First, the main structure of the high temperature gear pump The pump shaft seal adopts the mechanical seal of the double end bellows Second, the mechanical seal of the gear pump is insufficient (1) Because the production of the vinegar is a continuous operation, during the installation of the mechanical seal, the seal The fluid could not operate and the gear pump body temperature was as high as 31090°C, causing the graphite wedge ring to expand rapidly. After the sealant is applied, the temperature of the mechanical seal cavity decreases, and the wedge ring contracts, causing a leakage of the mechanical seal. For the mechanical seals that were replaced due to leaks, hydrostatic tests were performed and it was found that the wedge ring between the ring and the sleeve was the main factor causing the failure of the mechanical seal.

(2) The mechanical seal of this structure requires a high level of installation of maintenance personnel. During the installation process, it is not easy to accurately position, resulting in deflection of the rotating ring, resulting in leakage of the mechanical seal.

Third, the structural improvement of the gear pump mechanical seal shrinkage deformation of the wedge ring is the main reason for the mechanical failure of the gear pump, eliminating the wedge ring and shaft sleeve integration, can achieve the purpose of leakage control (see Figure 1 the lower part) . The shaft sleeve is re-machined, and the metal corrugated sheet is welded directly to the end face of the boss ring, and the moving ring is inlaid. The axial and radial dimensions of the collar depend on the axial distance and radial dimension of the thrust ring in the drawing. At the same time, in order to facilitate the assembly and disassembly of the assembly, a groove (width of 3 mm, depth of 3 mm) is provided at the root portion of the sleeve and a corresponding retainer is fitted.

Fourth, after the improvement of the gear pump mechanical seal, the main leakage point was eliminated. Before the improvement, the average service life of the mechanical seal was about 8 months. After the improvement, the mechanical seal runs smoothly and the failure rate is significantly reduced.