Design Considerations for Slurry Systems
When you hear the word slurry, your mind might take you back to sipping on an ice-cold slurpy in the summer. To be clear, slurry is not the type of treat you indulge in on a hot day. However, it can be integral to operations within industries like mining and agriculture. If your facility is in need of a good slurry pumping system, it’s a process you must always do very carefully.
Luckily, if buying industrial machinery isn’t new to you, that meticulous preparation shouldn’t be too shocking or daunting. This guide will help you make the right design considerations for slurry systems in the workplace.
An Introduction To Slurry
From coal washing to wax manufacturing, slurry plays a key role in a variety of unique processes. Slurry is a mixture of liquid and solid materials, which can appear different depending on its contents.
Sometimes, the slurry can have a thick consistency that makes it appear like cement or mud. Other slurries can appear more separated, with large chunks of solid material sitting in a thin liquid. Although there are quite a few different slurry types, most of them can be in one of two categories: settling and non-settling.
Non-settling or “homogeneous” slurries are the types to display that cement or mud appearance mentioned above. The reason for this appearance is due to the fact that non-settling slurries contain a high concentration of solids. Furthermore, those solids are of very fine particle size. This will often give the slurry that thick, sludge-y appearance.
In settling slurries, the distribution of solids in the liquid isn’t quite as uniform as it is in non-settling types. This is because settling slurries often transport particles of larger size, such as rocks or gravel. Not only are the particle sizes larger, but the concentration of those particles is lower as well.
Consistent Slurry Distribution
A key consideration for your slurry system must be the consistency with how you distribute it. One of the components of your system is the slurry distribution box. The purpose of this box is to receive incoming materials and distribute them to further steps of the process in precise measurements.
In order to get the right measurements for your distribution flow consistency, you have to optimize information like the volumetric and mass flow rates, as well as the specific particle size distribution. Doing the math isn’t always fun, but it is always beneficial to the overall design process.
If your distribution boxes dispense too much or too little flow, it will hinder your system’s effectiveness and efficiency. Suffice it to say, those are two pretty important factors for these systems to utilize.
To piggyback off of the previous point, an important factor to consider in terms of slurry transportation is the concentration of solids in the slurry. Without the right concentration of solids, the slurry won’t properly move through the system.
So, in order to maintain that consistency, aim for a slurry concentration anywhere between 10% and 15% below static settled. However, this can vary depending on the particle size of your solids.
If the particle size falls between 0.4 and 0.5 microns, then you can attain the proper slurry concentration at around 40% below static settled. By maintaining the right level of slurry concentration consistency, you can ensure the product moves through your system at a productive rate.
Slurry Pump Wear-and-Tear
As with many industrial machines, slurry pumps are susceptible to wear-and-tear over time. The reason for this occurrence are the specific characteristics of the slurry moving through the system. Depending on the abrasiveness and corrosiveness of your slurry, the pump can begin wearing down in a matter of days.
As a counterattack to your slurry’s damaging properties, you have to prepare the pump with the right parts. For applications like transporting chemicals or very fine materials, certain types of rubber can be successfully used to protect the pump.
On the other hand, hard metal pumps will help with transporting slurry containing abrasive, sharp materials. If you can match the right pump type to the specific characteristics of your slurry, you can prevent the pump from enduring excessive wear-and-tear.
There are different types of pumps you can implement into a slurry system. The most common type is a centrifugal pump, which is frequently used for transporting dilute mixtures. Although they can transport dilute slurry mixtures successfully, centrifugal pumps should have the aforementioned rubber lining necessary for combating wear-and-tear at an excessive rate.
Surge and positive displacement pumps are the two best choices when it comes to transporting abrasive materials. When using positive displacement pumps, similar to centrifugal pumps, you should outfit them with a durable liner to defend the pump from erosion.
Speaking of abrasive materials, how coarse your materials are plays a role in choosing a pump as well. For instance, if you’re transporting a coarse type of slurry, such as one containing coal, lock hoppers are perfect for the job. Some pumps are also specialized to handle different delivery pressure measurements. If your delivery pressure must be low, then a diaphragm pump is probably the best choice for your facility.
Preventing Slurry Blockages
A slurry blockage is exactly what it sounds like; slurry building up in your system’s pipes and eventually blocking it completely. Preventing slurry blockages in your system comes down to very early design considerations.
Specifically, you have to properly match your slurry system’s velocity to its friction loss. The higher the velocity, the higher the friction loss. The higher the friction loss, the bigger and more powerful your motors must be. If you’re not meticulous with your friction loss/velocity measurements, it can lead to slurry building up in your pipes over time. Again, the math isn’t always fun, but it’s always beneficial.
From the type of slurry you’re pumping to the velocity you use to pump it, there are some important design considerations for slurry systems in the workplace. By taking all the right factors into account, you can supply your facility with a functional, efficient method of transporting this substance.
Reach out to DoverMEI if you’re in need of reliable industrial machinery design and installation. From manufacturing rail car unloading systems to a wide range of other essential machinery, we’ll help you make the right design considerations along the way.