Three-Boiler Steam Soot Blowing System Retrofit: 150 Soot Blowers and Full-System Optimization

A reliable soot blowing system is not simply a collection of soot blowers.

Its performance depends on the correct selection of equipment, steam conditions, drainage design, boiler interfaces, control logic, installation quality, and long-term maintainability.

In this retrofit project, SHEENWAY carried out a comprehensive modernization of the steam soot blowing systems serving three industrial boilers at a large-scale energy and chemical complex in northern China.

The project involved the replacement of 150 soot blowers, together with modifications to the steam piping, drainage system, boiler wall interfaces, maintenance platforms, electrical components, and soot blowing control system.

Rather than treating the project as a straightforward equipment replacement, the engineering team approached it as a complete boiler soot blowing system optimization project.

Project Overview

The existing soot blowing systems had been in service for an extended period and required systematic modernization to improve operational reliability, maintainability, and heating-surface cleaning performance.

The overall retrofit scope included:

• 108 SW-SFBA Furnace Soot Blowers
• 42 SW-SLRX Long Retractable Soot Blowers
• Soot blowing steam piping modification
• Drainage system optimization
• Boiler wall interface and sealing reconstruction
• Insulation and refractory restoration
• Maintenance platform and railing modification
• Electrical and instrumentation work
• Soot blowing control system optimization
• Removal of existing equipment and installation of new soot blowers
• Cold commissioning and hot commissioning
• Performance verification
• Operator training and technical support

Each boiler was equipped with 36 furnace soot blowers and 14 long retractable soot blowers, creating a coordinated cleaning system covering both furnace water walls and downstream convective heating surfaces.

Regional Operating Environment

The project is located in a major energy and chemical industrial region in northern China, where large-scale process plants and utility systems are typically required to maintain stable operation over long production cycles.

For boiler auxiliary equipment in this type of facility, short-term functionality is only the starting point. Mechanical reliability, sealing performance, maintainability, and stable operation over extended service periods are equally important.

The surrounding region has a typical semi-arid continental climate, characterized by relatively dry conditions, frequent winds and airborne dust, long cold winters, and significant seasonal temperature variation.

These environmental conditions mean that soot blower engineering cannot focus exclusively on the high-temperature conditions inside the boiler.

Equipment located outside the furnace — including drive mechanisms, motors, electrical enclosures, limit switches, sealing components, and lubrication systems — must also be suitable for long-term exposure to demanding industrial conditions.

For this reason, the retrofit incorporated several reliability-oriented design considerations.

The soot blowers use enclosed or protected transmission arrangements to reduce the influence of dust and contamination on moving components. Motors were specified with IP55 protection and Class F insulation, while transmission and lubrication systems were designed for reliable long-term operation.

The regional operating environment also reinforced the importance of an effective steam drainage system.

Before steam enters a soot blower, accumulated condensate should be removed as effectively as possible so that suitable steam conditions can be established before each blowing cycle.

The project therefore did not treat the soot blowers as isolated pieces of equipment. The steam supply and drainage system was inspected and optimized as part of the overall retrofit.

The Challenge: More Than Replacing Aging Soot Blowers

The engineering assessment showed that replacing individual soot blowers alone would not fully address the requirements of the existing system.

The furnace soot blowers and long retractable soot blowers needed to be renewed to improve mechanical reliability, travel stability, position feedback, and heating-surface cleaning performance.

At the same time, several supporting systems also required attention.

Mechanical Reliability

The new soot blowers had to extend, retract, rotate, and return to their standby positions smoothly without sticking, abnormal interference, or unstable movement.

Steam Quality Before Soot Blowing

The steam piping and drainage arrangement had to minimize condensate retention and establish suitable steam conditions before each blowing cycle.

Boiler Wall Sealing

Wall boxes, embedded sleeves, and sealing structures had to accommodate boiler thermal expansion while maintaining reliable flue-gas sealing.

Control Reliability

The existing control strategy needed to be integrated with the new equipment and optimized according to actual boiler operating requirements rather than simply duplicated.

Maintainability

Equipment clearances, maintenance platforms, and surrounding structures also had to be considered so that inspection and routine maintenance could be carried out safely after the retrofit.

The project was therefore treated as a system engineering task rather than a conventional equipment supply contract.

Engineering Solution

1. SW-SFBA Furnace Soot Blowers for Water-Wall Cleaning

A total of 108 SW-SFBA Furnace Soot Blowers were installed for furnace cleaning.

These units are primarily designed for the removal of ash deposits and slag from boiler water walls.

During operation, the nozzle advances to the designated blowing position and then performs rotary soot blowing at a fixed point.

Depending on the characteristics of the deposits and the cleaning requirements of different furnace zones, parameters such as the blowing arc, number of rotations, and blowing pressure can be adjusted to achieve the required cleaning performance.

For this project, particular attention was given to:

• Stable forward and return movement
• Reliable fixed-position rotary blowing
• Appropriate blowing coverage
• Adjustable soot blowing parameters
• Reliable lift-valve operation
• Temperature-resistant lance components
• Reliable boiler wall sealing
• Local and remote operation
• Position monitoring and travel-limit protection

The final blowing parameters were determined according to actual boiler conditions, including flue-gas temperature, deposit characteristics, and the cleaning requirements of different heating surfaces.

2. SW-SLRX Long Retractable Soot Blowers for Convective Heating Surfaces

The project also included 42 SW-SLRX Long Retractable Soot Blowers, primarily serving downstream convective heating surfaces.

The project-specific soot blower stroke was approximately 10.4 meters, requiring a long-stroke configuration capable of reliably reaching and cleaning deep tube-bank sections.

Typical cleaning areas included:

• Superheaters
• Reheaters
• Economizers
• Other convective heating surfaces

During operation, the lance tube rotates while travelling into and out of the boiler, allowing the nozzle jets to follow the required cleaning trajectory across the heating surface.

For a soot blower with a travel distance exceeding ten meters, mechanical stability is particularly important.

The engineering design therefore placed particular emphasis on:

• Carriage stability
• Beam rigidity
• Lance tube support
• Reliable gear transmission
• Structural stability throughout the full travel
• Adequate clearance from boiler tubes and surrounding structures

Nozzle quantity, nozzle diameter, blowing-medium parameters, and jet configuration were selected according to the heating-surface arrangement and actual boiler operating conditions.

The objective was to achieve effective cleaning while avoiding unnecessary or excessive impact on boiler tubes.

Steam Piping and Drainage Optimization

One of the most important aspects of this project was the modification of the soot blowing steam piping and drainage system.

The retrofit included the removal, relocation, and replacement of selected branch pipes, valves, and related components.

The engineering objective was straightforward:

The soot blowing steam system should drain effectively and avoid unnecessary condensate retention.

During the assessment of the existing system, part of the drainage arrangement below the boiler operating platform was identified for optimization.

As part of the retrofit, the relevant drainage piping was modified and the drain valve size was increased from DN32 to DN50.

This modification was intended to:

• Increase condensate drainage capacity
• Reduce water retention in the soot blowing steam piping
• Shorten the pre-blowing drainage process
• Improve steam conditions before soot blowing
• Reduce the possibility of condensate entering the soot blower
• Improve consistency between individual blowing cycles

This part of the project demonstrates an important principle in soot blower engineering:

A correctly designed soot blower alone cannot guarantee effective cleaning if the steam supply and drainage conditions are unsuitable.

The blowing medium, piping arrangement, drainage system, and soot blower must therefore be considered as one complete system.

Boiler Wall Interface and Sealing Design

Replacing soot blowers on an existing boiler also requires careful engineering of the interface between the soot blower and the boiler casing.

For each installation position, the retrofit included corresponding work on components such as:

• Wall boxes
• Embedded sleeves
• Sealing boxes
• Insulation
• Refractory materials
• Supporting structures

The interface design had to satisfy two requirements simultaneously.

First, it needed to accommodate thermal expansion and relative movement during boiler operation.

Second, it had to maintain reliable flue-gas sealing around the soot blower penetration.

This helps prevent hot flue gas from leaking through the boiler wall interface while protecting both the soot blower and the surrounding operating area.

Material selection for embedded sleeves and other components exposed to elevated temperatures was also evaluated according to the actual service environment.

Before & After: On-Site Operating Comparison

One of the most direct ways to evaluate a soot blower retrofit is to observe the equipment under actual operating conditions.

Before Retrofit – Significant Steam Leakage

Existing soot blower operating before retrofit, showing significant visible steam leakage during operation.

Before the retrofit, significant visible steam leakage could be observed around the existing soot blowing equipment, indicating deterioration in the sealing and operating condition of the system.

After Retrofit – Stable Operation

New SHEENWAY soot blower operating after retrofit, demonstrating stable movement and improved sealing performance.

Following equipment replacement, sealing adjustment, installation and commissioning, the new soot blowers demonstrated smooth mechanical operation and significantly improved external sealing performance under the recorded operating conditions.

This direct before-and-after comparison demonstrates the practical result of the retrofit under actual boiler operating conditions.

Control System Optimization

The existing control system was not simply removed and replaced.

Where practical, the original control architecture was retained and integrated with the new soot blowers, while the blowing sequence and control logic were optimized according to actual boiler operating requirements.

The upgraded system incorporated functions including:

• Local operation
• Remote operation
• Forward and reverse movement
• Start and stop commands
• Travel-limit monitoring
• Fault indication
• Standby-position confirmation
• Interface with the plant control system

Equipment interlocks were also considered as part of the control philosophy.

If a soot blower failed to complete the required movement or did not return correctly to its standby position, the control system could identify the abnormal condition and prevent the blowing sequence from continuing under inappropriate conditions.

This provides an additional layer of protection for both the soot blower equipment and the boiler.

Reliability-Oriented Mechanical Design

Long-term reliability was one of the central requirements of the project.

The equipment design therefore incorporated multiple measures intended to support stable operation in a demanding industrial environment.

Transmission mechanisms were designed with enclosed or protected arrangements to reduce exposure to dust and contamination.

Gearboxes and moving components were designed for reliable lubrication and leakage prevention.

Motors were specified with:

• IP55 protection
• Class F insulation

For the furnace soot blowers, particular consideration was given to sealing reliability, high-temperature resistance, corrosion resistance, valve operation, and the durability of components exposed to boiler conditions.

For the long retractable soot blowers, the engineering focus included:

• Lance tube strength
• Structural rigidity
• Corrosion resistance
• High-temperature operating conditions
• Fatigue resistance
• Long-stroke travelling stability

Limit switches and position-feedback devices were incorporated to provide reliable information about soot blower movement and operating status.

Taken together, these design considerations addressed not only the conditions inside the boiler, but also the external industrial environment in which the equipment is expected to operate over extended service periods.

Installation and Commissioning

The project was executed on a boiler-by-boiler basis to coordinate the retrofit with the plant's shutdown and restart schedule.

The planned manufacturing and procurement period was approximately 40 days, while the on-site replacement work for each boiler was scheduled to be completed within approximately 15 days once the required construction conditions were available.

The site work included:

1. Removal and transportation of existing soot blowers
2. Modification of boiler wall interfaces
3. Installation of new soot blowers
4. Steam piping and drainage modification
5. Maintenance platform and railing adjustment
6. Electrical and control-system work
7. Cold commissioning
8. Hot commissioning
9. Performance verification
10. Operator training

SHEENWAY engineers provided technical support throughout installation and commissioning.

Cold Commissioning

Before steam operation, the engineering team checked items including:

• Valve operation
• Soot blower forward and return travel
• Limit-switch response
• Motor rotation direction
• Motor operating current
• Standby-position confirmation
• Control and feedback signals

Hot Commissioning

After the boiler returned to operating conditions, further verification included:

• Soot blowing steam pressure
• Steam flow conditions
• Piping and drainage operation
• Actual soot blower movement
• Control-system response
• Blowing sequence execution

The system proceeded through performance verification before final handover.

Quality Assurance and Long-Term Reliability

The project established clear requirements for the performance of the complete soot blowing system.

The equipment was required to:

• Achieve the intended soot blowing performance
• Extend and retract smoothly without abnormal sticking
• Maintain reliable sealing
• Avoid abnormal gearbox oil leakage
• Protect boiler heating surfaces from mechanical damage or excessive blowing
• Provide reliable position and fault feedback
• Return safely to the standby position after operation
• Maintain effective condensate drainage in the steam system

The project also included a 12-month warranty period after successful commissioning and handover.

This reflects an important principle of SHEENWAY's project approach:

Reliability is evaluated through actual operating performance, not only at the point of equipment delivery.

Why This Project Matters

Replacing 150 soot blowers across three boilers is already a substantial mechanical retrofit.

However, the scale of the equipment is only one part of the engineering value demonstrated by this project.

A reliable soot blowing system retrofit required the engineering team to coordinate:

• Boiler operating conditions
• Ash and slag characteristics
• Soot blower selection
• Lance and nozzle design
• Steam pressure and flow
• Steam drainage
• Boiler wall sealing
• Local environmental conditions
• Maintenance platforms
• Electrical systems
• Control logic
• Installation sequencing
• Cold and hot commissioning

The project demonstrates why soot blower retrofits should not be approached simply as one-for-one equipment replacement.

A successful modernization requires an understanding of how the soot blower, steam system, boiler structure, control system, site environment, and operating conditions interact as one complete cleaning system.

For SHEENWAY, the objective is not simply to manufacture a soot blower that fits an existing mounting position.

The objective is to understand the boiler, the operating environment, the cleaning requirements, and the limitations of the existing system — and then provide an engineered solution designed for reliable long-term operation.

SHEENWAY Soot Blower Retrofit Solutions

SHEENWAY provides engineering support and equipment for both new boiler soot blowing systems and retrofit projects, including:

• Furnace soot blowers
• Long retractable soot blowers
• Semi-retractable soot blowers
• Fixed rotary soot blowers
• Air preheater soot blowers
• SCR rake-type soot blowers
• Multi-medium soot blowers
• Soot blower replacement parts
• Steam piping and drainage optimization
• Soot blowing control system upgrades
• Installation and commissioning support

For retrofit projects, our engineering team can evaluate existing soot blower models, installation dimensions, boiler interfaces, operating parameters, site environment, and maintenance requirements to develop a replacement or system-upgrade solution suited to actual operating conditions.

Planning a soot blower replacement or boiler cleaning system retrofit? Contact SHEENWAY to discuss your existing equipment, boiler configuration, and operating requirements.