The vibratory screen should be compulsorily enclosed from the screen supporting platform level up to top of the screen. The enclosure should be provided either with maintenance walkway around or without walkways with a compact enclosure of the size of the screen only. Vibrating Screen For Coal Dressing
In such cases whenever there is a maintenance requirement, a provision should be kept either to take out some of the enclosure sheets or provide door type opening access for maintenance. Care should be taken to put back the sheets and close the door after maintenance is over. In all circumstances the enclosure has to be kept closed during operation of the crusher.
The enclosure should have only one opening for the belt conveyor and it should be provided with flexible rubber flaps to minimize the gap all around. A maximum of two inches gap on either sides of the belt conveyor should be kept.
It is generally reported that the units have to take out the screen plate and other big parts out of the enclosure for maintenance and therefore they need to keep one side permanently open. A proper opening of required size with a door type opening and closing arrangement can very well be provided. Even an arrangement like rolling shutter can be installed to open and close large area as per maintenance requirement.
It is also reported that the operators are often required to physically see the vibratory screen and therefore they need to keep one side open. Technically this cannot be acceptable reason. Once people get used to proper enclosure arrangement they may also get used to doing away with one side open concept. Coal Mine Plant Machinery
The experience in many other crushers who have installed full enclosures of the screen can certainly support this argument that the screen can be kept closed and would not have any operational problem.
The enclosure of the screen is a must for all small, medium and large category units and for all types of screens i.e., vibratory or rotary. For small capacity crushers with single rotary screen with manual retrieval from below the screen, the side enclosure can be provided with openable doors from either sides.
Depending on the wind directions, the retrieval of material can be done on the side downwind to the wind direction by opening of the door of that side but the other side door should be kept closed that means during crusher operation one side of the enclosure has to be always kept closed. Kenya Crusher