| 摘要 |
<p>The invention relates to a process for making refractory ceramic tubes and to an installation for carrying out said process. According to the invention, the process for making ceramic tubes from alumina, zirconia, lime, magnesia or clay of various refractive indexes, of diameters of 50...500 mm, thicknesses of more than 4 mm and length of up to 6 m, consists in shaping the tube by pouring a paste of the desired material into a tube-shaped shuttering rotated at 100...200 rpm, in order to achieve a radial acceleration of at least 10 m/s, and heated from the exterior, in order to dry the shaped tube, drying which is finished after 2 h, at the most, when the temperature inside the tube reaches 125°C, after which the heating is switched off and atmospheric air is blown through the tube, in order to cool it down to a temperature of less than 80°C and the dry tube is further subjected to baking at a temperature of up to 2100°C, in a horizontal rotary oven, followed by cooling and dismantling the tube, when the temperature in the oven is under 100°C. The installation claimed by the invention comprises a shuttering-pipe (1) for shaping and drying the ceramic tube, the pipe (1) being heated by an electrical resistor (2) insulated by a ceramic fibre coating (3) which is protected by a casing (4), the said pipe (1) being provided with two rolling rings (5) and two limiters (8) for setting the length of the tube (9), each limiter (8) being provided with an orifice (10) for discharging the vapour resulting from the paste humidity and a ceramic pipe (11) introduced into a refractory steel pipe (12), which form together the backing oven, between the ceramic pipe (11) and the steel pipe (12) there being placed an insulation (13) made of zirconia powder, while, onto the pipe (12) there is an insulation coating (15) made of ceramic fibres, the said insulation coating (15) being covered with a steel casing (14) to which each of the pipes (11 and 12) is fixed by a circular metal crown (16, 17) and at the ends of which there are welded two caps (18).</p> |
