Showing posts with label King-Gage. Show all posts
Showing posts with label King-Gage. Show all posts

Friday, November 30, 2018

LevelWAV Radar Level Transmitter

LevelWAV microwave level transmitterKING-GAGE LevelWAV microwave level transmitter provides continuous measurement of liquids in storage or processing vessels. Measurement is independent of dielectric constant, temperature, pressure and density variations. It is suitable to a broad range of level measurement and control applications including process conditions exhibiting visible vapors, foam, high temperature and/ or pressure. Level measurement is possible for highly corrosive materials (caustics, acids, solvents) and slurries.

For more information, contact Mountain States Engineering and Controls by calling 303-232-4100 or visit their web site at https://mnteng.com.

Download the LevelWAV brochure here.


Friday, November 10, 2017

Hydrostatic Pressure Liquid Level Measurement

differential pressure tank level indicator
Tank mounted differential pressure transmitter
measures hydrostatic pressure to derive liquid level
Image courtesy King-Gage
Liquid level can be inferred by accurately measuring the pressure produced by the height of a fluid column and knowing the density of the liquid measured. The measurement is comparative in nature, referencing some external pressure as a zero point. The zero point can be the surrounding atmospheric pressure, tank pressure, or the pressure exerted by another column of liquid contained elsewhere.

There are uncountable application scenarios, each with its own set of special conditions. Proper instrument selection, installation and calibration are essential to generating reliable and accurate results.

The King-Gage TeleSensor™ liquid level transmitters are specially designed to provide level measurements across a wide range of liquids using a force balance principle in a pneumatic sensor. Sensor output can be either a pneumatic signal or 4-20 mA. The pneumatic force balance arrangement provides immunity to long term drift, hysteresis and temperature changes. A diaphragm isolates the sensor from the process liquid. Mounting is compatible with 2", 3", or 4" class 150 ANSI flanges. Various options for diaphragm and flange materials are available to accommodate a range of process media.

More detail is provided in the document included below, along with application examples. Contact product specialists to share your application challenges and get effective solutions.

Wednesday, October 26, 2016

Continuous Liquid Level Measurement Using Bubbler Method

bubbler or downpipe liquid level measurement schematic
Bubbler or Downpipe Liquid Level Measurement Schematic
Courtesy King-Gage
Measuring liquid level in a tank or vessel can be accomplished in a number of ways, all of which require some arrangement of instrumentation to either infer the liquid level through measurement of a related physical property, or directly deliver the liquid level visually using a scaled gauge arrangement. One indirect method of level measurement, referred to as the bubbler or downpipe method, is so named because it employs a purging gas that continually vents from the bottom of a dip tube extending into a tank of liquid. Through a simple apparatus, the level of a liquid can be inferred by the amount a back pressure exerted upon the gas flowing through the tube.

Probably the greatest advantage of this method of liquid level measurement is that the subject liquid does not contact the sensing instrumentation. The only portion of the apparatus in contact with the liquid is a tube immersed into the tank. Selecting the proper material for the immersed tube is left to the user. An additional feature of this method is the entry of the sensing tube from the top of the tank, eliminating the need for a fitting below the liquid level surface.

Basically, a purge gas flows through the immersion tube and may bubble out the immersed end of the tube, which is open to allow the contained liquid to exert a hydrostatic pressure on the purge gas. The back pressure on the gas that is exerted by the liquid contained within the tank will vary directly with the depth of the liquid. The back pressure can be correlated to a liquid level. Further calculations, which would include the tank shape, dimensions, and the liquid density can provide an indication of the volume and mass of the liquid.

It is possible for a user to assemble the components necessary to put a bubbler level indicator into operation, but King-Gage produces a device which consolidates purge control, pressure measurement, level signal transmitter, and necessary connections into a single compact device. There are versions of this level transmitter for electric and pneumatic output signals. They also include an additional level of protection in the form of an internal diaphragm that further isolates the device from the measured medium.

More details, along with some good illustrations, are provided in the document below. Share your process measurement challenges with application specialists, combining your process expertise with their product application knowledge to develop effective solutions.


Thursday, July 16, 2015

Downpipe Liquid Level Sensor Purge Control

Downpipe bubbler type tank level indicator
Arrangement for bubbler type tank level indicator
with purge control
Courtesy King Gage
Industrial process control often requires the measurement of liquid inventory volume or mass. If the material is contained within a tank of known shape and dimensions, the volume can be determined accurately by measuring the level of the liquid. Various means are used to determine the liquid level. One of the simplest is the downpipe sensor, sometimes referred to as a "bubbler", where liquid level is inferentially derived using differential pressure. The downpipe is a length of pipe that is open at the end extending down into the liquid contained within the tank. The top end is connected to a purging device that provides a controlled flow of pressurized air or gas into the pipe. The pressure maintained within the downpipe will reach an equilibrium with the pressure produced by the hydrostatic force related to liquid level in the tank or vessel. Accurate measurement of this pressure, along with a thorough knowledge of the liquid's properties, can be used to determine the depth of the liquid within the tank and the corresponding volume.

King-Gage manufactures several industrial process level measurement devices incorporating downpipe purge technology and differential pressure measurement. They have applications in inventory monitoring, process control, hazardous and explosion zones, ballast monitoring, and other areas that benefit from their simple operation, low maintenance, and ruggedness. The company, in its own words describes the unit as an...
...extremely rugged unit designed specifically for hazardous areas requiring flameproof or ATEX (Ex d) rating. A proprietary wet check assembly ensures positive seal of fluids to ensure containment integrity. Loop powered transmitter provides 4-20mAdc output while components are isolated from the process media by a continuous air purge. Total consumption rate is less than 0.083 scfm for energy saving operation with external air/gas supply.The only internal element is a simple length of pipe extending into the tank.
Rugged design requires no setup or air flow adjustment due to its differential pressure regulation that avoids dynamic pressure drops common to other bubblers. This ensures highly accurate level measurement and repeatability within ± 0.2% while preventing turbulence or foaming of tank liquid. Applications include water/wastewater, sulfur pits, most free flowing liquids (including slurries) and temperatures in excess of 160 °C (320 °F) as the transmitter is effectively isolated from the process by the air purge.
The slides below illustrate various installation configurations, including one for explosion hazard areas. Contact an application engineer for more detailed information.


Wednesday, December 10, 2014

Improving Maintenance and Reliability of Bubbler Systems


According to Wikipedia "an air bubbler system uses a tube with an opening below the surface of the liquid level. A fixed flow of air is passed through the tube. Pressure in the tube is proportional to the depth (and density) of the liquid over the outlet of the tube."

A common problem with many bubbler systems used in water and wastewater systems is long term accuracy and reliability issues. The need for scheduled maintenance is required because of the possibility of  tampering, failed solenoids, changing air flow rates, or clogged downpipes due to crystal formation - particularly in wastewater applications with high entrapped solids.

A better approach is to use a level transmitter for purge control. This solution offers a highly engineered single component that is easily retrofitted to bubbler installations. These purge transmitters automatically maintain an extremely low flow continuous purge (less than 0.02 scfm) regardless of liquid depth, and minimizing formations of crystals in the downpipe. The lag time during dynamic level changes is also eliminated. Furthermore, bubbler operation is tamperproof because there is no external regulator or needle valve (or rotameter) – internally a fixed differential is maintained over a precision flow orifice.

Transmitter purge (or bubbler) technology works reliably in the presence of vapors, and, unlike ultrasonics, can be used in media temperatures of more than 350°F. Bubblers are normally used in applications where foam, solid debris, sewage sludge, or turbulence make ultrasonic, radar, or float switch devices ineffective. The purge transmitter is relative compact in size and allows for installations in tanks where other systems won’t fit.

The purge control transmitters require a compressed air supply (35-150 psig/2.4-10.3 bar) and provide a two-wire 4-20mA output that can be transmitted over substantial distances. The transmitter can be mounted directly outdoors or within small enclosed spaces at the measuring point or up to a hundred feet away.

More information on the purge transmitter may be download here.

Friday, July 11, 2014

Hydrostatic Tank Level Measurement

pressure transmitter
King-Gage pressure transmitter
One of the most proven and reliable methods of continuous tank level monitoring is remotely monitoring hydrostatic pressure.

Hydrostatic pressure is defined as "The pressure exerted by a fluid at equilibrium at a given point within the fluid, due to the force of gravity. Hydrostatic pressure increases in proportion to depth measured from the surface because of the increasing weight of fluid exerting downward force from above.

Pressure transmitters are a simple and accurate choice for measuring liquid level in storage tanks or processing tanks.

hydrostatic level
Typical hydrostatic level application
The principle behind hydrostatic, pressure-based, liquid level measurement is simple since pressure is proportional to the level of liquid multiplied by the specific gravity. The specific gravity of a liquid is the ratio of its own density to the density of water.

Alternatively, level equals the hydrostatic head pressure value divided by the density of the liquid.