Recovery boiler
The black liquor recovery boiler is the single most expensive asset in the chemical pulp mill. Operating these boilers with optimal internal energy consumption and keeping the boilers operational for whole seasons without outages requires advanced technical solutions.
General info
Recovery boilers recovers chemicals and energy
The Recovery boiler recovers chemicals and energy, which is used in the cooking stage where wood chips are refined to cellulose. The black liquor is a mixture of by-products from this separation process. All chemical pulp-mills rely on this chemical recovery cycle for their economical and sustainable operations.
About cleaning
Sootblowers are used for keeping the recovery boiler clean inside
Pulp mills stay competitive by lowering production costs per ton cellulose and one way of doing that is to increase cellulose production. Since the recovery boiler is so expensive, it is commonly operated at or above original design capacity which presents challenges with regard to availability and runnability. The most common reason for reduced availability is fouling of the boiler heating surfaces. To combat this, retractable steam sootblowers are used to keep the boiler insides clean.
Our motto
We go beyond technical specification
Like the recovery boiler operation, retractable steam sootblowers are operated at maximum capacity, meaning there is no additional cleaning capacity to increase boiler availability. It is in this setting that Heat Management introduces the patented High Impact Sootblowing System (HISS™), increasing the cleaning capacity of the existing steam sootblowers by 100 %. Benefits include increasing recovery boiler availability, cleanability and efficiency, while reducing steam consumption. HISS™ provides the mill with the necessary tool, allowing safe increase of production levels beyond technical specification i.e. process more black liquor in the boiler, without jeopardizing the process availability.
References on Recovery boilers
Mondi Dynäs, Sweden
The customer had problems with fouling on the primary and secondary superheaters. Steam temperature was dropping about 25 degrees Celsius in a span of two and a half months. The client saw a need for sootblowing more but also saving sootblowing steam. The bark boiler at the mill supports the production of steam in the facility and also uses oil as fuel during certain parts of the year when steam production is too low.
Mondi Stambolijski, Austria
Mondi Stambolijski was investigating steam savings initiatives in the recovery boiler and also looking for possibilities of future increases in the recovery boiler load. HISS™ was chosen to reduce the steam consumption of the steam sootblowers. The technology also gives the user the possibility of increasing the sootblowing cleaning capacity, to maintain high availability at an increased recovery boiler load.
Zellstoff Pöls, Austria
In 2020, Zellstoff Pöls AG made the investment to commission a sootblowing solution that were to be installed on all 86 of their sootblowers. The project evaluation has now been finalized and it revealed incredible results.
Södra Cell, Värö
In 2020 Södra Cell Värö initiated the Expansion 2.0 project, to increase production from 710 000 ADMT/year of NBSK pulp to 780 000 ADMT/year. The identified bottleneck was the recovery boiler. Read more about the results by downloading our case study.
Content related to Recovery boilers
Challenges for Power boilers
This white paper focuses mainly on challenges related to combusting complex fuels, such as domestic waste, industrial waste, and demolition waste. In the first chapter, we will present the challenges, solutions for increasing the efficiency and cleanliness of the boilers
Solutions for recovery boilers on pulp mills
Downloadable white paper about Solutions for recovery boilers on pulp mills. Get your copy today!
Comparison of infrasound and audible sound as an acoustic cleaning method
A free downloadable white paper focusing on Comparison of infrasound and audible sound as an acoustic cleaning method
