Complete Water Solutions was asked to provide a 100 GPM Reverse Osmosis System with ancillary equipment. The RO System is being used to provide feed water to the boiler system. The boilers are high-pressure steam boilers requiring low conductivity, low hardness, along with low silica levels. First complete water solutions to a water sample for analysis to determine the correct treatment options. The facility is currently using water directly off of Lake Michigan and at times will switch over to city water when needed. We took this into consideration when building the system.
The first piece of equipment was a multi-media filter used to trap particulate and sediment prior to the RO System. Because the water could be turbid at times, the multi-media filter would help in reducing the turbidity and particulate loading. The equipment selected was the Fleck 3150 with time digital controllers. The controllers were tied back to the PLC to force the media filters into regeneration and to let you know which units were online.
Next was the RO System – the 100 GPM RO System was equipped with an Allen Bradley 1400 Micrologix PLC also allowing the customer to control the RO Operations from the operator station. The RO System was equipped with Anti-scalant feed (hardness) and bisulfite feed (chlorine).
The 3rd piece of equipment that was selected was the polishing softener. The RO system will not remove all the hardness but will remove the majority. Even after the RO system, there was roughly 4-5 PPM of hardness left over. The polishing softener was put in place to remove that hardness. The units selected were a triplex fleck 2900 with nxt controllers. The softeners were equipped with a remote source for regeneration as not to use RO water or require the RO to run 100% of the time. Polishing softeners also save on space, water, and salt versus putting the softener up-stream of the RO System.
Savings Calculations: Pre Softening vs Post Softening
|Inlet Water Hardness||121 PPM|
|RO Permeate Hardness||5 PPM|
|Option A||Option B|
|Steam Load||28,109 PPH||18,740 PPH|
|Estimated Water Make-Up Per Hour||3,514 Gallons||2,343 Gallons|
|Estimated Water Make-Up Per Day||84,336 Gallon||56,232 Gallons|
|Estimated Annual Make-Up 365||30,782,640 Gallons||20,524,680 Gallons|
|PRE RO SOFTENER|
|Softener Pre RO Capacity Between Regen||90,000 Gallons|
|Salt Per Regeneration||450 Lbs|
|Waste Water Per Regeneration||1,315 Gallons|
|ESTIMATED ANNUAL USAGE PRE RO|
|Estimated Salt Usage||153,900 LBS||102,600 LBS|
|Estimated Waste Water||449,730 Gallons||299,820 Gallons|
|POST RO Softener|
|Softener Post RO Capacity Between Regen||300,000 Gallons|
|Salt Per Regeneration||75 Lbs|
|Waste Water Per Regeneration||228 Gallons|
|ESTIMATED ANNUAL USAGE POST RO|
|Estimated Salt Usage||7,725 LBS||5,175 LBS|
|Estimated Waste Water Usage||23,484 Gallons||15,732 Gallons|
|SAVINGS POST RO VS PRE RO SOFTENER|
|Salt Savings||146,175 LBS||97,425 LBS|
|Waste Water Savings||426,246 Gallons||284,088 Gallons|
The Savings for post-RO Softening was evident in the modeling.