IR heaters

An additional external heating source was used to solve this problem. Two Osram Xenophot HLX 64 635 (15 Volt, 150 Watt) IR heaters mounted on moveable support arms were used to heat the MS capillary tip, a third one was used to heat the FTIR capillary tip. These three heaters are controlled by one Eurotherm 808 controller with the measuring and the alarm thermocouples mounted near the small ball-joint of the MS heated transfer line/TGA furnace coupling, see Figure 6.6. The measurement of the FTIR/MS capillary tip temperatures was repeated using only these extra heating sources (no TGA furnace switched on), the results are listed in Table 6.2. 

IR heaters controll temperature, °C FTIR capillary tip temperature, °C MS capillary tip temperature, °C... 

A polymer solution containing dissolved or dispersed Cl particles is fed from the slot head onto a continuous band 2 whose surface adheres poorly to the polymer and which moves at a constant speed. Film formed on the band is dried by IR heaters 3. It is set and dried completely on contact with the cooling drums 4. The film sheet is then centered, its edges are trimmed by device 5 and it is wound onto roll 6. 

If an application requires part heating, dispensing equipment suppliers offer infrared (IR) heaters, heated contact tooling, or convection heaters. IR heaters can produce a fast temperature rise on a tightly focused area heated contact tooling is gentler heating, but has a slower ramp-up time than IR convection heaters use heated gas to evenly raise the temperature of multiple parts with dissimilar mass. 

There are two basic types of IR heaters electric IR and gas-fired IR (Figure 46.16). The most important element of the IR drying system is the IR emitter. These two types of IR heaters fit into three temperature ranges (1) 343°C-538°C (e.g gas and electric IR) (2) 538°C-1100°C (e.g gas and electric IR) and (3) 1100°C-2200°C (e.g., electric IR only). Electrically heated or natural-gas-heated units are used mainly to preheat the web, although these can be used in principle to carry out the entire drying process. IR temperatures are typically in the 650°C-1200°C range. Improved drying rates can be obtained by a combined radiation-convection system. 

The short-wave IR radiation can only be generated by an electric IR heater employing a tungsten heating element. A tungsten filament has small mass as well as low electrical resistance, which allows heavy current flow and very rapid heat up and cool down. The rate of response of various types of radiant heat sources can be an important criterion in the selection of a proper source for coating drying applications. 

Within the last 10 years, the use of IR heaters has been widely accepted for the drying of coated paper and paper-board. For example, when drying coating was applied to commercial- or publication-grade papers during the papermaking... 

Infrared Heater Types. Alternative IR heater types are shown in Fig. 47.4. 

Figure 40.18 shows the IR absorption spectrum of a 4-mil water film, which is a common ingredient of paper and latex coating. The first peak at 3 pm matches the radiation of medium-wave IR heaters. The second peak at 6 pm and the longer wavelength corresponds to the radiation spectrum of long-wave IR heaters. In order to be effectively heated, the water film requires radiation energy concentrated between... 

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