RAPID DRYING OF CERAMIC GREENWARES

摘要

Systems and methods for rapid drying of ceramic greenwares having a high graphite content are disclosed. The methods include employing microwave drying to bring the dryness of the ceramic greenware to a first select dryness and then employing close-coupled hot-air drying to bring the dryness to the final target dryness. The judicious use of close-coupled hot-air drying reduces end defects due to unevenness in the microwave drying process while also substantially speeding up the drying process. Various configurations for and combinations of microwave drying and close-coupled hot-air drying are disclosed.

主权项

1. A method of drying an extruded ceramic greenware having an array of open longitudinal cells and opposite input and output ends, comprising:
performing at least one microwave drying of the ceramic greenware to a dryness of about 70% to form a partially dried ceramic greenware; operably arranging the input end of the partially dried ceramic greenware relative to an output end of a close-coupled hot-air (CCHA) drying system to define a coupling distance Δx having a value in a range defined by −2″≦Δx≦10″; performing at least one CCHA drying of the partially dried ceramic greenware to form a dried ceramic greenware having a target dryness of at least 98% by passing CCHA through the ceramic greenware from the input end to the output end; and wherein the ceramic greenware has a dielectric constant ε=ε′+iε” that defines a loss tangent tan(δ)=ε″/ε′≧0.05.