Lamella Plate Settlers are one of the most important pieces to any water treatment system. Sedimentation is a key process to any water treatment plant. Depending on the process, plant age, and plant size, increasing plant capacity can become costly when upgrading a plant or designing a new plant. Lamella Plate Settlers are the most popular, cost effective, and space saving option used.
Factors that contribute to the cost of Lamella Plate Settler
- Loading Rate
- Plate Efficiency
- Plate Spacing
There are two main factors that go into pricing any Lamella Plate Settler system; loading rates and plate efficiency. Loading rates of 0.2 – 0.4 GPM/FT2 for a plate settler are typical. Plate efficiency is generally 80-90%. These factors are determined by the plants process. A typical Water Treatment plant will need a 0.3 loading rate with 80% plate efficiency. A Lamella Plate Settler system is typically never run at 100% since the full plate area is rarely ever used completely for settling particles. The bottom section of all Lamella settler plates are designed to take in sedimentation and also allow sedimentation to settle to the bottom of the basin. These two factors impact on how many plates a system will need. If there is lower efficiency rate or loading rate either will increase the amount of plates a system will need and increase the cost of the overall system.
An example cost of a Lamella Plate Settler that will operate at the typical water treatment plant of 0.3 loading rate and 80% plate efficiency is between $40,000 – $80,000 per mgd. This does include the troughs and support beams.
Materials for Lamella Settlers
Usually all plate settlers are made with 304 stainless steel. There are some cases where a different type of stainless steel is needed. Stainless Steel 316 is a solid option for this but adds an additional 10% to the overall cost of the system. Typically, a plate thickness is 24 gage stainless steel for water treatment plants. For a wastewater plant it is required to go to a thicker gauge, usually 22 gauge. This adds an additional 35% cost to a plate settler system. Also, fiberglass can be used for a plate settler as well. The material cost is about the same 304 stainless steel. The only downside is the life cycle cost of fiberglass. Eventually fiberglass will break from running water and exposure to sunlight and require replacement.
Add-ons for Lamella Settlers
There can be additional add-ons for a plate settler system. These are something that needs to be evaluated on a plant by plant basis since every plant is not made the same. They will be an individual plant’s choice on an as needed basis.
Effluent collection flume/trough are needed for some retro fit plants if the effluent troughs do not line up with the plate settler troughs. These can be an addition $300/ft2.
Sludge removal must also be considered. Typical options include, sludge vacuum, reciprocating scrapper, chain & flight, and cone bottoms sloping to a drain. Costs will vary depending upon the system and features chosen.