Cape-11P Guard RF Admittance Level Switch
The robust design is unaffected by buildup of dust, coal ash and other powdery ashes in dust collectors and ash bunkers at power plants.
Cape-11P Guard RF Admittance Level Switch is assembled with a stainless-steel protective sleeve on the basis of standard model of Cape-11A to withstand strong impaction. The robust design is unaffected by buildup of dust, coal ash and other powdery ashes in dust collectors and ash bunkers at power plants. The buildup immunity design of electronic circuits can effectively eliminate measurement errors on the probe and the vessel wall with great reliability and accuracy.
In Cape-11 RF series, a probe is designed to detect the change of capacitance and impedance between probe and vessel wall to realize level measurement and control. In its electronic unit, reactance between the measurement electrode and the wall of an empty vessel constitutes a balanced bridge circuit which outputs a stable oscillation signal. As the level rises, the measurement electrode is covered by the medium, and reactance between the electrode and the wall of the vessel changes. It causes an imbalance of the bridge circuit and stops the oscillation as a result. A post-circuit is designed to detect the change of output signal from the bridge circuit and generate an alarm signal. In addition, oscillation signal at radio frequency is not only applied to the measurement electrode but also applied to a shield pole through a 1: 1 voltage-follower, so measurement electrode and shield pole have the same electric potential, phase, and frequency, but these two electrodes are insulated from each other. Even if there is medium buildup on the probe, because there is no electric potential difference between measurement electrode and shield pole, the reactance change on shield pole has no effect on the detection of post-circuit. Therefore, only reactance change on the measurement electrode induced by the filled medium between the measurement electrode and the wall of the vessel will be detected by post-circuit. It eliminates the effect of medium buildup on level measurement.
● Assembled with a stainless-steel protective sleeve for strong impact resistance.
● Widely used in level measurement for coal ash, fly ash and dust in dust collectors and ash bunkers at power plants.
● With an external dual color LED indicator. Housing with electronic can be rotated to make the orientation of LED indicator convenient for long distance observation.
● Modular design for high reliability, easy installation and maintenance.
● Passed third party reliability tests and received certifications from the third party, guaranteed extremely high reliability.
| Applicable medium | Types of the medium | Coal ash, fly ash, dust |
| Dielectric constant | ≥1.6 | |
| Probe data | Probe length | 750～2000mm |
| Shield length | 90mm/240mm/300mm/590mm or customized | |
| Protective sleeve length | Probe length750～1200mm：210mm/370mm Probe length＞1200mm: customize | |
| Probe diameter | φ10mm | |
| Materials | Housing | Aluminum alloy |
| Inner housing | Plastic | |
| Probe metallic parts | 304 | |
| Probe insulation parts | PTFE | |
| Protective sleeve | 304 | |
| Power Supply | AC | 85～264V AC |
| DC | 18～30V DC | |
| Power consumption | ≤3W | |
| Switching Delay | When immersed | 1s |
| When laid bare | 1s | |
| Output | Relay | DPDT，8A/250V AC/30V DC |
| Relay delay | 0～30s Continuous adjustable | |
| Installation conditions | Process temperature | -40～250℃ |
| Ambient temperature | -40～70℃ | |
| Storage and transport temperature | -40～80℃ | |
| Certificates and approvals | Ingress Protection | IP66 |
● Ash hopper in ash conveying system at coal-fired power plant.
Cape-11P is assembled with a stainless-steel protective sleeve, can effectively protect the probe from impact damage.
● Alumina powder silo at smelting plant and pre-chamber in CDQ (Coke Dry Quenching) unit at steel plant.
● Raw meal silo and cement silo at cement plant.
