A paper humidifying device on a paper machine

Abstract

The invention relates to the field of paper making devices, in particular to a paper humidifying device on a paper making machine. The paper humidifying device comprises an upper humidifying box. The upper humidifying box comprises a box body, a heat exchanger, a separation plate and a steam pipeline. The heat exchanger, the separation plate and the steam pipeline are arranged in the box body. The heat exchanger comprises a steam inlet and a steam outlet. The steam pipeline is communicated with the steam outlet in the heat exchanger, the box body is arranged on paper conveyed by a roll shaft, the separation plate divides the box body into an upper part and a lower part, an installation room is arranged in the upper part, and a humidifying room is arranged between the separation plate and the paper. The heat exchanger and the steam pipeline both are arranged in the installation room, the heat exchanger is connected with the separation plate through heat conduction, a steam valve is arranged on the steam pipeline, and a nozzle on the steam valve is located in the humidifying room. The surface density and the printing effect of paper processed by the paper humidifying device on the paper making machine are greatly improved, and smoothness is achieved, and warping is avoided.

Description

technical field [0001] The invention relates to the field of papermaking equipment, in particular to paper humidifying equipment on a papermaking machine. Background technique [0002] The existing paper machine includes the following structure in sequence: sizing system→headbox→wire part→press part→drying part→calender→winding machine. However, the quality indicators "smoothness", "air permeability" and "tightness" of the paper produced by drying and calendering in the drying section are mutually restricted, and the overall quality of the paper cannot be guaranteed. Therefore, some people imagine calendering by calender before drying, but in practice, it will be found that this kind of semi-wet calendering cannot be realized at all. The reason is that the paper is wet as a whole before drying, including the inside and the surface. With calendering, the paper sticks to the calender rolls without forming. [0003] In addition, Chinese patent 201220737434.6 discloses a humid...

AI Technical Summary

Problems solved by technology

But, the weak point of this patent has two points: 1, the restriction of existing paper machine front process, paper machine mainly concentrates on the front side of paper for the processing of paper, also just means that if add on existing paper machine The humidification box of this patent must turn over the front and back of the paper, such as turning over by turning wheels, which greatly increases the volume of the papermaking equipment

The characteristic of steam is that it floats up irregularly. When the nozzle is under the paper, the gas flow direction of the floating steam is difficult to control, and the steam will slip out from the gaps on both sides of the paper width direction, resulting in uneven humidification and poor humidification effect.

[0004] Based on the above reasons, someone has designed an upper humidifying device with the nozzle above the paper, but in practice, it will be found that the operation of the upper humidifying device faces great technical difficulties, and the most prominent problem is that the steam will Condensation into water droplets, water droplets falling on the paper will damage the paper, the main reason for this problem is that a large amount of steam in the spray chamber floats up and contacts the top plate of the box body, and the temperature of the top plate of the box body is low, and the steam will flow under the top plate Liquefaction at end face

[0005] Therefore, there is an urgent need for a paper humidifying device that overcomes the technical problem that steam condenses into water droplets and falls off onto the paper to damage the quality of the paper.

Images