When sodium zeolite softened makeup is used, the need for boiler blowdown is usually determined by measurement of the boiler water conductivity, which provides an indirect measure of the boiler water dissolved solids. Other boiler water constituents such as chlorides, sodium, and silica are also used as a means of controlling blowdown.
Boiler Water Conductivity Measurement Fundamentals. As a boiler generates steam, any impurities which are in the boiler feedwater and which do not boil off with the steam will concentrate in the boiler water. Inside the boiler the heat generates steam bubbles inside the water.
When boiler water is carried over in steam, the dissolved solids content of the boiler water contaminates the steam, and steam sample conductivity increases. Measurement of this increase provides a rapid and reasonably accurate method for determining steam purity.
Water chemistry sensors for both feed water and boiler need monitoring as any impurities in this gets concentrated and gets carried over in the steam. Conductivity controls for water blowdown in the drum type boiler are a method to remove such concentrate.
Boiler Water Conductivity High Possible Causes: - Too low blow down - Condenser tube leakage - Poor DM make up water quality - Low pH of make up water Affect: - It can lead to scaling in the tubes if sustained over a period of time Corrective Action: - Increase blow down to maximum - Increase phosphate dosing to maintain pH - If condenser tube ...
Adjust continuous blowdown to maintain the conductivity of the boiler water within acceptable limits and blow down the mud drum on a regular basis. It is also important to blow the sludge out of all the dead legs of the low-water trips, water column, etc., on a regular basis to prevent sludge buildup in these areas.
TDS = Total Dissolved Solids (ppm) ρ = relative density of the boiler water at 15.5 o C. This is a manual method requiring measuring a cooled down sample with a very sensitive hydrometer. Measuring TDS with the conductivity method. TDS = 0.7 σ (2) where. σ = conductivity (μs/cm)
A conductivity meter measures the electrical resistance of the water. For boilers, the conductivity meter is used to check the boiler water conductivity and to calibrate the conductivity controller. Knowing the conductivity is important for determining the cycles of concentration and to ensure you are maximizes the amount of time you are ...
Boiler Water Tests What items are used for Boiler Water Tests? The most common items used for testing chemicals are listed on this page. The most popular items are hardness test kits, sulfite test kits, and conductivity meters.
Boiler feedwater treatment. Boiler water treatment is used to control alkalinity, prevent scaling, correct pH, and to control conductivity. The boiler water needs to be alkaline and not acidic, so that it does not ruin the tubes. There can be too much conductivity in the feed water when there are too many dissolved solids.