Water types and humidifier performance and …

1 Water types and humidifier performance and maintenanceWater and humidification: Water types (hard, soft and RO/DI Water ) The effects of Water in steam generating humidifiers Water level control systems and output performance performance and maintenance High-pressure atomizing system humidifier technology and associated Water types Fill Water affects on performance , maintenance , steam quality, and efficiency in non-electrode systems Products by energy source What do you want to do?Humidification is the process of transforming Water into vapor, and so it is not surprising that Water type has a great impact on humidifier performance (efficiency, output consistency, and control) and maintenance requirements.

2 In order to maintain RH and keep your humidification system running the way it was intended, it is important to understand how Water types affects humidifiers . This document introduces Water types that supply steam generating (isothermal) humidifiers and high-pressure atomizing (adiabatic) humidifiers , and explains how these Water types affect humidifier performance and maintenance . Page 2 DRI-STEEMW ater typesWater is often called the universal solvent because almost everything is soluble to some degree in Water . This property causes Water to become contaminated by many materials it contacts, with the mix of contaminants potentially varying greatly from one location to another.

3 There are three types of Water used in humidifiers : Hard Water (drinking, tap, or well Water ) Softened Water (hardness reduced through an ion exchange process) Reverse osmosis or deionized Water (forced through a membrane or ion removal)Hard waterHard Water is Water that contains metal ions (mainly calcium and magnesium carbonates and bicarbonates) but may include other substances. Hardness can be found in drinking Water , tap, or well Water . Softened waterSoftened Water is any Water that is treated to remove calcium and magnesium ions. Water softening is an ion exchange process where calcium and magnesium ions are replaced by sodium ions.

4 Sodium ions stay in solution in Water , unlike calcium and magnesium ions, and they do not attach to humidifier tank walls and heat exchangers as scale the way magnesium and calcium waterReverse osmosis (RO) Water has been forced through a special membrane under pressure. The process produces Water that is approximately 98% free of total dissolved solids (TDS).Deionized (DI) Water is purified with ions removed. These ions include positive ions such as sodium, calcium, iron, copper, and negative ions such as chloride and bromide. Deionized Water is created by taking conventional Water and exposing it to resins that attract and bind to the ions, removing them from the maintained RO/DI systems provide best performance and product longevityA well-maintained RO/DI system produces Water that is free of most or all total dissolved solids (TDS), including chlorides and other substances that can cause scale build up and/or 2-1: Which humidifier can I use with each Water type?

5 humidifier typeHard waterSoftened waterRO/DI waterElectric resistiveXXXE lectrodeX*X*GasXXXSTSXXXHigh-pressure atomizing systemX* Recommended microsiemen range for fill Water is Page 3 When hard Water is boiled into steam, certain particulates are left behind that cause scale build-up. Ions left behind could also corrode certain metals. What's in your Water ?Hard Water has calcium and magnesium compounds in it that are measured in grains of hardness. The higher the grains, the higher the hardness. Boiling Water promotes the precipitation of calcium and magnesium out of solution, where they fall out and can form scale. ScaleWhen calcium and magnesium dissolve in Water , the ions recombine and form a far less soluble compound called is caused by a chemical reaction between a metal (iron, aluminum, zinc, etc.)

6 And corrosive agents. Corrosion is the gradual destruction of material, usually metals, by chemical reaction with its environment. Corrosion degrades the useful properties of materials and structures including strength, appearance and permeability to liquids and alloys corrode merely from exposure to moisture in the air, but the process can be strongly affected by exposure to certain corrosive agents such as chlorides. Corrosion can be concentrated to form a pit or crack, or it can extend across a wide area more or less uniformly corroding the surface. The effects of Water in steam generating humidifiersTable 3-1:DRI-STEEM supply Water guidelinesTotal hardness0 to 500 ppmChlorides*RO or DI waterSoftened waterTap Water < 5 ppm< 25 ppm< 50 ppmpHRO, DI, or softened waterTap water7 to to < 15 ppm* Damage caused by chloride corrosion is not covered by your DRI-STEEM : Water that contains chlorides, and has low hardness, allows corrosion to proceed at faster may wish to take action to mitigate potential negative effects to your humidifier .

7 Supply Water outside of these guidelines may void your DRI-STEEM warranty. Please contact your DRI-STEEM Representative or DRI-STEEM Technical Support if you need Water guidelinesSupply Water quality is an important component of humidifier reliability and : Corrosive Water can decrease the service life of the humidifier . Excessive Water hardness can increase the humidifier maintenance requirements. To maximize humidifier service life and minimize humidifier maintenance , DRI-STEEM has established guidelines for supply Water . See Table 4 DRI-STEEMC onductivity probesConductivity probe systems (used in our standard- Water models) replace boiled-off Water periodically and therefore cause a temporary interruption in steam these systems, a probe with three rods of three lengths detects Water levels.

8 When Water reaches the top rod, the fill valve stops filling; when Water reaches the middle rod, the fill valve starts filling. Once Water no longer touches the bottom rod, heaters are de-energized for low- Water protection. The vertical distance between the ends of the top and middle rods defines how much Water is replaced when the fill valve is on, which corresponds to the time period of reduced or no steam output. Conductivity probe systems require a minimum level of minerals in the Water to operate and therefore do not work with RO/DI advantage of this type of Water level control is that it provides accurate Water level readings, allowing a predictable skim cycle for removing precipitated minerals by Water surface skimming with each fill cycle.

9 Skimming flushes floating particulates to the drain and dilutes the mineral concentration in the tank Water while causing minimal reduction in steam output. Surface skimming systems produce a negligible interruption to steam output because heaters remain on during skimming, and because tanks that are regularly skimmed require less tank draining and flushing. Draining and flushing a tank causes steam output to stop for the entire drain duration, which in some systems can be as long as 60 minutes. All DRI-STEEM skim durations are user-adjustable, allowing operators to change the length of time the tank skims, as well as the level systems and output controlTank-level icons indicate Water level at the Water level control probe.

10 Top probeMid probeLow probeFigure 4-1: Water level control for tap/softened Water systemsVLC-OM- 030 DRI-STEEM Page 5 Figure 5-2: Water level control for RO/DI Water systemsFigure 5-3:Low Water cutoff switch for RO/DI Water systemsSupply Water connectionFloat rodFloat ballOM-7396 humidifiers using RO/DI Water control Water levels using a float valve and low- Water cutoff opens normally open when float ball is at its lowest point on the stem, cutting power to the heaters or heat valve systemRO/DI Water is so pure, it is not conductive; therefore, RO/DI Water systems use a float valve to control Water levels. The fill is accomplished via a float ball attached to a mechanical valve.