Introduction to Liquid Redistribution Distributors:
To minimize the amplification effect caused by poor liquid distribution and to fully utilize the efficiency of the packing, it is essential to install a liquid distributor in the packing tower to evenly distribute the liquid over the packing layer. The quality of the initial liquid distribution not only affects the mass transfer efficiency of the packing but also influences its operational flexibility. Therefore, the liquid distributor is a crucial internal component within the packing tower. There are various types of distributors, and the selection is based on many factors, including distribution quality, operational flexibility, throughput, gas resistance, and levelness, among others [1].
Liquid Redistribution Classifier:
1. By fluid dynamics of distributors: Gravity-type liquid distributors (hole-type, weir-type, pressure-type liquid distributors, spray-type, porous pipe-type)
2. By the shape of the distributor: Tubular, Double-layer Tubing, Groove, Disc, Impulse, Nozzle, Pagoda, Lotus, Combination, etc.
3. By the form of liquid leaving the distributor: Hole flow type, overflow type.
4. By liquid distribution frequency: Single stage, multi-stage.
5. By combination method of distributors: tube groove, hole groove, groove disk
The function of the liquid redistributor:
The DN900 Plastic Liquid Collector and Redistributor is designed to uniformly distribute or redistribute liquids at the top of the packing or at a certain height, enhancing the effective surface area for mass and heat transfer, improving inter-phase contact, and thereby increasing the tower's efficiency.
The DN900 Liquid Collector's function is to correct the poor distribution of fluid volume and concentration within the tower, serving both a redistribution and a mixing role, with the latter being more crucial. Due to the poor concentration distribution within the packing layer, it's difficult to eliminate during the concentration process. An effective redistribution collector should ensure complete mixing of the fluid and even redistribution across the tower cross-section.
Laboratory tests have shown that the flow of liquid within the packing layer is not uniform plug flow, but rather exhibits channeling, skewing, and wall flow phenomena. This leads to amplification effects and end effects in the packing tower. The purpose of reasonably designing and selecting liquid initial distributors and redistributors is to minimize and prevent the amplification effects in the packing tower, thereby reducing the tower height and diameter, and lowering the cost or operational expenses.
Poor distribution of liquid within the packed tower is categorized into large-scale and small-scale. Small-scale poor distribution is caused by liquid channeling within the packing layer, while large-scale poor distribution is due to the liquid distributor, which can severely degrade the tower's efficiency. Tests indicate that the higher the packing efficiency, the greater the impact of liquid distribution quality on packing performance. For instance, when the liquid distribution quality reaches 50%, the actual theoretical plate number for a packing with a theoretical plate number of 20 per meter is only 11.5, and for a packing with a theoretical plate number of 8 per meter, it is only 5.5.
