Seawater Boiler and evaporator

Sea water boilers and evaporators benefit from merus technology.THENAMARIS INC, Shipping Company, Greece


The Problem

In every tanker there is at least one seawater boiler (evaporator), in which the seawater partially evaporates (at low pressure due to low temperature) and the residual brine is returned back into the sea. The produced water vapors are condensed at a cold surface and feed the ship’s fresh water tanks. Inside the heat exchanger of the evaporator a stony layer consisting of salt, lime and other solids contained in the seawater is gradually formed. This layer absorbs an essential part of the thermal energy, which is normally intended for the evaporation of the seawater.
As a result, the evaporator’s performance is reduced daily and the fresh water production becomes insufficient for the ship’s needs. When this point is reached, expensive fresh water has to be purchased at the harbors. The traditional solutions are chemical and mechanical cleaning. Both processes are hard, tough, unhealthy and expensive. It also means that the evaporator has to be stopped for many hours once per one to two months, which is not always convenient.

The Solution

We placed Merus® rings on the pipes which supplies sea water to the boiler and evaporator. The boiler was recently cleaned and the evaporator had not been cleaned lately and its daily fresh water production had already dropped noticeably as it usually did at this time. The flow rate was several m3/h.

The Result

The boiler and the evaporator did not need any cleaning again. Performance on bith units increased dramatically and within a short time the evaporator reached its highest limit, according to its specifications. This means that the scale was removed without chemical cleaning.
Aout one month after the installation of the rings the tanker’s engineer reported that the daily fresh water production of the evaporator, instead of dropping gradually, as it always did, had increased from 28 to 31 tons.

...Thats 3 TONS more water produced PER DAY

Merus® rings not only prevent the formation of new scale, but also manages to dissolve residual scale, which cannot be reached with chemicals and scrapers. Chemical and mechanical cleaning can never remove scale build up or rust 100%. It is technically impossible to reach all surface area of the internal system.
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