The engines of ships need to be cooled, just like with any other type of engine, although they usually use the water that they are navigating through in order to keep the engine cool. This means that ships and boats need to be properly equipped to prevent water leaking into the interior of the ship. If any cracks or leaks arise, it is possible for water to seep into the air system or the water system. The result can be that the boat or ship fills with water creating a sink hazard. Additionally, salts and minerals, and other debris can clog the cooling system. This includes aquatic plant and animal life, garbage, and mollusks. It can be extremely difficult to clean the heat exchanger tubes on a large ship. It’s not a task for a novice. It takes high level expertise and the correct heat exchanger cleaning equipment. Therefore, it is best to stay on a rigid maintenance schedule of heat exchanger cleaning.

In order to clean air to water heat exchangers, a high level of expertise is required because it is a labor intensive job that requires the technician to get access to the heat exchanger tubes and use a variety of heat exchanger cleaning equipment, which will include metal and plastic scrapers, chemical solutions, brushes, water jets. Before the job even begins, the heat exchanger tubes must be inspected to determine what equipment and manpower will be needed.

There are all sizes of heat exchangers because they are used in all sizes of boats and ships, from small recreational craft, to large tankers and aircraft carriers. Logically, the size of the heat exchanger tubes are relative to the size and needs of the boat. Some tubes are even less than one inch in diameter, while others are large enough for a adult male to fit clear inside. They can be hundreds of feet long too. The heat exchanger tubes that is, not the adult males. The tubes can also be constructed from a variety of different metals, which will be part of assessing the best cleaning method. It will also be considered as to whether there is a need to recoat the tubes. These are all variables that need to be taken into consideration before planning the best heat exchanger cleaning equipment for the job.

Old School Tube Cleaning Vs. New Techniques

With the older heat exchanger tube cleaning technologies, tube cleaning was not always very good, and refouling of the tubes would often happen very soon after cleaning because of the inefficiency of the cleaning. This is because the main method was water jetting. This method pushes water through the tubes in a single direction, and as a result, it was possible for the build up that was being cleared out. This method also created an increased need to recoat the surface, because it left some of the contamination on the sides of the tubes, leaving the tubes prone to corrosion. Some of the recoating was just putting a new surface right over top of the contaminants. This is like painting over a rust spot on your car. If you don’t remove all the rust, the new paint won’t take very well. The result was a high likelihood of refouling of the tubes.

New methods use a much higher pressure and employ the use of a rotating head, which clears the inner walls more completely because the head is in constant rotation. Therefore, the recoating takes better because it is on a much more effectively cleaned surface. In many cases the tube is nearly like new after the recoating has been completed.

There is also an environmental benefit to this method, as it only uses water to clean the heat exchanger tubes. There are no toxic chemicals used which is both eco-friendly, and more cost effective than using expensive and harmful chemicals. Our oceans and seas are the foundation for life on this planet, so this is a very important consideration. This method can be used for all metals, whether it is a soft brass or hard titanium, and it will not harm the metals used.

After a thorough heat exchanger cleaning, it is important to perform a extensive inspection. This is the time to detect leaks that were not noticed prior to cleaning. It is also an opportunity for the boat owner to see if the cleaning company has done their job well. This inspection is most often done with tiny robotic cameras. Other types of inspection include manual underwater inspections of the outer areas of the heat exchanger. The inspection allows the ship to be cleared as confirmed that the heat exchanger has been properly maintained, and the ship is seaworthy.

Heat exchanger tube cleaning is an essential part of the maintenance and service schedule of a boat or ship that ensures proper functioning of the ships engine. There have been many advances in heat exchanger cleaning equipment that have greatly increased the efficiency of heat exchanger tube cleaning, and simultaneously decreased the cost and reduced it’s environmental impact. Whether it is a small recreational craft, or a large military or industrial ship, it needs this important service on a regular basis in order to stay operational.

The oil refinery business is the epitome of big business. There are many types of expensive and specialized equipment that is used throughout all the stages, and the price tag becomes even bigger with off shore rigging. Although heat exchangers are a part of every device that transfers heat from one fluid to another, the shell and tube heat exchangers that are used in industry are especially important to maintain.

When a rig or plant needs to go down for maintenance, as I mentioned before, it costs thousands of dollars per hour. As a result, it remains a common industry practice to try and just use the heat exchanger as long as possible, even when the efficiency has dropped below 40%. Plants just do not want to shut down until heat exchanger tube cleaning becomes an absolute necessity.

Another standard practice is to shut down for a period of 21 days when they finally do go offline for maintenance and tube cleaning. This is really the standard more because it’s the way it’s always been done than because it is actually the best way to do things. Now, take into account the cost of down time, and ask yourself just what kind of cost you think is incurred by a 21 day shutdown. Now, just keep that thought in the back of your mind.

The old standby method of tube cleaning is pressure jetting water and essentially knocking loose all the scaling that has caused the fouling. This is an inefficient method. Although it does sort of work, it is difficult to get the u-bends satisfactorily and efficiently defouled.

Full replacement of a shell and tube heat exchanger is costly. Cutting off u-bends and rewelding them is inefficient, and sometimes either tricky or dangerous, depending on the logistics of the placement. Pressure jetting is outdated. So what can be done?

Recent developments in tube cleaning equipment technology can now allow shell and tube heat exchanger cleaning to be completed in just 3 hours. New methods include foam cleaning, laser cleaning, and newer “smart” technologies that can tell the difference between buildup that needs to be removed, and the surface of the tube itself. The “smart” metals back off when they get through the fouling, leaving the shell and tube heat exchanger intact.

By using newer technologies, and rethinking the old ways, plants can have more efficient output of their heat exchangers, less downtime, and more efficient tube cleaning. Especially with fuel costs rising as they are, it is time for the industry to take a look at more efficient tube cleaning equipment that will save money on the production end. Hopefully this savings will then pass on to the consumer.