Working principle and application of DSM screen
Sieve bend screen is mainly used for material classification, dehydration, and medium removal in the coal mines and other industries. The material is fed into the screen surface at a certain speed along the tangent direction. Due to the centrifugal force, the material layer moves close to the screen surface. When the material layer flows from one wedge wire to another, the edges of each wedge wire have a cutting effect on the material layer. Under the action of centrifugal force, the cut material is discharged through the screen gap and becomes the material under the screen. The uncut part of the material passes through the root sieve strip and becomes the material on the sieve.
Dsm vibrating screen is a kind of fixed slot screen with a certain radius of curvature and wraps angle. It has no moving parts, and its structure is relatively simple, but its processing capacity is large.
DSM screen plays the role of dehydration, medium removal, desliming, and classification slime recovery in the coal preparation process. According to the different feeding methods, it can be divided into two kinds: one is the gravity flow DSM screen without pressure feeding; the other is the pressure DSM screen with pressure feeding.
The DSM screen is mainly composed of a set of DSM screen surfaces, feeders, discharge funnel, and support. The screen strip used to make the curved screen surface is a trapezoidal screen strip, and the layout direction of the screen strip is perpendicular to the movement direction of the slurry on the screen surface. The screen bar is usually made of stainless steel and sometimes nylon.
When the screened slurry is fed to the screen surface along the tangent direction at a certain speed, under the action of centrifugal force, gravity, and friction, the slurry moves close to the screen surface. In the process of the material layer flowing from one screen bar to another, the edge of the screen bar has a cutting effect on the material layer, so that a part of water and fine particles are separated. This part of the material is cut by centrifugal force After being used, it is discharged through the screen gap and becomes the product under the screen; the uncut part of the material layer flows through the screen surface and becomes the product on the screen.
The flow velocity and thickness of each sieve strip are generally 1 / 2-1 / 4 of the gap width of the sieve strip. The larger particles in the sieved product are about 1 / 2 of the sieve gap.
The DSM screen can be made into different radii and angles according to needs. The commonly used angles are 45 °, 60 °, 90 °, 180 °, and 270 °.
The arc angles of 45 °, 60 °, and 90 ° are often used in the gravity flow DSM screen, which is used in the coal preparation plant and concentrator. Pressure type DSM screen, usually 180 ° and 270 ° radian, is used for grading operations in the grinding process of the cement industry.
Because of the great discharge capacity of the DSM screen, many coal preparation plants often use the DSM screen for pre dewatering before the dewatering screen, and the screen gap is generally 3-6 times larger than that of the dewatering screen in the next process, but it should not exceed 3mm.
The width of the DSM screen should be 150-200 mm smaller than that of the dewatering screen in the next process. DSM screen can also be used in series according to needs.
Due to the continuous improvement of the design, the manufacturer has also designed the screen frame according to the needs, which adopts the pivot steering structure and can rotate 180 ° DSM screen, extending the service life of the screen surface.
In addition, bluslot also developed a two-way DSM screen, which is composed of a vibrating motor, distributor, and screen box. The feature is that the screen box is composed of two side plates, a branch network steel pipe, two reverse installed screens, and a distribution plate. The screen is fixed at one end of the branch network steel pipe by pressing bar and wooden wedge, the other end of branch network steel pipe is fixed on the base, and the side plate is connected with the base; The vibrating motor is installed outside the screen box, and the distributor is installed on the top of the screen box. This two-way DSM screen uses two screens, which not only improves the processing capacity of the DSM screen, but also improves the screening efficiency of the DSM screen, and makes it very convenient to replace the screen.
The screen is mainly composed of sieve bend screen surface, screen frame, and support. There is a central rotating shaft in the middle of the screen frame. The screen frame can rotate 180 degrees with the central rotating shaft. The screen does not need to be disassembled to change the direction, so as to prolong the service life of the screen surface.
The coal slurry moves along the sieve bend screen surface. When it crosses a screen bar, the liquid flow collides with the sharp corner on the side of the screen bar, and the water tension on the surface of the particles is destroyed at the included angle of the screen bar. Therefore, a part of the water and fine particles are cut down and become the material under the screen.
Application scope of DSM screen:
It is used for product classification in mining, building materials, transportation, energy, chemical, and other industries.