Mannesmann Aktiengesellschaft

Mannesmannufer Aktiengesellschaft

Bruno Heinrich

Wilhelm Schwenk

Rolf Mangen

A blend of at least 35 percent alumina and not more than 45 percent calcium oxide is blended with sand at a sand-to-cement ratio preferably 1.8 and applied to the interior of a metal pipe, for example, by means of centrifugal application and compression. Following which the resulting lining is exposed to moisture for several hours which exposure step is in turn followed by an exposure to warm steam also for several hours.

Lining metal tubing with a corrosion- and abrasion-proof cement mortar

A dispersion of a polymer such as an acrylic resin, and of a surface-acting resin, such as a melamine resin, is added to a cement mortar having a sand-to-cement ratio of 1 to 3 and a water-to-cement ratio of 0.25 to 0.35, the resin being preferably approximately 10 parts by weight per 100 parts of cement. This blend is applied to the interior of a pipe and the pipe is rotated at a speed which is gradually increased in order to produce at least approximately 20-g forces on the material for compacting same for a few minutes.

Growing community of inventors

Duisburg, Germany

Bruno Heinrich