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Heat exchanger cleaning - reducing cleaning cycles


heat exchanger cleaningParameters such as the water quality and temperature in a heat exchanger, are responsible for fouling or scaling inside a heat exchanger and they are parameters which can be directly influenced - but they are not the only ones. There are also other parameters, such as details of the construction of a heat exchanger, the design of the water loop (material, open/closed system, blow down), which can not be directly influenced but do have a significant impact on cleaning cycles.
Pursanova TM stops or reduces the process of fouling in a heat exchanger. For details of our experience from the field, see table below. Depending on the application and the design of the system to be treated, Pursanova TM are either installed direct on the feed-line of the heat exchanger or in the case of an entirely treated cooling loop, it is not necessary to treat each single heat exchanger separately.
The design of a heat exchanger and its hydro dynamic quality are responsible for how fast and how strong fouling take place in a heat exchanger. Tubular heat exchanger have in general a better hydro dynamic design, because mostly a laminar flow inside is achieved. The somewhat less expensive plate heat exchanger have due to the design, inside areas where there is less flow.
In these areas with poorer flow, the fouling starts first and layers of calcium or other mineral start to build. From this starting point, the heat exchanger progressively plugs up and finally has to be cleaned. Integrated heat exchangers (e.g. cooling in a motor) have very often an unfavorable flow characteristic and have to be cleaned most often.

Pursanova TM is used world wide, with great success, in thousands of heat exchangers. The major applications are heat exchanger in cooling loops, heat exchanger for compressors, heat exchanger for air conditioning systems, as well as integrated heat exchanger in mold forms, machines and motors.

Lately Pursanova TM is treating Heat exchanger in the oil industry, where hydro carbons are heated or cooled. Even in this very critical applications improvements are observed.

The proper monitoring of the fouling or better the condition of the heat exchanger is essential to Pursanova TM and its customers. Pursanova TM is therefore regularly measuring the heat transfer coefficient of the heat exchanger, if there are the required data supplied. We provide our customers with trends, and are in the case of technical problem able to react very early and prevent eventual arising problems.

The picture to the right shows how the header of a two pass tubular heat exchanger got automatically cleaned in only 8 weeks time, without using any chemicals or mechanical action.

Table: Experience values - reducing service cycles at heat exchanger

tubular heat exchanger
plate heat exchanger
integrated heat exchanger
no more cleaning required
65%
35%
15%
cleaning cycles 5 times expanded
25%
50%
55%
minor difference in cleaning cycles
10%
15%
30%

The above shown values are valid for water with not more than 1500 TDS and temperatures until 100° Celsius. At higher TDS rates the success rates might be lower accordingly. Fouling caused by product or remaining of product, are as well able to be treated by Pursanova TM, but these has to be discussed separate.