KxS Retractable Refractometer DCM-20 PASVE® System
Purpose-built systems for kraft pulp mill applications
KxS offers three specialized DCM-20 PASVE® system configurations, each engineered to meet the specific demands of applications with the highest level of optical reliability. The DCM-20 PASVE® system for black liquor in evaporators and recovery boilers is our most widely used configuration.
DCM-20 PASVE® system for black liquor consists of:
- Retractable refractometer DCM-20 PASVE® sensor
- PASVE® Isolation valve
- Prism wash system with steam
- Modular connection unit MCU with wash relays
Other system variants are for:
- Green liquor: designed to resist heavy scaling and maintain accurate readings using prism wash with hot condensate water
- Brown stock washing filtrates: optimized for suspensions with abrasive content and minimal wash needs
All pulp mill applications are covered with same interchangeable sensor, reducing complexity in spare unit management.
PASVE® is a registered trademark of SATRON® Instruments Inc.
Patented KxS DCM-20 PASVE® safety design
KxS has designed the DCM-20 PASVE® system with patented safety features (patent FI131493) to protect both your process and your personnel. At the heart of the system is the PASVE® isolation valve, a field-proven solution trusted by the pulp industry with over 75,000 installations worldwide.
Four independent safety layers safeguard operator and prevent unintended sensor removal:
- Sensor safety stopper
- Safety guide
- Safety clamp
- Safety thread
Optimal footprint, easy installation​
The DCM-20 PASVE®, with its compact design, offers exceptional flexibility for choosing installation points in vertical and horizontal pipe lines within the pulp mill. Its small footprint ensures easy integration into various setups, optimizing space and service efficiency.
What makes DCM-20 PASVE® practically maintenance-free?
KxS DCM-20 PASVE® system is designed to operate longer and more reliably—with virtually no need for routine maintenance. This is a result of expertise, smart engineering, and advanced optical performance tailored for the toughest pulp mill conditions.
Key features
- Durable, industry-proven construction withstands high temperatures, scaling, pressure fluctuations, and chemical exposure.
- Most modern CMOS-based optics is accurate, and stable without sensitivity to light scatter.
- Advanced 6th generation image detection identifies only real fouling, triggering wash cycles only when truly needed. This reduces unnecessary washing that can cause prism erosion.
- Nozzle made of SAF2507 super duplex stainless steel for superior wear resistance and fully embedded in the hot process zone, maintaining high temperature and preventing clogging.
KxS Black liquor divert control system BLD for full BLRBAC compliance
KxS Black liquor divert control system BLD is strictly designed according to the BLRBAC Recommendation Chapter 4 Recommended Good Practice: Safe Firing of Black Liquor in Black Liquor Recovery Boilers. It consists of two DCM-20 PASVE® retractable refractometers installed in the firing liquor line, and a dedicated, PLC-based Divert control unit DCU that supervises the operation of each refractometer and applies the relevant divert or alarm actions should a fault or low solids liquor be detected.
In addition, the KxS three-refractometer configuration is aligned with the recommendations of the SNRBC and the FRBC.
Each refractometer is a completely independent measurement system. Each refractometer sends a separate mA output signal, which can be used by a distributed control system.
KxS Black liquor divert control system BLD:
- 2 or 3 Retractable refractometers DCM-20 PASVE® with PASVE® isolation valve
- Prism wash systems with steam
- 2 or 3 Modular connection units MCU with wash relays
- Divert control unit DCU
Reliability. Expertise. Personal service.
At KxS, we know that reliable process measurement goes beyond the refractometer itself. It requires a combination of expert guidance, precise installation, and tailored support to meet the unique challenges of each application.
Whether you are working with black liquor, green liquor, or brown stock washing filtrates, choosing the right components and installing them correctly is essential. That is why we offer dedicated expertise throughout the entire lifecycle of your DCM-20 PASVE® system—from configuration and installation to optimization and long-term support.
Instructional YouTube videos:
How to operate DCM-20 PASVE
Step-by-step guidance for inserting and removing refractometer and wash nozzle
Removing and inserting refractometer:
Inserting refractometer:
Removing refractometer: