Rev January.2012
0
3. VLC TECHNICAL DESCRIPTION
3.1 ViscoLine™-VLC Multitube heat exchanger description
The ViscoLine™-VLC heat exchanger operates on the classic shell and tube
principle, with the product flowing through a group of parallel tubes and the service
medium between and around the tubes. Turbulence for efficient heat transfer is
created by helical corrugations on the tubes. The shell tube is smooth. This type of
unit is ideal for the heating of water or CIP solutions by means of steam, heat
exchange applications to process low and average viscosity products. Products can
contain fibres and small particulates. Moreover VLC is also suitable for general
heating and cooling applications.
The basic principle of the Multitube VLC heat exchanger is shown in below.
Figure 1. Graphic Representation of the flow pattern in ViscoLine CIP unit
The heat exchanger is formed by a tube bundle (welded at both ends onto flat tube
plates) inside a smooth shell. External surface of these straight corrugated tube
bundle constitute the heat transfer surface. The product medium is supplied and
flows inside the tubes of the bundle and the service medium between and around
these tubes, counter-current to the product flow. Each exchanger has a bellow; the
purpose is to absorb the thermal expansion.
The Multitube VLC is designed for single pass operation, with all inner tubes
connected in parallel and in counter-current flow to the service medium. Multitube
VLC units are recommended to be used as single equipment in a system to satisfy
the thermal duty. However it is possible to connect two or more VLC units in series or
parallel when using steam/water (hot or cold) as a service media.
The Multitube VLC units are recommended to be installed vertically or
preferably with a 10
°
inclination to the floor, in order to ensure draining the
service media during start-up.
The VLC unit demands very little maintenance except for the union and flange
gaskets which need to be replaced at regular intervals. (see Figure 2 for location).
