Distance between dry mesh and stabilizer related components
If the distance between the dry mesh and the stabilizer is less than 5mm, the area between them will produce a small positive pressure, causing the paper to wrinkle, especially the edge of the paper flapping. Usually, if the paper has no other special requirements, the width of the stabilizer blow is about 60mm less than the width of the dryer surface. The width of the net should be about 20~60mm wider than the width of the stabilizer, otherwise the edge will not be able to produce negative pressure to flutter the paper edge. The width of the paper page should be less than the width of the stabilizer blow, and both sides should be at least 20mm or so, otherwise the edge blow will produce a small positive pressure under the dry net in the direction of the edge nozzle blow, causing the edge of the too wide paper to flutter.
Blowing air flow and pressure
If the air flow is insufficient, the vacuum generated in the relevant area between the dry net and the stabilizer is not enough, causing wrinkling and other operating problems, but the air flow is too large, which is harmful to the operation of the paper, and will cause the paper edge to flutter, especially the paper edge to lead paper is difficult. According to experience, under normal circumstances, the total gas supply pressure of 2000 and 4000 is 7000Pa, the static pressure is 6700Pa, and the gas flow rate is 1250m³/h/㎡; 4000 The total pumping pressure is -5000Pa and the gas flow rate is 600m³/h/㎡.
Surface temperature of dryer
Too low or too high the surface temperature of the dryer is easy to cause the paper to stick to the cylinder, resulting in the edge of the paper when the paper is broken or wrinkles during the opening process, and even broken paper.
Air permeability of dry mesh
In order for the web stabilizer to have a good operating performance, the dry mesh must have a suitable air permeability. If the permeability is too small, there is not enough vacuum between the dry mesh and the stabilizer; If the permeability is too large, it is easy to produce harmful airflow. Under normal circumstances, for paper machines with a speed exceeding 1500m/min, the air permeability requirements of a group of dry nets are 1500~ 1800, and the air permeability requirements of other groups of dry nets are 1800~2100(unit m³/h /㎡, 100Pa).
Paper banner moisture
Uneven moisture of the paper banner will cause difficulties in the vacuum adjustment of the web stabilizer during the opening process of the paper, so it is necessary to adjust the convection box, the mesh part and the press part to ensure that the water is even out of the press paper banner.
The influence of disturbed air flow in the hood
The disturbed air flow in the hood will cause the paper to leave the dry net, especially the paper from the press to the drying part, or from the vacuum roller to the next supply cylinder, which is manifested as the edge of the paper or the wide edge of the paper during the process of opening the paper. In general, under the condition of ensuring the sealing of the air tank, the disturbed air which is found to affect the stable operation needs to be properly shielded or blocked.
Shandong Fengxin Technology Development Co., Ltd. is a company specializing in the development, research and production of paper ventilation, drying, energy saving technology and equipment, and has achieved good results in the field of paper ventilation, drying and energy saving for many years. Fengxin closed air hood system design mainly includes the drying part closed air hood, air hood in various functions of the blower, waste heat recovery device, paper machine mesh moisture, high-speed Yanke hot air hood, all kinds of coating drying boxes, workshop ventilation system and supporting equipment.