Description

The DURAG D-UG660-20 is a high-performance, combined ultraviolet and infrared (UV/IR) flame scanner designed for the critical task of monitoring and safeguarding flames in industrial combustion processes. This sophisticated device is engineered to provide unambiguous flame detection in complex multi-burner environments, such as large utility boilers, process heaters, and industrial furnaces. Its core function is to reliably confirm the presence of a pilot or main flame, providing a vital signal to the burner management system (BMS) or safety shutdown system to prevent dangerous fuel accumulation and potential furnace explosions.

As a flagship model in DURAG’s extensive flame monitoring portfolio, the D-UG660-20 represents the pinnacle of optical flame detection technology. It utilizes a dual-spectrum sensing approach, analyzing both UV radiation and specific infrared flicker frequencies, which grants it exceptional immunity to false signals from hot refractory background radiation, other burners, or non-flame radiation sources. The integration of the D-UG660-20 into a combustion control system significantly enhances operational safety, ensures compliance with stringent international safety standards, and supports optimized fuel efficiency by allowing for tighter control of the combustion process. The robust design of the D-UG660-20 ensures dependable performance even in the harsh, high-vibration, and high-temperature environments typical of power generation and heavy industrial applications.

D-UG660-20 DURAG

Technical Specifications

Parameter Name	Parameter Value
Product Model	D-UG660-20
Manufacturer	DURAG GmbH
Product Type	Combined UV/IR Flame Scanner
Detection Principle	Ultraviolet (UV) & Infrared (IR) flicker (2.6 µm)
Viewing Angle	10° (typical)
Detection Range	Up to 3 meters (dependent on flame size and fuel)
Sensitivity	Adjustable via potentiometer or software
Output Signal	Relay (flame ON/OFF), 4-20 mA analog (flame intensity)
Input Power Supply	115/230 V AC, 50/60 Hz or 24 V DC (model dependent)
Operating Temperature	-20°C to +80°C (for electronics); up to +120°C with air purge
Housing Protection Rating	IP66 (dust-tight and protected against powerful water jets)
Electrical Connection	M20 x 1.5 conduit entry
Mounting	1½” NPT thread or flange mounting
Communication	Optional integrated display or configuration interface

Main Features and Advantages

The primary advantage of the DURAG D-UG660-20 is its superior discrimination capability achieved through dual-spectrum analysis. The UV sensor provides a fast and reliable response to the presence of a flame, while the IR flicker sensor analyzes the characteristic modulation frequency of a true hydrocarbon flame. This combination effectively filters out deceptive radiant background signals from hot walls or bricks, a common challenge in single-spectrum scanners. This results in the highest possible safety integrity, drastically reducing the risk of both false positives and false negatives, which are critical for safe burner operation.

The D-UG660-20 is designed for exceptional robustness and ease of integration. Its IP66-rated housing ensures complete protection against dust ingress and water jets, making it suitable for demanding outdoor and industrial installations. The device features flexible output options, including a definitive relay contact for the safety system and a 4-20 mA analog signal proportional to flame intensity, which is invaluable for combustion tuning and diagnostics. Furthermore, the sensitivity can be easily adjusted either locally via a potentiometer or remotely via software in advanced configurations, allowing for precise tuning to specific fuel types and burner characteristics without requiring hardware changes.

Application Field

The DURAG D-UG660-20 is specifically engineered for challenging flame detection applications across a wide spectrum of heavy industries. It is the scanner of choice in power generation, installed on coal-fired, oil-fired, and dual-fuel boilers where its ability to see through the luminous background of adjacent flames and hot refractory is paramount for safe light-off and continuous operation. In the oil and gas sector, the D-UG660-20 is deployed on process heaters, reformers, and furnaces in refineries and petrochemical plants, where its high reliability is essential for protecting multi-million dollar assets and ensuring personnel safety.

Beyond these, its applications extend to large industrial boilers used in pulp and paper mills, metallurgical processing plants, and cement production kilns. The scanner is particularly effective in applications burning difficult fuels like hydrogen-rich refinery gas or biomass, where flame characteristics can be variable and challenging to monitor. The D-UG660-20 is also ideally suited for installations where scanners must be mounted at a significant distance from the flame or have a limited view due to burner geometry, thanks to its adjustable sensitivity and powerful optical system.

Related Products

D-LX 210: A compact and economical IR flame scanner from DURAG, suitable for smaller, less complex single-burner applications.

D-UG 650: A combined UV/IR scanner with a slightly different feature set, often serving as an alternative within the same series.

D-LE 400 Series: A range of self-checking UV flame scanners for gas and oil applications, providing a high-safety solution without the IR channel.

D-RK 130/131: A control amplifier or flame relay unit designed to interface with and process signals from DURAG scanners like the D-UG660-20.

D-FS 100: A sighting telescope used for precise alignment of the D-UG660-20 during installation and maintenance, ensuring optimal viewing of the flame.

D-AC 200: An automatic retraction system, used to remotely withdraw the D-UG660-20 scanner from the furnace for maintenance or inspection without a boiler shutdown.

D-UG660-20 DURAG

Installation and Maintenance

Pre-installation preparation: Prior to installing the D-UG660-20, a thorough review of the burner front design and sighting path is essential. Ensure the chosen mounting location provides a clear, unobstructed view of the pilot and main flame, avoiding areas where quarls or other burners may block the line of sight. Verify that the required utilities, such as the correct power supply and compressed air for the optional air purge cooling system (if used in high-temperature locations), are available at the mounting point. Proper alignment is absolutely critical for the performance of the D-UG660-20.

Maintenance recommendations: Regular maintenance is key to long-term reliability. The viewing window of the D-UG660-20 should be inspected periodically and cleaned to remove any soot, dust, or oil film that could attenuate the optical signal. It is recommended to perform a functional test during scheduled boiler outages to verify the scanner’s response to a live flame and its rejection of background radiation. Check the integrity of the cable connections and the housing seal. Keeping a log of the analog flame signal strength can serve as a valuable diagnostic tool for tracking changes in burner performance over time.