Most units have installed dust suppression systems comprising water tank, pump, GI pipelines and many nozzles spraying at many locations, but the dust control is hardly satisfactory. This could be primarily due to some faults in the designing of spray systems such as improper layouts, improper location of sprays, inadequate knowledge about spray systems, too many nozzles thereby improper sprays, inadequate water pressure, absence of water filter leading to choking of nozzles etc. Lump Crusher

On one hand there are advantages of having planned crusher zone by ways of concentrating the emission generation activities but on the other hand, it has disadvantage in terms of very high level of ambient SPM concentration in and around crusher zone. The existing dust control systems in the zone are not adequate enough to control the fugitive emissions from the crusher operations.

In the absence of appropriate dust control mechanism, the gravity of environmental problem from such clusters is quite alarming and the ambient SPM levels are quite high in these clusters and since the airborne emissions in the respirable.

A study done by NPC at the Raisina Crusher Zone in Haryana reveals that the contribution by the zone in the ambient SPM level is 50857 µg/m3, which is more than 80 times higher than the prescribed standard of 600 µg/m3. This problem could be overcome by insisting on adoption of the advanced designs of dust containment cum suppression or dry collection systems by all units.

Once each unit attains dust free operations, then the "crusher zone" approach would be the best approach for siting of new crushers, provided basic infrastructure of road, electricity and water is provided by the State Government.

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.

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. Continuous flow ball mill

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.

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. Raymond Low-Side Roller Mill