Different Types of Packings in Distillation Columns

We see many types of industrial distillation including extractive, azeotropic, steam, vacuum, and fractional distillation. Industries that create beer, wine, and liquor, desalinate water, refine oil, and produce chemical products for home and industrial make use of distillation process. You see it in industries purifying and manufacturing rare gases oxygen, and nitrogen. Also, in those involved in the refining of crude oil, kerosene, and naphtha.

Use of packings in columns

The material gets packed into the column in different ways depending on the liquid undergoing distillation. The essential thing here is the geometry of the packing. This will alter for different liquids and also depends on the process. The first is the heli-pak where a metal wire remains wound around a twisted rectangular rod. This gives free space amounting to 83% and the metal used is mostly stainless steel though you might find bronze, nickel, monel, and nichrome. You can find out more about this from the Distillation Column Manufacturers & Suppliers in your locality.

 The next type of packing is the Pro-pak which consists of a metal ribbon. This ribbon has about 1000 tiny holes per square inch. The rectangular network of capillaries on the surface of the ribbon helps in the self-wetting process. Jagged burrs form on the reverse when dye gets pushed through the ribbon. The roughness of the burrs and the holes ensure that the process remains wet throughout. This improves the efficiency. Even at vapor velocities much lesser than flooding velocities, the packing remains effective for low liquid loads.

Ceramic saddle and wire mesh

Another type of packing commonly used is the wire mesh. This finds a use in fractional distillation and the material commonly used is stainless steel. Next is the ceramic saddle packing which finds a use when there is corrosive material to distill. Also, we use this if the material will react with metal packing. Though the efficiency is lesser than normal, it is useful when there are compatibility issues. The Column Tray Manufacturers & Suppliers will tell you more about it if you make inquiries.

The manufacturers can use packing as a series of small objects such as Raschig rings. Or, it can be structured packing as discussed above. Other than the surface area and the packing shape, another crucial factor for the distillation process is the liquid to the vapor ratio. When the liquid mixture enters the tower if the liquid to the vapor ratio is not correct then the correct process might not occur for the distillation. You need to have it evenly distributed across the surfaces.

Continuous vapor equilibrium curve

Unlike conventional tray distillation, the packed column has a continuous curve for vapor equilibrium. In the tray distillation, every tray will have a separate equilibrium point. We must calculate the theoretical plates for the separation efficiency when we are modeling packing columns. This we do in comparison to more traditional trays. Many chemical industries used packed bed reactors.  They use solid particles of catalysts to act on gas reactions inside tubular reactors. The surface of the catalyst takes part in these reactions. The packed bed gives a higher conversion for unit weight of catalyst used.