Drying equipment heater

Blowing hot air A typical arrangement is shown in Figure 31.9. The bus duct enclosure is provided with inlet and outlet valves at suitable locations. Hot air is supplied through the inlet valve until the interior of the enclosure is completely dry. The blowing equipment comprises an axial flow fan. a heater unit, an inlet air filter unit, pressure... 

A motor used in standby operation mode should be equipped with a space heater to keep the motor windings dry. In classified areas these space heaters must meet the surface temperature requirement of the specific hazardous area. 

Early SM boilers were manufactured with between two and four corrugated furnace tubes in wet-back and dry-back versions and generally incorporated heat recovery equipment such as economizers and air heaters. Some designs also provided for superheaters and for coal, oil, or gas fuel firing. Many of the best features are incorporated in the SM boilers commonly available today. 

Many processes are heat driven, take place at elevated temperatures, or require product drying. As a result, process heaters and dryers are common equipment in processing facilities. Many of these are fired units fueled by a variety of gas or liquid fuels frequently by natural gas. They may be used to heat a process stream directly, to heat an intermediate heat transfer fluid, or to... 

Cotton or wood pulp as delivered to nitrocellulose plants contains 6% or more of moisture. This moisture should be removed prior to nitration so that it does not bring about any dilution of the mixed acid and thereby change the course of the reaction. Cotton is usually transported in the form of compressed bales, which are opened and shredded before drying. Wood cellulose, in the form of pressed cellulose pulp or of crepe paper, is dealt with similarly. Dryers for dehydrating cotton or cellulose may be of various types. The simplest is the shelf drier, equipped with mechanical ventilation and heaters situated at the bottom, supplied with water or steam so as to maintain a temperature of 80-100°C inside the drier. 

These preliminary tests indicated an erratic response by the frozen book to the radiation. Equivalent drying did not occur with similar damaged materials. Whether the irregularities were caused by the material or the equipments performance was not evident. After the initial experiments with both dielectric and microwave heaters, the dielectric apparatus was chosen for additional experiments. This decision was based primarily upon this equipment s having the higher power capability. 

The critical need for equipment which would quickly thaw frozen materials was satisfied by use of these dielectric heaters. The librarians and conservator could identify the extent of damage to each item and effectively plan the restoration required. The economical application of dielectric and microwave drying to coated-paper books needs a major breakthrough to bring about success. 

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