Maximize Dewatering Efficiency: DAGYEE Launches Next-Gen Automated Polymer Preparation Unit

DAGYEE polymer preparation units: The Complete Technical FAQ

Introduction to DAGYEE Chemical Dosing Solutions

This document is designed for environmental engineers, plant operators, and procurement specialists who are designing Wastewater Treatment Plants (WWTP) or industrial sludge processing facilities. As a specialized manufacturer, DAGYEE focuses on engineering Automatic Polymer Dosing Systems that are reliable, efficient, and fully customizable. This guide explains the science, operation, and engineering behind our technology.

Section 1: Fundamentals & Working Principles

Q1: What exactly is a Polymer Preparation Unit, and why is it necessary?

A Polymer Preparation Unit (often called a Polyelectrolyte Preparation System or Auto-Dosing Unit) is a machine designed to automatically mix, age, and dose polymer solutions.

In wastewater treatment, polymers (specifically Polyacrylamide or PAM) are used as flocculants. However, PAM is difficult to handle. It comes as a dry powder or concentrated liquid that is extremely viscous. You cannot simply dump it into water; it requires:

Precise Dry Powder Feeding.
Controlled wetting to prevent clumps (known as "fish eyes").
Specific Maturation Time (aging) to allow the polymer chains to uncoil and become active.

A DAGYEE unit automates this entire process, ensuring you get a consistent Polymer Solution every time, which is critical for downstream processes like sludge dewatering.

Q2: How does the DAGYEE "Three-Chamber" design work?

Most DAGYEE systems utilize a continuous Three-Chamber System design to ensure continuous operation without batch downtime. The flow is as follows:

Preparation Tank (Chamber 1): The Dry Powder Feeder drops polymer into a wetting cone, where it mixes with water. A high-speed Mixing Agitator ensures the powder is fully dispersed into the water to begin dissolving.
Maturation Tank (Chamber 2): The solution overflows into the second tank. Here, a slow-speed mixer keeps the solution moving. This is the "aging" zone where the polymer molecules hydrate and expand. Without this step, the polymer efficiency is cut in half.
Dosing Tank (Chamber 3): The fully matured solution overflows into the final storage tank. From here, your Metering Pump draws the chemical to send it to your process (e.g., a Belt Press or DAF). Level Sensors in this tank control the entire automation cycle.

Q3: Why can’t I just mix polymer by hand in a tank?

Manual mixing is the leading cause of poor dewatering performance.

Fish Eyes: Manual mixing creates gelatinous clumps ("fish eyes") of un-dissolved polymer. These clumps clog pumps and do not react with sludge.
Inconsistency: A human cannot manually dose powder with the accuracy of a Variable Frequency Drive (VFD) screw feeder. This leads to fluctuating Solution Concentration.
Waste: Poorly mixed polymer is wasted money. A DAGYEE Automatic Dosing Device typically reduces chemical consumption by 20–30% compared to manual batching.

Q4: What types of chemicals can this system handle?

While primarily designed for Anionic Polymer and Cationic Polymer (PAM), our units are versatile.

Dry Powder: The standard hopper is designed for granules/powder.
Liquid Polymer: DAGYEE can install a liquid injection pump kit to handle concentrated liquid emulsion polymers instead of powder.
PAC/Coagulants: With modification, the tanks can be used for other chemical preparations, though they are optimized for viscous polymers.

Section 2: Technical Specifications & Engineering

Q5: How does the DAGYEE Powder Feeder ensure accuracy?

The heart of the machine is the Dry Powder Feeder.

We use a precision-machined screw auger driven by a VFD motor.
The VFD allows the operator to control the exact RPM of the screw.
Heated Pipe: To prevent the powder from absorbing moisture and clogging the outlet (a common issue in damp treatment plants), DAGYEE installs a heating element around the feeder discharge pipe.
Vacuum Loader (Optional): For safety, we can integrate a Vacuum Feeder to suck powder from bags on the ground up into the hopper, reducing dust and lifting injuries.

Q6: What is the standard range of Solution Concentration?

DAGYEE systems are designed to prepare solutions typically between 0.1% and 0.5% concentration.

Recommended: 0.1% to 0.25% is the industry standard for optimal maturation.
Viscosity Limit: If you try to mix >0.5%, the solution becomes too viscous (like jelly), and the Transfer Pump will struggle to move it. The internal piping and weirs are sized to handle the hydraulic flow of standard polymer viscosities.

Q7: What materials of construction does DAGYEE use?

As a custom manufacturer, we offer:

SS304 Stainless Steel: The standard for most municipal and general industrial applications. It offers good corrosion resistance and structural integrity.
SS316L Stainless Steel: Recommended for high-salinity environments (desalination plants) or corrosive chemical environments.
PP (Polypropylene): For specific applications involving highly corrosive acids where steel is unsuitable, we can fabricate the tanks from reinforced PP.

Q8: How is the water supply controlled?

The water inlet is controlled by a Solenoid Valve and a Flow Meter (Rotameter or Electromagnetic).

When the Level Sensor in the Dosing Tank drops to "Low," the PLC opens the water valve.
Simultaneously, the powder feeder starts.
The ratio of water flow to powder feed rate determines your concentration.
When the tank reaches "High," the system goes into Standby.

Section 3: Operation, Controls & Automation

Q9: Explain the PLC Control System.

DAGYEE units come with a fully integrated Control Panel.

PLC (Programmable Logic Controller): Usually Siemens or Schneider. It manages the logic (Start/Stop, Alarms, Time Delays).
HMI (Touch Screen): Allows the operator to easily adjust parameters.
Automation: The system is "Set and Forget." It automatically refills itself.
Dry Run Protection: If the water supply fails or the powder hopper is empty, the system alarms and shuts down to protect the equipment.

Q10: Does the system detect if the powder hopper is empty?

Yes. We install a Capacitive Level Sensor or a rotary paddle sensor inside the powder hopper.

Low Powder Alarm: When the powder gets low, a light flashes and an audible alarm sounds to alert the operator to refill the hopper.
This prevents the system from mixing "water only" which would dilute your process chemistry.

Q11: What is the required Maturation Time?

For Polyacrylamide, the scientific recommendation is 45 to 60 minutes of aging time.

DAGYEE sizes the tank volume ($V$) based on your required flow rate ($Q$) to ensure: $V / Q > 60 \text{ minutes}$.
If you undersize the unit (short retention time), you will use twice as much chemical to get the same result.

Q12: Can DAGYEE integrate the Dosing Pumps?

Yes. While the "Preparation Unit" makes the chemical, we can supply a Chemical Dosing Skid.

We mount the Metering Pump (Screw Pump or Diaphragm Pump) directly onto the unit or a separate skid.
The PLC can be programmed to control the output of these dosing pumps via a 4-20mA signal from your main SCADA system.

Section 4: Applications & Integration

Q13: How does this integrate with a Sludge Dewatering Screw Press?

The Sludge Dewatering process relies 100% on good flocculation.

The DAGYEE Polymer Unit prepares the PAM.
The Dosing Pump injects PAM into the sludge line just before the Screw Press.
The sludge and polymer mix in the Flocculation Tank.
Synergy: Because DAGYEE manufactures both Screw Presses and Polymer Units, we can perfectly match the sizing controls. For example, if the Screw Press stops, the Polymer Unit automatically goes into "Pause" mode.

Q14: Is this system suitable for Dissolved air flotation (DAF)?

Yes. DAF Systems often use a Coagulant (PAC) followed by a Flocculant (PAM).

The DAGYEE unit provides the PAM dosing.
For DAF, the floc needs to be light and large. Consistent polymer aging provided by our unit ensures the floc is robust enough to float without breaking apart.

Q15: Can it be used for Potable Water Treatment?

Yes, but the materials must be compliant.

We use food-grade lubricants and ensure the Stainless Steel is fully passivated.
For drinking water, precise dosage is critical to avoid residual chemicals in the water supply. Our high-accuracy feeders ensure compliance with health regulations.

Section 5: Customization & DAGYEE Advantages

Q16: I have limited space. Can DAGYEE change the dimensions?

Yes. This is our strength.

Standard units are rectangular.
If you have a narrow room, we can make the tank longer and thinner.
If you have a split-level facility, we can create a "Double-Deck" design where the preparation tank is stacked above the dosing tank.
Just send us your Layout Drawing, and our engineers will model a unit to fit.

Q17: Do you offer Explosion-Proof (Ex-Proof) options?

Yes. For refineries or petrochemical plants:

Motors: We use ATEX or Ex-d rated motors for the mixers and feeders.
Panel: We use Ex-proof control cabinets or can mount the non-Ex panel in a safe zone remote from the unit.
Sensors: We use intrinsically safe barriers for level sensors.

Q18: Can you add a secondary dilution system?

Yes. Sometimes you need to prepare the polymer at 0.5% (to save tank space) but dose it at 0.1% (for better mixing with sludge).

DAGYEE can install a Post-Dilution Static Mixer.
We add a water line and a static mixer at the outlet of the dosing pump to dilute the concentrated solution "inline" before it hits the process.

Q19: What voltage options are available?

We customize for the global market:

China/EU: 380V/400V, 50Hz, 3-Phase.
Americas: 440V/480V, 60Hz, 3-Phase.
Residential/Small Scale: 220V, Single Phase (for very small Mini-Units).

Section 6: Troubleshooting & Maintenance

Q20: What happens if the powder clumps (Fish Eyes)?

This usually means the wetting cone is blocked or the water pressure is too low.

Check: Is the heating ring on the feeder pipe working? (Damp powder clumps).
Check: Is the water pressure >2 bar? The spray nozzle needs pressure to disperse the powder curtain.
Clean: DAGYEE designs the wetting cone to be easily disassembled for cleaning.

Q21: How do I clean the tank?

Over time, polymer can leave a slimy film on the tank walls.

The tanks have a Bottom Drain Valve.
Flush with hot water.
Caution: Never wash polymer spills with just water on the floor—it becomes as slippery as ice. Use sand or sawdust to absorb spills first.

Q22: The powder feeder is accurate but the concentration varies.

Check the bulk density of your dry polymer.

Different brands of PAM have different densities.
If you switch chemical suppliers, you must recalibrate the feeder.
DAGYEE’s PLC allows you to run a "Calibration Mode" to weigh the output for 60 seconds and input the new weight to adjust the logic.

Section 7: Logistics, Warranty & Commercial

Q23: How is the unit shipped?

Small/Medium Units (500L - 2000L): Shipped fully assembled in a crate. Plug and Play.
Large Units (4000L+): May require the powder hopper and mixers to be detached to fit in a standard shipping container height. Re-assembly takes roughly 4 hours.

Q24: What is the lead time for a custom unit?

Standard Specs: 2 – 3 weeks.
Custom Dimensions/Materials: 4 – 5 weeks.
We keep stock of standard motors and pumps to expedite production.

Q25: What information is needed for a quote?

Polymer Type: (Powder or Liquid).
Dosing Capacity: (How many liters of solution do you need per hour?).
Maturation Time: (Standard is 60 mins, do you need more?).
Material: (SS304 or SS316).
Power Supply: (Voltage/Hz).
Accessories: (Do you need the dosing pumps included?).

Summary: Why Choose DAGYEE?

In the world of Flocculant Dosing, precision is everything. A poorly designed system will waste thousands of dollars in chemicals and cause process upsets in your dewatering equipment.

DAGYEE goes beyond being a simple assembler. We are a manufacturer that understands the fluid dynamics of polymer mixing. Our Three-Chamber Systems are built to last, fully automated, and tailored to fit your plant's specific constraints. Whether you need a simple Flocculant Preparation Unit or a complex, hazardous-area rated Polyelectrolyte System, we have the engineering capability to deliver.

Ready to Automate Your Chemical Dosing?

Stop wasting money on manual mixing and start ensuring process stability. Contact DAGYEE today for a technical proposal and a customized quote.

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