Selective cleaning of convective heating surfaces using water in boilers fired with waste, biomass and RDF Fuels with the most variable heating values and chemical compositions are used in incinerators and biomass boilers. Due to their tendency to develop complex deposits, waste, refuse derived fuels and biomass are seen as challenging energy sources.
Incinerators and biomass boilers often have low steam parameters for the sootblowers so intensive cleaning is not possible. The strong deposit build-up in the convective area can also mean that conventional steam sootblowers will not work effectively. Consequently, the fouling will continue to increase, causing unplanned downtimes and reduced boiler availability.
Our solution RX-SMART Helix-W is a fully automatic cleaning system using water as the cleaning medium. It consists of a long retractable sootblower and a media supply unit with modules for the pump, for water inlet, water outlet and an automation unit.
RX-SMART Helix-W employs two gear motors, one for the axial and one for the rotational movements. This enables the cleaning system to precisely position the water jet in the gaps between the heat exchanger tubes and perform the cleaning rotating without axial speed. This so-called Go-Stop-Clean-Go” mode avoids metal surfaces being hit by water and therefore thermal load. Sophisticated control of the water circuit ensures that the water jet will only be applied for cleaning and interrupted on the spot by a pressure-active nozzle. If no cleaning is performed, the nozzle stays closed so that the water cools the long retractable sootblower in a closed cooling circuit.
Results of the utilization of RX-SMART Helix-W
Removal of complex deposits in convective heating surfaces
Cleaning with water without thermal loading of heat exchanger pipes (Go-Stop-Clean-Go” mode)
On the spot starting and stopping of the water jet for cleaning minimises the amount of water poured into the boiler
Even narrow passes are cleaned reliably
Flue gas temperature remains in the rated range
Extension of boiler availability
More flexibility as to the fuel mix since cleaning intensity can be adjusted to the actual deposit situation at any time
No steam required for cleaning
The novel water control allows an immediate build-up and interruption of the water jet for cleaning – this new cleaning method is called the Go-Stop-Clean-Go” technique.