What is a tap-hole?

[Audio] What is a tap-hole?. . . . A hole which molten metal or slag is tapped off..

[Audio] Tap-hole. (Not commonly used at Metix) . . Spout tapping, Slag & Metal/Mat is tapped by tilting the furnace. (up to 45°). Non-continuous operation of furnace. Low purity of materials. . Bottom Tapping. . Metal is tapped up to slag level. There after slag can be tapped. The furnace is tilted up to 25°. Continuous operation of furnace. Low purity of materials. . Tilt/Top Tapping. . Slag & Metal/Mat is tapped by completely tilting the furnace. Non-continuous operation of furnace. Low purity of materials. ..

[Audio] The Hole. (More commonly used at Metix). . Combined tapping. . Slag & Metal/Mat is tapped by opening and closing the tap-hole. Continuous operation of furnace. Low purity materials. Round furnace has only one combined tap-hole. Rectangular furnace can have multiple combined tap-holes. . Dedicated Tapping. . Slag & Metal/Mat is tapped independently by their individual tap-holes by opening and closing of each tap-hole. Continuous operation of furnace. High purity materials. Slag or metal/ mat can be built-up until tapping is required. Round furnace has only two dedicated tap-holes. Rectangular furnace can have multiple dedicated tap-holes. Advantages of dedicated tapping: Water granulation. Dry air atomisation (sometimes with energy recovery). Sails of slag for slag products. Handling of corrosive/acidic slag. . Emergency Tap- Hole. . Tap-hole used for emergencies and draining of furnace for maintenance. Emergency tap-hole may tempt an emergency..

[Audio] Location of Tap-Holes in furnace. . The tap-hole is located close to the heart of the furnace to avoid unmelted product from being tapped..

[Audio] Opening of tap-hole. . Tap-holes are opened by a variety of methods . . Kiln Gun. Remington Masterblaster or Winchester. 8 Gauge Industrial Shotguns. . Soaking bar technique. From ' 80s to the ' 90s. It involved pushing/hammering a 50 mm bar through the mud in the tapping channel. . Manual or Automated/ Robotic Oxygen Lancing. Method use since 1901. Typically 3 and 6 m long, and 1/2", 3/8", and 1/4" in diameter. . 4. Drilling Average drill bit size 76mm dia by 1.5 m to 2m deep. . Stinger. They are used specifically when a smelting furnace has cooled down and the molten product has solidified. ( Works like Furnace Electrode).

[Audio] Closing of tap-hole. . Mud Gun . Method use since 1896. A injection like machine that injects " mud" into the tap-hole. . Combined systems. . 1. Combined tapping machines. . A mechanism that has both a mudgun and a drill. . 2. Slag Valve/ gate A valve or gate that is hydraulically opened and closed. ..

[Audio] Typical Mud guns & Drills. . Individual rail mount. . Combined rail mount. . Combined Column mount. . Individual pedestal mount. . combined pedestal mount. ..

[Audio] Launders. . Launders are placed under tap-holes to guide molten slag and/or metal/ mat to where it should go. To the ground, Ladle or granulation. Placed at an angle so gravity can do the work. Lined with lime or some kind of refectory to protect them. . Thins to consider . Fume extraction - Launder covers and Fume hood. Length of launder - ???mm Max . Angle of launder - ??°Min & ??°Max. Turning radius - ???..

[Audio] Refractory . . Refractory material or refractory is a material that is resistant to decomposition by heat, pressure, or chemical attack, and retains strength and form at high temperatures. . Refractory is used to line the furnace, Launders, Matte/ metal ladles, slag pots and floors to protect them and increase their lifespan. . Furnace brick lined refractory . . Metal ladle with damaged refractory . . Metal ladle prep for new refractory . ..

[Audio] Fume hood & launder covers. . All launders require Fume hoods and covers to capture the off gas. . Launder Cover Manipulator. ..

[Audio] Swinging and Tilting runners. . The runner is first tilted/ swigged to fill the hot metal ladle on one track and then tilted/ swigged back to fill the ladle on the other track. While the second ladle is being filled, the first one can be replaced with an empty so that the cast can be continued uninterrupted while several ladles are filled. They are usually equipped with hydraulic drives for providing the angles required for teeming of the hot metal. . Swinging runner. . Tilting runner. . Tilting runner with torpedo cars. ..

[Audio] Ladles. . We have 2 types of ladles: Mat/metal ladle and Slag pot. The ladle and the operation to follow will determine the height between the ground floor and the tapping floor. Ladles should not be placed under tapping floor, launder to carry molten slag, mat/metal pas tapping floor edge. . Mat/Metal Ladles. . Slag Pot. ..

[Audio] Ladle cars. . Used for transporting hot and cold slag and mat/metal ladles between furnace and casting floor. . Torpedo ladle car. . Mat/Metal ladle car. . Tilting slag pot rail car. . Mat/Metal ladle rail car. . Cascading Metal/slag ladles rail car. ..

[Audio] Separation by density. . When the metal and slag are tapped together through the same tap hole, they have to be separated post-tap hole. . Cascading. . Slag overflows from the metal ladle to the slag ladle. . Skimming. . Removing or hold back dirt or slag from the surface of the molten metal before or during pouring., . Skimming process. . Cascading process. ..

[Audio] Positioning of equipment around tap-hole. . When placing equipment keep in mind the following: , Lancing shield 6 to 8 meters away from Tap-Hole. Floor should extend 7 meters Minimum. Movement of tapping equipment. Visibility of working positions. Removal of gasses. Removal of molten slag or Metal/ mat. Floor refractory. ( 1 meter around tap-holes and launders)..

[Audio] Always be on the look out for clashes! . Typical clashes. . Clash between Tapping equipment and fume hood . . Clash between drill gearbox and floor refractory. . . Clash between Mudgun head and launder. . . TMT COMBINED TAPPING EQUIPMENT facing wrong way. . ..

[Audio] Summary. . . . Types of tapping in furnace. Spout tapping, Bottom tapping, Tilting/ Top tapping, Combined tapping, Dedicated tapping. . Tap-holes to be positioned as close to the furnace heart as possible. . Slag tap-hole always above Mat/Metal tap-hole. Emergency tap-hole positioned as close to the bottom of the furnace as possible.(May encourage emergency) Tapping floor 900mm minimum below Mat/Metal or combined tap-hole. . Opening of tap-hole done by one of the following methods. Kiln Gun, Soaking bar, Manual or Automated/ Robotic Oxygen Lancing, Drilling or Stinger graphite electrodes. . Closing of tap-hole done by one of the following methods. Mud gun or by sliding gate or valve. . Launders to be placed at an angle to guide molten slag or mat/metal. . Launders and ladles are lined with refractory. Refractory is also common in floors around tap-holes and launders. . Fume hoods and lander covers needed for fume extraction and floor cover to walk and drive over. . Slag pots and Mat/Metal ladle size and the process there after will determine the height between the ground floor and the tapping floor. . Separation by density done by process of skimming or cascading. . Keep in mind visibility of working stations. . Always be on the lookout for clashes. ..

[Audio] Setting out procedure. . Step 1. . Determine the height of the process after the launder. This will in turn determine the height of the launder end. . Step 2. . Determine the height of the launder through the length and angle. ( Launder should extend pas tapping floor edge) Keep in mind. Length of launder - ???Mm max angle of launder - ??°min & ??°max Turning radius - ??? . Step 3. . Determine tap-hole height & tapping floor height. Tapping floor to be placed 500mm minimum under launder or 900mm minimum under tap-hole. . Step 4 . Determine position of tapping equipment. Keep in mind. Movement of tapping equipment. Clearance to avoid clashes. . Step 5 . Determine position and size of fume hood. Keep in mind. Movement of tapping equipment. Clearance to avoid clashes. Fume extraction ability. Visibility of tapping equipment operating station. . Step 6. Determine position of lancing shield. (If applicable) Lancing shield opening should be directly over tap-hole. Keep in mind. Visibility of tap-hole. Lancing shield to be position between 6-8 meters away from top-hole If shield is movable, alternate position. Clearance for operator behind shield. . Step 7. . Determine position of tapping equipment operating station. Keep in mind visibility of tap-hole and tapping equipment. Clearance for operator behind station. . Step 8. . Determine the aria that needs refractory. 1m AROUND TAP-HOLE AND LAUNDERS. Keep in mind heat exposure. . Step 9. . Determine position and number of launder covers. Keep in mind safety. Fume extraction. Worker/equipment/ vehicle movement. Clearance for clashes. Launder maintenance. . Step 10. . Position the crawl for maintenance and replacement of the tapping equipment and the launders. Keep in mind clearance. Where the launders and tapping equipment should go. Weight = size of crawl. . Always be on the lookout for clashes. , , References. . Setting out procedure. Tap-Hole Setting out Procedure. . Server Links. . MC536 PCC - Furnace Tapping Floor. MC363 Sakura - Casting Bay. Mechanical Standards Register. . Video Links. . Winchester. Tap-hole Drilling Machines. Oxygen Lancing. Mud Gun. Cast house Animation. . Documents Links. . 'The tap-hole' – key to furnace performance. ..