100 ml to 10 l of water is consumed in the production of just one DIN A4 sheet of paper, depending on the raw material. Water is essential for all important process steps in paper production. It is intended as a suspension and transport medium for fibers and fillers, as a solvent for chemical additives and as a medium for forming the hydrogen bonds between the fibers. As such, paper in the sense we are familiar with cannot be produced without water. In the production process, water is recycled on a large scale. Wastewater is produced as excess recirculated water that is displaced by the fresh water used.
Pulp and paper industry
INVENT solutions for
Pulp and paper industry
Challenges for machine technology
Dealing with high calcium concentrations in paper production poses a challenge. The source of the increase in circulating water and waste water is calcium carbonate, which has been increasingly used in production as a cheap filler or coating pigment in recent years. This increases the calcium content in the waste paper, so that calcium is also increasingly being introduced into the wastewater via this secondary raw material. Too high concentrations can lead to operational problems with deposits and blockages in the waste water treatment. In addition, high temperatures and abrasive substances place high demands on the machine technology used, which is why know-how, quality and experience are essential for a successful project. INVENT has been successfully equipping wastewater treatment plants in the pulp and paper industry for more than 25 years, which makes us one of the leading experts in this field.
INVENT offers you mixing technology as well as mixing and aeration systems optimized for the respective mixing task and the process. Contact us here.
Product videos:
HYPERCLASSIC®-Mixing and Aeration System in the pulp and paper industry
- Neutralization
- Emergency Tank
- Storage and Equalization
- Hydrolysis
- Pre-Acidification
- Stripping
- Selector
- Carbon Removal
- Lime trap
- High Loaded MBBR
HYPERCLASSIC®-Mixer
To discharge wastewater into the public sewer system or an in-house biological treatment plant, the pH value must be within the permissible range of 6.5 to 9. To adjust the pH value, acids or bases are specifically added to achieve neutralization.
The CYBERPITCH®-Mixer is ideally suited for this purpose. Thanks to its robust design made of high-quality stainless steel and its flow-optimized blade design, it ensures effective and uniform mixing. The construction is specifically designed for turbulent flows, thus efficiently supporting the neutralization of wastewater.
The HYPERCLASSIC®-Mixer is also used for neutralization and stands out due to its high energy efficiency during tank content mixing. It is the preferred choice when effective neutralization and economical use of energy are both required.
HYPERCLASSIC®-Mixer
In emergency tanks, wastewater resulting from unforeseen leaks is collected and then either directed to a wastewater treatment plant or properly disposed of. To prevent build-up and sedimentation, the wastewater must be continuously mixed.
The HYPERCLASSIC®-Mixer is excellent for this purpose, as it provides particularly high circulation capacity, ensuring smooth operation.
HYPERCLASSIC®-Mixer
HYPERCLASSIC®-Mixing and Aeration System
In mixing and equalization basins, wastewater from various areas is collected and homogenized. This effectively prevents peak loads on the biological part of the treatment plant. In some cases, a mixing and equalization basin even serves as the sole treatment stage for wastewater directly on the company premises. Here, the wastewater is collected during the day and discharged into the municipal wastewater treatment plant at night when its load is at its lowest.
For this application, the HYPERCLASSIC®-Mixer is particularly suitable due to its high circulation capacity.
In some cases, mixing and equalization basins are aerated to prevent anaerobic conditions and enable the degradation of pollutants in advance. For these requirements, the HYPERCLASSIC®-Mixing and Aeration System offers an optimal solution, as it ensures both effective aeration and reliable mixing.
HYPERCLASSIC®-Mixer
During hydrolysis, complex macromolecules such as carbohydrates, proteins, and fats are broken down into shorter organic compounds with the help of enzymes, which act as biological catalysts.
The HYPERCLASSIC®-Mixer is distinguished by its particularly low-shear energy input while ensuring optimal homogenization of the tank content. Additionally, it significantly reduces the flow velocity at the water surface, completely preventing undesirable oxygen ingress.
HYPERCLASSIC®-Mixer
A sufficient initial acidification of the dissolved polymers to form short-chain organic acids is decisive for a stable and efficient process in anaerobic wastewater treatment and ultimately a high methane yield.
Since this process is carried out by anaerobic bacteria, it is essential to avoid oxygenation, for example via the water surface.
The HYPERCLASSIC®-Mixer is installed near the bottom and generates a strong radial bottom flow. Since the speed at the water surface has reduced to such an extent that oxygen entry is effectively prevented, the HYPERCLASSIC®-Mixer is particularly suitable for this agitating task. In addition, thanks to the high pumping capacity, it ensures that all of the wastewater is thoroughly mixed, thereby ensuring efficient utilization of the entire reactor.
iCBA®-Aeration System
HYPERCLASSIC®-Mixing and Aeration System
In stripping, substances are transferred from a liquid phase to the gas phase through desorption, applying Henry’s law. In this process, the liquid is brought into contact with a gas—typically air—using the countercurrent principle. In wastewater treatment, this method enables the removal of substances such as ammonia, hydrogen sulfide, mercaptans, phenols, organic halogen compounds, and hydrocarbons.
The iCBA®-Aeration System is particularly well-suited for introducing large volumes of gas. If solids also need to be kept in suspension, the HYPERCLASSIC®-Mixing and Aeration System provides an almost ideal solution, as it combines effective mixing and aeration.
HYPERCLASSIC®-Mixer
HYPERCLASSIC®-Mixing and Aeration System
In a selector, conditions are optimized to promote the growth of desired microorganisms over undesired ones. The selector is placed upstream of the biological treatment stage, where the return sludge is intensively mixed with fresh wastewater. A selector can be operated either aerated or non-aerated, with intensive mixing required in both cases.
For this reason, HYPERCLASSIC®-Mixers are particularly suitable for non-aerated selectors, while HYPERCLASSIC®-Mixing and Aeration Systems are ideal for aerated selectors.
HYPERDIVE®-Mixing and Aeration System
HYPERCLASSIC®-Mixing and Aeration System
During carbon elimination, carbon-based contaminants in wastewater are broken down into CO₂ by microorganisms. This requires an adequate oxygen supply for the bacteria while keeping the activated sludge flocs in suspension.
Especially in industrial wastewater treatment, where high concentrations of problematic substances often occur, the HYPERCLASSIC®– and HYPERDIVE®-Mixing and Aeration Systems have proven successful in hundreds of installations.
HYPERDIVE®-Mixing and Aeration System
HYPERCLASSIC®-Mixing and Aeration System
In so-called lime traps, dissolved lime in the water is precipitated by driving off carbon dioxide (CO₂) with air and then removed. This process requires the introduction of large amounts of gas and maintaining the lime in suspension to prevent deposits and blockages.
The clogging-resistant HYPERCLASSIC®-Mixing and Aeration System offers the optimal solution for this. It not only ensures the efficient introduction of large amounts of gas but also provides powerful mixing. This keeps the lime evenly in motion, ensuring smooth and effective precipitation and removal of the lime.
iCBA®-Aeration System
In the so-called MBBR process (Moving Bed Bio Reactor), microorganisms needed for wastewater treatment grow on special carrier materials inside the reactor. The high-load biofilm stage is designed to efficiently remove easily degradable dissolved substances before they reach the activated sludge tank. This system offers several advantages, including increased treatment capacity, improved process stability, and optimization of sludge properties.
In a high-load biological system, a large amount of oxygen or air is required, while the carrier materials must be gently circulated. For such applications, the iCBA®-Aeration System has proven to be highly reliable and efficient in hundreds of installations.
