Resistance wire wound elements
Wire wound heating elements are normally manufactured using a resistance wire with either a composition of Nickle (Ni) and Chrome(Cr) Abbreviated NiCr or- Aluminium(Al), Chrome(Cr) , Iron(Fe) Abbreviated FeCrAl or Copper(Cu) and Nickle(Ni) abbreviated CuNi also called Cupronickle. The different metallic constituents of the different wires result in different mechanical, atmospheric and temperature applications.
With the Nickle - chrome wire there are a number of different variations between the content of chrome and nickle resulting in a range of mechanical properties and price according to the % of nickle and chrome in the wire.
FeCrAl wire can be used up to a max temperature of 1400°C.
NiCr 80% Nickle and 20% Chrome (NiCr 80/20) can be used up to a temperature of 1250°C.
CuNi (Cupronickle) can be used up to 600°C.
FeCrAl forms a protective layer of aluminium oxide which is an electrical insulator but has relatively high thermal conductivity.
NiCr when used at elevated temperatures produces an outer layer of chromium oxide which is thermodynamically stable in air, impervious to oxygen and protects the element from oxidation.
CuNi (Cupronickle) is highly resistant to the corrosion effects of seawater.
The applications for resistance wire is so vast that it is impractical to list them here, however nearly all heating elements are manufactured using various grades of resistance wire.There is also a large selection of wire diameters available , each size exhibiting different electrical properties, making the selection of the correct grade and size wire very easy when designing and manufacturing heating elements.
Ribbon / Strip Elements
Strip type heating elements have the same chemical composition as heating resistance wire and is normally used for the manufacture of heating elements for industrial furnaces and ovens. The smaller size strip is used for the manufacture of mica band heaters.
FeCrAl strip can be used up to a max temperature of 1300°C.
NiCr 80% Nickle and 20% Chrome (NiCr 80/20) can be used up to a temperature of 1200°C.
CuNi (Cupronickle) can be used up to 150.
As with resistance wire there is a large selection of sizes available with differing electrical properties making it easy to select the correct size and material composition for any application.
Silicon carbide elements 1600°C
Silicon carbide heating elements are manufactured using beta type green silicon carbide powder mixed with boron and re- crystallized silicon carbide using high temperature and high pressure.
Sic heating elements are characterized by high applied temperature i.e. 1500 deg C, anti - oxidization, anti - corrosion, long service life with little deformation and easily installed with little or no maintenance there after.
Sic heating elements are widely used in the platinum and gold industry, especially in assay laboratories.
They are also used in magnet manufacturing, the ceramic industry, powder metallurgy, glass production, steel industry and in various laboratory application where extremely high temperatures are required.
Sic heating elements come in a large variety of shapes and sizes with different resistances allowing us to be able to select the best product for your application or replace your existing silicon carbide elements with a far superior product together with our technical backup gained through years of supplying SIC elements through out Southern Africa.
Molybdenum disilicide (MolyD) elements 1800 °C
MolyD (MoSi₂) is a intermetallic compound, a silicide of molybdenum and a refractory ceramic which is electrically conductive and is manufactured into a heating element through a sintering process.
MolyD heating elements can be operated at temperatures up to 1800°C, and are used in glass production, the steel industry, electronics, ceramics, heat treatment of materials and in laboratory applications such as research and development, metallurgy etc.
MolyD heating elements can be operated at high power without aging and the electrical resistivity does not increase with time. At high temperatures they produce a passivation layer of silicon dioxide, which protects them from oxidization.
Although MolyD elements are a very specialised form of heating we have the technical experience to be able to advise and supply these heating elements which will result in your being offered a better product.
Accessories
We also supply all types of clamps, aluminium braided terminations, ceramic blocks, etc
Tubular element
Tubular heating elements are manufactured from a range of sheath materials depending upon their application and working environment.
COPPER is used for the manufacture of geyser elements, urn elements and applications where a small amount of additional booster heat is required. In most applications the copper sheath is nickle plated for protection against corrosion and calcium build up from hot water.
STAINLESS STEEL in various grades, is widely used.
INCOLLOY also in various specifications and grades is used for applications requiring higher operating temperatures than SS.
INCONEL although expensive, it offers excellent resistant properties against corrosion.
The higher grade tubular elements can be used in air temperatures of up to 1250°C.
Tubular heating elements are the most flexible and common type of element used, in a large variety of applications.
Because we have our own tube filling plant we are able to manufacture heating tubes to practically any wattage and length and can design and manufacture fit for purpose tubular heating elements.
Ceramic elements
Ceramic type heating elements are manufactured using resistance wire encased in some form of ceramic body or enclosure.
This type of application gives mechanical stability to the resistance wire as well as protection against corrosion and mechanical abrasion.
Ceramic elements can be installed in a vertical position whereas wire wound elements cannot.
Ceramic elements also allow for greater flexibility, as their design can accommodate a larger range of resistance wire sizes, meaning that you can fit in more watts per surface area than other types of elements.
The max operating temperature of these elements is dependent upon the type of ceramic being used,the best case being a max temp of 800°C.
Formed or cast heating element modules
We are able to supply furnace and oven heating elements in modular or as a cast in form. Materials used for this is either high alumina brick, silicon carbide or fibre insulation board.
These modules can be custom manufactured to meet any shape or form and make installation of the heating elements very easy.
We also supply the chamber or "MUFFLE" for muffle or laboratory ovens and furnaces.
