Heating Elements for industries

Air Duct heaters


GENERAL CHARACTERISTICS

 

The standard electric Air Duct heaters (with finned and smooth heating elements), for Safe Area applications, are suitable for use in countless applications and industrial processes to create air or gas flows at controlled temperature.

 

Their design and relative dimensioning are carefully designed by our technical department in order to be easily inserted in ventilation ducts, air channels, ovens or autoclaves.

Their so called air window (also called “clear span”), which can be made either “air tight” or “not air tight”, is directly crossed by an air or process gas flow.

Finned heating elements can be installed or alternatively, non-finned smooth tubular elements (where the fluid to be heated contains suspended particles).

USE

The Air Duct electric heater with standard connection head (IP41 or IP55 configuration level) for Safe area (non ATEX) applications are suitable for installations in all kinds of application requiring ventilated and/or still air heating treatments.

  • Among the most common applications, it can be found:
  • Forced and natural convection air heating
  • Air conditioning systems (HVAC and ATU – air treatment unit)
  • Hot chambers, drying ovens, packaging machines, smoke elimination systems, air drying systems
  • Painting systems, preheating ovens, autoclaves heating

 

 CERTIFIED QUALITY PRODUCT

The entire production cycle of standard air duct heaters (for safe use) with smooth or finned heating elements, is subject to the strictest dimensional checks and electric tests in compliance with our own standards set forth ISO 9001:2008 certified Corporate Quality System, and in full compliance with the CEI/EN requirements in force.

Among the main above mentioned electric tests, this type of products is carefully subject to insulation resistance tests, dielectric rigidity tests, ohmic value and leakage current tests.

TECHNICAL DATA

This heaters typology is generally manufactured with specific powers (W/cm²) depending on whether they are for heat still or ventilated air.

In presence of air flow high circulation, higher specific powers can be reached, ranging between 3 and 7 W/cm2.

 

In designing this type of products, our technical department makes use of leading computer programs in establishing the dimensioning, and of performances thermodynamic calculators, in order to optimize the performances, keeping into consideration the same air duct electric heating operating conditions.

Thanks to the manufacturing experience accumulated during 50 years of activity on the national and international market, in the world economy all the main industrial sectors, our technical and marketing departments always provides the best technical and product design solutions, in addition to the most suitable materials, for the customer’s specific application.

Since the proposal stage, we stand out compared to national and international competitors, in supplying all technical details and results of the thermodynamic calculation, which shows the proper air duct electric heater dimensioning.

 

PRODUCT DESIGN USEFUL DATA

An air duct electric heater, consisting both of finned or smooth heating elements, requires the knowledge of some essential technical data for its product design:

  • CLEAR SPAN:  Side D x C (area cm²)
  • AIR DELIVERY: Air blown by the blower used to cool the heating bundle (m³/h)
  • PROTECTION DEGREE: Electric connection box protection level (for example IP41, IP55, IP65)
  • STAGES: Total installed heat capacity choking.
  • SUPPLY VOLTAGE : Supply voltage of the Single-phase and 3-phase electric duct heater, and kind of voltage supplied (Volts/1Ph. or Volts/3Ph.)
  • NOMINAL HEAT CAPACITY: Full heat capacity installed inside the air duct electric heater (kW)
  • DELTA T: Delta between Inlet and outlet air temperature (Delta T in °C)
  • PRESSURE DROP: Air Pressure difference between inlet and outlet air (mm H2O)
VERSION TYPE :

The air duct electric heaters can be manufactured in two types:

Channel ” type (for those duct heaters becoming an integral part of the ventilation duct system)

Drawer” type (for those duct heaters coupled to the plant system by a connecting flange)

In both cases, the heating elements installed inside are assembled through threaded bushes in order to facilitate the maintenance and damaged elements possible replacement.

The lower riveted door can be easily removed and grants an easy elements extraction / replacement.

Each heater is equipped with a safety device (if requested by the client) which limits the sheath’s temperature at an established value in case of heating elements surface overheating temperatures, suitable for preventing damages to the heater or to the system where it is installed. Based on the type of requested heat process, our technical department suggests the adoption of the most suitable thermocontrol device (control thermostat, safety thermostat, J or K thermocouple or PT100 thermistor).

Upon request, it is also possible to manufacture connection conveyors between the air channel and the air duct heater inlet and outlet sections.


STANDARD AIR DUCT ELECTRIC HEATERS INCLUDED IN OUR PRODUCT CATALOGUE

In presence of applications without particularly complicated heating exigences, when looking for products available for prompt / short delivery times, we have available a stock of standard smooth and finned heating elements of various power, sheathing and bending material (straight, U-shape or M-shape), as indicated in our product catalogue, for all still or circulating air heating applications, suitable for installation inside of metal frame casings (Carbon Steel or Stainless Steel) either for IP41 or IP55 finishing for prompt delivery.

GENERAL CHARACTERISTICS

The electric duct heaters are suitable for an easy installation inside the ventilation ducts and air conditioning systems for the direct heating of natural or forced convection air flow. Our production and finishing standards of these products stand out in terms of first quality materials that we select accurately within our production cycle, and in terms of reliability and quality/price ratio.

During 50 years of manufaturing, our corporate brand stood out in the production of electric air heating units and air duct electric heaters suitably designed for installation on air treatment machines and systems manufactured by the most renowned manufacturers of HVAC and AHU systems worldwide.

 

 

Air Duct Electric heaters with explosion-proof ATEX connection head

General description

 

The air duct electric heaters with ATEX certified electric connections head , are heaters commonly used in conditions of limited pressure (less than 0.2 bar) and forced circulation.

They are constituted by heating elements blocks (finned or non-finned) specifically designed and manufactured to offer high performances and at the same time, a high heat exchange.

Outlet Temperature (of the air flow thermally treated ) and surface Density (W/cm ²), in addition to the fluid type and speed (air or gas) in metres per second (m/s), are the variables jointly determining the temperature of the elements installed inside the air duct electric heaters.

In order to grant these products suitability for being installed in dangerous environments subject to explosion hazard, the electric connections are housed and hermetically protected inside one or more electric connections or heads housings for use in explosive environment.

ATEX air duct electric heaters with explosion-proof head are commonly used in low pressure operating conditions (<0.2 bar) and forced circulation. The immersion heating elements installed inside these special heaters are designed and positioned with a specific layout, in order to optimize the heat exchange.

The elements surface temperature depends on the outlet temperature required by the specific application and surface load allowed by the same (W / cm ²), in addition, naturally to the type of fluid to be heated and its speed, measured in metres per second(m/s ) or in kilograms per hour (Kg/h).

The electric connections head is the area under most stress, by the dangerous application, these heaters are subject to. Each air duct electric heater with explosion-proof head can have one or more ATEX certified heads and therefore, suitable for use in explosive environment..

We are able to manufacture explosion-proof air duct electric heaters with ATEX certified head (certified for use in explosive environment Eex-de,  Area 1 and 2 – II2G/D ATEX) with CE marking, manufactured in full compliance with the CEI and CENELEC standards in force.

This type of electric heaters is manufactured with high quality materials like carbon steel, stainless steel AISI-304, AISI-321, AISI-316 and Incoloy 800 (heating elements tube) and Galvanized Steel FeZn or Stainless Steel AISI-304/316 (only the frame-structure enclosing the elements and the electric contacts protection head IP65-IP66 and the supply inlets of the power stages and thermalregulation devices (NPT or GAS type).

Typical uses

  • Air heating and conditioning, heating of buildings and apartment blocks in dangerous activity environments
  • Packaging and wrapping systems in potentially dangerous installation locations and for use in dangerous activity environments
  • Heating of products and/or fluids considered dangerous, for example process air or gas (Argon, Nitrogen), used in industrial processes located within dangerous areas.

 

CERTIFIED QUALITY PRODUCTS

The entire production cycle of explosive-proof air ducts immersed electric heaters is subject to the strictest checks by supervisory bodies, performing severe controls at established frequencies, in full compliance with ATEX regulations.

In addition, this products typology is carefully subject to insulation resistance tests, dielectric rigidity tests, ohmic value and leakage current tests.

TECHNICAL DATA

In product designing this type of products, our technical department makes use of leading computer programs to establish their dimensioning, and of performances thermodynamic calculators, in order to optimize the performances, keeping into consideration the same air duct electric heather operating conditions.

Thanks to the manufacturing experience accumulated during 50 years of activity on the national and international market, in world economy all main industrial sectors, our technical and marketing department always provide the best technical and product design solutions, in addition to the most suitable materials, for the customer’s specific application.

Since the proposal stage, we stand out in comparison with national and international competitors, in supplying all technical details and thermodynamic calculation results, which show the proper air duct heather dimensioning.

 

PRODUCT DESIGN USEFUL DATA

The manufacturing of an air duct immersion electric heater, consisting both of finned or smooth heating elements, requires the knowledge of some essential technical data for its product design:

  • FLUID TYPE: GAS OR AIR
  • ATEX Code for OPERATING ENVIRONMENT (internal or external use, in presence of atmospheric agents)
  • OPERATING TEMPERATURE
  • CLEAR SPAN:  Side D x C (area cm²)
  • AIR CAPACITY : Air blown by the blower used to cool the immersion elements (m³/h)
  • PROTECTION DEGREE:  Airtight protection IP65 or IP66
  • STAGES: Total power installed choking
  • SUPPLY VOLTAGE: Air Duct electric heater Single-Phase and Three-Phase supply voltage, and voltage applied type (Volts/1Ph. or Volts/3Ph.)
  • RATED POWER: Total power installed for the air duct immersion electric heater (kW)
  • THERMAL DROP: Difference between the inlet and outlet air temperature (Delta T in °C)
  • PRESSURE LOSS: Pressure difference between air input and output (mm H2O)

Classe Temp. ATEX  /  ATEX Temp. Class
‘T6′: 85°C | ‘T5′: 100°C | ‘T4′: 135°C | ‘T3′: 200°C | ‘T2′: 300 | ‘T1′: 450°C
Lungh. Z.N.  /  Cold zone Lg. A B A B A B A B A B A B
300 mm T6 X T4 X T3 X T3 X T2 X T2 X
250 mm T6 X T4 X T3 X T3 X T2 X T2 X
200 mm T6 X T4 X T3 X T3 X T2 X -
150 mm T6 X T4 X T3 X - - -
100 mm T6 X T4 X T3 X - - -
0 mm T6 X - - - - -
Temp. Lavoro /  Working Temp. 0°C 100°C 150°C 200°C 250°C 300°C
Legenda:A = Classe Temp. / Temp. ClassB = Ex-proof head Temp.-proof allowance (X)= Yes (-)= Not

CONFIGURATION TYPE

Each heater is equipped with a safety device (upon customer request) limiting the sheath’s temperature in case of heating

elements surface possible overheating, which aims at preventing damages to the heater or to the system where it is installed. Depending on the type of process requested, our technical department suggests the adoption of the most suitable thermalcontrol device (control thermostat, safety thermostat, thermocouple J or K or thermoresistor PT100). It is also possible to equip air Duct electric heater with SCR device or power thyristor to be connected to the control panel and with control systems.

 

Air duct electric heaters (Cylindrical Air Duct Heaters)

GENERAL CHARACTERISTICS

Within the wide range of air electric heaters (with finned and non-finned elements), for safe area applications, there are also air duct electric heaters for cylindrical ducts, suitable for installation anytime there is the need to channel air flows at controlled temperature inside cylindrical ducts or channels. Their product design and relative dimensioning are carefully designed by our technical department in order to be easily introduced in the ventilation ducts and/or cylindrical shape air ventilation channels.

Non-finned smooth tubular heating elements are generally installed inside.

 

USE & MAIN APPLICATIONS

The cylindrical air duct electric heaters for cylindrical channels are generally manufactured with standard connections head IP44 version.

Among the most common applications, it can be found:

Smokes and gases draining

Air heating and conditioning inside cylindrical air channels

CERTIFIED QUALITY PRODUCT

The entire manufacturing cycle of cylindrical air ducts electric heaters is subject to the strictest dimensional checks and electric tests in compliance with the standards set forth by our own ISO 9001:2008 certified Corporate Quality System, and in full compliance with the CEI/EN requirements in force

This products typology is carefully subject to insulation resistance tests, dielectric rigidity tests, ohmic value and leakage current tests

 

MAIN TECHNICAL CHARACTERISTICS

  • Air heating unit – Class I
  • Carbon Steel painted connection head – protection index: IP44
  • Fe/Zn cylindrical channel (upon request, it is also available in Stainless Steel version)
  • Cable glands / Electric contacts supply outlets
  • Built-in safety thermostat with 85°C shut-off (upon request, it can be supplied also in the 110°C shut-off version.)
  • No. 1 or 2 power stages based on the standard models proposed (See catalogue) in Single-phase or 3-phase version
  • Heating elements Voltage ~230V (Air Duct electric heater including a variable number of elements – from 1 to 6 – with stainless steel pipe AISI-321 or AISI-304L  of Ø 6.4 mm for the Single-phase version and Ø 8 mm pipe for the 3-Phase version.

PRODUCT DESIGN USEFUL DATA (see graph here below)

SINGLE-PHASE VERSION (~230V / 1-Phase)

 

 

 

 

 

3-PHASE VERSION (~400V / 3-Phase Star or 3~230V Triangle connection)

 

General technical data

  • Cylindrical frame casings, can be customized with variable diameter from Ø 125-630 mm Galvanized-Steel (FeZn) or Stainless-Steel
  • Supply voltage: V230/400, for Single-Phase or 3-Phase wiring
  • Temperature-limiting thermostat or Temperature control thermostat
  • Connection housing (Galvanized-Steel or Stainless-Steel)
  • Upon request, optional flow switch

 

 


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