经过实践和分析,我们认为自动上料搅拌车粘罐原因可以分为两大类:即设计不合理和使用不当,主要有以下几种形式:
After practice and analysis, we believe that the causes of tank sticking can be divided into two categories: unreasonable design and improper use
(1)卸料残余率和叶片设计的不合理。从搅拌筒的内部结构看,自动上料搅拌车的拌筒是依靠回转的筒体带动其中的两条螺旋叶片所产生的螺旋运动,使混凝土获得既有“切向”又有“轴向”的复合运动,从而使搅拌筒具有搅拌和卸料的功能,因此形成这一螺旋运动的有关因素,诸如螺旋叶片的曲线参数,搅拌筒的几何形状和尺寸等对搅拌车的卸料残余率都有重要影响。而过大的卸料残余率意味着搅拌车在卸料结束后在自动上料搅拌车里会有更多的余料,因而更有可能因日积月累在搅拌罐中粘料。目前大多数厂家采用的是等角对数螺旋线叶片,在卸料残余率上还有很大的改进空间。
(1) The discharge residual rate and blade design are unreasonable. From the internal structure of the mixing drum, the mixing drum of the automatic feeding mixing truck relies on the spiral movement of the two spiral blades driven by the rotating drum, which makes the concrete obtain the compound movement of both "tangential" and "axial", so that the mixing drum has the function of mixing and discharging, Such as the curve parameters of the spiral blade, the geometry and size of the mixing drum have an important influence on the discharge residual rate of the mixer. The excessive discharge residual rate means that there will be more surplus materials in the automatic feeding mixer after the discharge, so it is more likely to stick in the mixing tank due to accumulation over time. At present, most manufacturers use equiangular logarithmic spiral blade, and there is still a lot of room for improvement in discharge residual rate.
(2)自动上料搅拌车工作环境温度过高。夏季在南方地区白天中午前后,环境温度经常超过30℃,在这种情况下运输混凝土,将会由于混凝土坍落度损失快以及罐体周围温度相对中心更高,因而混凝土更容易粘罐。
(2) The working environment temperature of automatic feeding mixer is too high. In summer, around noon in the daytime in southern China, the ambient temperature often exceeds 30 ℃. In this case, due to the rapid slump loss of concrete and the higher temperature around the tank, the concrete is easier to stick to the tank.
(3)运输距离过长。随着城市化的进程及城市规划的要求,越来越多的搅拌站被要求迁到郊区和郊县,与市区的距离越来越远,而由于混凝土这一产品的特殊性,任何预拌混凝土在未添加缓凝剂的情况下,都在1h左右进入初凝状态,如果这时才进行混凝土浇注施工,不但影响混凝土的工程质量,而且因混凝土失去流动性,易在搅拌筒及叶片上凝结,导致粘罐,严重时甚整车混凝土粘在罐内及造成液压设备的损坏,所以自动上料搅拌车运送预拌混凝土有其时间控制的输送半径,一般应控制在1h以内。
(3) The transportation distance is too long. With the process of urbanization and the requirements of urban planning, more and more mixing plants are required to move to the suburbs and counties, and the distance from the urban area is getting farther and farther. Due to the particularity of concrete, any premixed concrete without adding retarder will enter the initial setting state in one hour, It not only affects the engineering quality of concrete, but also because of the loss of fluidity of concrete, it is easy to coagulate on the mixing drum and blades, resulting in sticking to the tank. In serious cases, even the whole vehicle of concrete sticks to the tank and causes damage to the hydraulic equipment. Therefore, the automatic feeding mixer truck has its time controlled conveying radius for transporting premixed concrete, which should be generally controlled within 1h.
(4)使用维护不当。自动上料搅拌车驾驶员在搅拌车卸料完毕后未及时清理清洗搅拌罐内及叶片上残留的混凝土,在搅拌车回站过程中不转动搅拌罐,残留的混凝土干燥后凝固在拌筒及叶片上,以后就会越聚越多,形成粘罐现象。
(4) Improper use and maintenance. The driver of the automatic feeding mixer fails to clean the residual concrete in the mixing tank and on the blades after the unloading of the mixer, and does not rotate the mixing tank when the mixer returns to the station. The residual concrete solidifies on the mixing drum and blades after drying, and then it will gather more and more, forming the phenomenon of sticking to the tank.