PLICA (Latin for folded) is referring to our module design which comprises an elongated foil formed of a plurality of foil layers folded in zigzag fashion, while spacers are arranged between said foil layers.
The space between the foils are filled with spacers which functionality is to create a flow channel between foils and acts as a turbulence promotor to increase productivity.
Depending on whether the foil is made of a heat-conducting foil, a membrane foil or a combination thereof, the device is suitable as a heat exchanger, a membrane filter, or a combination thereof. In a combination of, for example, a heat-conducting foil and a membrane foil, a spacer is situated between at least two foil layers of one of these foils.
In a module, a single foil is used for the formation of several channels due to the folded structure. The number and length of the channels can easily be adjusted to optimized production and efficiency depending on process conditions.
Through headers, situated at both sides of the channels, a fluid can be introduced between the layers over the entire width of the elongated foil, after which the fluid can be discharged via the headers located near the first end and at the longitudinal sides, or vice versa. As a result, a good flow distribution over the entire area of the foil layer is realized.
The foil layers can be disposed within a cylindrical container which makes it possible to ensure and control a good pressure and/or flow distribution.
This cylindrical rolled up package of foil layers is a so called Archimedes spiral named after the great mathematic genius born in Italy.
The manufacturing method aims at easy manufacturing of a package consisting of folded foil(s) with spacers in between.
With this method a package of foil layers is formed from a single foil or a combination of two foils and a flexible thin spacer in combination with a number of spacers. The zigzag formation create two main spaces separated by the foil layer each consisting of several spacers.
Each spacer has two tubular supports which shields the foil against the possible sharp edges of the spacers. These tubular supports also to ensure an even distribution of process fluids through the channels acting as headers. The spacers are anchored to the tubular supports. The supports used on the inside, near the central axis of the module, are connected with two disk shaped elements which are rotated during winding. By providing tension during the production a tightly tautened roll is ensured.
The two disk shaped elements ensure an even distribution of the supports around the central axis which together with an exact same length for each spacer gives a perfect shaped cylinder after winding. Depending on the length of the foil layers and the thickness of the foil layers and spacers, a number of spiral windings will be formed giving a tremendously flexibility advantage in capacity and efficiency.
The fluid channels that are connected to the same space, and located close to the central axis and distant from the central axis respectively, serve as supply- and discharge channels, or vice versa. In this way, a perfect counter-current flow is created.
The fluid channels are simply separated from each other and easily accessible from either side of the cylindrical device. Integrated main cylindrical headers are placed on both sides of the cylinder providing a connection to external piping.