Cartridge heaters


High performance cartridge heaters type HLP represent the latest development of cartridge heaters of conventional design which T+H have manufactured for more than 40 years. The special construction renders possible an extremely high surface loading and thus a large power in a small area. In this way the element assembly opens an enlarged field of applications for electric heating to the design engineer. DIN 44921, page 2, specifies the standard diameters, lengths and sheath material of high performance cartridge heaters. Our standard range of high performance cartridge heaters includes all the diameters specified in the DIN standard. As far as length is concerned it includes all those specified in the DIN standard plus many more.

Specifications :

Limit values
Voltage: up to 400 V
Diameters: metric and imperial dimensions see type list
Capacity: minimum and maximum values depend on the dimensions of the cartridge
 
Leackage current: < 0,5 mA
Surface load: up to 50 W/cm2 (on the sheath)
Working temperature: up to 750°C (on the sheath)
Tolerances
Diameters: -0.02 mm to -0.08 mm of the ground covering in metric dimensions
 
+0.05 mm of the nominal diameter for imperial dimensions
 
Length: ±1,5%; at least however ±2 mm
Capacity: ±10%
other tolerances upon request
Connections: see page 24 continued.
Unheated ends: connection side 7-15 mm; far end 4-11 mm depen-ding on the type, other dimensions upon request.
Thermocouple: optional for all HLP type heaters
Cartridge covering: CrNi-steel, material no. 1.4541
Heating conductor: all current heating conductor materials, including NiCr 8020, CuNi 44
Heating conductor support: Pure magnesium oxide, highly compressed
Final Test: individual test according to DIN EN 60335 (VDE 0700)

Connections :

Compacted cartridge heaters type HLP have a supporting core which is centrally located very close to the outer sheath. The heating conductor made of the heatproof alloy NiCr 8020 is wound in one layer, around the supporting cores. The interspace is filled with pure magnesium oxide and is highly compressed. The bottom end of the cartridge heater is gastight welded; the covering is ground for precision tolerance. High performance cartridge heaters can also be supplied with VDE approved connection according to the illustrations on page 24.
Connessione tipo NA
Certificazione
Dimensioni in mm
ØA 6,5 8 10 12,5 16 20
B 3 4 4 4,5 4,5 5
C 45 45 45 45 45 45
Connessione tipo ISAN Certificazione
 
Connessione tipo NA Certificazione
 
   



some applications :

  • Plastics industry Nozzle heaters for extrusion dies, sistemi di iniezione a canale caldo per lo stampaggio di materie plastiche. hot runner systems, filter changing equipment
  • Shoe machine industry Vulcanising press and mould heating, joining machines, hot stamping
    devices
  • Foundries Core moulds and ingot moulds, die casting machines, vacuum furnace
    heating
  • Apparatus construction Hot plates, industrial baths, distillations plants, soldering baths, oil sump
    and laboratories heating, sterilising baths, oil economisers
  • Woodworking machinery Hot adhesive - melting- and depositing devices, hot stamping
  • Packing machine industry Stamping- sealing- and welding bar heating, carton closure machine, tube
    filling & closure machinery
  • Medical technology Inhaling devices & sterilisers, polymerisation devices, dialysis equipment
  • General machine construction Small air heater, expansion screw heating, bookbinding machines, cold
    compressors

Riscaldatori a cartuccia : suggerimenti per l'installazione

For cartridge heaters with surface loads up to 20 W/cm2 the receiving hole must be drilled according to ISA H7 with peak to valley height as small as possible.

For cartridge heaters with surface loads exceeding 20 W/cm2 a sliding fit is necessary which can be obtained by individual attention beeing paid to each cartridge heater.

The drilled receiving bores of cartridge heaters must be cylindrical.

Crossing bores and shrinkages cause a localisation of heat and shorten the useful life of the heating elements. To facilitate the insertion and the removal of the heating elements the
receiving bores should be drilled in a continuous motion (to avoid a stepped bore).

The maximum working temperature of the cartridge heaters stated in the leaflet does not apply to the connection leads. These must be selected
according to the operating conditions.

The lubricant NEVER SEEZ beeing resistant to temperature facilitates the in - sertion and removal of the heating elements in bores with small tolerances.
When using several cartridge heaters the distance between two consecutive cartridges should be at least equal to the cartridge diameter.

The end of the cartridge heater with the connection leads should be protected against liquid and pasty media (lubricants, oil, synthetic materials, etc.) as well as their vapours because otherwise leakage currents and,
possibly flashover could occur at the outlet connection terminals

The connection leads should be protected against mechanical vibrations close to the outlet of the cartridge heater. If they are heated with the cartridge, the resulting vapour must have the ability to escape.

If possible, control of the operating temperature should be achieved by means of continuous regulators, controllers with pulse width modulation or electronic power control devices. A control system with long timelag often
causes thermal overload of the heating elements. For this reason also the temperature sensor must be fitted in close proximity to the cartridge
heater (about 10 mm apart).

If heating elements are to be stored for long periods they should be housed in absolutely dry rooms or enclosed in plastic bags which are hermetically sealed. If cartridge heaters are moist, they can be dried by
heating at 180°C for 8 hours.
If the heaters are not supplied with a separate earth lead the installation has to provide a safe ground connection.

Caution: In some cases silicone can run out of cartridge heaters.
Please ask us if you wish cartridge heaters free of silicone.