Measuring instrument for porosity of granular mixtures in granary

Abstract

The invention provides a measuring instrument for the porosity of granular mixtures in a granary, belonging to a porosity measuring device. The measuring instrument is composed of a gas source, a pipeline, solenoid valves, pressure sensors, a signal line, a gas storage bottle, the granary, a hagioscope, a sleeve, an end cover, a region to be measured and a measuring instrument circuit device. The measuring instrument circuit device is composed of a single chip microcomputer, a pressure detection circuit, a driver, a display screen, a keyboard and a buzzer. The gas source is connected with the pipeline; the solenoid valves are arranged on the pipeline; the closed region to be measured is formed by the sleeve and the end cover; the region to be measured and the gas storage bottle are connected with the pipeline by branch pipes; the pressure sensors are arranged on the gas storage bottle and the end cover and are connected with the measuring instrument circuit device by the signal line. The device provided by the invention can be used for measuring in the granary, and thus a measured result is closer to the actual value; the porosity is solved in an air inflation manner and the properties and structures of the granular mixtures are not damaged; the measuring instrument has a high automation degree, has the advantages of rapid and accurate measurement, convenience for operation and simple structure, and overcomes the disadvantages of an existing device that the measured result does not accord with an actual storage condition, that the structure is complicated and that the cost is high.

Description

technical field [0001] An on-site measuring instrument for the porosity of granular bodies, which belongs to the porosity measuring device Background technique [0002] Under storage conditions, the porosity of granular bodies in different locations is not equal. Due to the extrusion of the upper granular body, the contact between the lower particles is closer and the porosity becomes smaller. In addition, vibration can also play a compaction role and reduce porosity. Existing porosity measurement devices only measure a small amount of samples, ignoring the influence of the self-weight and vibration of a large number of granular bodies, and cannot truly reflect the porosity of granular bodies under storage conditions. [0003] Common porosity measurement methods include liquid immersion method, three-dimensional imaging method, and gas equation of state method. Since the liquid immersion method will change the nature and structure of the water-absorbing test object, it ca...

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Problems solved by technology

Since the liquid immersion method will change the properties and structure of the water-absorbing test object, it cannot achieve the purpose of non-destructive testing, so it is not suitable for measuring the porosity of granular bodies (such as grain, flour), and is often used to measure poorly water-absorbing materials (such as rocks). ) porosity

In addition, the liquid has surface tension, and sometimes it is difficult to enter small holes or gaps, which increases the measurement error

The three-dimensional imaging method has the advantages of high precision and does not change the nature and structure of the object to be measured, but its equipment price is high, and the operation and maintenance conditions are high, so it is rarely used in actual measurement

The gas equation of state method is to artificially inject gas into the object to be tested, and obtain the porosity indirectly according to the pressure change. This method can be used for granular bodies, but the current equipment is not automatic enough and takes a long time

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