Papermaking sludge single screw extrusion machine shaft causes and solutions

Papermaking sludge special single screw extruder and the causes and solutions of 2020 - holding shaft 07 - 19 Liu Binbin zhao couni connect universe ( Henan parkway environmental protection technology co. , LTD. , henan xinxiang 453002). According to the characteristics of papermaking sludge is rich in fibre and the latest requirements of environmental protection, the development of targeted papermaking sludge single screw extrusion machine, used for papermaking sludge squeeze dewatering depth. Due to the required discharge dry degree is high, so in the design of the spiral shaft when selecting larger compression ratio ( 我= 3 ~ 5) And the discharge end extrusion pressure is very big. In use process, often appear on the discharge end 'holding shaft' phenomenon, namely material embrace together with screw axis rotation, not, advance with the rotation of the screw axis and neither feeding or discharging the phenomenon. Usually need to open the drum filter for clean up, spend a lot of manpower and material resources, the device can't work continuously. Aimed at this situation, we decided to analyze the equipment, the improvement, in order to eliminate the defects in this kind of work conditions. 1 analysis of the reasons for 'holding shaft and the train of thought to solve the problem through the analysis found that the reasons for' holding shaft, because the material and the screw axis is greater than the friction material and friction caused by the filter drum sieve. To solve the problem of 'holding shaft, must make the drum sieve filter with the material of the friction is greater than the material of screw shaft friction. Through the analysis of equipment structure, the cause of 'holding shaft basically has the following several aspects: (1) squeezing pressure, when the sludge discharging end from the screw axis under strong extrusion, the sludge density increase greatly, sludge and spiral shaft friction also increase, because other rich in tiny fiber in papermaking sludge, after the sludge by extrusion, the fines will increase on the surface of the friction with the screw axis. Screw axis body and surface roughness of spiral vane, because screw axis of body surface using hot pressing of stainless steel plate, packages with hot pressing stainless steel plate and screw shaft spiral blade body welding, caused the entire screw axis surface is rough. (3) screen hole shape, when open the screen into uniform round hole, the friction of the material and sieve is small, when drum filter with the screen into the length of the long hole in the same direction, the friction of the material and sieve is bigger. Now to analyze these problems one by one: the first, squeezing pressure, due to the need to gain political degrees of sludge, must rely on a strong extrusion ability to squeeze the moisture in sludge, therefore this article cannot be changed. Second, screw axis body and surface roughness of spiral vane, because the screw shaft are all made of stainless steel materials, and 1 m in diameter, 9 m in length, polishing processing, difficulty is too great, even complete polishing process, also can't ensure that can solve the problem of 'holding shaft. Third, although screen open hole growth helps the increase of the friction material and sieve, but under the condition of invariable mesh thickness, strength is reduced, and the frictional force increases is limited, can not fundamentally solve the problem of 'holding shaft, but will also increase the attrition rate of the material. Through the above analysis, we believe that only by the original equipment parts for perfect, cannot achieve the purpose of holding 'holding shaft, in view of this, we decided to change train of thought, can see on the structure of the filter drum find the breakthrough point, on the filter drum artificially set a anti-skid device, to achieve the purpose of prevent materials' holding shaft. 2 filter drum structure improvement first we analyze the original drawings of the filter drum, the original filter drum inner hole for a diameter & phi; 1000 mm round, consistent with helical cylindrical shaft size. Considering the existing processing conditions, we will design filter inside the drum circle into approximate elliptic, size 1075 mm long axis, short axis size 1000 mm, and between the two filter drum, namely the long axis increase 16 mm thick checkered plate, makes the checkered plate are separated by size and cylindrical spiral shaft is consistent, which is 1000 mm, and the elliptic cylindrical screw axis and short axis sizes consistent ( See figure 1) 。 Figure 1 filter drum structure is improved, checkered plate protruding into the filter drum hole about 37 mm. At work, can use non-slip surface material direction of rotation resistance to overcome the defects of less friction material and sieve material along with the rotation of the screw axis force, so as to solve the problem of 'holding shaft ( See figure 2) 。 Figure 2 as' holding shaft only appear in the discharge end of the extrusion pressure is very big, the last two filter drum, therefore, we will only last two filter with improved elliptic filter drum drum, and then increase the transition section between two kinds of filter drum, realize the two kinds of filter drum coupling, equipment structure as a whole. （ See figure 3) 。 Figure 33 conclusion based on the filter drum structure improvements, and run continuously for 72 h at the customer site inspection, did not appear 'holding shaft phenomenon, prove that the method is completely solve the' holding shaft 'problems in the operation of the equipment. Source: 'Chinese paper' 10th, 2017