Before commencing work, ensure that all power and water are shut off from the coil and furnace .
1. Raise and swing the lid to one side (if supplied).
2. Remove the old top cap material together with side and bottom lining material.
3. Remove back & front covers and terminal supplort blocks
4. Disconnect power leads at coil and tie leads back for clearance. When disconnecting the water cooled leads from the coil they should be marked, relative to coil connections to ensure correct reassembly. Take precautions that dirt is not allowed to enter the coil/lead and that the stud union are not damaged during coil removal.
5. Chip out and remove any infill material from around the tops of the vertical tie rods at furnace.
6. Remove the end nuts from one end of each horizontal top tie rods and then remove tie rods.
7. Lift away the top blocks, taking care as they are heavy.
8. Remove any internal material that wil prevent the coil being withdrawn.
9. Remove the teflon and high temperature gasketing material.
10. Check condition of coil supports. If split, broken or burned enough to be weakened, bind face. Remove the nuts. turns of the coil together with straps, rope or other suitable means so that when the coil is lifted out of the furnace the turns will not be pulled apart. A coil in this condition may be salvaged by repairing.
11. On small/medium furnace, remove nuts from above coil brackets. On larger furnaces using coil restrain assembly. Slacken the nuts allowing the coil clamp blocks to move outward.
12. Lifting the coil can be done in a number of ways, depending upon the type of equipment available for hoisting the coil out of the furnace and/or the condition of the coil. There are several points to be noted concerning the lifting devices (refer figure 1, 2 & 3). If the coll supports are intact, nylon straps, one each at 120 degree C and positioned as close to the coil supports as possible, may be used to lift the coll by hoist, crane, forklift, etc.
13. Some specific coils should be provided with hooks. These hooks must be of firm and size to permit insertion between the turns at the lower part of the coil section.
14. On all large furnace coils, a metal strap loop must be bolted to the upper end of four equidistant oil supports. A rigid lifting device must be fabricated which will pick up the coil at these four points.
PROCEDURE DURALINE FURNACE REASSEMBLING THE FURNACE COIL
The-following procedure should be followed while reassembling the coll:
1. Ensure that you have sufficient material and tools on hand.
2. Clean out all loose material and debris in the bottom of the furnace shell.
3. Lower the rings of Teflon and high-temperature gasketing material in the furnace, with the Teflon ring facing the coil. Place them concentric to the furnace shell.
4. Lower coil into position, ensuring that terminations are in correct position, check that these terminations are not damaged while lowering the coil.
5. Check that the coll brackets are in the correct position to fit over the tie rods.
6. On single tie rod, slacken nut below coil bracket to ensure coil is resting on bottom block and not the nuts.
7. After coil is refitted, replace upper nut. On dual tie rods, tighten the clamp block nuts to push block against the coil posts
8. Connect internal hoses. Refer to the coil water drawing and check that correct connections have been made. Hoses should be suitable for this type of application, being non-ductile, and must not have metal braid reinforcing. Use only non-magnetic stainless steel hose clamps.
9. Once this is satisfactory, the top block can be refitted.
10. Refit all tie rods, ensure that coil is central in furnace and the tighten all tie rod nuts.
11. Tighten nuts on coil bracket in small medium furnace and clamp block nuts on larger furnace.
12. The front & back cover can now be refitted.
13. Reconnect all water-cooled leads to the furnace manifold, checking that they are connected in correct position.
14. At any time during coil removal inspect the earth leak detector for damage and replace the spider wires as necessary using lengths of SS 304 wire welded to stubs of original probe. They must touch charge material.
15. It the coils has not been Coll grout, now is the lime to do it. use taper lining tools provided to ensure a proper taper on the coil coat.
16. Check all around to make sure installation is complete and all nuts, etc., are securely tightened. While water is running, check for leaks and tighten connections if necessary.
17. Refit all access covers and tighten all bolts.
REMOVAL OF HYDRAULIC CYLINDER
1. Note that hydraulic should be off and the system pressure relieved.
2. Disconnect hydraulic lines. Make note of the various connections and mark them so that they can be replaced correctly. Ensure that dirt cannot enter the hydraulic lines or the cylinder by securely fitting suitable caps on open pipes/fittings.
3. Slacken lock pin on the cylinder base lug and push the base pivot out.
4. Remove lock washer and bolt from the end of the cylinder head shaft.
5. The cylinder can now be removed. The cylinder can be repaired by a competent hydraulic engineer
REMOVAL OF PIVOT BEARING
1. Ensure that load is taken off the pivot pins by packing the furnace body up or using a suitable crane.
2. Remove the bearing covers.
3. With the furnace supported, the securing bolts for the bearing can be removed from the stanchion side plates.
4. Slide the bearing off the pivot shaft.
5. When replacing the bearing ensure that the shaft and bearing are well lubricated.