Brief description of weightless scale, design plan, measurement and application case of main operating parameters

Loss-in-weightfeeder is a kind of quantitative analysis weighing feeder machinery and equipment. From the main purpose, the loss-in-weightfeeder is used for dynamic and continuous weighing of the whole process, and can carry out the raw materials that must be continuously fed. Weighing and quantitative analysis operation, and there are instant total flow of raw materials and total total flow display information. From the basic principle, it is a static data weighing system. The weighing technology of the static data hopper scale is selected, and the weighing sensor is used to weigh the hopper. However, in the control panel of the weightless scale, the net weight lost per unit time of the hopper scale must be calculated and calculated to obtain the instantaneous total flow of raw materials. Figure 1 is a plan view of the principle of a weightlessness scale. A brief description of the weightless scale, the design plan of the main operating parameters, measurement and application cases Figure 1 The principle plan of the weightless scale Figure 1 The left is a schematic diagram of the structure of a weightless scale, when the weighing hopper must be empty, the discharge can be turned on The valve discharges, when the maximum material level is reached, the discharge valve is closed, and the weighing hopper is supported by a weightless scale. In order to make the weighing accurate, the upper and lower sides of the weighing hopper are all connected according to flexible channels or entrances and exits, so that the net weight of the front, rear, left, and right machinery and raw materials are not used on the weighing hopper. The right side of Figure 1 is a plan view of the whole process of the continuous feeder. The whole process of the continuous feeder has a cycle system (3 cycles system is indicated on the picture). Each cycle system consists of two cycle times: when the weighing hopper is empty, the discharge valve is opened to discharge, and the net weight of the raw material of the weighing hopper continues to increase. When the maximum material level is reached at t1, the discharge valve is closed. The screw conveyor has just started to pour material, and the weightlessness scale starts to work; after a period of time, when the net weight of the raw material of the weighing hopper continues to decrease and reaches the minimum level at time t2, the discharge valve opens again, and the period from t1 to t2 is effective. Cycle time of force feeder; after a period of time, when the net weight of the weighing hopper continues to increase and reaches the maximum level again at t3, the discharge valve is closed, and the period from t2 to t3 is the re-discharging cycle time , And so on. During the cycle time of the force feeder, monitor the speed ratio of the screw conveyor according to the instantaneous flow rate to achieve a stable feeder; during the re-discharging cycle time, the speed ratio of the screw conveyor keeps the speed ratio just before the start of the cycle time. Change to feeder with constant volume flow monitoring method. Because the weightlessness scale integrates dynamic weighing and static data weighing, it will interrupt the feeder and the continuous feeding, and the structure is convenient for sealing. It is suitable for concrete, quicklime powder, pulverized coal, food, medicine and other ultra-fine raw materials. The weight and seasoning control can achieve higher weighing precision and linearity. 2 Necessity of the design plan for the main parameters of the weightless scale operation When designing the weightless scale, the main operating parameters such as the discharge frequency, re-discharging volume, weighing hopper capacity, and re-discharging rate must be considered, otherwise the weightless scale will not be able to do everything. Working normally. Based on the analysis of the characteristics of a customer's purchase of a weightlessness scale from the manufacturer for on-site equipment maintenance, only three 100kg weighing sensors were purchased at the time of purchase. After being put into use, it was found that the zero point was unstable and the total flow sometimes had no display information and other common faults. Only after the manufacturer sent personnel to the site did they find out that the customer's raw material is boric acid, with a relative density of 1510kg/m3, and a larger total flow rate of only 36kg/h. The common total flow rate is 21~24kg/h. The total flow is so small, the hopper uses 3 100kg weighing sensor support points