vibrating sieve operation principle

The vibrating sieve(we also named vibrating screen or vibrating screener) are induced by pushing rods. depending on the method of excitation, single and double-sided screens are distinguished. a characteristic feature of the first  type is that the pushing rods induce vibrations through constant or temporary press on one side. the sieve returns to the state of equilibrium due to its resilience.

 

　　The double-sided screens impart full vibrations onto the sieve because they are connected to it rigidly.  An important role in both single- and double-sided screens is played by mesh tension, both in axial and transverse direction. attention should be paid to the fact that in the screens with a direct sieve excitation, due to continual sieve vibrations, the effect of removal of particles hard to screen and blocking the mesh from the sieve surface are achieved. the effect of selfcleaning is a very beneficial phenomenon which does not occur, or occurs to a too small extent, in the classical screens where sieves remain immobile.

 

　　Two basic designs of the screens are known. in the first one the sieve is driven by electromagnetic vibrators, each connected separately to the sieve by pushing rods. such a design is shown in fig. 3.membrane screens with vibrating sieves 

 

　　The inclination was twice as large as in the case of screens with immobile sieves. such big values of the angles and high accelerations caused significant velocities of material on the sieve amounting to 0.5 to 1.0 m/s. a characteristic feature of classification on the screens with vibrating sieves is a thin layer of material on the sieve. its thickness is equal or twice as large as the stated

 

　　Particle size. this provides very good stratification conditions. high efficiencies reaching 100% can be achieved, which is impossible in the classical screens. The process capacities are also much higher than those obtained in other screens. screens with vibrating sieves are able to self-clean the sieves. vibrations of the sieve surface cause that blocked particles are removed from the mesh. this feature may be a reason why higher process capacities are achieved and causes that these screens are especially suitable for screening of fine- and very fine-grained materials.membrane screens with vibrating sieves 

 

　　the discussed screens with sieves excited directly, and in particular the screens with driving frames, due to their specific construction, i.e. location of an electrovibrator outside the riddle side walls, are very suitable for wet screening. flat sieve geometryin the classical screens, i.e. the ones with immobile sieves, the layer on the screen is tossed evenly. in the screens with sieves excited directly, due to specific excitement of vibrations, the tossing of material on the sieve surface is different. to approach this phenomenon quantitatively, a description of the vibrating sieve geometry is proposed