SU787516A1 - Method of measuring wood pulp yield - Google Patents

Description

The invention relates to the pulp and paper industry, and in particular to methods for determining the yield of pulp.

A known method for determining the yield of wood pulp by determining the amount of dry matter in the raw wood and the amount of dry fiber in the product of defibrating wood raw material in the presence of recycled water 1.

However, the use of a known method for determining the yield of wood pulp gives an underestimate because the circulating water is not taken into account. In addition, the determination of the amount of dry fiber in a sample of the defibration product is made by scrapping a sample and then 2Q washing it. water, which is a labor-intensive operation and leads to an additional reduction in output.

The purpose of the invention is to increase the accuracy and reliability of the yield of wood 25 mass.

The goal is achieved by the fact that the amount of dry fiber is determined from individual samples of the product of the defibration, additionally measured

the amount of dry matter and the amount of dry fiber in samples of circulating water, and the yield is judged by the formula

HC - WB UE

W, i

. TOO

R

VvT

Sn VB yield of wood pulp,%;

where P is the amount of dry fiber in

Wr product sample defibration, g;

W. the amount of dry fiber in the sample of recycled water, g; amount of dry matter

n in the sample of the product of the defibration, g;

amount of dry matter

SB in the sample of recycled water, g; the amount of water in the sample of the product of the defibration, g; the amount of water in the sample of water from the mouthwater, g. R eme R. The coloration of the dry fiber in the sample of the defibration product is determined.

A mass sample is taken from the bath of the grinder. Three samples of 100 ml are taken from this sample. Samples are filtered on a Buchner column through a paper filter.

weighing to an accuracy of 0.0002 g. The casting, together with the filter, is removed and additionally dewatered to a moisture content of 50-55% by pressing manually or onto a press through several layers of filter paper. The castings are dried at and weighed to the accuracy of 0.0002 g, the filter weight is subtracted and the amount of dry fiber in the sample of the defibration product is determined. In the same way, the amount of dry fiber in a sample of recycled water is determined.

The amount of water and dry matter in the sample of the defibration product is determined. From the mass sample taken from the bath of the grinder, another 3 samples of 100 MP each are taken into porcelain crucibles or cups weighed to a constant weight with an accuracy of 0.0002 g. dried to constant weight at 105 s, subtract the weight of the crucible, and determine the weight of the dry matter in the sample. From the weight of the sample, subtract the weight of dry matter and determine the weight of water in the sample. In this way, the amount of dry matter and the amount of water in the circulating water sample are determined. The yield of pulp after defibration is determined from these values.

The table shows the comparative characteristics of the output; wood pulp 5 according to the proposed and known methods.

From the calculations in the table it can be seen that the proposed method for determining the yield of pulp is more accurate and reliable in comparison with the known method, namely, the accuracy of determination is increased by 5 ra, and the accuracy by 13%.

Claims (2)

The invention The method for determining the yield of wood pulp by determining the quantity. According to the proposed method .X; 4-1459.3 97.3, p 1h where X is the average standard deviation   (Y S Relative standard deviation 5 T- O00846 2. By a known method X SxX .- 1265,, 4 Standard deviation  (T S S Vl7,, 203 Relative standard deviation S, 4,203 VA of dry Bei ecTBa in wood raw materials and amounts of dry fiber in the product of defibrating wood raw material in the presence of recycled water, characterized in that, in order to increase the accuracy and reliability of the yield, the amount of dry matter and the amount of dry fiber are determined measure the amount of dry matter and the amount The first fiber in the samples of circulating airflow is the yield value judged by the form Wn-HC - Wft. U ,, 100 Sn-Vg - SB-Vn wood yield,%; the amount of dry fiber in the sample of the product defibration, g; W., the amount of dry fiber in the sample of circulating water, g; j - | the amount of dry matter in the sample product defibration, g; Sjj - the amount of dry matter in the sample of circulating water, g; Vj, - the amount of water in the sample product defibration, g Vft - the amount of water in the sample of recycled water, Sources of information taken into account in the examination 0 1, Pulp and paper industry. Express information, 17, 1960.