Mechanical face seals. Dynamic and thermal behavior

Articles [BM 5425] and [BM 5426] deal with seal technology, while articles [BM 5421] and [BM 5422] focus on the theory of friction face lubrication, illustrated by simple case studies.

The desirable operation of a seal results from adjusting the distance between the friction faces, ensuring a compromise between low leakage and low friction. This involves controlling the relative displacements of the rings and the deformations of their friction faces.

That's why this article is devoted, first of all, to studying the dynamic behavior of packing rings, in order to assess the conditions for stable operation ensuring an interfacial film of optimum thickness. Indeed, in many fields of application, the dynamic behavior of liquid seals remains stable, making them easier to model.

Next, the paper discusses heat dissipation in the interface and heat transfer by conduction and convection with the environment via solid rings. A simplified approach leading to a semi-analytical solution is presented. It is validated by a more elaborate numerical model. This establishes the temperature rise of the friction faces and the temperature variations within the rings. The useful thermal length of the rings and the required cooling rate can then be deduced.

The importance of thermal aspects is also highlighted in the article