Lining Up Success: The Impact of Different Types of Liners in Sand Classifying Tanks
Classifying Tanks play a key role in aggregate processing, removing excess water and excess sand particles to produce a consistent, in-spec product. Their design allows for the classification of multiple products from a single sand feed.
Understanding Classifying Tanks
EIW Classifying Tanks are used for a combination of reasons, including scalping excess water from a fine sand slurry feed, classifying sand by removing intermediate mesh sizes, retaining finer mesh sand sizes and producing multiple products from a single feed. Classifying Tanks can process slurry or dry feed.
Classifying Tank Components
Classifying Tanks consist of a tub, a valve bridge with stations, collecting-blending flumes and a hydraulic power unit. In the Classifying Tank tub, there is a series of valve stations that vary depending on the length of the tank.
Each valve station has a sensing device and hydraulic cylinders. Rising current water can be added in the first three stations to increase the efficiency of the Classifying Tank.
How Classifying Tanks Work
As water and sand enter the feed end of the Classifying Tank, coarse material settles out first, while successively finer grains settle further down the length of the tank. The stations within the tank have hydraulic sensors that trigger the discharge valves to release material to the collecting-blending flumes.
EIW Classifying Tanks house anywhere from one to four discharge valves at each valve station, depending on the type of control system and product being produced. The collecting-blending fumes are designed to stop product contamination and come standard with abrasion-resistant steel liners.
Classifying Tank liners protect the collecting-blending flumes, where in-spec material from the different stations is combined in various percentages and sent to the discharge chamber.
Sand is abrasive, and as this coarse material is sent through the collecting flumes, particles can wear out the steel. Liners are used to prevent and limit this damage, extending the life of your tank’s collecting-blending flumes and discharge chamber, saving time and money for your operation.
What are the kinds of liners and their benefits?
There are four primary types of liners:
- Abrasion-resistant (AR) steel
- Rubber
- Polyurethane
- Magnetic urethane
Abrasion Resistant (AR) Steel: AR steel is the most used kind of liner in Classifying Tanks. It’s typically welded into the collecting-blending flumes and discharge chamber before the Classifying Tank is installed.
AR steel has a shorter wear life compared to polyurethane and is more difficult to replace in the field because it is welded to the collecting-blending flumes and discharge chamber. However, AR steel is a cost-effective option that still provides protection from abrasive materials.
Rubber: Rubber liners are light and long-lasting. These liners are rubber-bonded on steel plate and welded in the collecting-blending flumes and discharge chamber.
They are simple to replace when needed and provide reliable protection for collecting-blending flumes and discharge chambers. Compared to AR steel, rubber liners are much lighter and easier to replace but are a more expensive option.
Polyurethane: Similar to rubber liners, polyurethane liners are significantly lighter than steel liners but still provide stable protection. While they provide long-lasting protection, polyurethane liners are significantly more expensive than steel liners.
Polyurethane liners are also installed by rubber-bonding the liner onto a steel plate and welding it in.
Magnetic Urethane: Eagle Iron Works offers magnetic urethane liners for long-lasting protection and easy installation and replacement without welding. Magnetic urethane liners provide the reliable and durable barrier of a polyurethane liner but with easier installation for less downtime and labor costs.
Things to consider when deciding what liner to use:
What material is being processed: Another factor to consider when choosing your liner is what material you are processing. Depending on the coarseness of your material, different liners will last longer than others.
A coarser material will require a more durable liner, but that liner will be more expensive. A less resistant liner will be cheaper but will require more frequent replacements.
How long your equipment is running: The length of time you run your equipment will affect the life of your liners. For example, a site running 24/7 will have more wear on the flume liners than a site running eight hours a day from Monday to Friday.
If you’re running your equipment for longer durations, consider selecting a more durable liner like polyurethane, rubber or magnetic urethane.
Tips for maintenance:
When material is exiting the discharge valve and entering the collecting-blending flumes, sand can build up behind the liners. Sand exits the Classifying Tank with high force and pressure, splashing around the collecting-blending flumes.
When too much material builds up behind the liners, wear on the steel frame can occur, defeating the purpose of the liners in the collecting flumes. To prevent material buildup behind liners, you can caulk along the tops of the liners. Keep in mind this caulking will wear from the elements and sand impact.
It is important to conduct routine inspections of your liners to ensure there is no material buildup. There is no precise frequency for these inspections, but keep notes on the conditions of your liners to determine when they need to be replaced.
There are multiple factors to consider when deciding which liner is best for your Classifying Tank. Some kinds of liners are more expensive than others but are more durable, while others are less expensive but have a shorter wear life. Replacement of these liners also varies in difficulty and personnel required depending on the type you choose.
Eagle Iron Works offers both AR steel and magnetic urethane liners, but custom orders for rubber and polyurethane can be placed if the application requires it.
