A polymer makedown system is the equipment that turns concentrated polymer, supplied as an emulsion liquid or a dry powder, into a dilute, fully activated solution ready to condition sludge for thickening and dewatering. Polymer will not work straight from the drum; it has to be wetted, mixed, given time to uncoil and hydrate, and then diluted to the right strength. This page explains each step of makedown, why aging and dilution matter, and how a SCADA system controls the water ratios and timing that decide whether the polymer performs.
Polymer Makedown System in one line: A polymer makedown system, also called a polymer blending unit, prepares a working polymer solution from neat emulsion or dry polymer by wetting it, mixing it with dilution water, aging it to let the molecules hydrate, and diluting it to the feed concentration. SCADA controls the initial dilution ratio, the aging time, and the post-dilution so the polymer is fully activated and delivered at the right strength for thickening and dewatering.
Polymers used to condition sludge are long-chain molecules that work by bridging small particles together into larger, water-shedding flocs, which is what lets a thickener or a dewatering press separate solids from water efficiently. In their concentrated as-delivered form, those long chains are coiled and inactive: an emulsion polymer holds the polymer as droplets in oil, and a dry polymer is a powder whose grains have not yet dissolved. To do their job, the chains must be uncoiled and fully hydrated in water, and that is what a makedown system accomplishes.
The first step is the initial wetting and mixing. For emulsion polymer, the neat product is metered into a stream of dilution water and passed through a mixing device that inverts the emulsion, releasing the polymer from the oil and beginning to disperse the chains. For dry polymer, a feeder meters powder into a wetting cone or eductor where each grain is thoroughly wetted as it enters the water, avoiding the fisheyes and clumps that form when dry polymer is dumped into water without proper wetting. Good initial mixing is critical, because chains that clump or are sheared too violently at this stage never activate fully.
After wetting and mixing, the polymer is at a mother, or stock, concentration but is not yet ready. This is where the makedown system differs from a simple chemical feed: the polymer needs time and gentle handling before it delivers its full strength, and skipping or rushing the makedown wastes polymer and money, because underactivated polymer is fed at a higher dose to compensate for chains that never uncoiled.
Aging is the quiet step that makes polymer work. After mixing, the solution is held in an aging tank, gently agitated, for a period that lets the coiled molecules fully uncoil and hydrate, developing their bridging ability. Aging time varies with the product, but too little aging leaves the polymer underdeveloped and weak, while the solution also cannot be held indefinitely because very dilute aged polymer degrades over time. The aging tank is often built with compartments so freshly mixed solution flows through and is drawn off only after it has spent the intended time hydrating.
Concentration ratios matter at two points. The initial makedown ratio sets the mother solution strength, and it must be strong enough to be stable yet dilute enough for the chains to hydrate; makedown too concentrated and the chains cannot uncoil, too dilute and tank volume and degradation become problems. After aging, many systems add a post-dilution step, injecting additional water just before the polymer reaches the sludge, because a very dilute polymer at the point of injection distributes and mixes into the sludge far more evenly than a thick stock solution, improving flocculation for the same mass of polymer.
The dilution water quality itself affects performance. Hard water, chlorinated water, or water with the wrong pH can degrade polymer or blunt its charge, so some plants condition the makedown water. The upshot is that a polymer makedown system is a small process in its own right, with several ratios and a residence time that all have to be right together: initial dilution, aging time, post-dilution, and the neat polymer feed rate that ultimately sets the dose delivered to the sludge.
A SCADA-controlled makedown system regulates the water and polymer flows to hold the concentrations and timing the operator sets. The dilution water is metered and the neat polymer feed, from an emulsion metering pump or a dry feeder, is paced against it to hold the initial makedown ratio, so the mother solution stays at target strength even if water pressure or polymer viscosity shifts. Level control on the aging tank governs how fresh solution is made down and drawn off, which sets the effective aging time, and the post-dilution water is metered as its own controlled ratio.
The most powerful arrangement ties the whole makedown to the process it serves. The polymer dose is often flow-paced against the sludge feed to the thickener or dewatering unit, so as more sludge is fed, more active polymer is delivered, holding the dose in mass of polymer per mass of solids. SCADA computes that dose from the sludge feed rate and the makedown concentration and adjusts the neat polymer feed accordingly, while totalizing polymer use so an operator can track consumption per ton of solids, which is a direct measure of both cost and how well the makedown is activating the polymer.
For plants running lean or across several sites, a cloud SCADA platform such as Merobix puts dilution ratio, aging tank level, post-dilution, sludge feed, and polymer consumption on one screen viewable from any browser. Because polymer is one of the larger recurring chemical costs at a solids-handling plant, trending consumption against solids processed reveals slowly rising usage that signals a makedown drifting off, a degrading batch, or a change in sludge. Alarms on a failed polymer pump, an empty tote, or a low aging-tank level catch the interruptions that would otherwise let a dewatering press run without conditioning and produce a wet, unhaulable cake.
As delivered, polymer molecules are coiled and inactive, and they need time in water to uncoil and fully hydrate before they develop their particle-bridging ability. Aging in a gently agitated tank gives them that time, and a properly aged solution flocculates far better than one fed immediately after mixing. Too little aging leaves the polymer weak, forcing a higher dose to compensate, while very dilute aged solution should not be held too long because it degrades.
Emulsion polymer arrives as polymer droplets suspended in oil, and makedown must invert the emulsion in a mixing device to release and disperse the polymer chains into water. Dry polymer arrives as a powder that must be carefully wetted, usually through a wetting cone or eductor, so each grain dissolves without forming clumps or fisheyes. Both then require mixing, aging, and dilution, but the initial wetting equipment differs between the two forms.
A very dilute polymer solution disperses and mixes into the sludge much more evenly than a thick stock solution, so injecting extra water just before the injection point improves flocculation for the same mass of polymer. Post-dilution effectively spreads the active polymer through the sludge so more of it contacts particles. SCADA meters the post-dilution water as its own controlled ratio, separate from the makedown ratio that sets the mother solution strength.
Merobix reads your field devices into a cloud SCADA - the real thing behind these terms, live in days from any browser.