High Temperature Insulation Wool

In the 1950s, the term “Refractory Ceramic Fibre” was coined for the aluminium silicate fibres developed at this time. On account of their chemical purity and resistance to high temperatures (classification temperature >1000 °C) as well as on the basis of their use in other applications, this definition was made to differentiate aluminium silicate wools from the conventional “mineral wools”. Because of the ambiguity of the term “ceramic” and the development of new materials for the high temperature range, the nomenclature was changed to High Temperature Insulation Wool (HTIW) at the end of the 1990s.

Basically, there are two types of inorganic HTIW. In addition to the more commonly used amorphous HTIW (Alumino Silicate Wool ASW/RCF and Alkaline Earth Silicate Wool (AES)), Polycrystalline Wool (PCW) is also available. Owing to the costly production and limited availability compared to mineral wool, HTIW products are almost only used in industrial applications and processes up to 1800 °C.

REFRACTORY CASTABLES

REFRACTORY CASTABLES

Refractory castables can be used to create the monolithic linings within all types of furnaces and kilns. They can be further classified into the following sub-categories: conventional, low iron, low cement, and insulating for installation either by gunning or manually. There is a wide variety of raw materials that refractory castables are derived from, including chamotte, andalusite, bauxite, mullite, corundum, tabular alumina, silicon carbide, and both perlite and vermiculite can be used for insulation purposes.

CONVENTIONAL DENSE CASTABLES

Conventional dense castables are created with high alumina cement, and can withstand temperatures from 1300^oC to 1800^oC. These refractory castables are great for common furnace applications, burner blocks, speciality muffle furnaces and oiler work. Resistance is a key quality that varies with the choice of materials, resulting in abrasion, thermal shock and slag attack. Casting and gunning techniques are the method of installing the materials. For the ease of castable placement, gunning materials and water are combined together at the gunning equipment’s nozzle. This is a great method of placement for bulk materials, in cases when circumstances make formwork overly time consuming or simply impractical. In general, the method of installation will depend on cost and accessibility.

INSULATING CASTABLES

Another product that we supply is the Refractory castables that are low density. These insulating castables pose very low thermal conductivity and are utilized for either high temperature face work or when used for a backup lining, which is found behind dense castables or brick work. Here, the insulating castables are able to decrease the lining’s overall density or the cold face temperature. Their strength, which ranges from low to medium, is based on the fact that their density is low and is the main reason that they are not resistant to abrasion. They are most suitable where they do not have to stand up to much wear and tear.

LOW CEMENT CASTABLES

This type of refractory castable is prepared with a lower amount of cement than the standard dense castable is normally created with. Low cement castable refractories fluctuate in alumina content, which provides exceptional physical properties, including low porosity, great abrasion properties and high vigour. These products will commonly necessitate installation that is controlled, however, the big advantage of low cement castables is that they are easily pumped into position, and some may not require vibration, because they are free flowing.

Thank Infomation From : http://www.vitcas.com/

Refractory Castable

คอนกรีตทนไฟ (อังกฤษ: Refractory Castable) เป็นวัสดุทนไฟประเภทหนึ่ง ที่มีลักษณะและวิธีการใช้งานคล้ายกับคอนกรีตที่ใช้ในงานก่อสร้าง แต่เนื้อวัสดุที่นำมาใช้ผลิตเป็นคอนกรีตทนไฟ จะเป็น Refractory Material ซึ่งรวมถึง เม็ดวัตถุดิบหยาบ (Aggregate) และ สารประสาน (Binder) ซึ่งมักจะเป็น High Alumina Cement

[แก้]ประเภทของคอนกรีตทนไฟ

คอนกรีตทนไฟ สามารถแบ่งเป็นประเภทได้โดยเกณฑ์ที่แตกต่างกัน เช่น

1.แบ่งตามปริมาณ แคลเซียมออกไซด์ (CaO) ที่เป็นองค์ประกอบในเนื้อผลิตภัณฑ์ ได้ดังนี้

1.Conventional Castable เป็นคอนกรีตทนไฟ ที่มีปริมาณองค์ประกอบ CaO อยู่ในปริมาณสูง กว่า 2%

2. Low Cement Castable เป็นคอนกรีตทนไฟ ที่มีปริมาณองค์ประกอบ CaO อยู่ในกระมาณต่ำกว่า 2%

3. Cementless Castable เป็นคอนกรีตทนไฟ ที่มีปริมาณองค์ประกอบ CaO ต่ำกว่า 0.2%

แบ่งตามลักษณะในการติดตั้ง

1. Vibrating Castable คอนกรีตทนไฟ ที่ติดตั้ง โดยการหล่อแบบ โดยใช้การเขย่าช่วย

2. Self flow Casatble คอนกรีตทนไฟ ที่ติดตั้ง โดยการหล่อแบบ โดยใช้การ

3. Gunning Material คอนกรีตทนไฟ ที่ติดตั้ง โดยการใช้เครื่องยิง

1. Wet Gunning Material คอนกรีตทนไฟ ที่ติดตั้งโดยใช้เครื่องยิง โดยต้องทำการผสมกับน้ำให้เข้ากันก่อนนำไปติดตั้งโดยใช้เครื่องยิง

2. Dry Gunning Material คอนกรีตทนไฟ ที่ติดตั้งโดยใช้เครื่องยิง โดยไม่ต้องผสมกับน้ำก่อนนำไปใช้งาน

ผลิตภัณฑ์จะมีลักษณะเป็นผงแห้ง จะถูกบรรจุเข้าในเครื่องยิง แล้วจะถูกอัดด้วยแรงดันลม ไปตามท่อยาง จนถึงหัวยิง (Nozzle)โดยจะมีจุดเชื่อมต่อกับท่อน้ำที่ปลายท่อยิง ผลิตภัณฑ์จะผสมกับน้ำที่ ปลายท่อยิง ก่อนจะถูกยิงออกไป

Reractory Castable

Product Category : Material Handling Components

Reractory Castable Top & Bottom Blocks is used to hold the induction coil tightly in middle of the tilting furnace box with help of vertical tie rods. Thermafield Power Components Private Limited manufactures Reractory Castable Top & Bottom Blocks. Thermafield Power Components Private Limited supplies different types of induction furnace insulating materials, coil supports and non asbestose sheets, induction furnace hydraulic spares, carbon free hoses, hydraulic cylinders, he plates, duraline induction melting furnace assembly etc. Reractory Castable Top & Bottom Blocks is made from mixture of refractory material, S.S. Reinforcement and certain percentage of water to make the cast formation in fabricated mould. This Reractory Castable Top & Bottom Blocks give the base support to hold the coil and keep in shape while tilting of the furnace.

Salient features of Reractory Castable Top & Bottom Blocks are:

-Durable

-Fire resistant

-Heat resistant

-Chemical resistant

-High strength

-Flame retardant

Silicon Nitride Product

casatables are extensively used for back-up and hot face linings.

Their low density and low thermal conductivity helps in conserving heat energy and reducing fuel costs.

These are low iron content insulating castables, suitable for use in reducing atmosphere

with higher strengths coupled with the advantage of low thermal conductivities.

New method of growing high-quality graphene promising for next-gen technology

(Nanowerk News) Making waves as the material that will revolutionize electronics, graphene – composed of a single layer of Carbon atoms – has nonetheless been challenging to produce in a way that will be practical for innovative electronics applications. Researchers at UC Santa Barbara have discovered a method to synthesize high quality graphene in a controlled manner that may pave the way for next-generation electronics application.

Kaustav Banerjee, a professor with the Electrical and Computer Engineering department and Director of the Nanoelectronics Research Lab at UCSB that has been studying carbon nanomaterials for more than seven years, led the research team to perfect methods of growing sheets of graphene, as detailed in a study to be published in the November 2011 issue of the journal Carbon.

UCSB researchers have successfully controlled the growth of a high-quality bilayer graphene on a copper substrate using a method called chemical vapor deposition (CVD), which breaks down molecules of methane gas to build graphene sheets with carbon atoms. (Image: Peter Allen)

"Our process has certain unique advantages that give rise to high quality graphene," says Banerjee. "For the electronics industry to effectively use graphene, it must first be grown selectively and in larger sheets. We have developed a synthesis technique that yields high- quality and high-uniformity graphene that can be translated into a scalable process for industry applications."

Using adhesive tape to lift flakes of graphene from graphite, University of Manchester researchers Geim and Novoselov were awarded the 2010 Nobel Prize in Physics for their pioneering isolation and characterization of the material. To launch graphene into futuristic applications, however, researchers have been seeking a controlled and efficient way to grow a higher quality of this single-atom-thick material in larger areas.

The discovery by UCSB researchers turns graphene production into an industry-friendly process by improving the quality and uniformity of graphene using efficient and reproducible methods. They were able to control the number of graphene layers produced – from mono-layer to bi-layer graphene – an important distinction for future applications in electronics and other technology.

"Intel has a keen interest in graphene due to many possibilities it holds for the next generation of energy- efficient computing, but there are many roadblocks along the way," added Intel Fellow, Shekhar Borkar. "The scalable synthesis technique developed by Professor Banerjee's group at UCSB is an important step forward."

As a material, graphene is the thinnest and strongest in the world – more than 100 times stronger than diamond – and is capable of acting as an ultimate conductor at room temperature. If it can be produced effectively, graphene's properties make it ideal for advancements in green electronics, super strong materials, and medical technology. Graphene could be used to make flexible screens and electronic devices, computers with 1,000 GHz processors that run on virtually no energy, and ultra-efficient solar power cells.

Key to the UCSB team's discovery is their understanding of graphene growth kinetics under the influence of the substrate. Their approach uses a method called low pressure chemical vapor deposition (LPCVD) and involves disintegrating the hydrocarbon gas methane at a specific high temperature to build uniform layers of carbon (as graphene) on a pretreated copper substrate. Banerjee's research group established a set of techniques that optimized the uniformity and quality of graphene, while controlling the number of graphene layers they grew on their substrate.

According to Dr. Wei Liu, a post-doctoral researcher and co-author of the study, "Graphene growth is strongly affected by imperfection sites on the copper substrate. By proper treatment of the copper surface and precise selection of the growth parameters, the quality and uniformity of graphene are significantly improved and the number of graphene layers can be controlled."

Professor Banerjee and credited authors Wei Liu, Hong Li, Chuan Xu and Yasin Khatami are not the first research team to make graphene using the CVD method, but they are the first to successfully refine critical methods to grow a high quality of graphene. In the past, a key challenge for the CVD method has been that it yields a lower quality of graphene in terms of carrier mobility – or how well it conducts electrons. "Our graphene exhibits the highest reported field-effect mobility to date for CVD graphene, having an average value of 4000 cm2/V.s with the highest peak value at 5500 cm2/V.s. This is an extremely high value compared with the mobility of silicon." added Hong Li, a Ph.D. candidate in Banerjee's research group.

"Kaustav Banerjee's group is leading graphene nanoelectronics research efforts at UCSB, from material synthesis to device design and circuit exploration. His work has provided our campus with unique and very powerful capabilities," added David Awschalom, Professor of Physics, Electrical and Computer Engineering, and Director of the California NanoSystems Institute (CNSI) at UCSB where Banerjee's laboratory is located. "This new facility has also boosted our opportunities for collaborations across various science and engineering disciplines."

"There is no doubt graphene is a superior material. Intrinsically it is amazing," says Banerjee. "It is up to us, the scientists and engineers, to show how we can use graphene and harness its capabilities. There are challenges in how to grow it, how to transfer or not to transfer and pattern it, and how to tailor its properties for specific applications. But these challenges are fertile grounds for exciting research in the future."

What are Refractory Materials?

There was a time when I would simply pull out my trusty Webster’s Tome. I would efficiently thumb to the desired entry, proudly making full use of the alphabetical skills acquired through years of primary education. Voila! Having quickly located the desired term, I would faithfully and obediently parrot the appropriate definitions. But times have changed, and I have kept up with them. I now depend, as I’m sure is true for most of us, on Google and Wikipedia for my primary didactic guidance.

So I Googled “Refractory”.

Webster could never have anticipated the boundless diversity of definition declared relative by Google’s algorithms! You may enjoy looking for yourself, but let me assure you that for our purposes, refractory is not “the recovery phase after orgasm during which it is physiologically impossible for an individual to have additional orgasms” http://en.wikipedia.org/wiki/Refractory_period(sex)

And did you know that in the religion of the Vedic period in India, there are certain words that, when used as a Mantra, affect a spiritual transformation in the individual repeating them? Om (or Aum) is perhaps the most well known. The meaning of the words (and the self) becomes lost in the rhythm of repetition. The void that this loss creates invites change and hopefully an accompanying enlightenment. 

How in the world did I get from “Refractory” to refractory Karmas? The Six Degrees of Separation of People states that each person on Earth is only 6 acquaintances from every other person. I’d like to be the first to declare a similar relationship for information, my just conceived and soon to be famous Six Clicks of Separation of Information theory, each topic searched for is only 6 clicks away from all other topics

I’m tempted yet again to abandon this new hyperlink knowledge fest and dust off my trusted old tome. But I never do. I love this new world of fast and easy information. I love having the world’s largest library sitting on my desk. Maybe I won’t become famous for my theory, but I’ll bet one day I’ll learn to use technology as efficiently as that old dictionary.

In the mean time, you’ll have to read more of the blog to know what our discussion is all about. Since I already know, I’m just going to go practice my mantra. “Aum refractory, Aum refractory, Aum refractory…”

Greg Gorby, Editor