Clarifier Installation: What You Need to Know
Before installing your slant plate clarifiers, there’s some information we want you to have that will enable you to run your clarifiers properly. The details matter here since slant plate clarifiers are highly technical wastewater treatment devices.
Keep reading to learn what you need to know about installing your clarifiers.
Your Pre-Start-Up Checklist
If you use plastic plates, keep them away from direct sunlight until they’re full of fluid.
Ensure that the top of the clarifier tank is level in both directions; otherwise, the distribution won’t be equal.
If you have two overflow weir plates, ensure that they’re level with themselves and each other, or you could have issues when more than one overflow box is present.
If you use a flash mixer and flocculator drive, check to ensure the oil levels are where they should be. You can find that information in the manufacturer’s instructions. Pay attention to whether ventilated oil-fill plugs are required, and install them if necessary.
If your gearboxes arrive full of oil, drain the oil until it’s down to the operating level, which you can check with a dipstick. Operating with too much oil in the gearbox can damage the seals.
If you have them, rotate your flash mixer and flocculator by hand to ensure free movement. This should be done before turning the system on.
Once the system is on, ensure they rotate in the correct direction. Stop the mixer and flocculator if they aren’t rotating in the right direction, as this can cause severe damage to the slant plate clarifiers.Install valves on the bottom drain port, the sludge sampling ports, the incoming piping, and the incoming ports. If you don’t install the incoming piping, blind flange the incoming ports and install the overflow plumbing.
Fill the clarifier tank with water. Watch the water overflow from the upper weir box(es), and adjust the overflow leveling plate to obtain level water flow out of a single box. If you have multiple overflow weir boxes, adjust each level so that there are equal amounts of flow between each weir box.
If needed, caulk any water flow paths under the top of the weir leveler.
In addition to these nine steps, you’ll also want to check on the polymer, feed stream air content, feed stream pH, feed pump, underflow pump, polymer solution, and the polymer pump. Finally, you should conduct a final leak check and final checkout of the equipment.
Let’s look at each of these steps in detail.
Polymer
It’s important to run a flocculating/settling test on the feed water using a polymer. If the test doesn’t provide the desired results, you’ll need to make changes to the incoming water to resolve the problem.
This test is recommended because the characteristics of water can drastically change between the time the water is tested initially vs. when it’s ready for filtration in the slant plate clarifier.
In addition to this test, we recommend frequent testing since the characteristics of the water can continually change. This is especially recommended for an operator unfamiliar with waste streams and how they evolve with plant evolutions.
Feed Stream Air Content
Before the feed water enters the clarifier system; you’ll want to eliminate any aeration.
Feed Stream pH
The water’s pH should be maintained as closely as possible to the process design. There’s usually an issue with pH when the water’s clarity goes bad. If you encounter problems with water clarity or flocculation, check the pH monitoring and control system to ensure everything is running correctly.
Feed Pump
The feed pump processes a predetermined number of gallons of water per minute. It’s important to ensure that the feed pump is not processing more water than it should, as this can cause quality issues. Make sure it is running according to the process design flow rate. The longer the water is in the feed pump, the better the clarifier will perform.
Additionally, the clarifier system will also operate better with low flow rates over a prolonged period than with high flow rates over a shorter period.
Underflow Pump
To get a ballpark figure for the necessary underflow capacity, you’ll use this formula:
(SS Feed / SS Underfeed) X Q Feed = Q Underflow
Where SS means suspended solids of the feed stream, Q is the flow rate of the feed in GPM.
Another way to understand this equation is by stating that the concentration of the suspended solids in the feed is divided by the concentration of the suspended solids in the underflow, multiplied by the feed rate into the clarifier equals the underflow feed rate.
Generally speaking, the underflow is somewhere between 10 to 15% of the feed flow.
Two sludge sampling ports come with the clarifier. Both are located on the lower cone and should be used to check the sludge level. Sludge should only be found on the bottom sampling port, not the upper one. If the underflow rate is too high, you’ll deal with prolonged detainment and excessive re-treatment of water.
Polymer Solution
You’ll want a 0.1% to 0.5% polymer solution. You’ll introduce the polymer using a two-tank blending system, such as a rapid mix tank and a flocculation tank. The polymer storage tank will take eight to 24 hours to reach pumping capacity at design flow rates.
You’ll want to fit the day tank with a mechanical mixer with a low-shear, medium pumping rate that operates between 350 to 500 RPM. If polymer makeup is necessary, wait until the pumping system is turned off so the polymer doesn’t clog the transfer pump.
Polymer Pump
Most metering pumps will work well. For optimal performance, pick a flexible one that can operate at 50% capacity.
Leak Check
Because a slant plate clarifier must be disassembled for shipment; you’ll want to check for leaks after it’s been reassembled. Filling the unit with water should do the trick.
Final Checkout
You’ll want to run water through the entire system to ensure everything works well. If, for some reason, this isn’t possible, you’ll want to run each system component instead.
Get Your Slant Plate Clarifiers from J.Mark Systems
Are you ready to take the next step and get slant plate clarifiers for your wastewater treatment or water filtration needs? Look no further. J.Mark Systems has everything you need.
With decades of experience installing wastewater treatment systems, you can trust us to provide you with the highest quality products, expertly delivered. Get started today with your water optimization audit to see what a slant plate clarifier from J.Mark Systems can do for you.