Trunnion blocks

Fig ure 5-15. The inlet support, with the trunnion blocks, supports the inlet casing and is designed for thermal expansion of the casing while maintaining the centerline of the unit. 

TUBE RESTS ON TRUNNION BLOCKS AT INLET B OUTLET. AT BOTTOM W CHANNEL IN CENTER OF STACK. 

Additional experimental data on graphite indicated that graphite growth occurred only in a direction p erpendicular to the axis of extrusion. In fact, para.iiel to the axis of extrusion some minor amount of contraction will occur. This fact permitted undercutting all Sides of the tube blocKS if trunnion blocks were used to give the required stack spacing. 

The top of each trimTion is undercut because verticrii growth will occur in the trunnion, io the aide to side direction the trunnion is full width [.,Z lattice si-scing). Expansion in the front to rear direction is matched by uxial contraction of the tube blocks, H Rf actor made the nrst se oI trunnion blocks. 

Shown, but not identified, in the Figure B-3 are the trunnion blocks provided at each junction between tube blocks These trunnion blocks provide a smaller I. D. bore than the tube blocks. Hence, the tube will be supported by the trunnion blocks. Moderator cooling tubes will be positioned over and under each except the front and rear most trunnion blocks, reducing the process tubes outer surface temperatures at the point of contact Moderator cooling tubes are also positioned midway between adjacent trunnion blocks. Hence, if distortion ultimately causes tube to contact the tube block, it will again contact cooled graphite. 

Figure 12-61 also illustrates three basic types of trunnion rollbearing assemblies. Antifriction pihow blocks are the most common on modern diyers however, when the dryer load requires larger than a 12.7- to 15.2-cm-diameter bearing on the trunnion shaft, the dead-shaft antifriction bearing is substituted. This represents a considerable cost saving compared with the larger pillow blocks. They are completely sealed and continuously bathed in lubricant. Pillow-block bushings are less often used. The thrust washers are difficult to seal against dust, and they draw more power. Thrust roll mountings are depicted also in Fig. 12-61. These are usually dead-shaft.

All drum filters (except the single-compartment filter) utilize a rotary-valve arrangement in the drum-axis support trunnion to facih-tate removal of filtrate and wash hquid and to allow introduction of air or gas for cake blowback if needed. The valve controls the relative duration of each cycle as well as providing dead portions of the cycle through the use of bridge blocks. A typical valve design is shown in Fig. 18-121. Internal piping manifolds connect the valve with various sections of the drum. 

HT 1 Hole Operation. Special procedure is necessary for operation with the HT 1 hole. The coffin is removed from the dolly by the crane and rolled over 180 on a special fixture. It is then lowered on the dolly with the trunnion riser blocks removed. When the coffin and dolly extensions are bolted on, the coffin is ready for use. 

Some typical cylindrical joints are gear to shaft, rotor to shaft, bearing into housing, tube into casting, cylinder liner into engine block, pulley to shaft, fan to shaft, trunnions into rollers and bushings into housings. 

---