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VärmeKabelTeknik Industrial heating – Silckone heaters
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Industrial heating – Silicone heaters VärmeKabelTeknik 2
Sil icone elements - Standard sizes
Part.no Width Length Power Voltage Part.no Width Length Power Voltage
40.0180.0 25 900 50 12 40.0065.0 100 100 100 240
40.0140.0 25 95 15 24 40.0070.0 100 200 200 240
40.0110.0 25 100 25 24 40.0075.0 100 325 325 240
40.0120.0 25 200 26 24 40.0080.0 100 500 500 240
40.0125.0 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
VärmeKabelTeknik Industrial heating – Silicone heaters
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Velox Sil icone Elements: Installation Guide
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.
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.
Important:
- Always start with clean surfaces. This is 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.
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.
Important::
Position the screws in such a way that the pressure is evenly distributed throughout the element surface. Large elements can be designed with holes for the screws. The pressuplate that is mounted on top of the elements must be stiff enough to distribute the pressurevenly throughout the surface. To help in distributing pressure and smoothing out any uneven spots, a layer of insulation may be putbetween plate and element.
Industrial heating – Silicone heaters VärmeKabelTeknik 4
Product sheet
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
Dimensions: From 10x10 mm (min) to 915 x 2800mm
Thickness: 1,5 mm (std) ‐ 0,5 mm (min).
Weight: 1,5 mm weighs 2,2 kg/m², 0,5 mm weihgs 0,65 kg/m².
Oper.temp: Continuous operation ‐ max 250°C.
Surface power Depending on the operating temperaturesee diagram 1.
Sheath temp. See Diagram 2
Voltage: Max. 480 V.
Current: Max. 30 Ampere
Maximum surface power „Rule of thumb“
0.75 W/cm² In open air
1.5 W/cm² Glued to metallic surface
2.3 W/cm² Clamped to metallic surface
Maximum resistance /cm²
31 Ω/cm²
Diagram 1
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
Diagram 2
VärmeKabelTeknik Industrial heating – Silicone heaters
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Barrel heaters
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 VärmeKabelTeknik 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.
VärmeKabelTeknik Industrial heating – Silicone heaters
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Control/Control cabinets
We build control cabinets of all sizes according to customer specifications using components and enclosures made by well‐known suppliers.
Alternative control devices:
• Electronic thermostat with NTC / PT‐100 sensor.
• Elektronic thermostat with temperature display
• Process regulator with one to ten channels and PC communication
• 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, diall ing wireless alarm devices.
• Fuse blown/Circuit‐breaker tripped alarms
• Earth‐leakage circuit‐breaker tripped alarms
• Temperature alarm
• Over‐current/Interruption alarm, and other alarms.
All types of enclosure designs
• IP 20 – IP65
• EX‐classified enclosures and components
• Enclosure materials: plastic, metal, aluminium, stainless steel
• For mounting on wall, floor or on foundation designed for ground installation.
Industrial heating – Silicone heaters VärmeKabelTeknik 8
Telephone: +46‐301‐418 40 – Email: [email protected] – 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