RU2358215C1 - Thermoelectric suspension device for grain drying temperature measurement - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: invention deals with design of bulk material temperature measurement devices in particular intended for grain drying temperature measurement. The proposed thermoelectric suspension device for grain drying temperature measurement is designed to be composed of an input power supply source, temperature sensors contained in a plastic shell and an electronic device interrogating the above sensors. Between the temperature sensors and the plastic shell they are contained in there is a flexible screen of an electrically conductive material inserted, earthed to the device housing. The temperature sensors are galvanically insulated. Between the galvanically insulated earthing contact of the sensors and/or earthing contact of the input power supply source and the housing there is a protective element mounted represented by a varistor providing for drain of electrostatic charge when exceeding the U value and electric circuit galvanic separation in case the potential value should be less than U where 460≤U≤480V.

EFFECT: prevention of static electricity accumulation of metal structural elements and internal electric circuits which may cause failure of both the electronic temperature sensor contained inside the suspension device and the controller electrically connected to the said sensors.

1 dwg

Description

The invention relates to devices for measuring the temperature of bulk materials, in particular for measuring temperature during drying of grain.

Known thermal suspension for measuring the temperature of bulk material, for example grain, containing an input power source, temperature sensors enclosed in a plastic shell, and an electronic device (controller) interrogating these sensors (patent SU 254159, 07.10.1969).

A disadvantage of the known device is that during operation of the storage of bulk materials on metal structural elements and internal electrical circuits, static electricity accumulates, which destroys both the electronic temperature sensors located inside the thermal suspension and the controller electrically connected to these sensors.

The objective of the invention is to remedy this drawback. The technical result achieved by the implementation of the invention is to increase the stability of operation and the service life of the thermal suspension. The problem is solved, and the technical result is achieved by the fact that in the thermosuspension for measuring the temperature when drying grain containing an input power source, temperature sensors enclosed in a plastic shell, and an electronic device that interrogates these sensors, between the temperature sensors and the plastic shell there is a flexible grounded the shield is made of conductive material on the housing, and the temperature sensors are galvanically isolated, while between the galvanically isolated grounding of the sensors and / or By grounding the input power source and the housing, a protective element is installed - a varistor, which ensures the discharge of electrostatic charge when its potential is greater than U, and galvanic isolation of electric circuits at a potential less than U, where 460≤U≤480 B. The proposed device is devoid of a lack of prototype, since due to the introduction of additional elements into the electrical circuits, static electricity is neutralized, incapacitating the temperature sensors and the controller.

The drawing schematically shows a thermal suspension.

The temperature suspension for measuring temperature during drying of grain contains an input power source (not shown in the drawing), temperature sensors 1 enclosed in a plastic shell 2, and an electronic device (not shown in the drawing) interrogating these sensors. Between the temperature sensors 1 and the plastic shell 2 is placed a flexible screen 3 of conductive material connected to the protective earth terminal of the thermal suspension. The temperature sensors 1 are galvanically isolated from the signals of the serial interface and the input circuits of the power source, while ensuring high noise immunity of the thermal suspension. Between the galvanically isolated grounding of the sensors and / or grounding of the input power source and the housing 4 of the device on which the shell with the sensors is suspended, a protective element is installed - a varistor (not shown in the drawing). When the potential of the electrostatic charge between these elements exceeds the value of U, the varistor ensures the discharge of electrostatic charge. Otherwise, due to the high electrical resistance of the element, galvanic isolation of the internal electrical circuits from the housing is ensured. The value of the potential U should be selected from the interval 460≤U≤480 B.

The thermal suspension is lowered from above into a container 5 for storing bulk materials (for example, in a silo of an elevator). The controller is structurally connected to the thermal suspension, and temperature sensors are connected to the controller using electrical conductors passing inside the thermal suspension. If electronic temperature sensors are used in the thermal suspension, the sensors receive electric power from the controller through the wires passing inside the thermal suspension and transmit digital temperature information to the controller.

Thermal suspension according to the claimed invention has significantly greater stability and duration. Since the grain has strong abrasive properties, it is preferable to use a thermal suspension with a plastic shell, since it has a higher abrasion resistance compared to metal.

Sources of information taken into account:

SU 1536217

1527518

254159 - prototype

263217

1303853

RU 11893

2002108028

2059304

51453

JP 59203932

1284718

GB 1296977

SU 1276889

1204900

Claims (1)

A temperature suspension for measuring temperature during drying of grain, containing an input power source, temperature sensors enclosed in a plastic shell, and an electronic device that interrogates these sensors, characterized in that a flexible screen, which is grounded on the body, is made of conductive material and is located between the temperature sensors and the plastic shell, and temperature sensors are galvanically isolated, while between the galvanically isolated grounding of the sensors and / or grounding of the input power source and the housing detecting security element - varistor providing drainage of electrostatic charge when its potential is greater than the value U, and galvanic isolation of electric circuits at a potential of less than U, where 460≤U≤480 B.