Dosing pump refers to a specialized pump that doses precise amounts of chemicals or additives into a water or wastewater stream to achieve specific treatment goals. Dosing pumps are central to water and wastewater treatment as they enable the controlled supply of chemicals, ensuring that chemical processes run efficiently, whether for flocculation, pH adjustment, disinfection or dosing of antiscalants.
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Technical basics and functionality of dosing pumps
Dosing pumps are designed for precision and repeat accuracy and can dose small quantities of chemical solutions or concentrated substances in a constant and controlled manner over long periods of time. They consist of a drive unit, a dosing head and a diaphragm or piston that is moved by the pump. The drive pushes the diaphragm or piston cyclically so that the chemical is pumped out of the dosing head at set intervals. Depending on the design and material, dosing pumps can also reliably pump aggressive media such as acids, alkalis or oxidizing agents.
Types of dosing pumps
There are different types of dosing pumps used in industrial water treatment, each with specific advantages and disadvantages depending on the area of application:
Diaphragm metering pumps:
- Diaphragm dosing pumps use a flexible diaphragm that is moved by hydraulic or mechanical pressure. This movement enables precise and uniform dosing without the chemical coming into direct contact with moving parts. This design minimizes wear and makes them ideal for aggressive or abrasive chemicals, such as those used in wastewater treatment.
Piston metering pumps:
- These pumps use a piston that moves up and down in a cylinder to meter the chemical. Piston metering pumps offer high precision and are often used in applications with low viscosity and non-aggressive chemicals. However, they are less suitable for abrasive media, as the piston is in direct contact with the liquid to be dosed.
Peristaltic metering pumps:
- These pumps are particularly flexible and are well suited for chemical solutions that are abrasive or contain solids. In a peristaltic metering pump, the chemical is pumped through a flexible hose system that is pushed by rollers or cams. This design reduces the risk of blockages and is ideal for highly viscous media or media containing solid particles.
Solenoid-controlled dosing pumps:
- These pumps use a magnetic system to drive the movement of the diaphragm. They are often smaller and suitable for applications where precise, small quantities of chemicals need to be dosed, such as in laboratory environments or for disinfection.
Applications and areas of use for dosing pumps
Dosing pumps are essential in industrial water and wastewater treatment, as they ensure the precise addition of chemicals and increase the efficiency of processes. Typical applications include:
1. precipitation and flocculation:
- Dosing pumps precisely dose precipitants such as aluminum sulfate or ferric chloride to remove impurities in the water. Precise dosing ensures that precipitation is effective and wastewater is cleaned efficiently.
Photo: ALMA CHEM MCW precipitation and flocculation plant with IBC dosing station for precipitant (left) and dosing and preparation station for the neutralizing agent milk of lime (right)
2. pH regulation:
- Precise dosing of acids (e.g. sulphuric acid) or bases (e.g. caustic soda) is required to neutralize acidic or alkaline wastewater. Dosing pumps enable precise addition in order to adjust the pH value of the water to the desired level.
Photo: Two-sided dosing station (acid & alkali) for the ALMA Neutra neutralization system, installed in the ALMA Modul technical room container
3. disinfection:
- In drinking water treatment or in cooling water circuits, dosing pumps are used to add disinfectants such as chlorine or hydrogen peroxide. These substances are highly effective, but also very reactive, so precise dosing is necessary to avoid overdosing and to ensure safe water treatment.
4. corrosion protection and anti-scaling:
- Dosing pumps add corrosion inhibitors or antiscalants to cooling or boiler water to prevent the build-up of limescale and corrosion of system components. The chemical must be dosed continuously and in exact quantities in order to optimally develop the protective effect and minimize chemical consumption.
5. membrane processes in reverse osmosis systems:
- Dosing pumps dose antiscalants and dispersants to prevent membrane fouling in reverse osmosis systems. This extends the service life of the membranes and increases the efficiency of the system.
Photo: Monitoring and dosing system for cooling water treatment ALMA Trol Std Assemply
ALMAWATECH dosing technology: Customized solutions for industrial water and wastewater treatment
ALMAWATECH offers a range of specialized dosing technology solutions that are optimally tailored to the needs of our customers and the requirements of industrial water and wastewater treatment. Our products are specially developed for precise, reliable and economical dosing:
1. ALMA FLOC AC - Automatic dosing and preparation station for flocculants:
- This station enables the precise and controlled addition of flocculants to optimize the aggregation and sedimentation of solids in wastewater. The automatic preparation process ensures that the flocculants are always available in the correct concentration, which guarantees consistent and reliable flocculation.
2. ALMA LIME - preparation and dosing station for milk of lime:
- For applications that require pH adjustment using milk of lime, the ALMA LIME offers an automated preparation and dosing solution. This station is robustly designed to prepare and dose milk of lime with high precision and is equipped with special seals that can withstand abrasive media.
3. ALMA dosing station for various delivery containers:
- Our delivery container-compatible dosing station enables easy integration and safe connection of IBC containers, 30/60 liter containers or 200 liter chemical drums to the dosing system. This is particularly advantageous in large systems with high chemical consumption, as dosing takes place directly from the large containers.
Photo: Double dosing station for 30 liter containers (foreground) and double IBC dosing station (background), dosing and preparation station for flocculants (right)
All our dosing stations are equipped with an automatic empty signal, overfill sensor and durable sealing materials (NBR, FKM, EPDM, etc.) to ensure a high level of operational safety and durability. These safety precautions ensure continuous monitoring of the operating status and enable uninterrupted operation, even with intensive use and large throughput volumes.
Control and load-proportional dosing: ALMAWATECH's advanced dosing technology
One of the key requirements in industrial dosing technology is the ability to adapt the dosing to the actual load of the water. ALMAWATECH offers a special control and online measurement system that enables load-proportional dosing. This intelligent control technology continuously monitors the water quality and adjusts the dosing quantity in real time to fluctuations in the water composition.
- Automatic adjustment of the dosing quantity: Based on the online measured values such as COD, TOC, pH, conductivity or turbidity value, the dosing is automatically regulated to ensure an optimum dosing quantity and avoid overdosing.
- Reduction of chemical consumption: The load-proportional dosing minimizes chemical consumption, which reduces operating costs and maximizes the efficiency of water treatment at the same time.
- Efficient control of dosing stations: The integrated control technology enables centralized control and monitoring of dosing stations, allowing for quick adaptation to changing water conditions.
Conclusion
Dosing pumps are a central element of industrial water and wastewater treatment and enable the precise and controlled supply of chemicals. ALMAWATECH offers advanced dosing pump solutions that are characterized by precision, robustness and efficiency and can be combined with our load-proportional control technology to ensure optimal chemical treatment. By using durable materials and focusing on the highest dosing accuracy, our dosing pumps are ideal for demanding applications and ensure stable and cost-efficient water treatment.
For further information on our products, please feel free to contact us at any time!
Photo: IBC dosing station with WHG collection tray (left) and ALMA LIME milk of lime dosing and preparation station (right)
