water for cooling or heating

In refineries water is used mostly for cooling purposes. As there are a lot of refineries are near the sea, seawater is often used as cooling water. In certain processes in a refinery there are temperatures of around 400°C required. If such high temperatures has to be cooled by water the equipment tend to very heavy scaling and fouling in heat exchangers. 
The cooling loops in the refineries are in most cases very long and very complex. Very often we are talking about a few kilometers of length of pipe lines, with hundred of branches and often several hundred heat exchangers or processes to cool.
We found a lot of refineries having big problems with the fouling of the heat exchangers, on both sides of the heat exchanger, the hydro carbon side, and as well on the water side.
Cleaning Heat Exchanger is therefore a constant issue in refineries or other industrial plants of such a size and complexity of the piping and tasks. Corrosion in all these complex cooling system is a big issue, if seawater is direct used for cooling purposes, corrosion is getting a real big problem.
Cleaning heat exchangers is a big task. Production has to be stopped, the heat exchanger has to be dismantled before cleaning can be done. If the scale or the fouling is not too hard hydro jetting can be used, but very often the scale and fouling is so hard, hydro jetting will be not able to remove the incrustations and the only chance is to use strong and aggressive chemicals. In cases where the where the tubes are totally blocked by scale even chemical cleaning is not enough. So the Cleaning of heat exchanger tubes, have to be done by drilling through each tube, using very long drillers.
All this common methods of cleaning heat exchanger or cleaning heat exchanger tubes, have direct influence on the lifetime of the heat exchanger. The acids are not only removing the scale or the fouling they are always affecting the metal as well. The drilling a heat exchanger tube is not an easy task either, if not done in the proper way, there is a risk the tube will be broken during this drilling.
We have seen cases where the life time of a heat exchangers, which have to be cleaned once a year, are only 3 years in total. This is raising the service and maintenance cost dramatic, and continuous replacement investments have been done.

Merus get control over the cooling loop

Merus proofed to get control over the fouling of either some stand alone heat exchanger, a whole part of a cooling loop or even the entire cooling system. If Merus takes care about the whole cooling system a lot of improvements are to be seen. There is far less or no fouling, the corrosion is brought under control, biological activities in the cooling water are stopped. All this factors lead to less effort in maintenance, better performance of the cooling, less emergency shut downs, and less need of chemicals treating the water.


A cooling system under control causes less service efforts and cost

It is obvious, having control over the cooling system, reduces the maintenance and service effort. Reducing the amount of chemicals used in a such a cooling loop, leads often to savings of several 100.000 USD a year.
Taking in to consideration the life time of the heat exchanger, which might be used 10 years instead of only 5 years, will save a lot of replacement investments. Here we don't have data, due to several reasons. Mostly in order to get reliable data, about the life time of the equipment, there should be considered time spans of 10 years. This haven't been done, or we didn't get such data from our customers. 

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Fouling heat exchanger 6 pass tubular

 

 

 

 

OG_2.3°Fouling