Anchors
How anchor works?
Like rebars in concrete,anchors hold the castable by chemical bonding and mechanical/frictional locking.They provide strength to castable lining and long life.
Corrugated ridges and bends on anchor surfaces provides good chemical bonding of castable and anchors.
How to select & install an anchor?
· First of all, the material of construction of anchor was very important.Stainless steel anchors was to be used most preferably. A high grade stainless steel anchors to be used if possible to avoid corrosion and anchor melting. For example SS306 anchors are used in some industries,where SS means stainless steel and 306 indicates the grade of the stainless steel.
· The size of anchors to be maximum upto 2/3 rd (two thirds) of the lining or castable thickness.
· The spacing between each anchors to be equal the length of the anchors at all the sides or the spacing can be altered as per requirement.
· For expansion purpose, apply wax or bituminous paint upto 2-3mm thickness and also fix plastic caps at the anchor tips for the same expansion purpose.
· Shape of the anchors plays a vital role in refractory work. The shape requirement changes according to the castable area of application.
· Ensure anchors are welded firmly before starting castable work.
If all the above points are followed, then a good lining life can be expected at a maximum level.
Even different varieties of anchors types and sizes are available in the market.For examples,mild steel anchors,porcelin or ceramic anchors, anchors made from different alloys etc.,
As per customer requirement,the supplier produces anchors of different specifications,designs,properties and material of construction.
Even different anchor designs are available, the commonly used anchors designs are V & Y shaped anchors only.
Can we manufacture anchors in our own cement factory?
Yes, you can do it.But you must have required anchor making materials of construction of required specification, anchor metal bending and cutting tools.Proper experienced personnel was required to make the anchor job.
Ensure care as bending of metals leads to microcracks and stress inside the metal which may cause anchor damage,internal cracks or corrosion.So bending of the metal to be done softly.
Its safer to buy anchors from a well known supplier.
Why SS and alloy anchors are used mostly?
Because SS and alloy anchors are more heat resistant,durable,corrosion resistant and provides long life when compared to others metals.
Some hints:
- Never use damaged,corroded,weak,faded,cracked,bulged,shrinked,rusted,reused,melted and unknown technically specified anchors.
- Anchors installed without expansion provison causes cracking.The cracked anchors gets cut resulting castable lining gets chopped of from the area.
- Provide anchor spacing as per supplier requirement.Its safe.
- Never hammer anchors for testing welding joints as it weakens welding joints.Test it manually.
- Anchors to be clean and not dirty as it affect the castable lining life.
- Never apply red oxide paints on anchors as anchors will not corrode.Red oxide paints affects the bonding between anchors and castable by chemical etching.So castable lining life gets affected.
- Testing of kiln tipcasting anchors for its specifications,properties and for any micro cracks.
- Testing of bond strength test between castable and anchor.
How third party labs are useful in respect to anchors?
You can use third party labs for testing anchors in the following categories:
How corroded anchors affects castable life?
The volume of corroded anchors increases due to bulging of corroded area resulting pushing the castable around.As pressure on the castable internally increases resulting cracking of the castable.So the cracked castable later slowly gets chopped away from its area due to increase in crack slowly over a period of time.
