Save Fuel & Protect Equipment while Reduce Emissions
This page was developed to help enhance your knowledge about different waterside scale types, how to properly remediate the problem, and how to prevent future scale buildup's from reaccuring.
Fired heaters are a critical piece of equipment for refineries and facilities around the world. With rising fuel costs and stringent emissions legislation, it is becoming increasingly important to ensure that mission critical assets, particularly fired heaters, are performing efficiently and at full capacity.
Maintaining these assets regularly will maintain output, increase asset life, reduce the likelihood of unplanned outages, reduce stack temperatures and emissions, and deliver a significant ROI..
Silica based (Hard Scale)
A very hard, dense and impervious scale. There is very little exothermic reaction with HydroCleanse. However, after enough contact time, the scale slowly dissolves. This type of scale is is mainly found in steam Boiler applications
Calcium Carbinate
Scale typically found in DHW and Heating loops. The deposits are usually very granular and sometimes in a very porous nature. Dropping it in a solution of Hydrocleanse can easily identify a calcium/Magnesium type deposit. Bubbles of Carbon dioxide will effervesce when dropped into solution.
Magnetite
Due to either corrosion or or iron contamination in the water, very dark colored, Iron deposited are most often magnetic. Magnitite is approximately 8 times more insulative than regular scale
In the higher temperature areas in the Boiler, the insulative effects from the scale will cause the metal wall surface to become overheated beyond what they are designed to withstand. The result is weakened metal or complete tube failure.
Scale Causes High Temperatures
Tube metal begins to weaken or breakdown at 700°F and softens at 950°F and typically tubes are designed to operate below 550°F. Combustion gases are typically in the range of 2,200°-2,700°F at the burner and progressively cool as they pass through the boiler. ONLY the boiler water is providing a cooling effect which prevents intense heat causing metal fatigue and tube failure.
Example: 100 PSI Operating Pressure, 3-pass Dry back, Firetube Boiler
The Difference Between Magnetite & Calcium/Magnesium Scales, and its Effects on Heat Transfer through Heat Exchangers
You will see the in the below illustration how scale not only weakens metal and destroys heat exchangers, but creates a thermal barrier which reduces heat transfer through the steel vessel. As scale accumulates, the vessel damage becomes greater, at a faster rate. efficiency is reduced with only a thin layer of scale.
Creep is a time-dependent tube deformation which occurs when a material is stressed at high temperature. Over a period of time with a continued load, the material will eventually rupture.
The temperature at which creep becomes important depends on the particular metal. For carbon steel, creep rupture becomes a design consideration at 800° F, for alloy steels at about 900° F and for austenitic stainless steels at about 1,040° F
Magnetite - scale
Magnetite has 8 times more insulative effect on heat transfer than regular Calcium scales due to its density. HydroClense will remove Magnetite scale.
Calcium/Magnesium - scale
The most commonly found scale in heating systems. This type of scale is removed quickly with HydroClense
Note: Magnetite is primarily type of scale found in modern hot water heating loops of commercial buildings plaguing heat exchangers, and causing premature failures. Extensive scale testing with EDS analysis of nearly a dozen site locations around the United States and found the results are consistent, Magnetite is a major problem for todays modern Hot Water Boilers. For more information on this internal study, and how to remediate your system contamination issues, contact us.
Give us a call now. We are confident and committed to resolving your system water quality/scale issues and partnering to keep your equipment descaled and operating at peak efficiency.
Questions? Call us.
Compare the difference between Magnetite & Calcium / Magnesium scales and its effects on fuel consumption.
Click above info boxes for full screen chart display
The above is a slideshow of before and after descaling various applications.