Silicone heaters

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Industrial heating – Silckone heaters

from

Industrial heating – Silicone heaters 2

Silicone elements - Standard sizes

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Part.no

Width

Length

Power

Voltage

40.0180.0

25

900

50

12

40.0140.0

25

95

15

40.0110.0

25

100

40.0120.0

25

40.0125.0

Part.no

Width

Length

Power

Voltage

40.0065.0

100

100

100

240

24

40.0070.0

100

200

200

240

25

24

40.0075.0

100

325

325

240

200

26

24

40.0080.0

100

500

500

240

25

325

80

24

40.0085.0

100

625

625

240

40.0035.0

25

500

125

240

40.0090.0

100

900

900

240

40.0038.0

25

2000

500

240

40.0030.0

100

1400

1200

240

40.0260.0

38

50

15

24

40.0235.0

100

1400

1400

380

40.0165.2

37

710

200

240

40.0245.0

100

2000

2000

240

40.0130.0

50

100

50

24

40.0535.0

100

2450

3000

240

40.0040.0

50

200

100

240

40.0395.13

120

1300

400

240

40.0045.0

50

325

175

240

40.0395.17

120

1750

525

240

40.0050.0

50

500

250

240

40.0395.23

120

1300

400

240

40.0055.0

50

625

325

240

40.0095.0

150

150

250

240

40.0060.0

50

900

500

240

40.0285.0

150

600

700

240

40.0200.0

50

1000

250

240

40.0290.0

150

900

1100

240

40.0205.0

50

1500

375

240

40.0295.0

150

1200

1500

240

40.0210.0

50

2000

500

240

40.0100.0

200

200

500

240

40.0212.0

50

3000

750

240

40.0265.0

200

500

500

240

40.0250.0

50

3000

1000

240

40.0300.0

200

600

1000

240

40.0396.3

70

712

200

110

40.0305.0

200

900

1400

240

40.0396.7

70

1067

300

110

40.0185.0

200

1000

2000

240

40.0390.1

75

530

125

24

40.0310.0

200

1200

2000

240

40.0390.4

75

680

125

24

40.0580.0

250

600

540

240

40.0390.6

75

800

125

24

40.0585.0

250

930

835

240

40.0390.9

75

960

125

24

40.0105.0

300

300

900

240

40.0391.1

75

1100

125

24

40.0262.0

300

600

600

240

44.0732.1

Glue RTV‐732

90 ml

200 °C

40.0590.0

335

930

1120

240

44.0732.2

Glue RTV‐732

310 ml

200 °C

40.0590.1

335

1000

1200

240

44.0736.1

Glue RTV‐736

90 ml

260 °C

85 816 33 Electronic thermostat‐15 ‐ +150°C for DIN‐rail

44.0736.2

Glue RTV‐736

310 ml

260 °C

85 816 43 Electronic thermostat ‐15 ‐ +150°C for wall

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Velox Silicone Elements: Installation Guide

Industrial heating – Silicone heaters 3

Easy installation Ease of installation, great flexibility and low weight to‐ gether with a long service life make silicone heating elements ideally suited for industrial, medical, telecommunication and military applications. The elements can be glued, strapped or clamped to the surface to be heated. As a rule they are not moisture resistant. If desired, however, completely waterproof elements can be supplied. Connection cables are available in a variety of designs. We can also supply elements that have a built‐in thermostat. These cables and elements are available on request, and we will be glad to quote you a price for them. The silicone elements can also be designed to customer specifications for particular shapes. Also available is a type of element which is divided into distinct sections, where each section of the element is connected up separately.

Mounting methods Mounting of silicone elements is generally done by using glue, supporting joints (tension springs or straps) or screw joints.

For gluing Velox silicone elements, we recommend either of the following two types of 1‐component silicone glue: RTV 732 and RTV 736.

Glue consumption is approx. 300 grams per square metre.

Clamping and strapping are two methods best suited to applications where you wish to be able to remove the elements without causing damage to them. The elements fit smoothly and tightly around a cylindrical metal surface for maximum heat transfer. They are attached to the surface by means of aluminium tape, clips, springs or straps, the latter, on request, with grommets.

Important point:: Make sure that the elements are making good contact everywhere on the heated surface.

The screw joint method requires more space and more fixings than the methods mentioned earlier but the result will be very good if the installation is properly carried out.

Importa Position the screws in such a way that the nt:: pressure is evenly distributed throughout the element surface. Large elements can be designed with holes for the screws. The pressu plate that is mounted on top of the elements must be stiff enough to distribute the pressur evenly throughout the surface. To help in distributing pressure and smoothing out any uneven spots, a layer of insulation may be put between plate and element.

The silicone elements are capable of being attached to the surface of a construction in a way that is right for that surface.

It‐is extremely important that the elements should be in close contact with surfaces which dissipate heat. This is to make certain that the elements have a long service life. For cylinder‐shaped pipes, tanks, barrels and the like, it is recommended that you use the hook and tension spring method of mounting. This gives you elements that are easy to remove and that always fit tightly onto the surface. If you choose to fasten the elements permanently, it is recommended that you glue them down using 1‐ or 2‐component silicone adhesive.

We would be happy to assist you with detailed instructions on how to apply silicone elements using different kinds of adhesive.

We also offer to carry out gluing of silicone elements in our workshop.

Gluing is a method of keeping the elements permanently fixed to the surface. It is relatively easy to use and ensures good heat transfer by conduction.

Importa - Always start with clean surfaces. This is nt: absolutely necessary when gluing.

- All dirt must be removed by careful cleaning - The glue must be applied evenly.

- The glue joint must be completely cured before it is subjected to any strain.

- When gluing, always follow the manufacturer’s instructions.

Industrial heating – Silicone heaters 4

Product sheet

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Technical construction The resistance wire is wound around a very thin fibreglass core. It is then laid out on a sheet of fibreglass‐rein‐forced silicone cloth and usually arranged in a symmetrical pattern. If desired, the spaces between the wire runs can be made smaller in some sections of the element in order to achieve a higher output in those areas. Next, a silicone cloth is put on top and the complete element is placed in a vacuum chamber, where all air is removed from it. Lastly, the element is vulcanized under pressure and a high temperature.

Technical data

Maximum surface power „Rule of thumb“

Dimensions:

From 10x10 mm (min) to 915 x 2800mm

0.75 W/cm²

In open air

Thickness:

1,5 mm (std) ‐ 0,5 mm (min).

1.5 W/cm²

Weight:

1,5 mm weighs 2,2 kg/m², 0,5 mm weihgs 0,65 kg/m².

Glued to metallic surface

2.3 W/cm²

Oper.temp:

Continuous operation ‐ max 250°C.

Clamped to metallic surface

Maximum resistance /cm²

31 Ω/cm²

Depending on the operating temperature Surface power see diagram 1.

Sheath temp. See Diagram 2 Voltage:

Max. 480 V.

Current:

Max. 30 Ampere

Diagram 1

Diagram 2

Special designs:

Build‐in thermostats Build‐in thermocouplers Waterproof element Different voltages Customer specified connection cables Extra thin constructions (0,5 mm) Unsymmetrical heat concentration Barrel heaters

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Barrel heaters

Industrial heating – Silicone heaters 5

The easy solution for heating and temperature maintenance of media in standard barrels (205 l)

These heaters are used, for example:

in the food industry for melting fats, honey, sugar products

in the chemical industry for keeping paint, glue, chemicals etc warm.

in the oil industry for transporting and storing frost sensitive oils and emulsions.

at airports for storing oils and de‐icing solvents

on building sites

Power output: 425 W/220V Weight: 0.9 kg SEMKO approved The barrel heater is supplied complete with a two‐metre connection cable, equipped with earth‐leakage circuit‐breaker.

Industrial heating – Silicone heaters 6

Temperature Control of Silicone Elements

As a rule, a silicone element requires some form of temperature control in order to ensure long element life and provide the desired temperature.

Because of the very small mass of a silicone element it will quickly come up in temperature, so control equipment with a relatively fast response is needed.

Where surface loads and temperatures are low and intervals between on and off long, electro‐ mechanic‐al thermostats of the bimetal type are often adequate for the purpose of limiting temperature.

Where surface loads and temperatures are higher, electronic thermostats are to be preferred.

If a silicone element is subjected to stress in the shape of continual cooling and heating‐up phases because of short intervals between on and off states, the life of the element will be significantly reduced. To avoid this, the best thing to do is apply the element power output proportionally or use a soft‐start regulator.

Thermostats, thermofuses and sensors of various types such as Pt‐100, thermocouples and thermistors, these can all be applied directly to the silicone elements, in accordance with customer specification.

Where you locate the sensors and thermostats is critical to the accuracy of the temperature control.

Generally speaking, the greater the distance between sensor and heating element, the greater will be the variations in element temperature.

When heating a liquid held in a container, it is advisable to use a sensor mounted with pocket for temperature control, together with an overheat protection device mounted on the elements.

Consultancy and construction assignments Värmekabelteknik has the specialist knowledge and experience required for heating‐foil applications, including both silicone element and control device expertise.

We can offer consultancy services and design, construction and delivery of complete installations.

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Control/Control cabinets

Industrial heating – Silicone heaters 7

We build control cabinets of all sizes according to customer specifications using components and enclosures made by well‐known suppliers.

All types of enclosure designs

• IP 20 – IP65

Alternative control devices:

• EX‐classified enclosures and components

• Electronic thermostat with NTC / PT‐100 sensor.

• Enclosure materials: plastic, metal, aluminium,

• Elektronic thermostat with temperature display • Process regulator with one to ten channels and PC communication

• For mounting on wall, floor or on foundation designed for ground installation.

• PC‐based thyristor‐control devices communicating remotely via mobile or fixed telephone (logging of current, temperature, wind and moisture, to name a few parameters).

• Cabinets controlled from a computer sub‐centre (DUC).

Alarm functions on cabinet front, alarm panels, pc network operation, dialling wireless alarm devices.

• Fuse blown/Circuit‐breaker tripped alarms • Earth‐leakage circuit‐breaker tripped alarms • Temperature alarm • Over‐current/Interruption alarm, and other alarms.

stainless steel

Industrial heating – Silicone heaters 8

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Telephone: +46‐301‐418 40 – Email: info@vkts.se – Homepage: www.vkts.se

Industrihuset

Södra Hedensbyn 43

S‐430 64 HÄLLINGSJÖ

S‐931 91 SKELLEFTEÅ

Sweden

Sweden

Fax: +46‐301‐418 70

Fax: +46‐910‐881 33