Conductivity Measurement in the Kraft Process
Accurately measure conductivity within the pulp & paper industry
Proven Reliability with Low Maintenance
Alkali concentration is a key process parameter that must be monitored at multiple locations within the kraft process including alkali concentration in the digester, residual black liquor in pulp wash stages, alkali concentration in causticizer tanks and green liquor alkali concentration. Alkali concentration is monitored using conductivity sensors instead of pH sensors due to the high process temperatures and thick pulp. Rosemount™ toroidal conductivity sensors are recommended for all applications within the kraft process due to their proven reliability with minimum maintenance. Toroidal sensors offer greater resistance to the effects of coating and corrosion than contacting conductivity sensors which is important due to the pulp and lime solids present in the process as well as the corrosive nature of the liquor used to delignify the wood.
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Product Solutions
The Rosemount 228 Toroidal Conductivity Sensor reliably measures conductivity in highly conductive electrolyte solutions up to 2 S/cm (2,000,000 µS/cm). These conductivity sensors work in dirty and corrosive applications where metal electrode sensors would otherwise fail. A robust sensor design makes the Rosemount 228 conductivity sensor ideal for measuring concentrations of acid, base and salt solutions.
- Meet challenging application requirements with a selection of chemical resistant body options including PEEK and Tefzel
- High vibration tolerance with reinforced internal metal frame design
- High temperature option for process temperatures up to 200 °C (392 °F) and suitable for use under high pressure up to 295 psig (2135 kPa [abs])
Process Connection
-20: 5/8 in. -11 UNC, -21: 3/4 in. MNPT
Valve Type
Recommended Valve: 1-1/2 in. full port ball valve
Materials of Construction
Wetted Materials:
Body Materials either glass-filled PEEK, glass-filled Tefzel™ or unfilled Tefzel; Option -20: EPDM gasket
Body Materials either glass-filled PEEK, glass-filled Tefzel™ or unfilled Tefzel; Option -20: EPDM gasket
The Rosemount 226 Toroidal Conductivity Sensor measures conductivity in highly conductive liquids up to 2 S/cm (2,000,000 μS/cm). This toroidal/inductive sensor has a robust fouling-resistant design which makes it ideal for measuring conductivity in harsh, corrosive and fibrous liquid applications.
- Toroidal sensor is resistant to plugging and suitable for liquids containing high levels of suspended solids due to large bore design
- Plugging resistant and suitable for liquids containing high levels of suspended solids due to large bore design
- High vibration tolerance with reinforced internal metal frame design
Temperature Range
32°F - 248°F (0°C - 120°C)
Maximum Pressure
295 psig (2135 kPa [abs])
Materials of Construction
Wetted Materials: Glass-filled PEEK, EPDM Gasket
The Rosemount 242 Flow Through Toroidal Conductivity Sensor features a noninvasive flow through design allowing for in-line installations without any obstruction to sample flow. This conductivity sensor is ideal for measuring conductivity in highly conductive liquids up to 2 S/cm (2,000,000 μS/cm) and for use in viscous, abrasive or fibrous liquids.
- Robust measurements - insensitive to process flow rate and direction
- Plugging resistant and suitable for liquids containing high levels of suspended solids
- Avoid accumulation of solids with no part of the conductivity sensor protruding into the sample flow
Measurement Range
Conductivity Range: 100 µS/cm to 2 S/cm
Weight
1" to 2": 22 lbs. (10kg)
3" to 4": 86 lbs. (39 kg)
3" to 4": 86 lbs. (39 kg)
Maximum Temperature
See Product Data Sheets for details.
The Rosemount 56 Dual Channel Transmitter is a line powered device that can accept inputs from pH/ORP sensors, ion selective electrode (ISE) sensors, flow, current, conductivity (contacting and toroidal) sensors, turbidity sensors, dissolved oxygen sensors, chlorine sensors and ozone sensors.
- Retrieve calibration and measurement information by accessing the data logger via USB
- Design efficient processes by utilizing the built-in PID controller
- At a glance view of pertinent information provided by the large customizable display
Certifications/Approvals
FM: Class I, Division 2, Groups A, B, C, & D • Class Il & lll, Division 2, Groups E, F,&G • T4
Weight
Rounded up to nearest lb or nearest 0.5 kg: 3 lbs/4 lbs (1.5 kg/2.0 kg)
Measurement Range
pH sensor: 0 to 14 pH
ORP Sensor: -1500 to +1500 mV
ORP Sensor: -1500 to +1500 mV
