DuroShell – Plate-and-shell made tougher
In the petrochemical industry, heat exchangers are put to use in a wide range of demanding positions. But too often, neither traditional shell-and-tube heat exchangers nor conventional plate-and-shell designs are up to the challenge. Whether due to high energy consumption, inefficient performance or fatigue problems, they can cut into productivity – and into profit margins.
If this sounds familiar, the time for change has come. Alfa Laval DuroShell is a compact plate-and-shell heat exchanger that has been specially engineered to provide high durability and thermal efficiency. It offers a versatile and reliable solution suitable for a whole spectrum of challenging petrochemical applications.
Regulating temperatures quickly and accurately is critical to both product quality and process yield in petrochemical production. But few heat exchange solutions have been able to offer the high efficiency and performance reliability that these demanding operations require. Alfa Laval DuroShell is different. With a robust design, high thermal transfer rate and low hold-up volume, it can secure reliable and cost-effective production in a variety of petrochemical applications.
As flexible as it is strong
Compact and exceptionally resistant to fatigue, DuroShell creates new possibilities through its unique strength and efficiency. Able to work with liquids, gases and two-phase mixtures, including a wide range of aggressive media, it stands out among heat exchangers in its duty range. DuroShell handles pressures up to 100 barg (1450 psig) in compliance with PED and ASME, along with temperatures as high as 450°C (842°F).
Built for your application
DuroShell is fully welded and gasket-free, with internal features that make it still more robust. Plates are available in 316L stainless steel or titanium, while the pressure vessel itself can be built in 316L stainless steel or carbon steel. Three different sizes are possible, with heat transfer surfaces ranging 2–235 m2 (21.5–2530 ft2) in area.
Why make the change from shell-and-tubes?
For many years, shell-and-tube heat exchangers were the standard choice for regulating temperatures in the most demanding petrochemical applications. But shell-and-tubes not only take up a great deal of valuable plant space, they also have high total lifecycle cost.
That’s one reason why many petrochemical producers have already switched to more compact plate-and-shell heat exchangers like Alfa Laval DuroShell. Thanks to groundbreaking engineering, DuroShell makes it possible to reduce energy consumption within a smaller footprint.
Small in size, big in savings
In an increasingly competitive global chemicals market, the ability to produce more at a lower cost has never been more important. DuroShell’s unique, compact design ensures a lower capital investment than traditional shell-and-tubes, while simultaneously allowing capacity to be added in a limited space. It also minimizes maintenance costs throughout the equipment’s lifecycle.
Of course, one of the biggest costs in production is energy. Here too, DuroShell provides new advantages. With thermal efficiency far greater than traditional shell-and-tubes, and even 15-20% higher than conventional plate-and-shell heat exchangers, it offers significant lifetime energy savings.
Plate-and-shell benefits made better
Many petrochemical businesses have already made the switch from bulky shell-and-tube heat exchangers. Unfortunately, conventional plate-and-shell designs frequently suffer from fatigue challenges in applications with high pressure and temperature demands. The result is unplanned downtime, leading to both a loss in production as well as time and money spent on maintenance and repairs.
A robust solution
DuroShell has been specifically created to meet the challenges of duties involving extreme variations in pressure or temperature. With its unique plate pattern and laser-welded, compact construction, it can withstand pressures up to 100 barg (1450 psig) as well as temperatures as high as 450°C (842°F). The innovative design offers a number of clear benefits over conventional plate-and-shells, including:
- More uptime and longer life due to greater fatigue resistance
- Higher operating pressures thanks to robust, patented construction
- Operational gains created by 15–20% higher thermal efficiency
- Installation savings through even more compact, lightweight design
- Greater reliability as a result of closed, fully welded construction
Discover the benefits
Learn how you can maximize uptime, cut cost and increase capacity by installing Alfa Laval DuroShell.
Or find out the reasons why your operation would benefit from switching from shell-and-tubes or replacing your existing plate-and shells.
Make a change to maximize uptime
More uptime in high-demand petrochemical positions
Make a change to cut costs
A heat exchanger for cutting costs in petrochemical production
Make a change to increase your capacity
A heat exchanger for increasing capacity in petrochemical production
5 reasons to make the switch from shell-and-tubes
5 ways to boost heat exchanger performance
Designed for demanding petrochemical duties
Petrochemical plants rely on heat exchangers in a number of critical positions. But traditional shell-and-tubes and even conventional plate-and-shells are unable to provide reliable performance in many applications due to material fatigue. As an extremely durable and efficient solution, Alfa Laval DuroShell minimizes risk while creating new process possibilities.
DuroShell for petrochemical production
DuroShell is a versatile, flexible heat exchanger suitable for numerous applications from simpler to ones with high temperature or high pressure demands.
Example positions for DuroShell include:
- Batch reactor cooler/heater
- Interchanger and process heat integration
- Overhead condenser
- Steam driven preheater
- Liquid-driven reboiler
DuroShell as a batch reactor cooler/heater
High fatigue resistance
Batch reactors often need to be heated and cooled during production processes, which can result in high fatigue for heat exchangers regulating temperature. DuroShell's superior fatigue resistance and durable design make it a perfect choice for these types of duties.
Precise temperature control
DuroShell has a small hold-up volume which increases the precision of reactor temperature control and allows for rapid temperature changes.
This can be beneficial when switching between heating during initiation of the reaction and cooling once the reaction has started.
Lower costs for heating, cooling and installation
Thanks to the small temperature approach and the possibility to operate with crossing temperatures, DuroShell can operate with lower grade steam, warmer cooling water or less cooling water than shell-and-tube and conventional plate-and-shell heat exchangers.
The high thermal efficiency results in a very compact unit, which in turn lowers installation costs.
The perfect condenser
DuroShell offers an excellent choice for condensing duties.
The short heat transfer area ensures a low pressure drop, making it possible to optimize production rate. DuroShell's superior thermal efficiency makes it a very compact unit, allowing for installation on top of a column with a minimum of support structures.
Condensing and subcooling in the same unit
With a DuroShell, it is possible to perform condensation and subcooling in the same unit. This saves installation costs as well as preventing flash gas from forming downstream.
Extra safety margin
DuroShell can perform condensing duties using warmer cooling water than a shell-and-tube or conventional plate-and-shell heat exchanger due to its close temperature approach. This can be a valuable safety margin on hot summer days when the cooling water is hotter than usual, ensuring production continues as expected.
Fatigue is often a problem for steam-driven preheaters with intermittent heating.
Using a DuroShell in this position can double the expected lifecycle compared to shell-and-tube and conventional plate-and-shell heat exchangers.
A DuroShell heat exchanger is up to five times smaller than a comparable shell-and-tube heat exchanger thanks to its high thermal efficiency. This lowers costs for both the heat exchanger and installation structures.
Use lower grade steam
Thanks to DuroShell close temperature approach, it is often possible to use lower grade steam compared to other types of heat exchangers. This saves energy and frees up possibilities to use the higher-grade steam for other purposes, such as increasing production.
Maximum heat recovery
Using recovered heat to drive a reboiler is a straightforward way to increase a plant's energy efficiency.
DuroShell can be configured to run with a very close temperature approach. This enables reboiler operation using heat from streams with much lower temperatures than a shell-and-tube would require, maximizing potential energy recovery.
The unique cut-wing plates give DuroShell a better flow distribution than conventional plate-and-shell heat exchangers.
DuroShell's patented plate pattern has much greater turbulent flow than shell-and-tubes. This results in less fouling and reduced maintenance needs and higher heat transfer performance
The only maintenance required is an occasional cleaning-in-place cycle.
Interchanger and process heat integration
Preheating streams with waste heat is an easy way to improve energy efficiency in a petrochemical plant.
Incoming stream can be heated with heat from outgoing stream (interchanger or feed/effluent heat exchanger) or by using heat from another unit operation (process heat integration).
Maximum heat recovery
DuroShell can maximize heat recovery thanks to its ability to operate with crossing temperatures and a small temperature approach.
The benefits of this are:
- Lower energy consumption
- Reduced cooling needs
- Debottlenecking and increased production
- Minimized utility investments for boilers and cooling systems
- Long temperature programmes
DuroShell can operate with multi-pass configurations, meaning the shell-side flow can pass through the heat exchanger multiple times. The temperature programme can then be longer than those of conventional plate-and-shell heat exchangers.
The highly turbulent flow in a DuroShell helps reduce fouling. This means that for duties where shell-and-tube and conventional plate-and-shells require mechanical cleaning, DuroShell can operate without any maintenance aside from a simple-to-operate cleaning-in-place cycle.
DuroShell secures uptime in coal tar oil depot
These were the major reasons for Rütgers to install two DuroShell plate-and-shell heat exchangers in its coal tar oil depot in Castrop-Rauxel, Germany.
Jacket cooler/heater in specialty chemicals plant
DuroShell’s ability to operate with crossing temperatures also minimizes the costs for steam or cooling water in the Swiss chemicals manufacturing plant.
Reactor temperature controller in green chemicals production
Green chemicals plant replaced failed heat exchanger with DuroShell, offering fatigue resistance up to 5 times higher than other plate-and-shell heat exchangers.
Reboiler in propane recovery system
High vaporization rate, compact size and high-pressure durability makes Alfa Laval DuroShell the ideal choice for Swedish producer of polyethylene plastic plant.
Tar oil cooling
A chemicals producer in Germany solved heavy fouling and clogging by replacing their shell-and-tube solution with a DuroShell plate-and-shell heat exchanger.
Optimized flow distribution and fatigue resistance
Patented design enables improved fluid distribution, mechanical strength and unparalleled fatigue resistance
Robust and efficient performance
A patented plate pattern optimizes thermal efficiency with improved fatigue resistance, flow distribution and mechanical strength
Less weight and added reliability
Alfa Laval's unique CutWing plates enable multipass within the shell, making the unit more compact and easier to install, since no external piping is required
Talk to an expert
We will be happy to discuss the benefits a DuroShell can bring you and show how we can help improve your operation.
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