(119e) Development of Structured Packings Using Additive Manufacturing and 3D Printing

Additive manufacturing (3D printing) has been assessed for the development of structured packings for humidity control at a spray dryer inlet. The desired air throughput for this application is a superficial velocity of 3.92 m/s. Two packing types were created using 3D printing, a layered, structured Pall ring, and a twisted sieve tray design. Experimental results were analysed to evaluate the throughput and mass transfer potential of the two packings. Whilst the structured Pall ring packing had a high mass transfer efficiency (NTU up to 1 for a packed height of m), the column flooded at gas velocities of 2.7 m/s and was hence unsuitable for the desired application. The pressure drop of the twisted sieve tray packing (420 Pa/m) was determined to be higher than that of Mellapak (700 Pa/m) at gas and liquid loadings of F_v=1 m/s(kg/m³)^0.5 and q_L = 5 m³/m²h, respectively. However, the twisted sieve tray packing did not flood at the required gas flow conditions and so had a suitable capacity. The twisted sieve tray packing achieved NTU up to 0.6 for a packed bed height of 0.2 m at the desired superficial velocity. Compared with industrial structured packing designs, such as Mellapak (250X), the structured Pall ring packing had a lower HTU, indicating better mass transfer performance than both the Mellapak and twisted sieve tray packing. The use of 3D printing allowed the timely and reliable design and construction of the two structured packings.