5 Converter Installation
5.1 Trunnion Bearing Pedestal and Trunnion Bearing
5.1.1 The installation of trunnion bearing pedestals shall comply with the following requirements:
1 The bearing pedestal and the bearing support shall be assembled as required by the design drawing，and the local clearance between the bearing pedestal and the wedge of bearing support shall be checked with the feeler gauge，being not larger than 0.05mm.
2 The installation of bearing pedestal at the fixed end shall comply with the following requirements:
1）The longitudinal and horizontal center lines shall be adjusted，and the measurement by plumb wire should be carried out，with the allowable deviation of 1.0mm.
2）The elevation shall be adjusted，and the measurement by optical instrument should be carried out，with the allowable deviation of±5.0mm.
3）The longitudinal levelness shall be adjusted，and the measurement by leveler should be carried out，with the allowable deviation of 0.10/1000.
4）The horizontal levelness shall be adjusted，and the measurement by leveler should be carried out，with the allowable deviation of 0.20/1000.The deviation should become smaller towards the furnace body.
3 The installation of bearing pedestal at the floating end shall comply with the following requirements:
1）The longitudinal and horizontal center lines shall be adjusted，and the measurement by plumb wire should be carried out，with the allowable deviation of 1.0mm.The deviation direction shall be consistent with that of the center line of bearing pedestal at fixed end.
2）The elevation difference of the bearing pedestal from the floating end to the fixed end shall be adjusted，and the measurement by optical instrument should be carried out，with the allowable deviation of 1.0mm.
3）The central distance of these two bearing pedestals shall be adjusted，and the measurement by tapeline should be carried out under the state of fixed counterbalance，with the allowable deviation of±1.0mm.
4）The diagonal relative error of these two bearing pedestals shall be adjusted，and the measurement by tapeline should be carried out under the state of fixed counterbalance，with the allowable deviation of 4.0mm.
5）The longitudinal levelness shall be adjusted，and the measurement by leveler should be carried out，with the allowable deviation of 0.10/1000.
6）The horizontal levelness shall be adjusted，and the measurement by leveler should be carried out，with the allowable deviation of 0.20/1000 for non-articulated structure and 0.10/1000 for articulated structure.The deviation should become smaller towards the furnace body.
5.1.2 The assembly of trunnion bearings shall comply with the following requirements:
1 In case the backing rings are supplied in parts，the trunnion bearings shall be assembled after completion of backing rings'assembly.
2 The trunnion bearings should be assembled with temperature difference method and according to the following procedures:
1）Clean up the bearings and trunnions.The bearings shall be checked to ensure no damage，rust，flexible turning or abnormal sound，and the trunnion shall be checked to ensure that its surface is smooth and it shall be applied with lubricating oil.
2）Measure the mounting dimensions of trunnions and bearings.The outside diameter of trunnion should be axially measured with an external micrometer at such three areas thereof as internal，middle and external areas respectively in 8-12 equal parts along the circumference.The inside diameter of bearing should be measured with an internal micrometer at such three areas thereof as its both ends and middle part in 8-12 equal parts along the circumference.After then，the interference value for assembly shall be calculated with the average value of the above two results，and within the corresponding tolerance after compared with the design.
3）The heating temperature of bearing should be calculated on the basis of actually-measured interference value together with the clearance required for assembly，and the expansion amount of bearings shall ensure the successful assembly of bearings and trunnions.The expansion amount should be controlled with two methods simultaneously，that is，measuring the heating temperature with a temperature monitor and controlling the expansion amount with a sample rod.The length of sample rod shall be the sum of the average value of actually-measured inside diameter of bearing and its required expansion amount.
4）The engine oil and bearing shall be heated via covering the oil groove with an electric heating element，or the bearing be heated with the hot air.After the bearing is up to the heating temperature，the temperature shall be held for appropriate period so as to ensure it evenly heated.
5）Prior to assembly of bearing，the parts inside of the bearing shall have been erected.
6）After properly heated，the bearing shall be assembled with trunnion.After they are positioned，appropriate measure shall be taken to prevent a clearance occurring between the bearing and the shaft shoulder in the process of cooling.
7）After completion of bearing assembly and cooling，whether the bearing can roll flexibly and is free of any defect shall be checked.
5.1.3 The assembly of trunnion bearing and bearing pedestal shall meet the requirement of the design technical document or related requirements of the current national standard General Code for Construction and Acceptance of Mechanical Equipment Installation Engineering GB 50231 in case of no related requirement in the design technical document.