Slurry density meter — inline density measurement

Density meter: continuous in-line measurement of slurry density

The density meters use a direct density measurement method based on weighing a constant volume of liquid flowing through a pipe. This method is ideal for measuring the density of complex multiphase liquids with suspended particles that tend to settle.

The key element of the instrument is a density sensor that significantly improves measurement accuracy by compensating for the main errors introduced by changing flow parameters: temperature, pressure and velocity. Taking these factors into account, the sensor accuracy is 0.1% of the measuring range. This makes it possible to handle most production tasks, achieving an overall reduced density measurement error in the process line within 0.5%.

https://youtu.be/45ngLs0DQl8

The density meter is a high-precision instrument designed to measure slurry density in closed and open slurry pipelines. It uses a volumetric-gravimetric measurement method based on sensors specifically designed for continuous liquid density measurement:

• In-plant accuracy of the instrument is 0.5%: an additional flow-velocity compensation channel, fast response and filtering algorithms make the instrument insensitive to velocity fluctuations and vibration on site.

• Fast response to density changes allows the density meter to be used for dynamic measurements: depending on the selected filtering parameters, the time to reach within 0.5% of the actual density value is 1 to 15 seconds for most applications.

• Simple and reliable integration into the process. Connection is made according to tie-in schemes developed by the company for various process areas. The bypass components, some of which are standard devices manufactured by our company, are made of rubber and other wear-resistant materials.

• The average service life of the density meters is 8 years. This is achieved by using stainless steels and abrasion-resistant materials in the design. The density meter components most subject to wear, the inlet and outlet devices, wear by no more than 0.4 mm per year of operation, with a lining thickness of 3–4 mm. These lining elements are removable and easily replaceable parts.

Functional features:
• Continuous density monitoring in the pipeline.
• Direct measurement method and linear scale.
• Protection of the pipe and sensor against abrasive wear, settling and build-up of material on the inner surface of the instrument.
• No moving parts and high overall system reliability.
• Remote display and control unit with on-site calibration function.

Main technical specifications:

Installation and process connection options for the density meter

The MAD-4 is installed in the process line via a bypass. Slurry is fed through a rubber hose with a diameter of 80 mm. The instrument has an internal working diameter of 68 mm and an outlet device with a diameter of 62 mm.
The sketch above shows a direct connection scheme (without a sump), which includes the following basic components:
• A sampler in the form of a rubber tee or a tapered throat.
• A shut-off mechanism in the form of a properly lined ball valve, a pinch device or a gate valve.
• A steel adapter pipe with a flushing fitting, used to attach the rubber hose and allow the system to be flushed with water.
• A feed hose made of standard rubber hose with an outer diameter of 80 mm (inner diameter 75 mm).
• An inlet pipe made of stainless steel with an abrasion-resistant lining.
• An instrument stand made of steel plate
at least 8 mm thick, rigidly fixed at the installation site.
• A drain made of thick-walled pipe with a diameter of 200–300 mm. The measuring point is provided with a water supply for flushing the instrument during calibration. To prevent the flow from swirling around its axis, the slurry feed is arranged so that the hose axis, including at bends, lies in a single plane. The basic components may vary depending on the bypass configuration. The company provides the customer with recommendations on the design of connection points for specific process tie-in tasks.

To simplify the bypass components and improve ease and reliability of operation, it is recommended to include a small-volume sump in the connection scheme. The connection scheme using a sump is shown above and has the following features:
• The sampler is a simple overflow of slurry from the box into the sump.
• The shut-off mechanism is a gate with a rubber washer (the washer is a replaceable part, which increases the reliability and maintainability of the mechanism when working with abrasive media).
• The sump is a small open tank made of sheet steel.
Using a sump makes it possible to:
• Eliminate complex pinch devices, replacing them with a simple and reliable gate.
• Improve access to the bypass components for flushing and inspection.
• Make it convenient to take samples for on-site calibration of the instrument.
The following tie-in options have been successfully tested:
• In slurry distributors on magnetic separators
• In an open launder at the discharge of a primary grinding mill
• In a receiving box at the classifier overflow

To order a density meter, call +380503072727
The managers of Dredgers of Ukraine look forward to your call and will be happy to help you!