The basic type of ordinary drum The drum is the most important container equipment in tanning production, and can be used for all wet processing operations of tanning. It can also be used for soft leather products such as shoe upper leather, garment leather, sofa leather, glove leather, etc., soft and piled suede leather, moisture regain and even wetness of dry leather, and soft rolling of fur.
The drum is mainly composed of a frame, a drum body and its transmission device, The drum body is a wooden or steel rotary cylinder on which 1-2 drum doors are opened. During operation, put the skin and the operating fluid together into the drum and rotate to stir and subject the skin to moderate bending and stretching, so as to speed up the reaction process and improve product quality and purpose.
The main structural dimensions of the drum body are the inner diameter D and the inner length L. The size and proportion are related to the application, production batch, process method, etc. According to the different wet processing processes, drums of various specifications have been finalized and manufactured to meet the processing needs of different processes.
The immersion drum is suitable for pre-tanning operations such as immersion, dehydration, and liming expansion. It requires moderate mechanical action and large volume. Generally, the ratio of inner diameter D to inner length L is D/L=1-1.2. The diameter of the commonly used drum is 2.5-4.5m, the length is 2.5-4.2m, and the speed is 2-6r/min. When the diameter of the drum is 4.5m and the length is 4.2m, the maximum loading capacity can reach 30t. It can load 300-500 pieces of cowhide at a time when it is used for water immersion and depilation expansion.
The structural size and speed of the vegetable tanning drum are similar to those of the immersion drum. The difference is that the solid shaft is used to increase the load. The volume utilization rate can reach more than 65%. It is suitable to install short baffles with high strength and adopt automatic exhaust. The valve removes the gas produced during the vegetable tanning process, and is equipped with timing forward and reverse devices to eliminate the phenomenon of skin wrapping. The iron parts in the drum body need to be coated with copper to prevent the vegetable tanning agent from deteriorating and blackening in contact with iron, which will affect the quality of vegetable tanned leather.
The chrome tanning drum is suitable for wet processing such as deliming, softening, pickling tanning, dyeing and refueling, etc. It requires a strong stirring effect. The ratio of the inner diameter of the drum to the inner length D/L=1.2-2.0, and the diameter of the commonly used drum is 2.2- 3.5m, length 1.6-2.5m, wooden stakes are installed on the inner wall of the drum, and the rotating speed of the drum is 9-14r/min, which is determined according to the size of the drum. The load of the soft drum is small, the speed is high (n=19r/min), the ratio of the inner diameter of the drum to the inner length is about 1.8, and the mechanical action is strong.
In recent decades, with the needs of environmental protection and the requirements of new process methods and finishing, the structure of ordinary drums has been continuously improved. Strengthen the circulation of the operating liquid in the drum, and discharge the waste water in a directional manner, which is beneficial to diversion treatment; use detection devices and heating systems to precisely control process parameters and improve product quality; use computer for program control, automatic feeding, mechanized loading and unloading, convenient operation and reduced labor Strength, lower material consumption, less pollution.
Post time: Nov-24-2022
