The Bauer screening machine and the Somerville flat plate screening machine are two key fiber screening equipment in pulp and paper laboratories, but their design intentions, working principles, and application scenarios are fundamentally different.

1 Different core objectives and functional positioning

1、This is the most fundamental difference between the two. The core function of the Bauer screening instrument isFiber length grading. It is an analytical instrument designed to systematically and continuously separate a representative slurry sample into multiple fractions (such as long fibers, medium fibers, short fibers, and fine fibers) based on fiber length, in order to obtain a complete fiber length distribution map. The purpose is to conduct in-depth research on the morphological characteristics of the slurry.

2、The core function of the Somerville flat screen slurry machine isDetermination of crude slag content. It is a quality control equipment designed to quickly, accurately, and standardly screen out coarse fiber bundles, undissolved fractions, impurities, and other defects (collectively referred to as "coarse slag") contained in the slurry, and calculate their percentage in the total amount. The purpose is not to analyze fiber distribution, but to evaluate the cleanliness of the pulp and the efficiency of the cooking, screening and washing sections.

II The working principle and operating process are different

1、The Bauer screening instrument is based on the principle of combining gravity settling with multi-stage screening for phase separation. It consists of a series of top to bottom, gradually decreasing sieve aperture (such as30The eyes50The eyes100The eyes200The sealed screen chamber of the mesh is connected in series. The slurry suspension naturally settles by gravity in a static water column, and fibers of different lengths and settling velocities are gradually intercepted by corresponding aperture sieves. The entire process takes a long time (about20-30Each fraction needs to be collected, dried, and weighed in minutes, and the process is quite complex.

2、The Samerville flat plate screening machine is based on the principle of single-stage flat plate screening and mechanical flushing. It consists of a device with a specific aperture (usually0.25mmor0.15mm）The sealed chamber consists of a flat sieve plate and a rotating wiper plate. During operation, the scraper generates a uniform water flow, forcing fine fibers to be washed away through the sieve plate while retaining coarse slag on the sieve plate. The operation process is simple and fast (approximately)5-10Finally, only collect, dry, and weigh the residue on the sieve.

III The output result is different from the application scenario

1、The output result of the Bauer sieve analyzer is a set of data, which is the mass percentage of the retained material in each sieve and the sample in the bottom collector. These data can be used to draw fiber distribution curves and calculate parameters such as average length. It is mainly used in scientific research, process optimization, and new product development, such as precise evaluation of pulping/Grinding effect, prediction of paper physical strength, analysis of different pulp ratios, etc.

2、The output result of the Somerville flat screen slurry machine is a single indicator, namely the coarse slag rate（%）. This value is directly used to determine whether the slurry grade is qualified. It is mainly used for daily quality control in the production process, and is a standardized routine testing method for rapid detection of steam decomposition degree and evaluation of screening and purification efficiency on chemical pulp and semi chemical pulp production lines. It follows theISO 1762Waiting for international standards.

In summary, the Bauer screening device is like aResearcher, conducting detailed dissection and analysis of fiber populations; The Samoville flat screen slurry machine is like a "quality inspector", focusing on quickly picking out the "unqualified products". Both play their respective roles in the laboratory, complementing each other and jointly ensuring the quality system from slurry research and development to production.