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Method of estimation of PM10 fine particle concentration during operation of centrifugal friction rollers

One of the solutions to increase the storage capacity and speed of handling palletized goods in warehouses is the use of gravity pallet racking. As elements of the safe operation of such conveyors, centrifugal friction rollers are widely used, which ensure the speed of the pallet within the limits that do not exceed the permissible values. During the operation of centrifugal friction rollers, wear products — brake dust, which have an adverse effect on the human body, may enter the atmosphere. Therefore, an urgent task is to study the operation of friction-type brake rollers from the point of view of the environmental assessment of the released brake dust. The paper assesses the concentration of fine particles with dimensions from 10 micrometers to 2.5 micrometers during the operation of centrifugal friction rollers in gravity pallet racks, and proposes a method for estimating their concentration in the warehouse working area. The coefficient of environmental friendliness of the design of the brake roller of the friction type has been introduced, which is one of the factors determining the maximum number of braking, and takes values from 0 to 1.0 for various designs of the friction roller — closed type, ventilated and open type. The results of an experimental study of materials for friction pairs of brake rollers show that the maximum amount of braking is provided at a pressure on the friction lining of 0.1 MPa, which corresponds to a pallet weight of 1000 kg. An example of using the methodology for estimating the concentration of particles in the working area for a warehouse consisting of one block of gravity racks for pallets 1200x800x1500 mm (length x width x height), weighing 1000 kg, with a total number of 546 pallet places is considered. Analysis of the results showed that the maximum number of pallet braking at which the maximum permissible concentration of particles with a dimension of 10 micrometers to 2.5 micrometers is reached and the maximum turnover of the warehouse can serve as a comprehensive assessment of its environmental friendliness.