Research On The Key Technology Of Dust Reduction In Shotcreting Machine

The shotcrete operation on the anchor and shotcrete working face is one of the main dust sources of underground dust.During the shotcrete operation,a large amount of cement dust will be generated.The dust mainly comes from the two points of the shotcrete machine and the injection.The thesis adopts the research method of combining laboratory experiment and field application to study the key technology of dust control for feeding,blanking,and mixing of the shotcrete machine,and the results obtained are as follows:(1)The law of dust generation from the feed opening of the shotcrete machine was researched,and the main influencing factors of the dust generation from the feed opening of the shotcrete machine were found to be the height of the feed opening and the moisture-cement ratio of the tidal material,and the following experimental studies were carried out: When the blanking height is(0.3?0.5)m and the moisture-cement ratio is 0.2%?0.4%,the dust output of the spraying machine is the lowest.(2)A technical solution for spraying machine control dust removal is proposed:1)The height of the spraying machine is reduced to(0.3?0.5)m by controlling the moisture-to-cement ratio of 0.2% to 0.4% and adopting a scraper conveyor to feed the material.Reduce the amount of dust produced during the feeding opening of the shotcrete machine;2)According to the characteristics of the dust source dispersion such as the feeding opening of the scraper machine,the remaining air outlet of the shotcrete machine,the gap between the rotor and the sealing plate,the development of a reasonable dust control cover will be used to disperse the dust.The dust source points are controlled centrally,and then the dust generated at these points is pumped into the dust collector for purification treatment by means of negative pressure dust extraction;3)A reasonable dust control hood structure and dust control process parameters are researched,and the dust control of the whole machine is obtained.Process parameters.(3)The main factors that affect the dust removal effect of the wet dust collector(filter aperture,filter wind speed and air-water ratio)were tested and studied,and the best parameters were obtained.At the same time,the classification dust removal efficiency of the wet dust collector was studied,and the classification dust removal efficiency of the wet dust collector was obtained.(4)The anti-sticking and dewatering technology of the wet dust removal of the shotcrete machine was tested and researched,and the best technical parameters were obtained,which effectively reduced the cement dust binding amount and significantly improved the dewatering efficiency.The spraying machine dust suppression system conducted field experiments on the bolting and spraying working face of Xinqiao Coal Mine showed that the dust reduction efficiency of the spraying machine and the 5m position on the downwind side of the feed inlet reached more than 99%,and the dust reduction at the feed inlet The efficiency has reached more than 96%,and the dust reduction effect is remarkable.