Basic structure of paper machine (1)
According to the needs of the papermaking process, the paper machine has a variety of structures, generally consisting of components such as flow, forming, pressing, drying, finishing, coiling and transmission, and auxiliary systems and other supporting equipment.
It is composed of head box, breast roll, forming wire, suction box and flat roll. The headbox spreader evenly sprays the slurry sent by the flow system to the forming wire, and the slurry speed should match the wire speed. Controlling the pulp speed and wire speed is the main factor in the selection of the headbox type. The fully enclosed hydraulic headbox adjusts the pulp speed by adjusting the feeding pressure of the pulp pump, which is suitable for high-speed paper machines; the air cushion headbox adjusts the speed by adjusting the air cushion pressure, while the open high headbox The speed is adjusted by adjusting the height of the pulp level in the box, which is suitable for medium-speed paper machines; the open compartment headbox is suitable for low-speed paper machines. The forming wire is an endless loop web. Between the breast roll and the flat roll, a horizontal or slightly inclined flat web surface is formed. As the working section of the pulp dewatering, it is customarily called the wire mesh, so it is called the long network. If the endless forming net is placed on a circular net cage, it becomes an arc-shaped dehydration forming working section, which is called a circular net. If a steel mesh drum drilled with holes is used to draw a vacuum from the shaft end to accelerate the dehydration of the pulp on the forming wire surface, it is called a vacuum cylinder or vacuum forming wire. If the pulp is clamped between two Fourdrinier wires and the two wires are simultaneously dehydrated and formed, it is called a sandwich wire former (Figure 2). These formers use different forms of dewatering elements to accelerate the dewatering of the pulp on the web. Components are classified into three categories: stationary, rotating and both. Static components such as dewatering plates, arc vacuum boxes, etc., rotating components such as table rolls, vacuum forming rolls, etc. In addition to using a single-form former to form Fourdrinier paper machine, cylinder paper machine, and interlock paper machine, there is also a forming section that combines multi-fourdrinier, multi-cylinder, multi-cylinder and multi-form fourdrinier hybrid formers. .