JPH06307763A - Wind velocity measuring apparatus for cereal drying facility - Google Patents

Abstract

PURPOSE:To measure a wind velocity without considerable influence of dust by providing a pressure receiving plate perpendicular to a windward in a duct for forming an air duct, detecting a force to be operated at the plate by pressure detecting means, and calculating the velocity from a detected result. CONSTITUTION:A wind velocity measuring apparatus 20 is provided, in place, in a duct 19 for forming a suction air passage to a blower in a cereal drying facility in a country elevator, etc. The apparatus 20 has a pressure receiving plate 22 opposed perpendicularly toward a windward at a stay 21 installed laterally in the duct 19, and a force to be operated at the plate 22 is detected by a load cell 23. A detection signal of the cell 23 is output as a digital control signal (a) through a load cell controller 24, a converter 25 and an A/D converter 26, and a speed of the blower is controlled by the signal (a) and an output signal of a metering unit provided in a material charging hopper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the speed of dry air in a grain drying facility such as a rice center or a country elevator.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for electrically measuring the wind speed, a hot wire system for detecting the temperature change of a heating wire due to the wind to convert the wind speed, or a propeller rotation speed due to the wind is used as the wind speed. The propeller type to convert is used.

[0003]

The former hot wire type has a drawback that it cannot be detected when dust or foreign matter is attached to or clogged with its sensor part, and the dry air of the grain drying facility described above has dust released from grains. Therefore, when it is used for measuring the wind speed of such dry air, it is necessary to provide a means for preventing dust from adhering to the sensor section, which is expensive. Further, the latter propeller type has a large apparatus and is difficult to be installed in a duct forming an air passage for dry air. The present invention has been made in view of such an actual situation, and is provided with a wind speed measuring device of a grain drying facility which is less affected by dust and which can be installed in a small duct or the like. To aim.

[0004]

In order to achieve the above object, the present invention is characterized in that a pressure receiving plate is arranged in a duct forming an air passage at a right angle toward the windward side, and a force acting on the pressure receiving plate. Is detected by the pressure detecting means, and the wind speed is calculated based on the detection result.

[0005]

In FIG. 2, the dynamic pressure Pd in the duct 19 is: Pd = γv ² / 2g (mmAq) γ: Specific weight of air v: Wind velocity g: Acceleration of gravity, and the wind velocity v is proportional to the dynamic pressure Pd. Have a relationship. here,
The area of the pressure receiving plate 21 arranged at a right angle in the duct is A
(M ² ) and the force received is P (kg), the force received by the pressure receiving plate 21 per unit area, that is, the dynamic pressure Pd is P / A (kg / m
² ) Therefore, from the above equation, the wind speed v is obtained by the following equation. v = (2gP / γA) ^1/2 · c ₁ c ₂ c ₁ : correction coefficient for entrainment on the rear surface of the pressure receiving plate c ₂ : correction coefficient for dust concentration where the force P received by the pressure receiving plate 21 is the load cell, etc. The wind speed v can be calculated from the above equation by detecting with the pressure detecting means.

[0006]

As described above, according to the present invention, since the pressure receiving plate and the pressure detecting means for detecting the force acting on the pressure receiving plate are provided in a compact structure, the pressure receiving plate can be easily installed in the duct. , It became possible to measure the wind speed without being affected by dust, even in the case of dry grain air containing dust.

[0007]

EXAMPLE FIG. 1 shows a schematic structure of a grain drying facility. The grain storage tank 1 of this grain storage / drying facility is formed in a cylindrical shape, and the grain input port 3 equipped with the dispersion device 2 for stretching is provided in the ceiling part of the grain storage tank 1, and the grain input into the raw material input hopper 4 is performed. Is a hoisting device 5 and a lateral feeding conveyor line 6
It is designed to be supplied to the grain input port 3 via.
A floor surface 7 configured as a ventilation surface is provided at a lower portion of the storage tank 1, and an air exhaust chamber 8 is arranged below the ventilation floor surface 7 and an outside air introduction port 9 is provided at an upper portion of the storage tank 1. A temperature control air intake duct 10 is provided. Further, a carry-out auger 11 is installed in the lower portion of the storage tank 1, and a transfer device 12 that carries out the grains taken out from the center of the ventilation floor 7 to the outside of the machine is installed in the air exhaust chamber 8. . A blower 13 is communicatively connected to the air exhaust chamber 8 so that the air introduced from the outside air inlet 9 of the storage tank 1 is sucked and flowed downward to dry the accumulated grains 14 of the storage tank 1. There is. The electric motor 15 with an inverter that drives the blower 13 is configured to be speed-controlled via the control device 16. The control device 16 has a calculation recording device 18 connected to a weighing device 17 provided in the raw material feeding hopper 4, and a wind speed / velocity measurement provided at a proper position in a duct 19 forming an air intake path leading to the blower 13. The device 20 is connected, and the speed of the blower 13 is controlled based on the information from the calculation recording device 18 and the wind speed measuring device 20.

The structure of the wind speed measuring device 20 is shown in FIG. This wind velocity measuring device 20 is a load cell which is an example of a pressure receiving plate 22 facing a wind 21 at a right angle to a stay 21 installed across the duct 19 and a pressure detecting mechanism for detecting a force acting on the pressure receiving plate 22. 23, and sends a detection signal from the load cell 23 to the load cell controller 2
4, it is taken out as a digital control signal a via the converter 25 and the A / D converter 26, or taken out as an analog control signal b from the converter 25. In addition to the pressure detecting means using the load cell 23 as described above, as shown in FIG. 3, the pressure receiving plate 2 is elastically supported by springs 27 so as to be capable of rearward displacement.
The core 28a of the differential transformer 28 may be connected to the pressure transformer 3, and the differential transformer 28 may detect the amount of displacement of the pressure receiving plate 23 which is displaced backward by receiving the wind pressure.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

[Figure 1] Schematic configuration diagram of the grain dry storage facility

FIG. 2 is a block diagram of a wind speed measuring device.

FIG. 3 is a configuration diagram of another embodiment of the pressure detection mechanism.

[Explanation of symbols]

 19 duct 22 pressure plate

Claims (1)

[Claims] 1. A pressure receiving plate (22) is disposed at a right angle to the windward in a duct (19) forming an air passage, and a force acting on this pressure receiving plate (22) is detected by a pressure detecting means, A wind speed measuring device for a grain drying facility configured to calculate a wind speed based on the detection result.