## 2 Model and Experimental Research
### Dust Settler Segment Experimental Tests of Air Filter Multicyclone
#### 2.5.3 Reasearch Results Analysis  
The test results of the separation efficiency values for single cyclones from the left (L) column in the \(S_{MT}\) segment of the MT multi-cyclone are shown in Figure 21.  
As the cyclone's position moves away from the suction nozzle, the cyclone separation efficiency values of the segment, whose settling chamber is a common part for all cyclones, are decreasing. For the first (I) cyclone, a separation efficiency of 98.2% was recorded in the column, and for the last (VII), a separation efficiency of 93.7%. There was a 5% difference in cyclone separation efficiency, which results is mainly caused by the decreasing values of the suction streams (suction rates) from these cyclones--as demonstrated by the flow tests of the multi-cyclone and its dust settling device. A decrease in the cyclone separation efficiency may also be caused by the interaction of the swirled streams flowing out of the cyclones and flowing into the common chamber of the dust settling chamber, and can even lead to the possibility of reverse flows in the cyclones located on the periphery of the multi-cyclone.  
The separation efficiency values for the same cyclones in the segment in which the dust settling chamber structure was changed (the chamber was divided into suction channels) show much smaller differences, although a slight decrease in the cyclone efficiency is noticeable with their location being further from the suction connector--depicted in Figure 21. The efficiency separation values from cyclone No. I, from which dust is sectioned through channel No. 1, is clearly higher than the efficiency of the other cyclones in the column and has a value of 96.8%. The cyclone separation efficiency, from which suction takes place through the separate channels 2, 3 and 4, is slightly lower and ranges from 96.1-96.4%. After changing the structure of the dust settling chamber, the separation efficiency of the first two cyclones (I and II) decreased, while the remaining cyclones achieved higher efficiency values, with the highest increase (about 3%) recorded for the last (VII) cyclone in the column.  
A slight decrease in the cyclone separation efficiency of the tested dust settling column with a chamber structure that guarantees even suction may be caused by the impact of the main (purified air) \(Q_{G}\) streams flowing from the cyclones in the chamber area, where the measuring filter insert is located. The different distances of the cyclone outlet pipes from the segment of the main stream outlet can cause different pressure drops for these streams (the further the cyclone is located, the greater the pressure drop) in the cyclone in the outlet stub pipe section, and for the individual cyclones. The air stream exiting the cyclone furthest from the main stream outlet port may be less than the value of the air stream exiting the cyclone directly at the outlet port. The lower value of the air stream means a lower speed and, at the same time, a lower inertial force, and thus the cyclone obtains efficient dust removal at a lower level.  
Figure 21: Separation efficiency values for single cyclones of left column (L) in MT multi-cyclone segment for the original version of the settle and after division into suction channels–variant D of settling tank.