Abstract: Apparatus and methods for decreasing pressure of drilling fluid within a region between an impeller and a housing of a power generation module (PGM). The apparatus comprises a shaft extending from and rotatable relative to the housing; The impeller is coupled with the shaft external to the housing and includes a group of blades that rotate the impeller as the drilling fluid flows past the PGM. The impeller further includes another group of blades that decrease the pressure of the drilling fluid within the region between the impeller and the housing when the impeller is rotating.

Abstract: Apparatus and methods for decreasing pressure of drilling fluid within a region between an impeller and a housing of a power generation module (PGM). The apparatus comprises a shaft extending from and rotatable relative to the housing; The impeller is coupled with the shaft external to the housing and includes a group of blades that rotate the impeller as the drilling fluid flows past the PGM. The impeller further includes another group of blades that decrease the pressure of the drilling fluid within the region between the impeller and the housing when the impeller is rotating.

Abstract: The disclosure is about a desiccant box comprising at least one wall defining an inside compartment containing a desiccant material. The box is designed so that: at a first temperature value, the inside compartment is a substantially vapor tight closed compartment, at a second temperature value superior to the first temperature value, at least a portion of the box is permeable to vapor so that vapor can penetrate into the inside compartment.