Pulping and papermaking is a rigorous activity that involves metering, mixing, and pumping a broad range of chemicals and abrasive materials often at high temperature. Selection of the appropriate paper and pulping pumps is critical to ensure the corrosive and abrasive chemical mixtures are transferred without wearing out or causing damage to the pump.
Common Pump Applications
Wood Chipping / Debarking
Paper and pulp production starts with the cutting down of trees into logs followed by debarking and chipping to prepare the raw materials for the paper processing cycle. The wood chips are then fed into a large digester tank where, with the help of acid, the lignin is dissolved to help separate the plant fibers. Additives and dyes are then added to the wood-free pulp solution. The whole process requires the pumping of corrosive and abrasive slurries as they move from one location to another, an activity that can cause significant damage to conventional centrifugal pumps.
Pumps used in pulp and paper industry should be rugged enough to withstand the harsh conditions that wood chipping operations exert. March Pumps carries a range of heavy-duty, high-quality construction pumps that prevent clogging of the system by debris from woodchips, pulp, and rocks. Our line of pumps for debarking process includes purpose-designed submersible slurry pumps and self-priming Pumps.
During the deinking industrial process, the printing ink is removed from paper fibers of recycled paper to make deinked pulp. Ink is detached from the fibers by a combination of mechanical action and chemical means, where harsh chemical additives ranging from sulfuric acid to sodium hydroxide are commonly used. Froth flotation is then used to separate ink particles from the pulp whereby ink is skimmed off the top while the pulp sinks to the bottom and is pumped out.
At March Pumps, we carry a range of purpose-built pumps for the de-inking process including slurry pumps, submersible pumps, mag-drive pumps, and self-priming pumps that have a high tolerance for the harsh conditions that the pulp and paper industry processes impose.
Stock preparation is where the papermaking process starts. During the process, pulp and cellulose fibers are mixed, refined, diluted, and fed into the paper machine. Some additives are also included to produce the desired qualities in the final product.
Stock preparation is a rigorous mechanical and chemical process that requires heavy-duty pumps to perform optimally even under stressful conditions. At March Pumps, we offer a variety of pumps for chemical processes that transfer pulp and liquid mixtures from one process to the other with high consistency. These include slurry pumps, submersible pumps, mag-drive pumps, and self-priming pumps with high-performance capabilities.
Wet End Chemical Preparation
The wet end, also known as the forming section, is a part of the paper-making process where a continuous rotating wire mesh sucks water from the paper through a vacuum. Several wet end additives including starch, fillers, sizing and fixing agents, dyes, and optical brighteners are then added to enhance certain qualities of the finished paper like retention and dry strength. These chemicals are metered and fed into the stock using positive displacement pumps.
Pumps used in wet end chemical preparation need to be calibrated to deliver the right amount of dye and other additives during paper-making. They should also have a high tolerance for the difficult conditions that viscous liquids containing starch and other additives exert. We carry a line of slurry pumps, submersible pumps, mag-drive pumps, and self-priming pumps that are purpose-built to handle the rigors of the paper-making industry.
Starch is a wet end additive applied to paper to give a stronger, smoother writing and printing surface. After water, fiber, and fillers, starch makes up the highest volume of raw material in paper grades containing mineral fillers. During paper-making, cationic starch is heated to form a paste-like solution. It is then metered and steadily pumped into the paper stock mixture.
Pumps used in starch preparation need to be calibrated to deliver the right amount of starch and other additives during the wet end process in paper-making. They should also have a high tolerance for the rough conditions that the viscous liquids involved exert. We carry a line of pumps that are purpose-built to handle the rigors of the wet end processes in the paper-making industry.
Wastewater and Sludge Dewatering
The pulp and paper production process creates byproducts that include pulp mill sludge, grit, lime, mud and other effluents that need constant removal from the processing site. Dewatering and management of pulp and paper mill sludge pose many challenges, including a high budget that takes up over half of the total wastewater treatment costs. It is therefore important to have a sustainable and cost-effective method of transferring paper mill waste without harming the environment.
When disposing of sludge, you need a robust pumping system that can withstand the harsh conditions that viscous waste-water, sludge, and other chemicals exert. We carry a wide variety of pumps that are specifically built to handle the rigors of sludge and wastewater management in the paper-making industry.
Slurry Pumps for Paper and Pulp Industry
March Pumps industrial slurry pumps are built for an extensive range of applications including the transfer of process chemicals and wastewater generated by the paper and pulp industry. Our non-clog pumps are designed to move slurry, sand, and other materials efficiently and are capable of pumping solids up to 2112 GPM with as much as 102 HP. We offer a wide range of models including 3-inch, 4-inch, 6-inch, and 8-inch sizes.
Self-Priming Surface Paper Pulp Pumps
Made of highly durable material, March Pumps’ centrifugal self-priming pumps are purpose-built for transferring pulp mill sludge, process chemicals, and raw and wastewater for the paper-making industry. Our versatile slurry pumps outperform other conventional self-priming pumps when it comes to providing powerful suction for heavy muck and debris, making the transfer of difficult slurries more manageable. We carry a wide selection of electrical self-priming slurry pumps with max flows ranging from 14 to 80 GPM available in 3-inch, 4-inch, 6-inch, and 8-inch sizes.
Flooded Suction Paper Pulp Pumps
Flooded suction pumps function through a suctioned chamber that is regularly filled with a gravity-fed liquid. They are always primed and ready for operation and can be deployed in many different pump applications. What makes them different from submersible pumps is that they sit outside of the tank or hopper holding the slurry or fluid. At March Pumps we offer a range of flooded suction paper pulp pumps that are suited for pumping slurry, highly viscous material, and abrasive liquids.
Submersible Paper Pulp Pumps
Submersible pumps are designed to be operated while fully submerged in the liquid that is being transferred. They do not need priming and can be used to draw water from deep sources. Our submersible pumps for the paper industry are built to withstand the tough operating conditions that pulp processing applications demand including dewatering and pumping sludge. They have an exceptional sealing system and are easy to maintain, making them the go-to pulp pump for your pulp and pulp processing applications.
Positive Displacement Paper Pulp Pumps
A positive displacement pump will move fluid by trapping a fixed amount of it before forcing it into a discharge pipe with the aid of a mechanical device such as a piston or plunger. March Pumps’ positive displacement pumps are deployed in a wide number of industrial applications where they transfer large volumes of harsh and viscous liquids that would otherwise be impossible to convey when using traditional centrifugal pumps. This makes our pumps ideal for the paper and pulp industry which constantly needs to move sludge and slurries that do not lend themselves to transportation using traditional pump systems.
Paper & Pulp Pumping Problems
Transporting Wood Chips and Tree Bark
To prepare raw materials for the paper processing cycle, logs undergo debarking and chipping before being converted into pulp. Woodchips and tree bark are very abrasive and do not lend themselves to transport by conventional pumps. This poses headaches when moving the chippings into the pulp digester tanks. Selecting the right kind of pulp and paper equipment is important to avoid loss of pump suction or complete pumping machinery breakdown.
Pulp Digester Tanks
Because of their viscous and abrasive nature, wood chips and pulp are problematic materials to transfer with pumps. They require careful selection of pumps as conventional centrifugal pumps eventually lose their tolerance and suction power when subjected to tough pulp pumping conditions.
Pulp Bleaching Process
Pulp bleaching is the use of chemicals like chlorine dioxide and hydrogen peroxide to break down residual lignin in the pulp. The pumps used to introduce bleaching agents and other additives into the pulp mixture need to be robust to withstand the corrosive and viscous nature of the slurry mixtures. Selection of the right type of pump for pulp bleaching process is therefore critical to avoid frequent pulp equipment breakdowns and other maintenance issues.
Pulp Slurry Transfer
Pulp slurry transfer involves the transportation of pulp suspensions from one part of the plant to another. Pulp slurries are heavy, viscous, and abrasive meaning that the pumps used in their transfer should be designed to withstand corrosive materials and solids that may clog the system. Selection of the right type of pump for pulp slurry transfer is therefore critical to avoid frequent pulp equipment failure and other maintenance concerns.