Mixmate Polymer Feed System Selection


Below are typical answers to the questions asked about our Polymer Feed System, MixMate ®, Selection. Use the tables in the Specifications and Model Numbering Guide Sections to select a MixMate® for your application. First, determine the following:

  1. The number and size of flowmeter needed,
  2. The mixer number and size
  3. If any of the options are needed in your system

If you read through these customer examples and the application notes, you will find that we try to build up your depth of polymer feed equipment knowledge. You are not expected to design your own system, we can help with that, but reviewing this information will give you an idea of what data we will need to provide recommendations.

I. Waste Water Treatment (WWT)IV. Gravel Pit WWT
Q1: 5 ppm
2: 1-3 MGD
3: Anionic emulsion
4: 1 %
5: 0.5 %
6: 60 psi
7: Open discharge
Q1: 100ppm
2: 1-5 MGD
3: Anionic emulsion
4: 1 %
5: 0.5 %
6: 50 psi
7: Open discharge
II. Municipal WWTV. Industrial WWT
Q1: 5-10 ppm
2: 4-10 MGD
3: Solution
4: 5 %
5: 5 %
6: 50 psi
7: 25 psi
Q1:10 ppm
2:10,000 gal/batch/hour 5 minutes to deliver
3:Non-ionic emulsion
4:1 %
5:0.5 %
6:40 psi
7:20 psi
III. Municipal WWTVI. Industrial WWT
Q1: 1 ppm
2: 50-100 MGD
3: Cationic emulsion
4: 1 %
5: 0.5 %
6: 60 psi
7: Open discharge
Q1:10 ppm
2:10,000 gal/batch/hour 2 minutes to deliver
4:3 %
5:3 %
6:80 psi
7:Open discharge
Here is one solution for each of the sets of application answers listed above:
I. Waste Water Treatment
At 1 MGD, 5 ppm is 5 gallons of neat polymer in 24 hours — 3 MGD would mean 15 gallons of polymer. To make a 1 % polymer solution, you’d need 1500 gpd of water (divide by 24 and 60, or 1440, to get 1.04 gpm). Check the tables on page two of the Specifications, and the shaded boxes indicate a 1/8″ nozzle and 3/8″ mixer. Emulsion polymers generally require both primary and dilution flowmeters, typically of the same size to achieve a 0.5 % final product concentration. The Model Numbering Guide gives a part number for the MixMate as an M032-322-XXX.*
II. Municipal WWT
At 10 MGD, 10 ppm is 100 gallons of neat polymer in 24 hours. To make a 5 % solution, you’d need 20 times as much primary dilution water — usually, a single flowmeter is adequate for a solution polymer. With 2,000 gpd of water, you’d have 1.39 gpm. The tables indicate a 1/8″ nozzle and 3/8″ mixer — you might need to swap out to a 1/4″ nozzle if the actual pressure loss is too great since you only have a 25 psi differential to work with. This system would benefit by having the pressure gauge option. The Numbering Guide shows an M032-313-XXX.
III. Municipal WWT
At 100 MGD, 1ppm is 100 gpd of polymer or 4.2 gph. The primary water would be 420 gph, or 7 gpm, for a 1 % solution. Emulsion polymers typically need two flowmeters, so with a 50 % secondary dilution, two 1-10 gpm units would be best. Please note that at 50 MGD you would be dipping into the lower (and less efficient) half of the flow range, so you might try to encourage the customer to run a bit higher secondary water dilution rate to keep up the overall system flow rate (and thus the flow velocity through the mixer). The tables and Guide indicate a model M102-425-XXX.
IV. Gravel Pit WWT
Heavy suspended solids can call for a lot of polymer. At 5 MGD, 100 ppm is 500 gpd of polymer (the quickest solution is sometimes looking at 100 gpd for 1 MGD, then multiplying by the actual GPD number). At 1 %, the primary water would be 34.7 gpm, and with an emulsion that would call for two 20-100 gpm flowmeters. If they run as low as 1 MGD, the application may call for some custom plumbing and flowmeters, or it may be enough to keep the secondary flowmeter rate high. The tables show the best nozzle is 3/4″ and the best mixer 2″. The model number would then be an M202-626-XXX.
* XXX = Option Choices
One question not currently addressed by the list of questions in the Selection Section is whether the treatment system will work on a batch or continuous basis. Many industrial systems, in particular, treat their wastewater in batches. If this is the case, we also need to know how much time in the treatment cycle we have to get the polymer delivered into the customer’s tank, sump, etc.
V. Industrial WWW
At 10,000 gallons per batch, 10 ppm is 0.1 gallons of polymer. With 5 minutes to deliver the polymer, that’s 1.2 gph. With a 1 % solution and an emulsion product, the application would call for two 0.5 – 5.0 gpm flowmeters (leaving room for flowmeter adjustment). With the relatively low-pressure differential, lean toward a 1/4″ nozzle and 3/8″ mixer. The model number would be M032-424-XXX.
VI. Industrial WWT
At 10,000 gallons per batch, 10 ppm is 0.1 gallons of polymer. With only 2 minutes of delivery time, that’s 3.0 gph of polymer. At a 3 % solution, that’s 300 gph (or 5 gpm) of water. Leaving room for adjustment, select one 1.0 – 10.0 gpm flowmeter. Since pressure is not a problem, pick the 1/4″ nozzle and 3/4″ mixer. Please note that you might need to go to a 1″ mixer if two flowmeters are used. The actual mixer pressure loss per element, due to their special trimming for the polymer application, is about half the theoretical calculation shown in the table — i.e., the number in the table is approximately the actual pressure loss for a two element mixer. The difference between actual and theoretical pressure loss is one reason to promote the three pressure gauge assemblies. The MixMate model would be an M072-415-XXX.