Abstract: Provided are vessels having at least one tube with at least one aperture formed therein to input fluid, to extract fluid, or both, to or from the interior or exterior of the vessel. Such fluids may contain solid materials. The fluid may be exerted or expelled out of the at least one aperture so as to prevent formation of undesirable or collateral materials, such as ash or slag, or to reduce the formation or accumulation of such materials, or even to reduce or remove any collateral materials otherwise might be created and deposited within the process vessel. Fluid may also be extracted through one or more apertures. In other embodiments, one or more apertured tubes are disposed exterior to the process vessel so as to enable removal of material accumulating on the exterior of the vessel or application of material on the exterior of the vessel.