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这种投砂器的结构如图1所示。它主要由钢砂筒和挡砂孔眼接手等组成。钢砂筒是用与反循环钻具同径的岩心管制成,上部车有连接89毫米连接管的内丝扣,内丝扣下端钻有装砂用的孔眼(孔眼直径20毫米)。钢砂筒的下部车
The structure of this sand thrower is shown in Figure 1. It is mainly composed of steel tube and sand hole to take over and other components. The steel drum is made of a core pipe of the same diameter as the reverse circulation drill. The upper car has an inner threaded hook for connecting the 89 mm connecting pipe. The lower end of the threaded hook has a hole for installing sand (hole diameter: 20 mm). The lower part of the steel drum