Classification Of Sifting Machines
Sieving machine is divided into two types of fixed screen and movable sieve, and the movable sieve is divided into rotating sieve and vibrating screen. Most of the fixed screens are fitted with grate to the inlet of the crusher to prevent the material from exceeding the specification. Most of the rotary sieve is formed by the plate sieve into a multi angle or circular cylinder, its simple structure and long life, but low production rate, bulky, large, but rarely used.
Sieving machine commonly known as sieve. A wide variety of sieves, generally according to the structure of the screen and the form of movement to be divided into the following types:
The fixed sieve is the simplest and oldest sieving machine, the sieve is composed of many parallel sieve strips, the direction of arrangement is the same or perpendicular to the direction of the material flow. Sieve surface into horizontal installation (dehydration) or tilt installation, work fixed, the material by weight along the screen slide and screening. Fixed sieve is divided into fixed sieve and bar sieve two kinds. Sieve sieve hole is generally square or circular, the bar sieve hole is usually sieve, the screen angle is generally 25 degrees to 85 degrees. The former sieve strip is thicker, the sieve seam is larger (general ≥25 mm), for coarse grain grade sieving, the latter sieve strip is small (general 0.25~1 mm), uses in the slurry the preliminary dehydration. A fixed sieve is used in a concentrator, usually for coarse or medium crushing prior screening. It is simple in structure and convenient in manufacture. Without power, the ore can be unloaded directly onto the sieve surface.
The working part of the drum sieve is cylindrical or conical sieve tube, the symmetrical axis of the sieve tube is fitted with a rotating shaft, and the whole sieve revolves around the axis of the cylinder body, and the axis is fitted into a small inclination in general condition. The cone-shaped sieve tube is horizontally mounted and the material is given from the small end of the cylinder, and with the sieve tube rotation is taken up, when reaching a certain altitude, due to the gravity effect of the fall, fine-grade material from the cylinder surface of the sieve hole through, coarse-grained material from the other end of the cylinder discharge, so constantly rise and fall movement to achieve the screening of materials. The rotational speed of the cylindrical sieve is very low, the work is steady, the power balance is good, can be used for coarse, medium material sieving and dehydration.
Vibrating screen structure consists of four parts, high-frequency vibration motor, first-class fixed-grid sieve and two-grade grading fixed lattice sieve, vibrating spring and casing. The support or the Hanging sieve box uses the spring component, the Sieve box vibration relies on the exciter. Vibrating screen is an elastic vibration system, and its amplitude can be changed by the influence of feed quantity and other dynamic factors. Vibrating screen is characterized by high frequency, small amplitude, inclination of sieve surface and sieve rate, and the higher the flow velocity of sieve surface, the faster the material is to jump on screen, so the productivity and sieving efficiency are high. The vibrating screen is suitable for various sieving operations in the coal preparation plant, many kinds.