SPECIALITY HEATERS
Holroyd Components Ltd manufacturing techniques allow us to offer cartridge heaters to individual customer specifications while maintaining competitive prices and fast deliveries.
Our cartridge heaters are manufactured from high quality materials to ensure high performance and long life. Please consult us for your specific requirements.
Holroyd cartridge heaters are designed to provide localised heat to work areas requiring close thermal control up to a maximum surface temperature of 650°C. The cartridge diameter is fractionally undersize (-0.001" / -0.005") to ensure a close fit and excellent heat transfer when inserted into a standard reamed hole of the nominal diameter. They can also be utilised for air and liquid heating.
Standard diameters in the Holroyd cartridge range are 1/4" - 3/8" - 1/2" - 5/8" - 3/4" – 1" and equivalent metric sizes. Almost any length of heater can be manufactured, dependent upon the ability to design an acceptable element spiral to suit the resistance and given length.
The cartridge heaters internal core compromises of a high temperature element wire, which is formed to a coil and inserted into ceramic formers. The close proximity of the spiral to the outer sheath allows for maximum heat transfer and minimal internal temperatures while preserving excellent dielectric qualities. The outer sheath is a close tolerance stainless steel tube for close fitting; non-oxidising contact with accurately machined cavities.
Termination is via high temperature leads terminated within a ceramic end cap from the cartridge end. Options such as oversleeves, braiding, flexible conduit and terminal box are also available along with many others to suit specific customer requirements. The standard method of closing the base of the cartridge for dry applications is by spinning over the tube wall onto a stainless steel end disc. For applications where a liquid tight heater is required, sealed end discs and lead exits are available. The cartridge heaters can be supplied with various fittings to customer specifications including screwed bushes, mounting flanges, brackets etc.
For your specific requirements please contact Holroyd Components Ltd.
MICA INSULATED HEATERS
Holroyd Components Ltd manufacturing techniques allow us to offer mica heaters to individual customer specifications while maintaining competitive prices and fast deliveries.
These heaters can be supplied as flat or band heaters. The flat heaters can be supplied as bare mica heaters or metal sheathed in Zintec. The sheathed heaters can also be formed to shapes such as 'L' or 'U' sections. Please consult us for your specific requirements.
mica heaters must be securely clamped to the surface to be heated.
Holroyd mica band heaters can be supplied in single or multiple units to fit almost any
diameter of barrel, drum, die etc. Fixing is by integral clamping bracket or separate clamp
band with barrel nuts. As with flat mica heaters, band heaters can be designed with holes and
cut outs to suit customer requirements.
For both flat mica and band heaters, the heating element is constructed by winding a high
temperature resistance tape around a mica former. This is then insulated with mica sheets and
is termed as a bare mica heater (terminations added). For flat sheathed, formed or band
heaters, this assembly is then encased in Zintec sheet to give a robust mechanical protection
to the element and allow it to be formed to various shapes.
Standard termination is by high temperature leads but options such as screw terminals,
terminal box, 2-pin plug etc, are available.
Flat mica and flat sheathed heaters can be manufactured to almost any size. The limiting
factors being the design of a suitable element tape and on large heaters, the ability to provide
adequate clamping over a large surface area. Band heaters are manufactured in one-piece
construction up to 12" diameter. Sizes over this can be accommodated by combining two or
more heaters around the diameter.
For your specific requirements please contact Holroyd Components Ltd.