活塞式混凝土湿喷机喷射脉动产生原因与消除方法探讨  

Discussion on Causes of Injecting Pulsation in Piston Type Wet Concrete Injector and Its Troubleshooting

作　　者：冯开林[1] 张志兵[1] 高波[1] 苏学成[1] 

机构地区：[1]山东科技大学机器人研究中心

出　　处：《工程机械》2007年第9期22-25,共4页Construction Machinery and Equipment

摘　　要：国内开发的活塞式湿喷机虽然在结构上与国外产品并无多大不同,但却没有掌握泵送喷射过程消除"脉动"的方法。分析活塞式混凝土湿喷机喷射过程产生"脉动"现象的两个主要原因分别为:(1)由于活塞式湿喷机在进行活塞切换时的切换时间造成了混凝土喷射过程的"脉动";(2)活塞式湿喷机在吸料过程混凝土缸吸料不足,使混凝土不能完全填充混凝土缸,从而造成喷射时的"脉动"产生。针对这两个主要原因提出两种对应解决方案"筑峰填谷"法和"充浆单元"法。"筑峰填谷法"核心思想就是让双活塞在交替往复推送混凝土时的速度可调,即在双柱塞刚刚完成切换时让活塞以较快的速度向前推送一小段行程,然后再以正常的速度向前推进。这样就在正常的输送中形成了混凝土的一个"堆积",这个"堆积"(比喻成波峰)在较长输送管路内被削弱正好可以填补刚刚由于双活塞切换而成的混凝土"断续"(比喻成波谷)使不连续现象得以改善。"充浆单元"法就是强制填充两主混凝土缸以保证其100%填充,使输送管路的空气段(或称该气体间隔)最小,即输送泵缸的填充是靠外界高压来帮助完成的,而不是靠大气压。由于这种方式加快了填充速度,切换过程的有效时间重叠被充分利用从而保证了双缸在切换时间内都向输送管路推送混凝土。这种积极因素避免了混凝土柱状体变成静止,也就避免了输送管路中混凝土圆柱再重新加速以及输送高压使混凝土柱状体再次发生磨损和断裂,客观上降低了能耗。更重要的是由于活塞每次推送混凝土都被完全充满,因此提高了混凝土输出量,保证了一个比较均匀的输送流量速度,消除了"脉动"现象,也能使喷浆尾部的软管不再摆动。在研制成的"煤矿井下的湿喷作业系统"中应用了"筑峰填谷"法,并进行了试验验证。Domestically developed piston type wet concrete injector presents little difference in structures compared with foreign products, but method to eliminate pulsation in pumping and injecting processes has not been mastered. Two main causes resulting in pulsation are: 1. shifting time when a wet injector shifts pistons causes the pulse; 2. the concrete cylinder of a piston type wet injector sucks materials inadequately in material suction process so that concrete can't fully fill the concrete cylinder, which also causes pulse. Aiming at the two causes, two countermeasures, Peak-building plus Valley-filling (shortened as PV) and Pressurized Material Filling (shortened as PF), are suggested. The kernel concept in PV is to make the speeds adjustable when two pistons alternately and reciprocatedly thrust concrete, that is, the two pistons are a bit accelerated in a short distance when they just finish shifting and then thrust in normal speed. In this way, a concrete pile is formed in normal concrete delivering. The pile (described as a peak) is sucked in the long delivering pipe, which just fill up the concrete break (described as valley) due to piston shifting and the uncontinuity is improved. PF method is to force the filling of the two concrete cylinders and ensure them 100% filled, which minimizes the air segment in the pipe (or be called as air interval), which means the filling of delivering cylinders is fulfilled with outside pressure in stead of atmospheric pressure. In the latter mode, overlapped piston shifting time is fully utilized because material filling speed is increased so that both cylinders are thrusting concrete to the delivering pipe during the shifting period. This positive factor prevents concrete column from being stationary so a reaccelerating on concrete column in delivering pipe is avoided and wear and fracture of the column under high delivering pressure are also prevented, which reduces energy consumption. More important, concrete output is increased because the cylinders are fully filled wh

关 键 词：活塞式混凝土湿喷机 脉动性喷射 原因 消除 方法 

分 类 号：TB533.1[理学—物理] TU643[理学—声学]