Switches Indicators & Gauges

Bulksolids Flow Sensor is a microwave based non-contact solids flow sensor. It utilizes the Doppler Effect to detect the movement of solid materials (such as powders and granules) in pneumatic pipelines. These sensors are very low cost and reliable which makes them ideal for monitoring the flow of bulk solids in vacuum pipelines, ducts, air slides, gravity chutes, feeders and at transfer points in vibrating chutes, conveyer belts and bucket elevators.

The sensor has wide variety of applications in a range of industries such as the Cement Making, Iron Making (Blast Furnace), Agriculture and Food processing industries.

Functionality

The sensing head transmits microwaves toward the target material. A section of the microwaves are reflected back to the head which contains a sensor. The sensor analyses whether the microwaves are from a moving or stationary object. The highly-penetrable microwave passes through a buildup on the head and even through pipe made of non-conducting materials such as plastics.

Features

• Minimally affected by dirt and other non-metallic material on the sensing head, steam and airborne particles.
• Can be used in high temperature and high pressure
• Can detect hazardous materials.
• Mounted flush, no intrusion or damage to material flow.
• Built-in amplifier enables easy installation and wiring; lightweight and compact.

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.