Optimum Conditions for Blast Cleaning of Steel Plate

Abstract

Technological investigations are described in which practical blast cleaning of steel plate was simulated in the laboratory.

The rate of cleaning is found to increase when more abrasive per unit of time is discharged. This means that high pressure, a large nozzle and a wide valve for metering the abrasive flow are advantageous, but the actual setting of these variables should be mutually adjusted. The optimum blasting angle for removing millscale is about 45°, and the optimum nozzle-to-work distance is 55–75 cm. The smaller the abrasive grains, the quicker is the cleaning process. Under otherwise constant conditions, air consumption decreases as the abrasive transport is increased. High cleaning rates are advantageous because they lead to lower costs per unit area for labour and power, whilst for abrasive increase only slightly.