh, is removed from the crushing chamber and enters the next stage of the technological process.
Features of hammer mills
Hammer equipment is used in many sectors of the agricultural sector, mainly in the process of making flour. It has also found wide application in the livestock department - here they are used to grind compound feeds and prepare additives for incorporation into the feed.
Special types of systems are also used in industry - for grinding ceramics, glass, stone. Hammer mills earned their popularity for a reason. This was facilitated by a number of beneficial advantages:
- Simplicity of design.
- High degree of reliability.
- Small dimensions.
- Dynamic operating modes.
- High speed grain processing.
- Easy to maintain and use.
But the use of this type of equipment in some situations is impractical due to the high cost of electricity. This creates certain difficulties for medium and small enterprises.
Classification of hammer mills
Hammer mills are classified according to several indicators. The first of these is power. According to her, all equipment is divided into equipment for private farms (up to 1.6 kW) and industrial crushers (up to 32 kW). The second important characteristic is performance, which divides all devices into 5 sizes:
I. Able to process 5-6 tons of products per hour, used in large feed mills and to create flour.
II. 2-3 tons of products are crushed and used at district factories or feed mills.
III. Productivity 1-2 t / h, they are in demand in the feed workshops.
IV. They crush from 500 kg to 1 ton per hour of work, can be found at large livestock facilities.
V. Grind from 100 to 150 kg / h, used for the manufacture of additives.
In addition, hammer mills can be divided into separate types due to the peculiarities of their design, the implemented technology of grinding grain and the method of removal of the finished product.
Hammer crushers are produced by both domestic and foreign companies. Both Russian and foreign technology has its own characteristics and advantages realized by technologies for improving quality and reducing production costs.
Hammer Mills M-8 and DM
Let's consider separate models. Domestic hammer mill M-8 has long remained a sought-after technique in the agricultural sector. It has three modifications and is used for grinding grain, creating feed for cattle and threshing corn cobs. Its main advantage is productivity, which is about 22 tons per hour.
The hammer mill for DM grain , as well as its modification of DDM, was also widely used. Among themselves, the designs differ only in size and technical characteristics. A feature of this equipment is serviceability - to access the main working elements, it is enough to open a special hatch.
Another distinguishing feature is the ability to transport finished products mechanically and pneumatically. In the first case, the crushed material is discharged by a
conveyor belt, and in the second case, by air draft created by an additionally mounted pneumatic receiver.
Reversible hammer mills
Users consider A1-DDP and A1-DDR models to be popular reverse crushers from a Russian manufacturer. The devices have some differences in design and technical performance, but the principle of operation is the same. Such equipment is mainly used for grinding cereals and membranous crops, meal.
For the full use of shock surfaces, a hammer mill of reversible action was calculated. Such structures include a symmetrical crushing chamber, which allows them to work by rotating the rotor in different directions. This increases the service life, since the beats are used on both sides.
Foreign mills for fine grinding
Judging by customer reviews, the Impact mill is the most popular worldwide. The success of the device was guaranteed by its design, which incorporates two annular chambers. The grinding process takes place in two stages:
- The grain mass enters the hopper with hammers rotating along a smaller radius - preliminary grinding occurs.
- Sufficiently shredded material “seeps” into the second chamber through the cells, where fine and uniform grinding is carried out.
Another fairly popular instance for fine crushing was the unit of the Japanese company "Kagawa". A design feature is the presence of blades in the form of dihedral wedges, which are equipped with guide plates. They are located with packages of hammers and during operation provide a fine grinding of products.
The main advantage that is inherent in all foreign representatives is reliability. That's what the reviews say. Buyers are pleased that, as a rule, repair of hammer mills from abroad does not have to be carried out for decades, if the rules of operation and maintenance are observed.
Other purpose of hammer mills
Not everyone knows that hammer mills have found their application in the mining industry, mainly for processing coal, peat, and shale. Here they are used to bring raw materials to a purchasing state.
Based on the reviews, it can be concluded that among all the representatives in Russia, the MMT hammer mill with indices of 200 or 800 is used more often than others. One of their features is the possibility of combining the drying and crushing of products. The technique is a rational solution for technological processes of creating powders and processing of mineral raw materials.