REMOVAL OF PROCESS DUST FROM GAS EMISSIONS IN JET-BUBBLE CONTACTORS

In the dairy industry, the production of dry milk products involves energy-intensive drying units where fine particles (0-30 μm) are often lost through exhaust air. While primary purification via cyclone banks achieves an efficiency of 95-97.7%, actual product losses can exceed 1% of the dryer's capacity, especially in older systems. Given that fine particles under 5 μm are prone to escaping these systems, there is a clear economic and environmental imperative to implement a second stage of purification. This study evaluates the use of a scrubber equipped with jet-bubble contact devices operating in an active hydrodynamic bubbling mode as a secondary purification stage. Experimental research was conducted using a laboratory test bench modified with a vibrating feeder to ensure uniform product dosing and an aspiration scheme to prevent dust leaks. The study focused on two distinct purification zones within the apparatus: a coarse zone in the initial sections and a fine zone within the foam layer under intense bubbling conditions. The analysis of experimental data reveals that the efficiency of capturing dry milk from the air stream is at least 99%. Based on these results, an industrial exhaust air purification scheme was proposed, integrating the scrubber after the primary cyclone stage. In this configuration, the captured milk-water mixture is processed through a foam separator and milk filter before being redirected to vacuum evaporators for further processing, thereby recovering valuable raw materials.