PFISTER DRW: Easy maintenance fuel dosing for optimal burning

Accurate fuel dosing can be the difference between your process burning too fast and just right. Between fuel economy and high fuel costs. Between optimum production levels and failing to meet your targets. The PFISTER DRW rotor weighfeeder is designed for the utmost accuracy.

Equipped with ProsCon® advanced weighing technology, the rotor weighfeeder is able to automatically adapt the rotor speed based on automatic information about the rotor loading and material density. The more material, the slower it moves, ensuring the feed rate is always consistent.

The complete PFISTER® DRW system comprises extraction of the material from the storage silo/hopper, weighing, dosing and material transfer into the pneumatic conveying line that feeds the burner. You can’t afford downtime in a system like this, so we’ve created a simple design that ensures minimal moving parts and high availability. All measuring parts and drives are accessible from the outside so maintenance is easy and safe. Feed rates of up to 50 tonnes per hour are possible.

Your pyroprocess is a delicate system requiring precise fuel input for optimum combustion.
Too much, too little, too fast, too slow – all these factors can have an input on the process and on the final product quality. But most fuel is not uniform. Coal dust, lignite, petcoke – the mass, shape and density can vary from one supplier to the next and even within shipments. 
So how do you deal with that?

The PFISTER® DRW’s ProsCon® advanced weighing electronics ensure that whatever goes into the rotor weighfeeder is weighed and measured, so that the feed through to the burner is highly consistent. Consistent fuel dosing equals consistent combustion, and that can only be a good thing for your business.

Whereas many rotor weighfeeders react to changing fuel composition after the fact, the PFISTER DRW is designed to be proactive, adjusting the feed rate before the fuel leaves the rotor weighfeeder. This gives you highly accurate fuel dosing in the short and long-term. When it’s something as important as getting fuel to the burner, you can’t afford for your equipment to go down.

The PFISTER DRW is designed with minimal moving parts. Less moving parts, less maintenance. And what little there is to maintain can be accessed from the outside, meaning the work can be done in situ with little risk to maintenance personnel. No cleaning is required, so you can expect high availability from your rotor weighfeeder. And the low power consumption and low maintenance mean the PFISTER DRW is very cost-efficient. All good news for your process.

Automatic gap adjustment with AutoGAP 2.0

Achieving the proper gap width in your DRW rotor weighfeeder makes the difference between high levels of wear and tear and smooth operation. If the gap is too small, you risk blockages. Too big and feeding accuracy is impacted, plus wear increases. Either way, you end up with high maintenance costs and reduced equipment life. Manual adjustment is possible only when the machine is stopped – by which point the damage may have already been done.

The PFISTER® AutoGAP 2.0 uses three distance sensors to automatically adjust and control the gap width during feeder operation. Preventing blockages and jams eliminates the need for reactive maintenance and moves you to a much easier – much less stressful – preventive maintenance plan.

To help ensure the smooth running of your machine, AutoGAP 2.0 can be supplied with WiFi dashboard to monitor equipment performance, including motor current, speed, GAP position, and to set new parameters.

Used in combination with PFISTER Wear Index you can process and analyse your data for more efficient, more effective maintenance planning.

If yes, this means that your quantities of primary fuel usage will probably decrease.

PFISTER FEEDflex™ is part of our solution strategy to support customers’ sustainability efforts. It allows you to dose very small quantities of pulverized fuel pulsation-free down to 60kg per hour and without CO spikes. FEEDflex upgrade does not affect the maximum feed rate your DRW rotor weighfeeder currently achieves. You can still use it up to its maximum capacity as required in the kiln start-up. PFISTER FEEDflex reduces fuel cost with a fast ROI.

The PFISTER® DRW rotor weighfeeder is designed for dosing pulverised fuel, such as lignite, coal dust, petcoke or oil shale. But all PFISTER rotor weighfeeders use the same weighing and dosing principle.

Material is extracted from the storage silo and transported in the rotor chambers from the inlet to the outlet. The rotor body is mounted on bearings, which form a weighing axis eccentric to the rotor shaft and through the middle of the inlet and outlet. A load cell weighs the content in the rotor gravimetrically, providing the bulk material mass in kilograms and this is stored together with the relative rotor wheel position. The rotor speed is controlled accordingly – more material, less speed; less material, more speed. The rotor weighfeeder then discharges the material at the outlet.

Flexible fuel dosing solutions with PFISTER® DRW

The PFISTER DRW rotor weighfeeder can be used in a wide variety of applications. We can help you decide on the optimal installation. Whether you choose a downpipe to connect the silo outlet with the rotor weighfeeder, or an intermediate calibration hopper to enable online calibration, FLSmidth has the expertise and equipment to complete your solution, exactly to your specifications.

Other installation options include multiple rotor weighfeeders beneath one coal dust silo, or a block system solution whereby a special explosion-proof coal dust silo is provided with a rotor weighfeeder attached. These solutions are in use at cement plants, thermal power plants and nickel plants, among other applications.