The problems related to heat exchanger fouling and scaling as well as their economic and environmental impact are commonly known as fouling and include both organic and inorganic deposits, also referred to as scaling. There are a number of various types of fouling that can be distinguished depending on application, environment and water quality.
A loose, gelatinous amorphous deposit will usually form in heat exchangers, which tends to harden on the surfaces being heated. This will often result in pitting provoked by local deposits forming galvanic cells. To remedy this situation, numerous means and processes are employed. In their essential structures, these processes such as acid treatment and mechanical cleaning can be classified as intermittent and continuous. Yes, they are very effective, however, in principle, they require for the system operation to be interrupted. Furthermore, between the pertinent heat exchanger cleaning operations a period of reduced heat transfer efficiency has to be considered.
The continuous process include the processing of cooling water by constant addition of chemicals, in order that the formation or adherence of abrasive materials as well as the application of sponge balls, are among the methods gaining more ground in the last few years. However, to guarantee an optimal equipment performance at minimal energy cost without interrupting operations, an automatic tube cleaning system such as the innovative Eqobrush should be considered in heat exchanger cleaning.
The beauty of an automatic tube cleaning system is the simplicity of its process. The brush cleaning system consists of two catch baskets and one brush for each heat exchanger tube. By reversing the direction of the cooling water flow, the brush is pressed through the tube and at the other end it is accepted by the basket. When the cooling water stream is diverted again in the normal direction, the brush will then return into the catch basket located at the delivery end, the inner walls of the tubes thus being cleaned now.
The cleaning action of the brush makes it possible to remove loose, gelatinous deposits from the internal surface of the tube without any restriction and hard deposits, tending to adhere more strongly, will not even the opportunity to form. Moreover, sludge accumulations or other contaminations will be avoided as well.
The prevention of build-up and fouling in the equipment has a number of advantages such as:
• Reduce overall fouling related cost.
• Electric energy consumption in chiller condensers.
• Fossile energy consumption in industrial heat exchangers due to efficient heat transfer.
• Energy consumption in system pumps.
• Minimization of scheduled and unscheduled downtimes.
• Save water in the cooling tower.
• Save chemicals on manual cleaning.
• Equipment lifetime extension.
• Reduction of Capex for new projects.
The decision-making process on fouling can be driven by the need to solve an acute and recurring problem in the production. A heat exchanger or condenser subject to excessive fouling with the need to be serviced or manually cleaned in between scheduled turnaround moments will obviously benefit from on-line cleaning and the economic advantages are not likely to be challenged.