kaidi KD-DV21 high temperature radar level meter High temperature molten salt radar

Principle

The general principle of high temperature molten salt radar is that the radar emits electromagnetic waves at the top of the tank, and the electromagnetic waves are received by the radar after they encounter the medium reflection. The frequency difference δf between the received signal and the emitted signal is proportional to the distance R to the surface of the medium: R = C (speed) * δf (frequency difference) / 2 / K (FM slope). Because the speed of light C and the FM slope K are known, the frequency difference δf is estimated and the distance R to the material surface at the radar installation position can be obtained, and then the height of the material level is obtained by subtracting the spatial distance from the radar to the material surface (referred to as the empty height) from the known total height of the tank.

Features:

1. millimetre wave radar with a measurement accuracy of up to ±2mm and a minimum blind spot of 0.1m.

2. Smaller antenna size to meet more working conditions measurement.

3. Multiple lens antennas, smaller emission angle, more concentrated energy, stronger echo signal, under the same working conditions, compared to  

The radar has a higher reliability than other radar products.

4. stronger penetration, even in the case of adhesion and condensation. 

5. greater dynamic signal range for more stable measurements in low dielectric constant media. 

6. Multiple measurement modes, with a radar response time of less than 1S in fast measurement mode.

Products

 DV-21Product Introducion

Measuring medium: liquid

Measuring range: 30m

Process connection: Flange ≥ DN80

Process temperature: -40～600℃

Process pressure: -0.1 to 1.0 MPa

 Antenna size: 75mm lens antenna + quartz glass insulation

Accuracy: ±2mm

Protection class: IP67

Centre frequency: 80GHz     

Emission angle: 3°

Power source: 2-wire/DC24V

Four-wire/AC220V

Housing: Aluminium/plastic/stainless steel

Signal output: 2-wire/4.... .20mA/HART protocol

Installation requirements

 Mounting: Flange mounting

 The minimum distance of the instrument from the tank wall should be 200mm when flange mounting is used.   

①  datum ② centre of the vessel or axis of symmetry

 Installation requirements: When installing the instrument avoid installing it above the inlet and try to avoid various objects that affect the  

 signal, e.g. stirring paddles

                                                             Measuring solids                       Measuring liquids

In extremely complex operating conditions, the instrument will function without any obstructions within a 20 cm radius from the radar mounting point.

Diagram of the installation receiver

The maximum mounting stub height H max depends on the mounting stub diameter D and the size of the product launch angle.

Excessively long mounting stubs can affect the radar performance.

l Supply voltage

(4 to 20) mA/HART (2-wire system) The supply power and the output current signal share a common two-wire shielded cable line. See technical data for specific supply voltage range.

(4-20) mA (4-wire) The power supply needs to be supplied separately, and the power supply and current signal use a four-core shielded cable (the current signal can be output simultaneously with the RS485 interface; a six-core shielded cable is required for the simultaneous output).

RS485/Modbus The power supply needs to be powered separately and a four-core shielded cable is used for the power and digital (the current signal can be output at the same time as the RS485 interface, a six-core shielded cable is required for the simultaneous output).

l Connection

The 24V two-wire wiring diagram is as follows：

 Four-wire, two-room wiring diagram as follows：

l Safety guidance

Please observe the requirements of the local electrical installation regulations!

Please observe the requirements of local regulations for the health and safety of personnel. All work on the electrical components of the instrument must be carried out by properly trained professionals.

Check the instrument's nameplate to ensure that the product specifications meet your requirements. Make sure that the supply voltage corresponds to the requirements on the instrument's nameplate.

l Protection class

This instrument fully meets the requirements of protection class IP66/67. Please ensure that the cable sealing head is watertight. Picture below：

How to ensure that the installation meets the requirements of IP67:

Please ensure that the sealing head is not damaged.

Please ensure that the cable is not damaged.

Please ensure that the cable used meets the requirements of the electrical connection specification.

Before entering the electrical connection, bend the cable downwards to ensure that water does not flow into the housing, see ①

Please tighten the cable sealing head, see ②

Structure dimensions

v Case dimensions (Unit mm) 

            Cast aluminium case

            Stainless steel case

v Product dimensions (Unit mm) 

Technical specifications 

Process connection Flange / Material 304 stainless steel, PP 304 stainless steel + PTFE flanged

Antenna type PTFE + quartz glass insulation

Housing Cast aluminium / Stainless steel

Sealing between housing and housing cover Silicone rubber

Housing sight glass Polycarbonate

Grounding terminal Stainless steel

Supply voltage

2-wire system                                      (15-28) V DC                 

 Power consumption max 80mA DC24V/ 2W

                                 Allowable ripple <100Hz Uss < lV

                                 (100 to 100K) Hz Uss < l0mV

Dual chamber housing  

(198-242) V AC   4-wire

110V AC 4-wire

Cable parameters 

Cable entry/plug      1 x M 20xl.5 Cable entry

                                 1 blind plug M20xl.5

                                 Terminal Wire cross section 2.5 mm²

Output parameters 

Output signal (4 to 20) mA / HART protocol

                            Resolution 1 mm

                            Fault signal Current output constant; 20. 5mA; 22mA; 3.9mA

Integration time (0 to 20)s, adjustable

Blind zone 0.1m/0.2m/0.3m

Max. measuring distance 30 m

Measuring interval approx. 1 s (depending on parameter setting)

Adjustment time approx. 1 sec (depending on parameter setting)

Operating storage and transport temperature (-40 to 600) °C  

Relative humidity ˂ 95%

Pressure Max. 1.0 MPa

Vibration resistance Mechanical vibration l0m/s² , (10 to 150)Hz

Instrument linearity

Beam angle

The beam angle is the angle of the beam at which the energy density of a radar wave reaches half of its maximum value (3 dB width). The microwave emits a signal beyond the

outside the beam range and can be reflected by interfering objects.

The larger the antenna size, the smaller the beam angle α and the less interference echoes are generated.

For more accurate measurements, avoid installing any internal devices (e.g. limit switches, temperature sensors, bases, vacuum rings, heating coils, baffles, etc.) within the signal beam range.

Instrument linearity

High temperature molten salt radar selection