Drum dryers system

For drying small fabrieated parts, a helieal drum dryer is often employed. This maehine eonsists of a perforated, rotating stainless steel drum eonveyor that employs a high veloeity airknife system to provide eontinuous throughput and 100 % drying of small, fabrieated parts. 

Double-cell system, in soil and ground water treatment, 25 835 Double crucible technique, 11 135-136 Double-deck kiln, 15 530 Double-drum dryers, 9 134 Double-drum separator, 15 446 Double-effect distillation, 10 153 Double end point titration method,... 

Atmospheric air at the rate of 6.1 million SCFD is compressed to 160 psig in a two-stage compressor JJ-1 that is provided with an intercooler and a knockout drum. Then it proceeds to a packed tower T-l where it is scrubbed with recirculating caustic soda solution. Overhead from T-l is cooled to 14°F in a refrigerated exchanger. After removal of the condensate, this stream proceeds to a dryer system that consists principally of two vessels F-l and F-2 packed with solid desiccant. 

The strands move through large drum dryers which reduce the moisture content to about 2 or 6%, the difference being whether liquid or dry resin is to be used. Because a desired moisture level into the press is about 6—7% me, a liquid resin adds water to the system and requires a lower flake moisture than a dry resin. 

Pastes and melts are spread as a thin film on a surface where they are dried and cooled, respectively. Subsequently scraped off to yield solid product. Drum drying, flaking, melt cooling, endless belt processing, slating, pastille formation. Drum dryers, drum flakers, endless belt systems... 

Cost data for drum dryers, rotary dryers, tray dryers, and tumble dryers are presented in Figs. 16-29 through 16-32. The data available cover both atmospheric and pressure systems. 

Description of a Drum Drying System A detergent drying plant handles 86,722 Ib/day of a slurry containing 52% solids and makes 45,923 Ib/day of product containing 2% water. The dryers are two sets of steam-heated double drums, each 3.5 ft dia by 10 ft, with a total surface of 440 sqft. Each drum is driven with a 10 HP motor wifh a variable... 

Drum dryers are classified on the basis of the number of drums as single-drum dryers and double-drum dryers. A typical feed arranganent for a drum dryer is given in Figure 24.12. The product is collected in the trough and is conveyed toward one end of the drum. By completely enclosing the system, these dryers may be operated under vacuum for heat-sensitive materials that may otherwise spoil at atmospheric pressure. 

A pilot-plant, double-drum dryer modified to produce low-moisture flakes from a wide range of fruit purees has been described [46]. Products with a relatively high fiber content such as apples, guavas, apricots, bananas, papayas, and cranberries could be dried successfully without additives. Purees with a low fiber content such as raspberries, strawberries, and blueberries required the addition of fiber (low methoxyl pectin, up to 1%) to aid in the sheet formation at the doctor blade. The modification consisted of incorporation of variable-speed take-off rolls, cool airflow directed at the doctor blade area, and a ventilation system to remove saturated air from the area beneath the drums. 

There are two types of through-air dryers often used in the textile industry (1) suction or perforated drum drying systems and (2) convection ovens with tenter frames for fixing the transverse dimension of the product while it is transported through the oven. 

Pulse combustion drying combines high economic of direct fire heating system with high intensity of drying of disperse material. Typical power consumption is 3,000-3,500 kJ/kg H2O evaporated (4,500 to -11,500 for spray dryer and 3,200-6,500 for drum dryer) [53,54]. The main advantages of pulse combustion drying are as follows ... 

Similar considerations can be made for steam-heated batch and continuous drum dryers. The automatic system presented in [70] also takes into account and compensates for any fluctuations of heating steam pressure. 

Microprocessor-based control system had also been implemented in a solar-tunnel dryer [35] and a pneumatic drum dryer [36],... 

The literature on FLC has been growing rapidly in recent years, making it difficult to present a comprehensive listing of the wide variety of applications that have been made. Among these are an experimental warm-water plant [65], temperature control of stirred tank reactor [66], activated sludge wastewater treatment process [67], cement kiln [68,69], and startup of catalytic reactor [70]. In drying applications, FLC systems have been developed for simulated rotary dryers [71-73], deep-bed grain and food dryers [74-76], fluidized-bed dryers [77,78], and drum dryers [79]. 

M.M. Stefanovic and M.B. Stakic, Computer system for the control of a pneumatic drum dryer. Proceedings of the Ilth International Drying Symposium IDS 98, Vol. A, pp. 597-604,... 

The drum dryer was first patented for use in the manufacture of pregelatinized starch in Germany by Mahler and Supf in 1921. Since then a host of other patents have appeared especially in the United States where extensive variations of feeding methods, number and configuration of drums, heating system and product removal were considered. The diameter of the drum varies from 0.45 to 1.5 m and its length varies from 1 to 3 m. The thickness of the drum wall is between 2 and 4 cm. The drum dryer is classified... 

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