Sandwich Steaming belongs to the latest developments of steaming technology.
Sandwich Steaming is a combined method derived from depth and surface steaming. Steam is induced simultaneously from the surface and the depth of the soil. Therefore the area which is already equipped with a depth steaming system is covered with a steaming hood and steam induced from underneath and above the soil. Steaming sheets are not suitable since a high pressure underneath the soil of up to 30mm water column occurs underneath the cover. Hence spike hoods are exclusively used – an enhancement of regular steaming hoods.
Sandwich Steaming has several advantages. On the one hand, energy insertion can be increased to up to 120 kg steam per m²/h. This result is that up to 30% of energy and hence fuel (oil) can be saved in comparison to conventional steaming methods such as sheet steaming. The increased energy insertion leads to an accelerated heating of soil which reduces heat loss due to thermal conduction in accordance to energy savings. Furthermore, only half of the steaming time is needed for Sandwich Steaming.