Alfa Laval DuroShell sets a bold new standard for LPG/E cargo condensers
With the new Alfa Laval DuroShell plate-and-shell heat exchanger, Alfa Laval significantly strengthens its lead in LPG/E cargo reliquefaction. DuroShell features an innovative construction that dramatically increases resistance to thermal and pressure fatigue.
Alfa Laval DuroShell is a specially engineered plate-and-shell heat exchanger with unique design capabilities. Already used in the offshore oil and gas industry, it is now being introduced for demanding marine duties such as LPG/E cargo reliquefaction. An innovative construction and a patented roller coaster plate pattern make DuroShell significantly more robust, allowing it to condense cargo with a higher ethane content.
"DuroShell is a remarkable advance in heat exchanger design," says Matilda Mellby, Application Manager, Gas Components at Alfa Laval. "As an LPG/E cargo condenser, it provides far greater resistance to temperature and pressure extremes than most other welded solutions."
Reliquefaction of ethane-rich LPG/E
DuroShell strengthens Alfa Laval’s leadership in heat exchangers for LPG/E cargo condensation, where the Alfa Laval AlfaRex plate heat exchanger is standard today. Like AlfaRex, DuroShell is a laser-welded solution combining high thermal efficiency with a very small footprint. But whereas AlfaRex handles pressures of around 30 bar and temperatures down to -50°C, DuroShell withstands pressures up to 35 bar when titanium plates are used, along with temperatures as low as ‑198°C.
"An extended pressure range is important as the ethane level in LPG/E increases," says Mellby. "DuroShell is more than robust enough to handle ethane condensation, which demands pressures in excess of 30 bar."
A rugged yet simple solution
The robustness of DuroShell is the result of many factors, including the patented roller coaster pattern of its cut-wing plates. The roller coaster pattern ensures even expansion around the plate circumference, which eliminates potential weak spots and increases the heat exchanger lifetime. In addition, the entire plate pack is pre-compressed, which minimizes the effect of large differences and variations in temperature.
Further strength is added by the distribution tubes that extend through the laser-welded plate pack. These relieve stress on the plate pack itself, while at the same time ensuring the best distribution of media. Together with the roller coaster pattern, which creates high turbulence even at low velocities, the distribution tubes ensure excellent thermal performance.
"The DuroShell design merges stability with thermal efficiency, and it minimizes fouling to ensure high performance over time," says Mellby. "For LPG/E cargo reliquefaction, no solution compares to DuroShell in simplicity, capability or reliability."
Source: Alfa LavalPosted On:26-Aug-2016
Credits: www.hellenicshippingnews.com |
Tankers: West African Suezmax freight rates show signs of recovery amid heavier fixing
West African Suezmax freight rates have begun to show signs of recovery after a prolonged period of weakness, with fixing levels increasing for September, shipping sources said this week.
The WAF-UK Continent route, basis 130,000 mt, was assessed Worldscale 10 higher at w45 Wednesday, having spent the previous 10 days mired at w35.
On the fixture front Eni placed the Pserimos on subjects at w42.5 for a Bonga-Brofjorden voyage on September 13-14 while a US refiner was later heard to have taken the Pentathlon at w45 for a WAF-USAC run off the same loading dates.
The rising rates were attributed to a reduction in WAF VLCC fixtures along with an increase in Suezmax fixing across multiple regions. "We've seen potential VLCC cargoes split in WAF with cargoes going on the traditional WAF-East VLCC route on Suezmaxes. There has also been a really large amount of fuel oil inquiry for US Gulf Coast to the East which has taken some potential WAF ships away," said a shipbroker.
The rising Suezmax inquiries served to boost shipowner sentiment although the WAF position list had not yet become particularly tight. "The owners are creating momentum but it’s not as if there is no tonnage around. There are still plenty of ships there," said the shipbroker.
According to another broker's position list there were around 21 ships available prior to the fixing window, versus 27 at the beginning of the week.
The WAF Suezmax sector has been hit hard in recent months by a number of Nigerian crude outages, with lower demand for this type of ship in what is traditionally its biggest loading area.
While freight rates have increased this week, time charter equivalent returns of around $7,000 are still a far cry from the earnings enjoyed by owners for much of the past two years. "It's still rubbish. A little bit better but still rubbish," said a shipbroker.
Source: PlattsPosted On:26-Aug-2016
Credits: www.hellenicshippingnews.com |
