Pillow plates may appear decorative at first glance, but they are in fact highly advanced heat-exchange technology.
They are created by joining two thin stainless-steel plates into a sealed channel, which is then pressurized and “inflated.” This forms the familiar raised pattern through which a medium; such as glycol, water, or steam, circulates to heat or cool the product inside the tank.
The photo shows a tank undergoing the pressure test of its pillow-plate jacket. After welding, each tank is subjected to several standard inspections to ensure that the construction fully meets all quality requirements. Only when every test is passed is the tank approved for use.
In tank construction, there are four common systems to heat or cool a product. At Deprest, we apply all of them, depending on the process and the required temperature control:
- Bain-marie / double-walled tank: the tank is placed in a bath of heating or cooling medium.
- Half-pipe jacket: a half-round pipe is welded around the tank in a spiral, creating an external channel.
- Pillow plates: profiled plates with internal channels, as shown in this project.
- Internal coil (coil/serpentine): a tube system inside the tank through which the medium flows.
Each method offers its own advantages, but the goal is always the same: stable and reliable temperature control tailored to the customer’s process.