Microwave barrier level sensors SIUR-03V

Microwave barrier level sensors SIUR‑03V are designed for point‑level control of bulk material filling in bunkers. The sensors are also used as microwave blockage detectors in transfer chutes and other pipelines intended for conveying bulk materials.

• SIUR‑03V microwave sensors are characterized by high reliability; they have no components subject to wear that would limit their service life. The SIUR‑03V microwave barrier level sensors are installed in such a way that no elements of the microwave sensor enter the tank (reservoir), which allows them to be used with coarse materials (ore, crushed stone, etc.).

• In comparison with commonly used rotary and vibration sensors, microwave barrier level sensors are insensitive to material build‑up, are not subject to abrasive wear, and require absolutely no maintenance. The microwave signal freely penetrates the falling stream of material, which enables SIUR‑03V microwave sensors to be used in any dusty environment, including during loading of bulk material.
• Another advantage of SIUR‑03V microwave sensors is their operability in extreme operating conditions. The propagation of the microwave probing signal is unaffected by either the ambient temperature or the presence of dust in the air (even at high dust concentrations). For the wavelength range used in the SIUR‑03V sensor (3 cm), even rain does not significantly affect the propagation of the probing signal. The sensors have found wide application in boiler houses using wood waste for control and automatic regulation of the level of burning fuel, and in dry coke quenching plants.

SIUR‑03V sensors are reliable, immune to radio interference and mains noise, are maintenance‑free, and, compared to radioisotope sensors, are completely safe for personnel.

For probing through thick concrete and brick walls of high‑temperature furnaces and boilers, production of microwave sensors SIUR‑03V2.5M with extremely high sensitivity of 90 dB has been launched (with such sensitivity, the signal from the transmitter unit is reliably received by the receiver unit at distances up to 800 m). The list and prices of manufactured microwave sensors are given in the catalogue.

For using SIUR‑03V microwave barrier level sensors as blockage detectors, a version of the sensor with a built‑in receiver of the reflected microwave signal (based on the Doppler effect) is employed. Based on this signal, the SIUR‑03V microwave sensors monitor material movement in the pipeline, which makes it possible to detect, at an early stage, the moment when the bulk material forms a plug that prevents further material conveying.

The maximum allowable overpressure for SIUR‑03V sensors is 10 bar.

The warranty period for all SIUR‑03V2 sensors is 24 months.

SIUR‑03V microwave barrier level sensors are used at numerous industrial facilities in Russia and in many countries worldwide.

In particular, they are regularly purchased by coke‑chemical enterprises in China (see here: https://fizepr.ru/news/siur-03v25m-na-vystavke-v-kitae).

The photograph shows a batch of SIUR‑03V2.4 microwave barrier level sensors prepared for shipment to a customer.

OPERATING PRINCIPLE

The microwave barrier level sensor consists of a receiving unit and a transmitting unit, which are installed on opposite walls of the tank at the monitored level. Radiation and reception of radio waves by the antennas are performed through openings in the tank walls. The transmitter emits radio waves into the tank via the antenna connected to it; these waves pass through the second antenna to the receiver, where they are converted into an output signal.

It should be noted here that for operation of microwave sensors of the SIUR‑03V2.5M series with extremely high sensitivity, no holes need to be made in concrete or brick walls.

The criterion for the presence or absence of bulk material at the monitored level in the tank is the degree of absorption of the emitted radio signal along the path from the transmitting antenna to the receiving antenna. In this case, it is understood that when passing through bulk material, the power of the radio signal is attenuated by at least a factor of 3 to 5 compared to propagation in free space. It has been established experimentally that the radio signal, when passing through a layer of cement, ore, crushed stone, sand, or coal with a thickness of 30‑50 cm or more, is attenuated by at least a factor of 10. A detailed description of the operating principle of the sensor is given in patent RU2631519.

VERSIONS OF MICROWAVE LEVEL SENSOR

INSTALLATION OPTIONS

Depending on the installation site and the specific technological features of the production process, there are several options for mounting microwave level sensors. The microwave sensor can be installed either on the side walls of the bunker or on its top wall. In the latter case, steel pipes with an internal diameter of at least 26 mm should be used to transmit the probing signal to the monitored level. It should be noted that the length of the pipes and the quality of their surface finish are not critical.