SU1381393A1 - Method of determining dust content of aggregates - Google Patents

Abstract

The invention relates to a measurement technique, in particular, to a method for determining the content of a vile dust-like fraction in free-flowing media, in particular in aggregates of concrete, and is intended for use in the construction industry, and can also be used in other sectors of the national economy where it is necessary to control the content of dust and other light fine particles in the raw materials, for example, in agriculture, chemical industry; 1 and foundry (molding sands). In order to increase the accuracy of the determination, the contact pressure of the layer of material on the bottom of the vibrororgan is determined during the process of the material vibrating by the vibroorgan before and after removing the fines. Dust calculated by the formula. Removal of dust particles is carried out at a sweep rate of 0.5-1 m / s, a height of the layer of material no more than 150-200 mm and 1 or more accelerations of vibroorgan vibrations in the range of 10-40 m / m. 1 hp f-ly, 1 ill. (L with

Description

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The invention relates to a measurement technique, in particular, to a method for determining the content of a fine dust-like fraction in granular media, in particular in aggregates of concrete, and is intended for use in the construction industry, and can also be used in folk farms where it is necessary to control the content pulverized and other light fine particles in raw materials, for example, in agriculture, chemical products, casting, foundry (molding sands), etc.

The purpose of the invention is to increase the accuracy of determination.

The drawing shows a diagram of the device for carrying out the proposed method.

The device contains a vibroorgan 1, with a porous bottom 2, a force-measuring device 3, a cyclone 4, a fan 5, an electric motor 6, a recording device 7. Position 3 shows a sample of the test material.

The method is carried out as follows;

: Vibroorgan 1 is loaded with sample 8 of the test material and vibrational vibrations are reported, the mode of which should be stationary and ensure single-period movement of the sample of material with continuous separation of the layer from the bottom of the vibroorgan 1. The thickness of the sample layer of the test material should not heat 150-200 mm the load carrying body must be at least 10 m / s.

: The upper limit of the acceleration of the vibration b is limited by the value of 40 m / s, since, as more acceleration occurs, not a single-diode movement of the layer of the vibrating plate of the material being moved. This leads to the fact that there is a non-stationary vibration-mixing layer of material: which makes it difficult to carry out the necessary measurements and reduces their accuracy. Using a force measuring device 3, the contact pressure of a sample of the test dust material P on the bottom of the vibroorgan 1 is determined and fixed with the aid of a registering device 7. The fan is turned on and the test

tuemy material. The purge rate is limited to 0.5-1 m / s, since at a higher speed an intensive removal of the useful fraction with a particle size of more than 0.14 mm begins, and at a lower speed, the efficiency of the dedusting process decreases sharply.

After punching at the same vibration parameters, the contact pressure P of the dust-free material is determined. The dust content of the material is determined by the formula

P

P - P

.100%,

where P - dustiness of the material,%;

P, is the contact pressure of the layer of material on the bottom of the vibroorgan,

P - contact pressure

of the material on the bottom of the vibroorgan, kg / m.

Claims (2)

1. A method for determining the dust content of concrete aggregates, including testing samples of dusty and dust-free material, characterized in that, in order to increase the accuracy of determination, the dusty material vibrates, the contact pressure of the layer of dusty material at the bottom of the vibro body is removed from the dusty material Pshvidnye particles by blowing air flow, determine the magnitude of the contact pressure of the layer of dust-free material on the bottom of the vibroorgan, and the dust content of the P material is determined by the formula. P P, - Pr 100%, where P is the contact pressure of the layer the material on the bottom of the vibroorgan, P - the contact pressure of the layer dust-free material on vibroorgan, kg / m; 2. The method according to Claim 1, characterized in that dust particles less than 0.14 mm in size are removed from the layer with a height of 150-200 mm at a speed of 0.5-1 m / s with accelerations of vibroorganic vibrations of 10-40 m / s .