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Precoat’s Zinc Phosphate Sludge Removal

Source: CoilWorld.com

Houston, Texas – November 1, 2004 – Precoat Metals, one of the leading suppliers of metal coil coating services has been applying protective and decorative coatings to their customers steel and aluminum coils, using a continuous process coating line. With 10 coating lines at eight plant locations, they are one of the largest metal coil coating companies in the world.

The Problem

On the company’s Houston, TX coating line, zinc phosphate is applied to steel coils to serve as a protective coating. A by-product of the coil coating process is a sludge formed from the zinc phosphate, water and etching compound, which ends up settling to the bottom of the coating line’s tank unit.

The more sludge that accumulates, the less efficient the metal coating process becomes. The zinc phosphate sludge which settles at the bottom of the tank requires periodic removal, requiring a contracted vacuum truck service every three months, costing Precoat Metals $6,500 per removal in addition to as much as eight hours of metal coating production which averaged approximately $3000 per hour… Based on the cleaning schedule frequency, Precoat calculated that the companys out-of-pocket costs for this process would amount to $26,000 plus production losses exceeding this amount. At this rate it was calculated that the company estimated that its annual cleaning bill could amount to more than $120,000 along with inconvenience of the cleaning process itself.

Precoat Finds Solution

Therefore, the company was seeking a better way to handle its cleaning process. Since Precoat had been using CentraSep Centrifuge Fluid Filtration machines on other coil coating lines, but for different purposes, they consulted with Midwest Engineered Products, manufacturers of the CentraSep system to determine if that system could work to solve its zinc phosphate removal problem. Midwest accepted this challenge and after completing on-site material tests, concluded that the CentraSep system would work.

Precoat installed the centrifugal liquid solid separator as part of the pretreatment section of it coil coating in 2002 and put it to work removing the zinc phosphate from the process water. Results were very satisfying for Precoat. The new system had paid for itself in less than two years by eliminating the need for the quarterly zinc phosphate tank cleaning costs.

Benefits Realized

Besides the cost savings realized, Precoat has seen numerous benefits from the installation of its centrifuge fluid filtration system. It has eliminated tedious and expensive pump and shovel tank cleaning, reduced production downtime, and extended process fluid life. In addition it has improved heat transfer, reduced labor costs, reduced separated material disposal costs and provided worry-free operation with no filtering media required.

How the System Operates

On the zinc phosphate metal coil coating line the sludge by-product is pumped directly to the centrifuge unit, where—reaching spinning speeds up to more than 2000 times the force of gravity—even the smallest particles of zinc phosphate are removed from the water and etching bath. The resulting fluids can then be recycled and reused in the coating process. The zinc phosphate particles are collected on the centrifuge’s bowl wall where after a degree of accumulation and based on a predetermined process cycle, they are automatically scraped and discharged into a receptacle. The centrifuge filtering and scraping cycles are PLC programming controlled allowing continuous cycling and operation with virtually no operator attention.

The centrifuge system is built not only to solve tough fluid filtering problems, but to be reliable and worry-free. All parts that come in contact with the process fluids are constructed of 316 stainless steel for dependability and ease of maintenance. According to Robert Pagel, Precoat’s maintenance foreman at the Houston facility, Midwest trained our line personnel and made sure everything was running smoothly, and they’re quick to respond whenever we need them.

About CentraSep Technologies

CentraSep Technologies develops, manufactures, sells and services the CentraSep liquid -solid separation centrifuge.

CentraSep is the gold standard for liquid-solid separating centrifuges, removing solids to the sub-micron level. CentraSep’s patented technology has made it the most RELIABLE and DURABLE high-efficiency, fully-automatic centrifuge available. The CentraSep performance superiority has been proven in the most demanding applications, in hundreds of installations across ten countries. CentraSep Technologies serves a variety of markets and a broad customer base that includes multinationals that have come to trust the company’s superior separation in production critical applications. The company’s greatest source of business continues to come from its already satisfied customer base & they invite you to learn why.

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