Optimizing the critical level measurements in delayed coker units NUCLEAR LEVEL DEVICES ON COKE DRUMS

Delayed coking − an overview Global refiners are always seeking new techniques to optimize their refinery assets with the purpose of maximizing their profitability. Most refiners look for methods to convert lower value residual into higher value products. In other words, refiners are searching for bottom of the barrel conversion technologies such as visbreaking, delayed coking and resid hydrocracking, either ebullated bed or slurry hydrocrackers (Sawarkar et al, 2007). Since delayed coking is one of the most profitable units in the refinery and it has a lower initial cost than some of the other...

To measure the level inside the coke drum with the NBS, two things must be given (see Figure 3): 1. he neutrons must be scattered back to the T detector, since the source and detector are in the same housing. 2. econdly the neutrons must be thermalized or S slowed down by the process material. If the neutrons are not thermalized, they have too much energy to be detected by the sensor and travel through the device undetected (Hart, 2014). Fig. 3 Principle of a neutron backscatter measurement Carbon Atoms Hydrogen Atoms One of the most effective means of thermalizing neutrons is using hydrogen...

DCU process control with continuous gamma level measurement During normal operation of the delayed coker, vapor can vary greatly as seen in Figure 6. This trend graph is from a nuclear density point located at the top tangent where only the density of the vapor in the drum is measured. At point 1 in the graph, the vapor density is close to zero since the drum is cold and empty. Between point 1 and 2, some of the overhead vapor from the online drum is directed to the standby drum to preheat it. This helps to prevent thermal stress on the vessel when it is time to add hot resid feed to the drum...

The use of gamma continuous levels on delayed coke drums has greatly enhanced the operator’s ability to increase throughput to the delayed coking unit. This enhancement contrasts with the use of neutron backscatter devices which are only point measurements. The use of gamma continuous levels not only can increase the throughput but can also increase the operability time by reducing the potential of foamovers. Referring to Figure 8, at point 3 there is a foamup that is being recorded by the gamma continuous levels system. Most foam-ups happen after the switching of drums, which is primarily due...

COMMITTED TO TECHNOLOGICAL LEADERSHIP Outstanding long-term stability A reliable measurement is vital for the operation of a process and is therefore, our highest priority. Berthold’s detectors operate consitantly irrespective of changes in ambient temperature. Even drastic temperature shifts, e.g. from winter to summer don’t influence the measurement drift. Due to various patented technologies for detector stabilization and the use of cosmic radiation as an external reference source, the detectors output has an accuracy of under 0.001% per °C temperature change. Apart from employing these cutting-edge...

Berthold Technologies stands for excellent know-how, high quality and reliability. The customer is always the focus of our solution. We know our business! Using our varied product portfolio, our enormous specialized knowledge and extensive experience, we develop suitable solutions together with our customers for new, individual measurement tasks in a wide variety of industries and applications. Berthold Technologies is specialised in radiometric process measurements for 70 years. This is our core competence with state-of-the-art and cutting edge products and solutions covering a vast range of...