Fire system for a paper machine: fireproofing a flammable giant

Donat Czapski

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Project challenges

  • the machine was only 35% complete, which made it impossible for us to run a proper on-site verification and identify bottlenecks
  • the investor was keen on keeping a strict deadline due to costs
  • fire installation works had to run simultaneously with machine installation

The solution

  • we took the initiative to design the fire extinguishing system from scratch
  • we cooperated closely with key stakeholders of the project
  • to avoid clashes with other teams, we introduced flexible working hours for our installers (including at night)

It was the largest machine we had ever secured against a fire. A true giant, 160 meters long and 12 high (525 ft long and 40 ft height). This is much longer than a football field and as high as a four-story building.

However, it was not the size that posed the biggest challenge here. “Collossus”, as we nicknamed the machine, was completed only 35% on the day of the site visit. This meant that it was virtually impossible for us to plan our activities well in advance.

Million-euro machine at risk of more than paper fire

The investor, one of Europe’s leading paper manufacturers, decided to replace an old paper machine. This would allow them to double their production capacity to 1,000 tons of finished product per day. Such machines require state-of-the-art fire protection, not only because of the tons of paper nearby .

One of the key steps in the paper manufacturing process is drying. The produced paper webs (up to several hundred meters long) are rolled into huge bales. They dry on drums that are heated from the inside with hot oil (at a temperature above the flash point).

The hydraulic systems of the paper machine are another potential hazard. Because they operate under high pressure, any unsealing leads to a massive splash of flammable oil.

In 2022, a Spanish factory completely burnt down when an oil hose malfunctioned. See the video below to understand the potential danger of an oil leak.

To make matters worse, the machine and its immediate surroundings are coated with thick layers of cellulose dust. And let us not forget hundreds of rotating parts, bearings, and rollers, which, when overheated, can also be a source of ignition!

Long story short, there is a machine worth hundreds of millions of euros with a high risk of fire. Its burning or stopping is a huge loss, often exceeding the cost of building a fire protection system.

Fire is a real threat to a paper plant!

Three fires at one plant

In 2019, firefighters fought a fire at the No. 2 paper machine at a factory in Poland for more than five hours. The fire was very large, covering about 300 m2 (~3.2K sq ft). Two years later, production dust caught fire in  on paper machine No. 4 at the same plant. In 2022, in turn, a defect in a component of the paper machine No. 7 caused a fire that required six firefighting units to extinguish.

One hour of fire, two months of downtime

The fire at Argentina’s 2020 paper mill lasted just one hour, but it took two months of intensive work to clean up the damage. Restoring the damaged paper-making machine required, among other things, the supply of new parts and repairing damage to hydraulic, electrical and automation systems.

Fire consumes buildings and goods

In 2023, a fire at an Italian factory that produces tissues destroyed a warehouse building. Fifteen thousand pallets of tissue products were also lost to fire.

Little wonder, then, that insurance companies deny insurance to such industrial facilities, unless they have proper fire protection. Before they present their offers to industrial plants, they perform meticulous inspections and risk assessments. In particular, they investigate the compliance of the fire protection solutions used with standards commonly accepted in the industry (FM Global, NFPA, VdS). The level of protection applied and its reliability usually affect the final insurance premium quote.

The insurer will agree to sign a contract only when the machine is secured against fire.

Source: www.voith.com

Fireproofing a paper machine you don’t see: errors everywhere

Imagine you are a mechanic who is asked by a customer to do complex repairs on a car and a caravan in one day. You agree, provided that you do a quick inspection of both vehicles beforehand. The customer agrees, however, that on the day of inspection, they bring only the caravan to the workshop.

This is what we dealt with, and worse. Neither the machine nor the design nor the bill of materials were ready on the day of the site visit.  Two weeks later when we entered the site, we still had to operate as if blindfolded.

However, what we did receive were plumbing calculations. Fortunately, we had them checked by our internal fire system design department. It turned out that they were erroneous: pipes of too small diameter (DN100 instead of DN150) were selected. Had we relied on the original assumptions, the fire installation would not have achieved the required capacity.

Ensuring user-friendly fire installation

The main part of the provided fire system consisted of:

  • deluge valves (two existing ones, which had to be adapted to the new requirements, and four new ones)
  • a master sprinkler system and a spray nozzle system.

The entire system was divided into six independently activated extinguishing sections. The master installation acts as a fire detector. When a fire outbreak causes the sprinkler glass to burst, the pressure in the system drops, which immediately activates the spray nozzle system in the section.

A cost-optimized detection system launches 6 sprinkler sections.

For us, it was obvious that the fire extinguishing installation not only has to do its job, but also has to be user-friendly for the machine and safe for the device itself. That is why we consulted the person delegated by the manufacturer of the device to supervise the installation.

For example, part of the fire extinguishing system ran directly over the cardboard baler. This was dangerous because the vibrations of the machine could loosen the bolts that hold the installation pipes. This could pose risk of damage to the machine, its stoppage, and huge losses.

We could not use lock nuts, as the supplier of the fastening system did not have the required hot-dip galvanized M6 nut in its offer. To solve this problem, we used a special substance to prevent loosening, a proven solution from the automotive industry.

Installation: 300 hours of (team)work, even at night

The investor’s priority was to have the machine built and operational as soon as possible. With incomplete blueprints and an approaching deadline, we decided to take over the design of the fire protection installation. The solutions we developed on an ongoing basis were then consulted with the investor, the design company, and the machine supplier.

Due to the lack of a detailed blueprint, to complete the installation of the fire system, we monitored the status of works on an ongoing basis and made purchases as needed.  We knew that we had to work hand in hand with the assembly crews on site. To reduce the risk of clashing, we decided to work part of the time at night. As a result, our teams worked nearly 300 hours in this way.

Success through expert know-how and honest communication

The completion of the task was only possible thanks to close cooperation with the investor, the design company, and representatives of the device manufacturer and VdS. Both the investor and the external design bureau did what they could to provide us with the best possible conditions for the task. Thanks to sincere communication, together we brought the task to a smooth acceptance and launch of the installation.

Although our team did their best, it was not possible to complete the task within the expected time. However, in the face of the challenges we faced, our good relationship with the investor.

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