Evaporator Upgrade

by Ibon Ezkerra | LDX Solutions, Inc.

LDX Solutions provided custom solutions to upgrade a client’s existing evaporation line while also adding a new parallel line. All project targets were met, including increasing the evaporation capacity by more than 30%. This project was not without challenges including limited space, the existing evaporation line, and external factors such as supply chain delays. LDX Solutions was able to find effective solutions to every challenge, leveraging many years of combined experience, expertise, and consistent communication throughout the entire project, to complete the upgrade on time and within budget.

Evaporator Upgrade: Challenges & Solutions

How would you respond to an underperforming evaporator system? Initially, your team would most likely contact the original supplier to find a solution. What happens when the issue isn’t resolved, and the evaporator system continues to fail to reach its designed capacity? What if, after years of underperformance, you now need greater than 100%? What do you do? Where do you go?

A mill in Portugal found itself in this exact position. They were running an 11 body, seven-effect evaporator system. The system could only achieve about 90% of the designed capacity. After years of subpar performance, it was imperative that the mill team find someone to deliver a solution and do so as efficiently as possible.

The mill needed a remedy to solve the existing problems and allow them to increase evaporation capacity more than 30%. They wanted to utilize as much of the existing equipment as possible while integrating a condensate stripper system and be capable of adding a future ash treatment system (ATS) to the process.

The underperforming evaporation system was causing the mill to suffer. Time was of the essence and was a driving consideration when selecting the right company to complete the project. The best team would be able to do it all— design, engineering, fabrication, manufacturing, installation—and do it in the quickest, most efficient manner possible.

Here, the Scope of Supply included the following:

• 370 tph evaporation
• New tubular falling film evaporators integrated into the existing set, operating in liquor
  and vapor parallel to existing bodies
• New finishing concentrator operates in series with existing ones
• Concentrators mode switching, and piping does NOT change
• New surface condenser added to handle the increase in vapor load
• Upgraded condensate stripping system
• New stripping system including a falling film evaporative reflux condenser

Solution

LDX Solutions stepped up to the plate with its Lundberg® line of branded products. Unlike engineering firms, LDX Solutions has the capability to do everything in-house — including design, engineering, manufacturing, fabrication, installation, and aftermarket support. This gives LDX Solutions an advantage when completing projects where quality communication and planning are critical to success.

Every engineering team knows that a project begins long before feet hit the ground on site. This is especially true for a brownfield project. What happens before a project kicks off sets the stage for how and when the project will be completed.

While time was clearly a factor, our team knew that it was important to not rush the initial phases. We predicted that the more communication and planning we invested here, the more time we would save when it came to execution.

LDX Solutions Project Manager Aitziber Sanchez stated, “One extra hour of engineering here can save 10 hours on site.” The proposal phase set the stage for the rest of the project and foreshadowed what would drive the project’s success—communication and planning.

Facing Challenges

It is nearly unheard of to have a project executed without some challenges along the way. Upgrades of existing processes pose unique challenges for engineering teams and this project was no exception. Anticipating challenges and continuously communicating during the entirety of the project ensured that the challenges were met, and the project completed within budget and on time.

Challenge 1 – Lack of Space

During an upgrade, the team must work with the existing space and equipment which is not always ideal. A number of the challenges faced during this project involved both the unique layout of the space and the existing evaporation line. Notably, the lack of available area posed a significant.

Solution

Communication and planning played a paramount role in ensuring that the project could be successfully completed given the constraints of the space. The old adage “measure twice, cut once” came to life during this project and the results were spectacular.

The design of the project was carefully and meticulously planned and utilized both technology and experience. Measuring and design were enhanced with 3D scanning of the site, which allowed nearly everything to be matched to the site prior to installation.

Sanchez explained, “With brownfield projects, 3D scanning of the area helps the designer to route piping and erect structures avoiding almost 100% of the interference.”
Sanchez added, “It was amazing to see how everything was matching on site like a LEGO!”

Visual comparison between the 3D model, that was developed working together between EU and North American design departments, and the final real result.

Challenge 2 – Existing Evaporation Line

As mentioned above, one of the biggest challenges involved the existing space (or lack thereof). There were a lot of unknowns with the existing evaporation line that needed to be resolved not knowing how the existing evaporation would behave once both lines were to be working in parallel. While installing a new Lundberg® line would give the design capacity, the contract guarantees were linked to both lines. This meant that both lines needed to be functioning and the existing evaporation line could not continue to function at 90%

Solution

We knew that our extensive experience in the pulp and paper industry would be an asset. Our engineers were knowledgeable and brought a wealth evaporator design and operational knowhow to the project. This knowledge made it possible to troubleshoot the deficiencies within the existing evaporation line and once the deficiencies were understood and verified solutions were put into place that allowed both lines to meet the design parameters, avoiding any misbalance between them and assuring contract capacity guarantees were met. Our engineers continued to be available for the duration of the project.

LDX Solutions placed great importance on selecting experienced and knowledgeable mechanical and electrical contractors to assist with the existing evaporation line. We chose to work with companies who were already working with the client and were familiar with the client’s needs. The team of contractors were readily available throughout the project. This meant that they were able to assist during critical moments.

Putting together a team that had both the requisite knowledge and familiarity with the existing evaporation line allowed for a successful upgrade. To minimize tie-ins and downtime, minimal changes were made to the existing evaporator and concentrator process configuration. Additionally, an automated weak liquor wash system was provided to maintain the effectiveness of the concentrator bodies.

Once the final acceptance for the evaporation contract was signed, the mill decided to add an Ash Treatment System to remove chlorides and potassium salts and reclaim valuable sodium back to the process. LDX Solutions was awarded this project as well. The ATS system eliminates fouling associated with potassium and chlorides in the economizer bank within the recovery boiler. This optimizes boiler capacity and uptime, saves energy by reducing soot blowing steam, and reduces the risk for corrosion.

Challenge 3 – Market Instability

Not every challenge can be anticipated. The past few years have been racked with uncertainty and many external factors can impact a project’s timeline. As the project progressed, our team faced steel supply chain delays and market instability due primarily to the war in Ukraine. These delays ate into precious extra time.

Solution

It was impossible for our team to anticipate all the issues brought on by market instability. Our team relied on our thorough design planning to ensure that we met our deadlines. Careful and complete engineering helped to ensure that the erection on site was almost perfect without deviations. This included prefabrication of platforms and stairs as well as most of the piping.

This project was awarded on a fixed price EPC basis and the total change orders to the client were less than 2% of the contract value.

The success was driven by constant communication with everyone involved including the client, suppliers, procurement, project management, finance, technical, and design.

Delivering Results

LDX Solutions delivered the desired results. We tailor-made solutions to optimize the existing
evaporation line while also adding a new parallel line featuring Lundberg® evaporation technology
to meet all the project targets including the following:

• Increase overall capacity by more than 30%
• Tune the existing line
• Minimize tie-ins and downtime
• Reduce mill water consumption
• Improve the process economy
• Completion by deadline

The very real challenges during the project were met by a talented team dedicated to superior solutions. This project serves as an example of how LDX Solutions leverages quality communication and thorough planning to provide clients with exceptional outcomes.