Dilution water addition device and method for adjusting cross-direction paper basis weight

Abstract

The invention discloses a dilution water addition device and method for adjusting cross-direction paper basis weight.The device comprises a headbox, a dilution water header pipe, dilution water branch pipes and a concentration adjusting module; pulp distributing branch pipes are arranged in the headbox in a multi-column and side-by-side mode, the concentration adjusting module is arranged above the pulp distributing branch pipes and internally provided with multiple dilution water channels, and each dilution water channel is located above the corresponding column of pulp distributing branch pipes; multiple dilution water branch pipes are distributed on the dilution water header pipe, each dilution water branch pipe is communicated with a pulp distributing header pipe through the corresponding dilution water channel, and the flow direction of dilution water in each dilution water channel is opposite to that of pulp in the corresponding pulp distributing branch pipe.The method comprises the steps that the dilution water provided by the dilution water header pipe is distributed through the dilution water branch pipes and then enters the pulp distributing header pipe through the dilution water channels, and the dilution water is sent out by the pulp distributing branch pipes after being mixed with the pulp which is about to enter the pulp distributing branch pipes.By means of the dilution water addition device and method for adjusting the cross-direction paper basis weight, addition of the dilution water does not affect the outlet flow rates of the pulp distributing branch pipes, and the transverse flow phenomenon is effectively avoided.

Description

technical field [0001] The invention relates to the technical field of pulping and papermaking, in particular to a dilution water adding device and method for adjusting paper banner quantification. Background technique [0002] The invention and application of the method of locally adjusting the pulp concentration to control the full-width quantitative method has greatly improved the paper's quantitative distribution level and the uniformity of fiber orientation. The adjustment method of the dilution water headbox is to add dilution water in the stock distribution tube bundle along the transverse direction of the headbox, and adjust the slurry concentration of each tube in the stock distribution tube bundle by changing the amount of dilution water, so as to achieve the purpose of adjusting the paper banner quantitative. [0003] At present, since the slurry distribution branch pipes are generally multi-row, and the case of one row is rare, and in order to achieve the ideal a...

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Problems solved by technology

[0003] At present, since the slurry distribution branch pipes are generally multi-row, and the case of one row is rare, and in order to achieve the ideal adjustment effect, each slurry distribution branch pipe must be added with dilution water, and must be connected with a dilution water branch pipe. Therefore, the dilution water branch pipe must be installed in the middle of each row of slurry branch pipes, and then separate multiple branch pipes to connect multiple slurry distribution pipes in a row. There are two problems in this way of adding. First, the size of the dilution water branch pipes Restricted by the arrangement position of the slurry distribution pipe, when the distance between columns in the slurry distribution pipe is very small, the size of the dilution water branch pipe must also be made very small; secondly, the slurry distribution pipe consists of multiple rows and columns. Adding dilution water branch pipes between each row of pulp branch pipes is very difficult to manufacture, and the manufacturing cost is greatly increased. Especially in order to avoid pulp hanging, papermaking requires very high processing accuracy in the headbox, which increases the cost of the dilution water release device. Manufacturing difficulty and processing cost

[0004] In addition, adding dilution water to the slurry distribution branch pipe of the headbox will usually affect the flow rate at the outlet of the slurry distribution branch pipe. The more dilution water is added, the greater the flow rate at the outlet of the slurry distribution branch pipe. No cross flow is the basic principle of headbox design. Requirements, in the dilution water headbox, it is very necessary to avoid cross flow, because the cross flow of the slurry after the distribution branch pipe will affect the adjustment effect of the dilution water, and the cross flow will affect the fiber orientation in the spraying of the headbox

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