Siemens And Long Products
New recommendations from the Refined Bitumen Associaton meant an adjustment to bitumen deliveries for Long Products in Rye. Siemens worked with the RBA on the study and in designing a solution. Rye Products is the first company in the UK to use the new system.
Bitumen is derived from the distillation of crude oil. The supply process starts from large storage tanks based on the refineries and, in order for it to remain fluid, it must be stored and transported at temperatures of between 150ºC and 200ºC, which gives it a transportation radius of around 200miles to minimise temperature drop.
Once it reaches its destination it is transferred into large bitumen storage tanks which is where the problem lies. Bitumen tanks have been common place within the industry for a number of years and, as a result, a number of new and old tanks exist. This means that there are tanks of varying volumes and sizes within the marketplace, an important factor when considering delivery of bitumen and the issue of spillage.
A recent study commissioned by the Refined Bitumen Association (RBA) identified over-spilling as a major health and safety risk posing serious injury on sites due to the temperatures at which bitumen is stored and its high thermal capacity. The study identifies five key areas relating to the origin of spills. These are:
- Knowledge of tank dimensions
- Use of incorrect conversion factors
- Unsuitable or wrongly applied tank content measurement instrumentation
- Incorrect interpretation of tank content measurement information
- Poor communication between the delivery tanker driver and the operators.
Working alongside the RBA, Siemens was one of the contributing technology suppliers assisting in the development of the study. It partnered with Pressvess and BOX Telematics to try and find solutions to the problems highlighted. Long Products of Rye is the first company in the UK to buy the solution, which is based on the study’s findings.
The study showed that correctly determining ullage space is crucial to the prevention of spills. Establishing the true storage capacity of a tank before the ullage space can be determined is vitally important.
Tanks are currently manufactured and specified by their volumetric capacityDerek Moore, UK level product manager at Siemens explains.
“Typically, the industry assumes that one cubic metre of capacity is equal to one ton of storage space when, in fact, according to the RBA, bitumen has a worst case density value of 0.92t/m3 and therefore a 100m3 tank will only hold 92tons of bitumen.
“The problem may be exacerbated further if a tank is converted for bitumen use and a heater and overflow pipes added as this will reduce the capacity of the tank to approximately 88 tons. The guide also stipulates that 10% of the tank capacity should remain unused, therefore reducing the safe working capacity of a tank to just 79.2tons,” he says.
Content measurement
Another important element is the correct installation of equipment and it is only through experience that the right technology may be applied and installed in the correct position.
In the past, companies have lost the benefit of investment in the latest instrumentation due to poor installation practices.
Recent advancements in technology may also have left some existing installations with underperforming measurements. It is important that manufacturers are consulted during the specification and installation process to ensure it is done correctly.
Understanding the information
With tanker drivers often delivering bitumen to any number of sites, all with varying rules and information, it is not surprising that information is sometimes misinterpreted.
Moore explains: “A simple example of this is a level measurement device displaying 57 to the operator, who then has to decide if there is sufficient ullage to accept a full tanker delivery. The operator is often confused as to whether the 57 is tons, percent or m3. The tanker driver therefore often relies on the site alarm, but even these differ from site to site,” he says.
With this in mind, Siemens developed a local alarm panel for the tanker driver and plant operator that is compliant with the RBA guidelines.
The manufacturer’s diagram of the tank parameters is also displayed on the front of the panel, enabling anyone viewing it to clearly understand what is being displayed and the exact available capacity and measurement. This system also enables common visual and audible indication to delivery personnel and also includes a traffic light system as recommended by the RBA.
The information recorded can then be enhanced by the box telemetry, which extends the information to all parties providing real time visibility of the tank contents to remote staff, such as the purchasing scheduler and the bitumen supplier, through an internet web page.
Because the localised level indicator can be seen by all parties the system is perfect for incorporating into a Vendor Management System. The plant operator can give the bitumen suppliers the right to see the storage tanks online and raise their own orders to fill up the tanks, as per the service level agreement, or even supply bitumen on a ‘just in time’ basis.
“The level data and trends of usage can be viewed in real time or retained as a historic report for year-on-year comparison. The alarm system is designed with green signifying available ullage, amber a high level and red a high-high level. The box can also be easily expanded to take on additional inputs such as stone storage, flow rates and temperature, providing the end user with full visibility of the process.
“This integrated solution opens up communication channels to all parties in the supply chain, making the information visible in order to anticipate customer demand and to ensure an un-interrupted supply. Above all, it offers reduced costs, increased profitability, and improved service levels and site safety,” says Moore.
Long products sources its bitumen from BP a member of the RBA. To tighten up on health and safety, Long’s technical director Chris Homes has bought into the Siemens solution. He has had his 25year-old tanks retro-fitted with a control box and sensors (see picture). It is set to be fully up and running in late June or early July.
He says having a system designed in conjunction with the RBA helps set his mind at rest that his staff have the best protection they can get. He also feels the system works better than some other solutons he looked at because of the design.
“The sensors are on a guiding wire. Because my tanks are old the ports on top are very small. The guiding wire means we can thread the sensors in. This makes much better sense in retro-fitting.
“My tip to others choosing it would be to consider the flanges. We had to modify one by making an adaptor so it would fit. But overall I’m very pleased. It’s easy to use, gives lots of info and even looks good,” he says.