METHOD FOR MEASURING A FLOW, INSTALLATION UNIT AND MEASURING APPARATUS

摘要

The present invention is based on the problem of directly establishing, in situ, the optical accessibility for optical flow measuring methods or for an optical calibration method in the volumetric flow measurement of fluids in flow systems without the measurement or calibration measurement itself influencing the flow conditions and, in particular, without having to interrupt system operation. The present invention solves this problem by virtue of the fact that, during system operation, a weld-on pipe of the apparatus according to the invention is welded onto the flow system in a fluid-tight manner in the region of the flow measurement to be carried out, a shut-off fitting is mounted on said pipe, the flow system is drilled out of the apparatus according to the invention using a known pressurized drilling method (hot-tapping method), an insertion window is inserted into the apparatus housing and is locked therein in such a manner that that side of the insertion window which faces the fluid corresponds to the flow system contour at this location, and the insertion apparatus is finally removed from the apparatus housing again, and a sight glass is mounted on the apparatus housing, with the result that the optical accessibility to the fluid for optical flow measurements is established at this location of the system during system operation without influencing the flow in the system flow channel or the flow boundary layer of the system and without having to interrupt system operation. The entire process is carried out in this case by means of the appropriate use of the shut-off fitting and by means of sealing elements between the insertion apparatus and the apparatus housing without fluid leaking from the flow system and the apparatus according to the invention.