Giant immersion heaters Electric heat versus traditional steam heat

Vulcanic-Czepek products are mainly intended for the German market. The contacts that have evolved throughout the years have led to cooperative ventures with plant engineering firms in Scandinavia and the Netherlands, which in the words of Jean Lachaud, a member of the Board of Management and authorised signatory, have a „multiplier function“. The company is also represented by a free agent in Austria. Whereas in 1996 exports accounted for 15% of turnover, the figure this year is almost 20%.

The Hanau-based company manufactures and sells electrothermal installations for mechanical engineering plants, the process industry and consumer goods production. According to Wolfgang Vogler, a sales engineer at Vulcanic-Czepek, „these installa-tions are all used to heat liquids and gases. Our product spectrum extends from single heating elements through screwed and flanged heaters as well as air and flow heaters to complete heater installations incorporating both our own components and bought-in products.“

Lachaud adds: „Our biggest competitor is not so much a specific company as steam heating in general, which is the standard solution installed in nearly all large chemical plants. If the required heat output is between 200 and 300 kW, however, the benefits of electric heaters are particularly evident – a compact design, a simple connection principle and minimal maintenance.“

Flanged heaters, gas and air heaters are especially interesting for the pharmaceutical and chemical industries as well as for the production of foodstuffs. Both these product groups are characterised by a very high efficiency of around 95%.

Electric flanged heaters are used to directly heat liquid or compressed-gas starting materials upstream of conversion processes, as well as to indirectly heat plants and plant components with the aid of water or organic heat-transfer media.

The heaters can be installed in tanks and boiler systems using a blank flange. The heating elements that are welded into this blank flange resemble immersion heaters in terms of their design and function. The number of heating elements, their diameter and the materials that are used are dependent on the particular application.

The heating elements consist of a tubular metal jacket containing a coiled heating wire. The space between the heating wire and the metal jacket is filled with highly compressed magnesium oxide. This performs two functions: it is an electrical insulator and a heat conductor in one. The heating elements can be up to 6 m in length and between 6.5 and 16 mm in diameter. The heating jackets are made from different materials according to the intended application, for example steel, stainless steel (1.4541) or special steels such as Inconell or Incoloy. If the electric flanged heaters are to be used to directly heat aggressive or corrosive media, it is possible to coat the heating elements.

The output of the flanged heaters ranges from 1 to 700 kW. They are available with nominal diameters from DN 40 to DN 500 and for nominal pressures of up to PN 160. Thanks to the explosion-proof enclosures of the electrical housings in accordance with EN 50014 ff., the flanged heaters can also be used in potentially explosive atmospheres. Heating water in heating circuits is one important application of electric flanged heaters. However, lime deposits may form on the heating elements. These reduce the effectiveness of the heat exchange and in the long term also cause the heating elements to be destroyed, on account of the excessively high thermal load that is placed on them. This problem can be countered by installing a water-softening plant upstream or by using safety temperature-limiting devices. The latter are connected directly to the surface of the heating elements and measure their surface temperature. If there is any likelihood of a heating element overheating, they cause the complete plant to be shut down. Deposits are not only formed as a result of heating water, however, but also when organic heat-transfer oils decompose. According to Vogler, thermal decomposition can be prevented by reducing the surface load on the heating elements, in other words by limiting the operating temperature.

The flow heaters are a more advanced version of the flanged heaters. They consist of a flanged heater integrated in a flow duct. These systems are available for a connected load of up to 300 kW. The maximum nominal diameter of the flow passage is DN 500. Flow heaters are used to directly heat pressurised gases or liquid media, such as water, heat-transfer oils or chemicals.

Electric air heaters are used to directly heat air or non-pressurised gases. They permit application temperatures of up to 600 °C. The air heaters consist of the above-mentioned heating elements integrated in a duct. On both sides of this duct are rectangular frame flanges that enable the heater to be installed in a ducting or piping system.

The maximum connected load of the air heaters is 1.5 MW, which can be subdivided into several switching steps.

The heater ducting system is always made of stainless steel (1.4541 or 1.4571). The heating element jackets are made of high-temperature-resistant chromium-nickel steels, such as Incoloy 800. The electric air heaters are available in various sizes from 200 x 200 mm to 1.50 x 1.50 m. Special dimensions can be supplied on request. These heaters are also available with the Ex e type of protection as well as with optional temperature-limiting devices and thermostats for use in potentially explosive atmospheres.

„One of the most important applications of the air heaters“, explains Vogler, “ is catalytic afterburning of flue gases. This process is often essential in order to ensure compliance with the statutory framework of environmental legislation. It takes place at around 400 to 450 °C. The flue gases must be heated to the required reaction temperature before they can be treated. This is the role of the electric air heaters from Vulcanic-Czepek.“(le)

Vulcanic-Czepek

Fax: ++49/6181/571285

Further information cpp-246

Vulcanic-Czepek can look back on a brief, but eventful, history. The company, whose activities were concentrated from the outset on the field of electric heat generation, was founded in 1980 by Günter Czepek. The French firm of Vulcanic S.A., also a supplier of electrothermal equipment, acquired an 80% share in Czepek’s company in 1990. With a workforce of 200, Vulcanic produces trace heating systems, drum heaters, heater mats and frost-resistant cables in Paris and Dijon.

In the early 1990s Vulcanic Czepek acquired 85% of the Thuringia-based firm of Triatherm Sonneberg GmbH, which manufactures ceramic insulating materials for electrothermal applications. In 1994 the production of heating tubes was then transferred to Sonneberg.

In the mid-1990s Vulcanic-Czepek suffered a drop in sales. The Hanau company was subsequently taken over 100% by Vulcanic S.A. in response to this negative economic trend.

Vulcanic-Czepek currently employs a staff of around 25 in Hanau and 80 to 90 in Sonneberg. In 1997 the firm achieved a turnover of DM 6.7 million. A significant increase of turnover is planned for 1998. In the words of Jean Lachaud, a member of the Board of Management and authorised signatory, „Today Vulcanic-Czepek is a competitive corporation with extremely lean, efficient structures. Our turnover to date amounts to at least DM 7.0 million, and it seems likely that we will achieve our target.“