JPS6360305A - Kneading method of mixer in asphalt plant - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a kneading method using a mixer in an asphalt plant for manufacturing asphalt mixture, which is a road paving material.

Conventional mixers for asphalt plants are designed with the mixer's kneading capacity, the rotational speed of the kneading blades, etc. depending on the desired mixing capacity, and therefore, the conventional kneading blades always rotate at a constant rotational speed.

Problems to be Solved by the Invention What is desired in this type of mixer is to knead more uniformly in a shorter time, but as long as the kneading blades are rotated at a constant rotation speed as in the past, the kneading efficiency can be improved. cannot be expected.

Means for Solving the Problems The present invention was developed in view of the above-mentioned points. Aggregates and stone powder of various particle sizes are put into a mixer, and dry mixing is performed by high-speed rotation of kneading blades. To provide a kneading method for a mixer in an asphalt plant, which can produce high-quality asphalt mixture by kneading materials uniformly and efficiently in a short time by performing kneading by rotating blades at low speed. .

Example First, to explain the general structure of the main body of an asphalt plant, l is an aggregate storage tank with a vibrating sieve, in which aggregate heated by a dryer (not shown), which is a heating device, is vertically conveyed. It is supplied through a packet elevator 2, which is a device, and stored according to particle size. and,
Based on the formulation of the asphalt mixture to be manufactured, a predetermined amount of aggregate of various particle sizes is weighed in an aggregate measuring tank 3 and fed into a mixer 4, and stone powder stored in a stone powder storage tank 5 is weighed in a stone powder measuring tank 6. A predetermined amount of asphalt is sprayed in the asphalt measuring tank 7, and the drive motor 8
The kneading blades 9 are rotated to perform kneading.

In the present invention, the drive motor 8 employs a two-stage variable speed motor or a continuously variable speed motor so that the rotational speed of the kneading blades 9 can be changed.

Therefore, the kneading method of the present invention efficiently kneads the materials in the mixer 4 by switching the rotational speed of the kneading blades 9 into two stages of high-speed kneading and low-speed kneading.

(a) High-speed mixing process First, a predetermined amount of aggregate and stone powder are put into the mixer 4, and the mixing blades 9 rotate at the rotation speed of the mixing blades 9 to mix only the solids and powder (dry mixing) in the absence of asphalt. Since this dry mixing, which is performed by increasing the rotation speed, is a mixture of solids and granules, increasing the rotational speed of the kneading blades 9 increases the effect of uniformly dispersing the materials, and allows uniform mixing in a short time.

(b) Low-speed kneading process After completion of the above-mentioned dry mixing, asphalt is started to be sprayed into the mixer 4 and kneaded by lowering the rotational speed of the kneading blades 9. When asphalt is sprayed into the mixer 4 and the rotational speed of the kneading blades 9 is high, aggregates, stone powder, and fine particles of asphalt are constantly stirred without settling, causing a phenomenon in which the mixed material floats. The manufactured asphalt mixture also becomes sticky, and the fine particles stick together, resulting in defective asphalt coating and making it impossible to manufacture high-quality asphalt mixture.For this reason, after asphalt spraying, the mixing blade 9 By kneading at a lower rotation speed and eliminating the floating phenomenon of the mixture, high-quality asphalt mixture is manufactured.

The specific rotational speed for high-speed kneading and low-speed kneading varies depending on the capacity of the mixer, the type of asphalt mixture to be manufactured, etc., but the rotational speed is determined as appropriate by visually observing the movement of the mixed material during actual operational tests. .

Effects of the Invention As described above, in the present invention, aggregate and stone powder, which are relatively easy to mix, are first dry-mixed for a short period of time by the relatively fast rotation of the kneading blades 9 to uniformly disperse the materials. Asphalt is sprayed and the rotational speed of the kneading blades 9 is lowered to eliminate floating of fine particles of asphalt mixture, thereby efficiently producing high quality asphalt mixture.

[Brief explanation of the drawing]

Claims (1)

[Claims] A method for mixing with a mixer in an asphalt plant, characterized in that aggregates and stone powder of various particle sizes are put into a mixer, and dry mixing is performed by high-speed rotation of mixing blades, and after asphalt is added, kneading is performed by low-speed rotation of mixing blades. .