# Measurement of Amount for Steel Abrasive Material Transported by Special Scraper Conveyor
## 5 Conclusions  
This scientific research work presents results concerning the behavior of an innovative collection transport system used for the transport of highly abrasive materials. Due to the high abrasiveness, the construction of the machine is designed so that the active components of the machine wading in the abrasive material are made of materials that are as resistant to the effects of abrasion as possible. The flexible material of the transport rakes has been chosen, which is ideal for an abrasive environment, but this flexibility of the transport component causes uncertainties in the transport system regarding the linearity of the transport function of this system. Although it is possible to eliminate these uncertainties by changing the material of the active components, i.e., by replacing the rubber with a solid material, this solid material does not withstand the abrasive transport process. For this reason, a compromise must be sought with this new transport system. This compromise is to find stable and unstable areas of transport, when the system is still working and when, on the contrary, it is no longer working. Subsequently, the solution is to use only stable areas of the equipment when transporting the abrasive material. For this reason, the system was measured in different filling and speed setting modes. Two grains of a highly abrasive material, STEEL GRIT, were used for this measurement--see Figure 4. With this material, the actual values of transport capacity were measured depending on the speed of movement of wiper membranes and on the conveyor load--see Table 2. Experimentalmeasurements were performed using a special test and measuring equipment that was designed in the Bulk Solids Centre Czech Republic at the Technical University Ostrava. The special test and measuring device consists of a functional segment of a collecting floor conveyor with installed measuring points (Figure 3). This measuring stand has proven to measure the behavior of the transported material along the transport line and has made it possible to measure the following operating characteristics: force required to move the wiper membranes, transport speed of bulk material, speed of wiper membrane movement and conveyor filling. The measurement of forces can be seen in the graph of Figure 6, where it is possible to observe positive forces when moving the rubber rakes of the empty conveyor system forwards and negative forces in the backward direction. The maximum dynamic peaks reach 25 N with this reaction force. If loose material is poured into the system, it resists movement, which can be seen in Figures 7 and 8. In the forward movement, when the abrasive material is pushed in the direction of transport by means of the rake, we can observe an increase in the reaction force to values depending on the filling of the transport system. For a load of 10 kg, these reaction forces are around 100 N and for a load of 45 kg around 370 N. The backward movement also shows an increase in this reaction force, which is caused by the sliding of the bent rubber over the layer of abrasive material, where this layer serves to protect the lower part of the conveyor trough. The reaction forces of the return stroke are in the dynamic peaks at a load of 10 kg around 40 N and at a load of 45 kg around 150 N. It was found that the conveyor system was sufficiently designed, and during the measurements for all filling and speeds, this system was not stopped due to a well-designed drive with a sufficient excess supply of reaction force transmitted to the rakes. Based on other measured data, the areas of stability and instability of traffic were plotted in the graphs--see Figures 10 and 11. From these graphs, we see that if the system is overloaded, the steepness of the transported volume curve decreases sharply. According to the observation of the device, this process is caused by rubber rakes. When moving forward, the rubber rake cannot sink its edge into the material if a state of overfilling occurs.