TUBE CLEANING INFORMATION
ELLIOTT SCOTT LTD. TUBE & PIPE TOOLS
Tube Cleaners – Boilers/Heat Exchangers/Condensers
Why clean tubes?
To function efficiently, every tube-type heat exchanging device, whether a hot water or steam boiler, condenser, or an exchanger heating or cooling a liquid or gas, requires that the surface of the tubes be clean and scale-free.
The formation of mud deposits or hard or soft scale on the transfer surfaces of tubes can drastically reduce the flow of heat through the tube walls. These formations may consist of silicates, sulphates, sulphites, carbonates, calcium, organic growths etc. The fact is that all scale formations are insulators and therefore their presence in heat exchangers cannot be tolerated. Quite often, the fouling agents that cause scale also have chemical characteristics that are highly corrosive to the tube material.
In addition to the gradual but increasing loss of heat exchange efficiency, a build-up of scale on a tube’s inner diameter gradually decreases the flow of either the coolant or the fluid to be cooled through the apparatus.
As the flow through the heat exchanger and the efficiency of the heater or cooler decreases, the entire system must work harder calling for increased pump capacity, increased flow of fuels, etc to overcome the deteriorating effectiveness of the device. This together with the possible damage to tube walls by the corrosive nature of some of the deposits creates a strong argument for maintaining scale-free heat transfer surfaces.
What are tube conditions?
Two points with regard to the tube to be cleaned must be taken into consideration. First, dimensional information on the tube itself and second, the type of tube deposit. Dimensional information must include the tube inside diameter (i/d) or the tube outside diameter (o/d) and wall thickness, length, whether it is straight or curved, if curved, the minimum radius of curvature, and other pertinent dimensional considerations.
Which tube cleaner to use?
There are basically two options to consider when selecting suitable tube cleaning equipment to fit the application, either an Internal or External type.
An Internal cleaner is one in which both the drive motor and the cleaning tool enter the tube and is generally used for cleaning the straight or curved tubes found in boilers, stills, reactors and other heat exchanger type apparatus with comparatively large tubes.
An External cleaner, is one whereon the driving motor is external to the tube and driving via flexible shafting or a length of rigid, hollow shafting to which the cleaning tool is attached.
What type of drive motor ?
Drive motors are dependent upon the facilities available for their operation and maybe air-driven, water-driven or electrically powered. Air or water driven motors are generally preferred since the driving medium provides a flushing action to carry away the scale from the inside of the tubes during the cleaning process. An electrically driven cleaner does not have an exhaust so does not have this feature.
Selection of tube cleaning components
An investigation should be made of the typical tube deposit to be removed – whether thick, hard, soft, powdery, wet, gummy etc. The type of deposit normally determines the type of tube cutter, drill or brush that will be used.
The following ‘Tube cleaning information form’ should then be completed and returned to us. Upon receipt we will make specific equipment recommendations along with a quotation to match such selection.
Our tube cleaning kits are very popular across a wide range of Industry Groups throughout New Zealand.
Typical users are: Dairy/Food and Meat Processors, District Health Boards, Timber/Sawmill Operators, HVAC customers/ Users/Contractors, City Councils, Energy Companies.
Elliott Scott Ltd turbo machinery + tube and pipe products