A range of vortex flowmeters for non-corrosive fluids are available from Randburg-based flow specialists C&F Technologies. The Coolpoint range consists of an in-line flowmeter that uses the vortex shedding principle to measure the flow of non-corrosive liquids.
In a vortex flowmeter, the fluid flows around a bluff body, generating vortices (eddies) that move downstream. The vortices form alternately, from one side to the other and are sensed by a piezoelectric sensor housed in a sensor tube mounted directly downstream of the bluff body and which picks up the pressure zones created by the vortices. The piezo-electric sensor generates a frequency that is directly proportional to the vortices created by the fluid flowing past the bluff body and which are themselves proportional to flow. The sensor output is then amplified by the electronics to give an indication of flow rate as well as a 4 to 20 mA output for remote monitoring and control purposes. Flow units are selectable in either GPM or LPM units on an LED display and solid-state relays are included should an alarm or pulse output (for totalising) be required. The solid-state relays can be set over the range from 15% to 90% of full-scale flow and can easily be configured as NC (normally-closed) or NO (normally open), or as a pulse output for remote totalising.
Coolpoint flowmeters can be used on low viscosity, clean or dirty water - like liquids that are compatible with brass, SS, PVDF, Viton and Kalrez. Metered fluids should not include long fibres or a significant level of abrasive solids. However, should abrasive wear of the bluff body take place over time, the bluff body, as well as the sensor, is replaceable.
Typical applications include cooling applications using water, 50% solutions of glycol, and water-soluble machine coolant (up to 10%). These applications are found in most process industries, such as rubber, steel, fabrication, manufacturing, refining, paper, chemical, food, petrochemical, mining and power. The Coolpoint is not suitable for gases or air, or for use with flammable liquids.
For best results, the Coolpoint vortex flowmeter may be installed in any position as long as proper piping installation requirements are observed. This includes sufficient support of adjacent piping to minimise any process vibration that would otherwise incur errors. It is also recommended that unions of the same pipe size, together with full-port isolation ball valves be installed for ease of removal and servicing of the flowmeter if necessary. In order to achieve the stated accuracy (2,0% for 1/4" to 1/2" sizes and 1,0% for 3/4"-4" sizes) the Coolpoint should be installed in a straight pipe-run of at least 10 pipe-diameters upstream of the meter and with at least five pipe-diameters of straight pipe downstream. Throttle valves, if they are used, should always be installed downstream of the flowmeter and in order to ensure the proper development of vortices the process system should impart a minimum back-pressure on the flowmeter of at least 70 kPa.
Manufactured by Universal Flow Monitors of the USA, the Coolpoint range of vortex flowmeters was originally designed for HVAC cooling circuit applications but has since found ready use in a great many industrial applications where low-cost flow measurement is also required. Soon to be available in SS, the current offering is a brass body version with PVDF sensor and Viton or Kalrez seals, the Coolpoint units are offered in sizes from 1/4" to 2" meter size with NPT or BSP connection threads, and with Ansi 150# flanged units in 3" and 4" sizes. Being manufactured in sizes down to 1/4" makes the Coolpoint rather unique in that most manufacturers do not generally offer a vortex flowmeter in sizes any smaller than a 1" meter size. This makes the Coolpoint particularly attractive for those applications where a low cost flow transmitter is an essential requirement.
An enhancement of the Coolpoint is the Calpoint, a vortex flowmeter that incorporates a temperature sensor with transmitter, as well as the flow transmitter in the one flow device, making it very useful and well priced for those applications where both flow and temperature need to be monitored. Analog outputs are 4 to 20 mA and alarm/pulse outputs are solid-state relay. The flow units require a separate 24 V d.c. power supply, with the Coolpoint being a 5-wire device and the Calpoint being an 8-wire device if all functions are utilised in each model.
For more information contact John Gill, C & F Technologies, 011 792 4588, [email protected], www.cftechflowmeters.co.za
| Tel: | +27 11 792 4588 |
| Email: | [email protected] |
| www: | www.flowmeters.co.za |
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