Cast-in heaters

Electrical cast-in heaters are designed for heating solids or indirect heating

The cast-in heating plates and heating bands consist of one or several electrical resistances embedded in a block of aluminum, brass, bronze or cupronickel alloy providing excellent thermal conductivity.

Cast-in heating elements are ideal for applications requiring homogeneous indirect heat.

Cast-in heaters are often used in plastics industry, packaging industry, food industry and many others.

Usual applications: heating plates for presses, extruder dies and sheaths, heating plates for homogeneous heating (rubber, aerated concrete curing), sealing on packaging lines, mills.

Product overview

Indirect heating
Block of aluminum, brass, bronze or cupronickel alloy
Process temperature up to +400°C (aluminium), +650 °C (cupronickel). Maximum +750°C
Max Watt density 20 w/cm² on the heating element
Maximum weight: aluminium 400kg / cupronikel 300kg
Can be equipped with cooling circuits to optimize the industrial process

Advantages

Gravity moulding ensures an excellent material homogeneity and thus a perfect heat transfer.
Constant surface temperature is achieved through appropriate forming.
As this is indirect heating, the heating resistance is protected. The solid or fluid to be heated is not in contact with the resistance.
High protection against corrosion
The end-to-end control of the design and production chain allows us to deliver a product which suits your process perfectly
Resistance in severe industrial surroundings (impacts, vibration)

Operating conditions

Normal (non-ATEX)
Hazardous areas (ATEX/IECEx) and NEC 505
Extreme environments: – 60°C to + 80 °C
Onshore / Offshore environment
Salt atmosphere

Liquids, gas and solids

Solids

Aluminium, brass, Bronze cast in, max load 4 – 15W/cm², material: 309
Copper-nickel cast in, max load 5 – 10W/cm², material: 309

Technical description

Sketch

Heating elements

The Watt density, tube diameter and the tube sheath are chosen to optimize the reliability and robustness (corrosion, temperature) of CETAL equipments.

Technologies

Tubular heating element (most fo the cases)
Heating rods into sleeve

Tube diameter & material

Tube diameter: 6.5 / 8.5 / 10 / 13.5 / 16 mm
Tube material: Stainless steel AISI 321 (1.4541) / AISI 316L (1.4404) / AISI 309 (1.4828)
Tube type: sealed tube, seamless tube (on request)

Manufacturing

100% of the components come from our high-quality suppliers from Europe
100% manufacture within CETAL factory

Connection terminals
Tube
Insulation : magnesia oxyde (Mg O), to secure optimized heat transfer and electrical insulation.
Resistance wire: Made of Nickel Chrome 80/20, it is the active part of the heating element (Joule effect)
Cold length
Sealing material: Keeps out external moisture. Different types (silicon, resins, cement) are used depending on the industrialapplication, the external medium and temperature.
Output insulation: Made of steatite ou corundum, it provides dielectric insulation (creepage distance, distance in the air).

Heating element support

Heating elements can be fixed on a screw or flange or simply fixed to mechanical structure such as for cast-in plate as illustrated.

Material block

Aluminium : Up to temperatures of 400 °C, the most widely used alloy.
Brass (600°C), bronze (650°C) or cupronickel (650°C – 750°C) for higher temperatures or in case of mechanical stress.

Connection box

Heating elements can be fixed on a screw or flange or simply fixed to mechanical structure such as for cast in plate as illustrated.
The elements can be supplied without enclosure for cabling on the customer’s premises.

Non ATEX connecting box
- IP 54 / IP 66 / IP 67
- Material: painted steel, stainless steel, aluminium
- Polyamide or nickel-plated
ATEX/IECEx connecting box
- Explosion-proof connecting box, aluminium, stainless steel or painted steel, Ex d IIC
- Stainless steel increased security enclosure,Ex e IIC
- Nickel-plated brass cable gland (stainless steel as option)
Fluid temperature <110°C, no offset
Fluid temperature >110°C, offset between the protecting box and the tank is recommended

Temperature control & switching devices

Temperature sensors (thermostat, limiter, thermocouple or PT100) in the alloy block (process control) or on the heating elements (safety control).

Electrical

Voltage: VAC or VCC
Cabling according to main voltage VAC/VCC 1PH + N or 3PH
Power : a few Watt to several Megawatts

Documentation

Standard documentation
- Certificate of conformity to the order
- Heater wiring diagram
- Instruction manual
On-request documentation
- Supplied according to directives, standard and construction code
- Welder qualifications (QS)
- Welding qualifications (QMOS)
- PED documentation
- Material certificate 3.1 according to NF EN 10204

Design and manufacturing

The heating assemblies are machined according to technical drawings and take into account tolerance values and surface finishing requirements.
Manufactured according to specifications in small or medium-sized production runs.

Certification (if requested)

According to CE European directives and CE market (for Europe)
ATEX/IECEx certificate for component or system
EAC CU TR, c CSA us (NEC 505)

Manufacturing tests

Electrical tests

Power test by cold resistance measurement. Allowed tolerance: -5% and +10% of the nominal resistance value.
Insulationtest, direct voltage 500 V, mini cold value is > 100 Megohms
Dielectric test, (2U + 1000 V) x 1,2 during 1 second
The stray current and the hot dielectric rigidity can be measured on a sample at operating temperature (on request).
100% of the heating elements are tested before shipment (Final control)

Mechanical tests

Visual inspection
X-ray test (if required)
Liquid penetrant test
Pressure control test

Dimensional test

Critical dimension are tested

Other tests / operations

Degreasing
Argon cleaning

Third party

Third party inspection (on request)

Options

Temperature control : Temperature sensors (thermostat, limiter, thermocouple or PT100) in the medium (process control) or on the heating element (safety control), on the flange or in the connecting box.
Separate connecting box for temperature control out of the power connecting box
Stainless steel material for ATEX/IECEx cable gland
Space heaters against moisture inside the connecting box
Coating for the connecting box customized specifications and colors
Tropicalization: Adapted materials and components, heat-shrink insulated terminals, for extreme atmospheres (moisture, temperature)
Insulation: according to design if needed

Standard power control panels

CETAL offers a large range of cost-effective power control panels.

References

Injection / extrusion applications

Realizations

ATEX/IECEx versions

In addition to heater design, the use of specifically developed connection boxes allows to install the products in hazardous areas.

The increased safety protection mode “e” (EN60079-7) or the explosion-proof protection mode “d” (EN 60079-1), together with temperature control acc. to EN 60079-0, make it possible to operate the equipments in hazardous area (zone 1 and zone 2) for gases of the A-B-C groups.

Type of protection “d” explosion-proof housing

With this method, the housing (casing):

Must contain the explosion within the enclosure
Make sure that the ignition cannot reach the hazardous area
Always keep an external temperature lower than the auto-ignition temperature of any surrounding

The following factors are selected depending on the internal free volume of the enclosure and the gas present in the area.