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5.2. Design calculation of autoclave vessel

Autoclave vessel is modelled by thin plate finite elements, while the supports were

modelled using volume finite elements (Fig. 5.2).

Calculations of existing vessel were performed for a pressure 0.3 kN/cm

and

temperature 200

C, with a difference of 20

The existing autoclave vessel design was examined for two situations: with no

blockage and with a blockage in the support zone with two neighbouring device seg-

ments. Blockage of the area between two slant plates resulted in fluid pressure only from

one side. This enabled following conclusion for the calculation of the existing autoclave

vessel, when blocked in the segment support:



vessel deformation in the segment support zone increased significantly , followed

by an unfavourable shape;



the maximum stress value acts in the whole shell zone around the segment

support, reaching the value 19.8 kN/cm



exaggerated stress concentration affected complete autoclave shell around the

segment support.

5.3. Calculation of redesigned autoclave vessel

Calculation of no blockedvessel revealed the state of strains and stresses in regular

service conditions, and for the vessel blocked in the segment support zone possible

occurrence of cracks was indicated. Redesigned model indicated an important impro-

vement in stress distribution (Fig. 5.3).

5.4. Defining activities required for evaluation of the remaining autoclave

The proposed improvement of vessel design required overhaul and reconstruction of

segment supports and segments of the emptying device should assure an extension of

continuous autoclave operation in the redesigned zone for a long service life.

Proposed project of autoclave vessel service life extension should be based the

assessment of remnant operating life, through an experimental-numerical procedure:



select one autoclave as a representative for the assessment of the remnant life;,



visual inspection of the complete autoclave vessel;



inspection with the testing of all welded joints;



measuring plate thickness of the whole autoclave vessel;,



determination of parameters for the facture mechanics;



experimental dynamic measurement of strain and temperature during service;

numerical procedure for calculating of the remnant operating time based experimental

procedures.

6. NUMERICAL AND EXPERIMENTAL DIAGNOSTICS OF THE BEHAVIOUR

OF THE PALETTE-PACK MACHINE

Considered machine packs one palette in eight cycles, each with five sacks of 50 kg.

Packing of the tours is in cross positions. One cycle is consisted of following operations:

lifting with rotation of the palette to the position for packing, moving 5 sacks from the

transporter to the palette, descending the palette and lifting to the position for removing

air from sacks and descending the palette for the beginning of the next cycle. The whole

palette is packed in minimum 40 seconds.