Seeking help with problems related to the demister in falling film evaporators

August 18th, take a look – urgent need for expert help

There are many types of demisters; you are probably referring to the wire mesh-type demister.

Most of them are assembled in sections, which facilitates subsequent inspection and replacement

The commonly used ones are plate-type or wire mesh type! It’s usually due to welding issues! It’s visible as soon as the upper seal is opened!

Baffle type demisters are formed by assembling individual demisting elements into louver-like grids, which are then combined into a whole depending on the required area.

The smaller ones can be in whole pieces, while the larger ones are divided into multiple pieces, making them easy to install and transport

For the demister in film evaporators (falling-film evaporators or rising-film evaporators), whether an advanced fan-type high-efficiency gas-liquid demisting and defogging separator is used or a traditional fiber-type demister (metal wire mesh or non-metallic fiber pads), as well as whether the design is modular or unitary, all these factors depend on the relationship between the overall size of the demister and the size of the access holes for maintenance. Generally speaking, when the minimum two-dimensional composite dimension of the entire demister assembly is smaller than the inner diameter of the manhole, and the space between the installation location of the demister and the manhole meets the requirements for installing, maintaining, and removing the entire demister, it is advisable to design the demister components as integrated modules in order to reduce the complexity of assembling these components inside the evaporator. Conversely, the modular structure of the demister internals needs to be considered. Especially for traditional screen-type demisters, due to the structure and performance of their internal components, it is necessary to consider regular maintenance, inspection, and replacement of these components during operation. The modular structure greatly facilitates maintenance, inspection, and replacement by operators. As for advanced feather-leaf type high-efficiency gas-liquid demisting and defoaming separators, due to their resistance to clogging, high operating efficiency, compact size, and long service life of their internal components – which generally eliminates the need for complete replacement of these components – as well as minimal maintenance requirements, it is feasible to install such separators entirely before welding the evaporator shell heads together. If the evaporator shell is completed before the fan-type high-efficiency gas-liquid demisting and defogging separator is delivered to the factory, the module structure needs to be carefully considered based on the minimum two-dimensional composite dimensions of the overall demisting internals, the inner diameter of the manhole, as well as the constraints imposed by the available installation space. In either case, the designers and manufacturers of the demister need to carefully examine in advance the space constraints within the evaporator where the demister will be installed, in order to decide properly whether to use a modular or a unitary design for the demister. For the technical parameters of the feather-leaf type high-efficiency gas-liquid demisting and defogging separators as well as other types of demisting separators, please visit http://bbs.hcbbs.com/thread-1354814-1-1.html on this HCH Chemicals forum for more information