Heat exchangers provide a kind of system that permits the transfer of heat between two or more fluids. In these devices, the fluids are generally separated by a wall to prevent them from mixing. The ‘Floating head’ type of heat exchanger is one of the most commonly used heat exchangers. It is basically a ‘shell and tube’ heat exchanger that includes parts like the shell, shell-side and tube-side nozzles, tubes, channels of tube-sides, tube sheets, baffles, channel covers, and pass divider.
The system design of the floating head heat exchanger resolves several issues related to thermal gradients.
Types of floating head heat exchanger
The floating head heat exchangers are classified into four types as per the difference in their design. These are an outside-packed lantern ring, an outside-packed stuffing box, a pull-through, and a split-ring.
Glance through the details of each of these ‘floating head’ type of heat exchanger:
Floating Head Heat Exchanger Outside-Packed Lantern Ring
This kind of heat exchanger was initially used popularly because of its removable construction system. However, it has a high tendency of leakage due to the lack of a positive seal. Such limitations lead to its unsuitability in handling hazardous fluids or high pressure. The outside-packed lantern ring type has only two tubes fitted in it.
Floating Head Heat Exchanger Outside-Packed Stuffing Box
Like the above type, the outside-packed stuffing box has no positive seal, making it vulnerable to leakage. For this reason, it faces the same problems as the outside-packed lantern ring design. However, there are four tubes in the stuffing-box type of heat exchanger, enhancing the speed of heat transference from one medium to another.
Floating Head Heat Exchanger Pull-Through Bundle
In this type of heat exchanger, one tube sheet is quite small, allowing it to be pulled easily across the shell. Similarly, it is possible to pull its gasket-fitted bonnet. This makes the insides of the shell easily accessible to be checked, cleaned, and repaired. The downside of this design is that it accommodates a fewer number of tubes compared to other designs. This results in less space for the bolt circle and bonnet flange.
Floating Head Heat Exchanger Split-Ring
A split-ring design overcomes most of the issues posed by the pull-through bundle. In this type of heat exchanger, the floating head’s bonnet is fastened to a split backing used in place of the tube sheet. With this arrangement, sufficient space is created for the tubes, which couldn’t be held in a pull-through design. Further, the split-ring design also harbors a ‘pull through’ attribute like the heat exchanger system’s pull-through type.
The last two types of heat exchangers cause lesser leakage in comparison to the first two types.
Floating head heat exchanger hydrotest procedure video:
Floating head heat exchanger maintenance procedure video: