Drying ovens continuous process

There are three types of continuous process drying ovens, depending on the mode of operation ... 

Another modification to the vertical coke oven process, dry quenching of the coke as first developed in the GIS (13), started becoming of interest in the 1960s and has continued to grow steadily. Using dry quenching, the coke is discharged into a hot car and is quickly transported and dumped into a... 

Drying and milling the resulting wet pigment presscakes, possibly preceded by extrusion or granulation, finally affords the desired pigment powder. Drying may be carried out either by a continuous process on a conveyor belt or as a batch operation in a convection oven. 

After the forming process, the drying process follows. In earlier times bricks were dried outside and consequently people were dependent on the weather. Nowadays brick production is a continuous process and the bricks are dried in drying chambers. Hot air, partly from the cooling phase of the ovens, is transported to those chambers and ventilators ensure a proper air circulation. 

Vacuum Dry (1A, IB). The frozen books were placed horizontally on the floor of the chamber. The heated walls melted the ice. A vacuum pump was applied to evaporate the water from the books. Pumping was continued until the books returned to their original weight. The process produced for drying IB was exactly the same as 1A however, the samples were dried in separate independent experiments. The book dried in the 1A experiment was frozen, while the book dried in the IB experiment was placed in the drying oven immediately after the standard drainage period. 

Dry-heat tunnel sterilization is a continuous conduction process in contrast to the batch processes in ovens. A continuous conduction process is one in which a predetermined quantity of items is subject to a continuous conduction cycle at a predetermined rate to effect sterilization and/or depyrogenation. ... 

Figure 8.40. Schematic diagram of the continuous process of fabric impregnation by polyaniline. Numbers indicate (I) (3) (17) for tanks, (2) (4) (7) (10) (14) (16) for fabric, (5) (13) respectively for oxidising and acidic showers, (6) for monomer bath, (8) (15) for drying ovens, (9) for oxidizing bath, (11) for polymerisation step and (12) for acidic bath.

The ceramic industry has, for many years, examined the use of microwaves for drying purposes. Today, several uses are operating successfully. One such system, MCB Ceramics in Toronto, Canada, uses microwaves at two stages to replace a slow, hand-operated batch system with a continuous process. A 27 kW microwave oven is used to speed up the initial drying in the mold to 20 min from its previous 1 h, during which the microwaves are applied for only 2 min. The final drying used to take 24 h but now is done with microwaves in only 8 min, after which the piece is glazed and fired. The process is used to produce small bathroom accessories such as towel bar holders and soap dishes [23]. 

The use of nylon-11 for powder coatings or dry coatings (qv) has been developed in response to a growing concern for the environment (44) (see Coating PROCESSES, powder technology). Electrostatic deposition allows thin films to be appHed to metal substrates. Once the powder is appHed, it must be melted and coalesced into a continuous plastic film. Eorced draft or irradiant ovens are used for fusion, and because no polymerization or cross-linkage are required for curing, coated objects can be processed quickly and air-cooled (45). 

Esveld et a/.81,82 developed a continuous dry media reactor (CDMR) for pilot-scale applications. It consisted of a multi-modal tunnel microwave cavity operating at a frequency of 2.45 GHz with a power range from 0 to 6 kW irradiated on a surface of 0.6 m2. Temperatures of up to 250°C were achieved. A web conveyor travelling at 17 cm min-1 transported the solid-phase reaction mixture to the oven in low, open Pyrex supports closely packed on a polytetrafluoroethylene (PTFE)-coated glass fibre. An open flat bed process was employed to facilitate easy evaporation. 

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