A larger diameter means shorter tubes are needed and reduces the flow area. If the designer wishes to maintain the shell style but still adjust this section of the exchanger to modify the pressure drop, he or she might consider increasing the shell diameter.

X-type shells are most predominantly used for shell-side condensers and gas coolers, according to Thermopedia. However, they are positioned directly opposite each other, rather than one being on the far right side and the other on the far left. Like the E-type, this shell has one inlet and one outlet valve. If the divided flow pattern provided by I- and J-type shells still isn’t enough to limit the pressure drop for an application, designers might turn to the X-type shell. This may be referred to as the I-type shell, though that’s not as common. In other models, the J-type shell is reconfigured to have a single outlet but two inlet valves. When this happens, designers can opt for a J-type shell, which has two outlet valves to divide the flow. Though the E-type is most popular, it may allow the pressure drop to exceed the maximum.

The most common shell used for heat exchanger design is the E-type, which has one inlet and one outlet valve and allows shell-side fluid to make a single pass. Shell designs that limit shell-side pressure drop There are a number of ways to reduce the shell-side pressure drop that are related to three of the most important elements of shell and tube heat exchanger design: the shell, the tubes and the baffles. In these instances, designers must come up with creative strategies to limit the pressure to ensure an efficient process. Typically, problems related to pressure drop involve having too high a flow rate, leading to excessive pressure. However, if the pressure drop is well below the maximum limit, it means the fluid could flow faster and therefore increase efficiency. Surpassing this measurement can lead to an inefficient or harmful operation, where the flow rate is too high for the equipment. The goal of the designer is to allow the shell and tube heat exchanger get as close to the maximum allowable pressure drop without exceeding it. Every heat exchanger has a maximum allowable pressure drop that depends on a number of factors, including what the unit is used for, the fluids incorporated into the process and more. Pressure drop is one of the most important design considerations before fabricating a shell and tube heat exchanger. Shell style can help limit or increase pressure drop.

Number of tubes in heat exchanger