Application of ELL Non-contact Level Transmitter in the Field of Warehousing and Logistics

ELL Sonar Non-contact Level Transmitter Application

The traffic of ports has been increasing year by year, and the transportation capacity of liquid chemicals has been improved over the past years, which has promoted the development of wharf tank storage and warehousing business. Some storage wharfs are facing a series of safety and environmental issues due to their long-term engagement in the handling and packaging of liquid chemicals. With the continuous promotion of the national safety production special rectification activities, the regulatory authorities are gradually strengthening their efforts in safety supervision. They are constantly increasing the requirements for enterprise service intelligence, management intelligence, and production intelligence. It is urgent to do a good job in enterprise automation management, strengthen the construction of SIS system, and use intelligent means to monitor major hazards.

This case came from a chemical wharf in Jiangsu Province, China. As the transformation time of this enterprise was limited, it was necessary to stop production for cleaning tanks, drilling and welding flange if the enterprise chose to install contact level measurement meters or radar level gauges, of which the quantity and construction cost were huge. It may also cause great production losses.

ELL Non-contact level transmitter is the first to attain SIL3 (Safety Integrity Level 3) certification in the field of non-contact level measurement. It is safe, highly accurate, and easy to install and debug, and there is no need to operate with flame and stop production when being installed. Our products help the enterprise complete the SIS system transformation and construction safely and efficiently within the specified time!

Measurement Difficulties and Solutions

22 DHE ELL-FI non-contact level transmitters were used in the storage tank farm of this wharf. All vessels to be measured were vertical tanks. They were installed with radar and connected to the DCS system. So the tank farm needed a set of meters with different measurement principle to connect to the SIS system for monitoring at the same time.

Problem 01: The media in tanks are complex and changeable

Due to the huge traffic of the port terminal and the media stored and serviced by the chemical wharf are various, the media in each tank could be changeable. This requires the non-contact level transmitter to respond timely and conduct accurate tracking measurement after different media being stored in tanks.

The non-contact level measurement technology is based on the principle of sonar echo ranging. When the measuring medium changes, the propagation speed of sonar in the medium will also change. If the transmitter uses the propagation speed of the original medium for processing and accounting, the measured data will have a deviation. How to make the meter not be affected by the media change and accomplish the accurate measurement has become a big problem.

Solution

Invented by DHE, the “automatic calibration technology” could intelligently and automatically find (generate) the accurate propagation speed of ultrasound in each medium, and track and calculate the liquid level based on it, without manual adjustment by staff. The patented "automatic frequency conversion technology" can automatically change the transmission frequency of the sensor according to the different acoustic impedance of the medium, ensure the quality of the echo signal, and meet the requirements of stable tracking of the liquid level.

Problem 02: Tank bottom deposit caused by side outlet pipe

Most of the vertical tanks are allocated with the side outlet pipe which may lead to the bottom deposit in tanks. The measurement probe of the non-contact level transmitter should be installed at the tank bottom. The thickness of the sediment at the bottom of the tank directly affects the stability of the liquid level measurement, or even fail the measurement.

Solution

The anti-deposition liquid level measurement probe of DHE, together with the unique signal analysis and tracking method, enables the level transmitter to be stably applied to most of the tanks with serious deposition.

Problem 03: Frequency liquid inlet and outlet make stable tracking difficult

The nature of the storage industry determines that the liquid in and out of the storage tank is relatively frequent, and the sonar echo signal propagates in the liquid with constantly changing level, which may cause the liquid level measured to jump.

Solution

The patented "micro vibration analysis" of DHE, an advanced ultrasonic echo signal processing technology, can analyze the echo signal characteristics of hundreds of liquid media. It can also intelligently and automatically optimize, track, calculate the liquid level and eliminate the impact of liquid inlet and outlet impact on the liquid level measurement, which makes non-contact level transmitter always track level stably, and ensures the continuous and accurate output measurement data.

Parameters of ELL-FI Non-contact Level Transmitter:

Output signal: two-wire system/four-wire system 4~20ma/HART/Modbus total load on-site/TCP industrial etherne

Measurement accuracy: ± 1mm

Explosion-proof, anti-corrosion and protection grade: Ex d IIC T6 Gb, Ex ia IIB T6 Ga, WF1, WF2, IP67

Meter housing: double-chamber housing, die-cast aluminum alloy/stainless steel 316L

Allowable temperature of measuring probe: (- 60~+220) ° C, customizable

Relative humidity: 0~95%