Целлюлозно машина (ключ проекта)

The double wire former is composed of hydraulic headbox, dewatering system, pressure dewatering box, wire stretcher, rectifier and cleaning system. Press section covers vacuum pre-press, vacuum press and wide nip press. This press section is designed based on a full consideration of pulp machines features to make sure that pulp machine has a better dewatering efficiency. The principle of drying the pulp board is flotation without contact, in the multi-stack dryer; the number of blow boxes and their layout depend on the actual production capacity. The paper sheet runs between the top and the bottom blow boxes. Its dried by the impingement air containing the heat energy and the impinging power, the air cushion supports the paper sheet to guarantee a stable running of sheet. The top and the bottom blow boxes are lifted by the cylinder to allow for the maintence and cleaning. With a view to utilizing the power to a great extent, we usually apply a two-step heat recovery system to the hot air circulation outside the pulp board dryer. The primary air-air heat recovery unit uses the hot wet air exhausted from the top of the dryer to preheat fresh air. Being preheated, the fresh air is heated to the required temperature in heat exchanger before conveyed to the bottom of the dryer. The secondary airwater heat recovery unit heats the process water and ventilation water by utilizing the remaining heat of he waste air. A set of cooling air supply system is located at the bottom of the dryer. The pulp board is cooled before it leaves the drying section. The drying section can be shortened by more than half, so that investment in civil construction is greatly saved. The dryer is easy to adjust the water contained in web, and to achieve a uniform dryness across the width of web. As the tension working on the pulp board in drying section becomes smaller, the pulp board can run more stably, and the possibility of web-break is diminished.