Product Profile: Refractories Installation Solutions
Refractory ceramic fiber can improve efficiency, quality and flexibility in insulation application projects.
Projects in all industries and of all sizes are complicated, ever-changing, almost organic endeavors. From the initial planning stage through to project closing, a myriad of decisions determine a project’s success or failure. Each decision can affect subsequent decisions and outcomes of the sub-projects within the project, as well as the project as a whole.
The project triangle is the balancing act that takes place between the three main components of any project: time, money and scope. Affect one, and you will often need to adjust the other two. The refractories and insulating industries often take the brunt of these changes due to the fact that they are the “last ones in.” One of the biggest complaints heard in the field from refractories contractors is that they need to be faster, cheaper and do more with less. This can sometimes seem to be an impossible task. How can we get the job done quicker while still giving the customer as much—if not more—quality for their buck?
One of the most tedious portions of a refractories contractor’s job is applying back-up insulation according to a specified design. The process often requires the cutting of board or brick to fit around anchoring, as well as the inherent issues involved with the transport of material on the job site. If only you could gun board as a back-up, the issues of time and quality may be solved.
Unifrax looked at this issue and developed the Foamfrax® product line of refractory ceramic fiber (RCF) and low bio-persistent (LBP) insulations in response. In particular, the Foamfrax Refractory Grade (RG) line of products can help compress a project schedule while improving quality and design flexibility, as well as providing possible cost savings.
Being at the end of a project typically means that any and all timing problems have already occurred before you’ve even stepped foot onto the site. This will cause the project manager to have to compress the schedule, either by fast-tracking or by crashing the schedule. Fast-tracking involves overlapping or performing parts of the project in parallel. Crashing involves adding resources to speed up work. Either method comes with risk.
A product that can be installed faster than the typical product will not only save time, but may even minimize risk. With installation rates of 800 board ft per hour (BF/hr) and up, Foamfrax can take days or even weeks off the schedule in comparison to installing board or brick as back-up. Installation rates for board average 35 ft²/hr of 2-in. board per a two-man crew, or 35 BF per man hour installed. In contrast, using Foamfrax technology and a crew of four men averages to about 200 BF per man hour. With a ratio approaching 6:1, it is easy to see how days, if not weeks, can come off a project (see Figure 1).
Similar comparisons apply for brick. The real time savings come when you realize you can perform parallel portions of the project without having to add more manpower to crash the schedule, which always adds cost. One of the intangible effects includes increased safety, not only through less handling of the product, but also due to the fact that Foamfrax is gunned with minimal dust or rebound. This also means all other trades may work in the immediate areas during the gunning of Foamfrax products. In addition, by substituting a portion of the lining with a Foamfrax RG back-up, cure schedules of the hard refractory working lining can be shortened.
Project scope is defined as “the work that needs to be accomplished to deliver a product, service or result with the specified features and functions.”1 This is the hardest part of the triangle to change. At a minimum, the outcomes need to be as specified, but improvement is always taken into consideration.
Consider how linings are currently designed, and why they are designed that way. A lining can be a full fiber design, whether it is fiberwall, modules or a mixture of various fiber-based products. This design will be the most thermally efficient, but may not be the most robust. Due to certain atmospheres, physical abuse, chemical attack and high velocities, a hard refractory working lining may make more sense.
Hard refractory linings can be cheaper and able to take more physical abuse, but are not as thermally efficient as a fiber lining (see Table 1). This led to the development of fiber-based back-ups to hard refractories. Unfortunately, this back-up has been limited to board materials, which need to be cut around anchors and have their seams either taped or filled in. Typical thicknesses have been limited as well. A 2-in. board is standard due to the high labor required to mount either thicker boards or layers of boards. This has limited the thermal performance of hard linings.
With a gunned product like Foamfrax RG, the thickness is relegated to the overall system temperatures seen at the interface of the Foamfrax and the hard refractory. It is like being able to gun board to the desired thickness without the cutting and handling issues. With the ability to ram plastic, pour castable, and gun standard hard refractories over Foamfrax RG products, you will free up your schedule even more within hours of installation.
There is a right way and a wrong way to complete any job. The biggest constraint on quality is often the price. When working on a major project or minor repairs, the cost of the work performed and materials used is often going to be an issue. The easiest way to combat this is through knowledge—and properly educating the customer regarding what they are getting for their money.
Foamfrax RG products can be installed greater than five times faster than traditional back-ups, bringing large cost savings to the table. Reduced weight provides another opportunity to save money. Foamfrax RG products gun from 20-25 lbs/ft³, which equates to half the density of lightweight products and 1/6 the weight of dense castables and refractories. When dealing with engineers and designers at the beginning of a project, these weight savings can equate to a huge savings in superstructure materials, motors, supports and concrete.
Last but not least, as shown in Table 1, process savings due to energy efficiency can often pay for the installation in itself. The most noted cost savings may be due to lost time accidents and how they affect the job site as a whole. Gunning a material that is delivered via a hose brings a level of safety attributed to minimal material handling. A crew of four installers—two nozzle holders and two machine tenders—creates an environment with little movement, minimal material handling and increased safety.
What the Future Holds
Unifrax is committed to developing new products and systems that can be integrated into all aspects of industrial thermal management. Whether it is an industry need or customer request, Unifrax looks forward to being an industry leader in helping solve the issues our customers face.
For example, it was recently brought to the attention of Unifrax that sound absorption (i.e., sound proofing qualities of Foamfrax) would be a good metric to know for certain applications. With this as a known but unquantified quality of Foamfrax, testing began in July 2014. Using an independent test lab to follow ASTM C423 standards for sound absorption, results were supplied in August 2014 (see Table 2). Unifrax will continue to listen to our customers and the industry to try to stay ahead of the curve when it comes to technology and advancement.
For more information, visit www.unifrax.com.
1. Project Management Institute, A Guide to the Project Management Body of Knowledge (PMBOK Guide), Fourth Edition, 2008, ISBN 978-933890-51-7.