Water often plays a key role in production. The process of manufacturing paper is dependent upon the uninhibited flow of filtered water. Maintaining a water-delivery system can prove costly when the system is outdated or simply not fit for the application at hand. This was the challenge faced by a manufacturer of paper-based industrial and consumer products.
The New England manufacturing center produces industrial wipes, a highly specialized operation involving the use of a bag and cartridge water filtration system. A well, located approximately two miles away from the plant, provides water for the process. The characteristics of the source water posed a unique problem.
Well water generally is harder due to high iron, calcium and manganese content. When used in a manufacturing or process application, such solids can become an issue, affecting the quality of the end product while increasing manufacturing costs. The water quality put the plant’s antiquated filtering system under a great deal of performance pressure — to which it did not respond well. Bag and cartridge replacement was an all-too-frequent necessity, resulting in high downtime and increased maintenance related costs. The application called for a water delivery system capable of producing 1,000 gallons per minute while being able to filter the particles affecting the manufacturing process.
Filtering Well Water
The need for frequent bag and cartridge changes, weekly maintenance requirements and manifold re-manufacturing (resulting from wear on the high pressure pumps) became overwhelming. It was clear that the incurred manufacturing costs and extended lead times due to excessive downtime needed to be reviewed.
Traditional sand-based filtering systems are static in nature; therefore, they are susceptible to both solid saturation and clogging. These weaknesses increase the possibility of small-sized contaminants bypassing the filtering media. Such water treatment solutions would not meet the company’s objectives when treating well water.
The plant runs various different types of products for which 400 to 1,000 gallons per minute of water may be required. To address the challenging source water, a new water filtration system was selected. The high capacity media filter combines crossflow dynamics with microsand media to achieve submicron filtration performance. The effluent water quality reduces the requirement to replace disposable filters downstream. Due to its automatic backwash system, the unit requires little or no operator involvement, potentially further reducing labor costs. Also, the filtration system does not require adjustments to compensate for increases or decreases in flow rates.
Due to the customer’s short and long-term production goals, a system rated at 1,000 gallons per minute was chosen. This presented a space problem because the plant, built in the 1940s, was not designed to accommodate such a system.
An installation site was selected near the piping for the water source, but its small footprint made it necessary to custom-design a unique system. A network of vessels, stainless steel pneumatic valves, and a control panel equipped with a programmable logic controller (PLC) that acts as the system’s brain had to fit in a small installation footprint.
Faced with both footprint and height restrictions, engineers designed a customized system. The filtration system’s modular design also offered the opportunity to grow the system’s capacity with ease. This allowed for small and — if needed — large changes to the manufacturing capabilities in the future.
The original intention was to have the filtration system support the existing bag and filter setup. However, the filtration capabilities have exceeded the papermaker’s expectations, resulting in the microsand filtration unit being considered for use as a stand-alone filtration system.
Filter Retrofit Results
- Water samples were taken before and after the installation of the new water filtration system. Seventy percent of particles under 2 microns in size were removed in a single pass. The advantages provided by the updated filtration system include:
- The low maintenance system reduces labor costs.
- Submicron filtration reduces the effects of fouling
- Less chemicals are required to clean the water filtration system, resulting in decreased chemical expenses.
- Reducing the usage rate, and ultimately the spend, on a consumable type product like filter bags further reduced maintenance costs. There are fewer
- bags to maintain or replace, ultimately requiring less manual labor.
- Pump wear was reduced, eliminating the requirement to send out the manifolds for remanufacturing every three months.
In addition, less maintenance resulted in less downtime for the facility, improving production.