Process Automation Blocked Chute Detectors are used to detect blockages in process chutes. The spillage of hot or corrosive materials can cause blockages that are essential to be detected the potential blockage before it occurs. The material build up on the side of the chutes is detected as an early indication that the safe functioning maximum level has been reached. The functioning of the machine is the ceased to enable excess to be removed and cleaned before it causes blockages to occur.
WADECO
WADECO have produced a range of Microwave level switches (available from Semrad) that detects blockages in containers, tanks, vessels, chutes, silos, bunkers and sumps. They are non-contact (they are flush mounted through the chute wall, this means that nothing overhangs into the chute to block/hinder materials from flowing through the chute) and maintenance free sensors which make them a reliable choice for blockage detection. The sensor consists of a transmitter (which emits a continuous, low power microwave beam and output relay is released when the beam is obstructed) and a receiver which are installed face-to face. The sensor is unaffected by surface contaminants, flames, steam, vapor or airborne particles.
There are two different modes that can be selected on the detector; broken beam or unbroken beam, depending on the type of material that is being detected.
WADECO sensors use the heterodyne detection method. This give produces detection output that is proportional to the received power level. This allows detection with a minimum received power and greatly increases the operating range/penetrability without any increase in the power of the transmitted microwave radiation.
The sensor may also be used as a proximity switch for detection of vehicles e.g. dump trucks, rail cars etc.
The NivoCONT is a contact style level switch which is based on the conductivity principle. The NivoCONT is primarily design for use in liquids for pump control.
How they work:
The NivoCONT contains probes which are immersed into the tank. These probes work as contacts for an electric circuit. A connection is then established between the probes and the conductive liquid. This connection is converted to an output signal. The length of the probe should be proportional to the size of the tank and the level that is being detected. When the probe is no longer submerged it triggers a response to indicate that the tank level is too low. Up to four separate probes can be placed within the tank depending on the model to enable for detection at several different levels.
Advantages:
- Contains no moving parts (i.e. it has a high reliability rating and does not break easily).
- Self cleaning (i.e. low maintenance).
- Contains flexible cable extensions of up to 20 meters (ideal for use in larger tanks).
A range of NivoCONT products can be purchase from Samrad (a switch and levels distributor). For more information click here to see what Samrad have to offer you.
Author: indicatorgauge Categories: Automatic Tank Gauge, Level Gauge, Level Switch, Level Transmitter, Level controllers, level sensors Tags: level control, level controller, Level Gauge, level measurement, level monitoring, level sensor, level sensors, Level Switch, Level Transmitter, liquid level, liquid level switch, sensors
The NivoFloat is a type of level switch made from polypropylene. It is a level switch from drinking water to sewage, however it can also be used from tanks and basins. The NivoFloat operates using the float position which triggers the gravitational force which operates an indicator microswitch.
The NivoFLoat is molded with a double chamber as well as a final remolding finish which ensures that it is completely airtight and water tight. This means that it can be submerged in water without any concern for the device being damaged by water.
The body is made from non-toxic materials and the operation switch is 100% mercury free. This device is therefore safe to be used in drinking water tanks.
The NivoFLoat operates in a medium temperature range of between 0 and 50 degrees. The user has direct pump control (up to 1.1 kW) when using the device. This device is battery operated which means that there is no need for external power supply.
How the NivoFloat works
The NivoFloat device is connected to a cable that suspends it within a tank. It contains a sensor that detects when it is no longer submerged in water (i.e. the tank is empty). It then sends a message to the fill controls to refill the tank. This is an automatic process that removes the need for someone to come around and check to ensure that the tanks have not emptied.
Semrad
Semrad Pty Ltd is a leading Australian distributor of level switches and transmitters, designed specifically for harsh industrial applications, including caustic and chemical solutions. The distribute NivoFloat devices. To find out more about NivoFloat visit Semrad.