JPS6015445B2 - How to feed mixed materials into a twin-screw concrete mixer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for introducing kneaded materials into a Nito type concrete mixer used as a kneading device in a batcher plant for producing ready-mixed concrete.

A two-shaft concrete mixer has two mixing shafts with spirally supported mixing blades arranged in parallel between opposing side walls of a mixing tank, and mixes concrete by rotating the mixing shafts in opposite directions. However, the materials to be mixed into this mixer are fed with gravel, sand, cement, water, etc., which are pre-measured in the measuring tank located above.
Although the admixture is continuously added at regular intervals, the kneading load on the mixer is greatest when gravel is added.

In view of the above points, the present inventor proposed that when introducing gravel into the mixer, by jogging the gravel input gate to intermittently introduce gravel, the mixing load will be reduced, and the mixing condition of the concrete will be lower than that of the conventional one. The present invention is proposed with the aim of reducing power consumption and reducing wear and tear on various parts of the mixer by reducing the kneading load. That is, the present invention is a two-shaft concrete mixer in which two kneading shafts arranged in parallel in a kneading tank are rotated in opposite directions to mix the kneaded materials, and the kneaded materials are immersed in the moat mixing tank. At this time, the gravel input gate is jogged to intermittently input gravel. Hereinafter, the present invention will be explained based on the accompanying drawings. Figure 1 shows a mixing performance test in which mixed materials such as gravel, sand, cement, and water were charged into a twin-shaft concrete mixer with a mixing capacity of 2.0 mm and a power of 6 trays W under varying feeding conditions. The load power value during kneading was measured. Figure 2 is a diagram showing the order and method of adding the kneaded materials in the kneading performance test.
The maximum size of coarse aggregate is 2 broadsides, 18 slumps, 1125 k9 gravel, 930 k9 sand.
Cement: 305k9/m, water: 188k9/m, admixture: 34k9/m. Feeding condition A in Figure 2 is a conventional method in which water and sand are first fed into the mixer at the same time.
After 3 seconds, gravel was continuously introduced, and after 8 seconds, cement was introduced. In condition B, the order of introducing the kneaded materials was the same as in condition A, and only the gravel input gate was operated by jogging. Gravel is intermittently immersed into the mixer by repeatedly closing the gravel input gate for 2 seconds and closing it for 1 second.For input condition C, the interval between jogging operations of the gravel input gate is larger than for input condition B. gravel input gate 2
Gravel is put into the mixer by repeating the second stop and two second close. Graphs A, B, and C in FIG. 1 show the measured crosstalk load power values of the mixer when the kneaded materials were charged into the mixer under the above-mentioned charging conditions A, B, and C. As is clear from FIG. 1, when the kneaded materials are put into the mixer, the kneading load becomes large and the kneading load power value becomes high, but if the kneading is carried out sufficiently, the crosstalk load power value becomes small. If the gravel input gate is jogged to intermittently introduce gravel, the kneading load power value can be reduced, and if the interval between jogging operations of the gravel input gate is increased, the kneading load power value can be further reduced. This can be seen from the graph. Moreover, the kneading condition was almost the same after 42 sands had passed since the start of adding the mixed wire material, and there was no problem in kneading and mixing. It is thought that the larger the interval between jogging operations of the gravel input gate, the smaller the mixed tread load power value will be, but this needs to be taken into consideration as appropriate in consideration of the kneading time. As described above, the present invention reduces the crosstalk load power value of the mixer by jogging the gravel input gate and intermittently inputting gravel when charging the mixed bran material into the two-pole type concrete mixer. It is possible to save energy by making the mixer smaller, and it is also possible to reduce the power required for the mixer.

Furthermore, by reducing the mixer kneading load, the frictional resistance between the mixed bran material and the various parts of the mixer is reduced, which has the secondary effect of reducing the wear of the various parts of the mixer, such as the kneading blades.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the mixing load power value of the mixer when changing the charging conditions of hawking materials in a Nimari type concrete mixer, and Figure 2 shows the order and method of charging the mixing materials. It is a diagram. Figure 1 Figure 2

Claims (1)

[Claims] 1. In a two-screw concrete mixer that rotates two kneading shafts arranged in parallel in a mixing tank in opposite directions to mix the material, the gravel input gate is closed when the material is put into the mixing tank. A method for introducing mixed materials into a twin-shaft concrete mixer, characterized in that gravel is intermittently introduced through a jogging operation.