A brick that exuberates energy
Sushant Sarin, Executive VP- Commercial Line, TATA AIG General Insurance, tells us the importance of refractory fire brick that are used in high-end production materials and how these help in conserving energy.
REFRACTORY FIRE BRICK
A fire brick is a block of refractory ceramic material used in lining furnaces, kilns, fireboxes and fireplaces. A refractory brick is designed mainly to withstand high heat but should also usually have a low thermal conductivity to save energy. Usually dense refractory bricks are used in applications with extreme mechanical, chemical or thermal stresses, such as the inside of a wood-fired kiln or a furnace, which is subject to abrasion from wood, fluxing from ash or slag and high temperatures. Dense refractory bricks have a high thermal mass which is sometimes a useful property in that they will retain heat example, in a pizza oven after the fire has been taken out. Kiln bricks are made by firing a clay based composition in the kiln until it is partly vitrified, and for special purposes may also be glazed. The maximum service temperature increases with increasing alumina content and kiln bricks can be obtained with an alumina content of 80 per cent and above. LESS DENSE REFRACTORY BRICKS In other less harsh situations, such as a natural gas fired kiln, more porous bricks are a better choice, usually referred to as Insulation Bricks. They are weaker, but they are much lighter, easier to form, and insulate far better than dense bricks. In this case they have a low thermal mass and so cannot be used to store heat. Insulation bricks have a better thermal shock resistance than dense firebricks but the main disadvantage is their low strength. PACKING AND TRANSPORT The refractory bricks are largely transported in shipping containers. Because refractory materials are heavy, they reach the container weight limit before the container’s volume limit. Hence, such cargoes require dunnage for blocking and bracing the pallets inside the containers. For maximum space utilisation (weight v/s volume) it is advisable to use 20 feet container than a 40 container. The refractory material are also considered fragile and hence their shipping requires special attention. There are numerous incidents noted where the pallets are loaded inside the containers with marginal gaps on sides or in middle space and this allows pallets to move during transportation or sea voyage and the cargo gets damaged. Hence it is prudent to employ use of adequate bracing and blocking inside the containers. As long as adequate blocking & bracing procedures are followed, there should be no major causes of concern. SAFE MEASURES Safe worthy packing, marking and transportation rom vendor to consumer is important: All parts should be protected against damage, vibration, rain, dirt and corrosion. Bricks are stacked on pallets with corner protections so as to prevent any physical damages like edge chipping, transit breakage/cracks; handling breakages while storage and application or any other. The vendor has the obligation to mark all individual parts clear and durable to allow easy identification during erection works. All individual items contained in one packing are to be listed in the respective packing list. For all shelf life items, date of manufacturing, batch number and date of expiry shall be legibly stencilled on the bag itself. Consumer’s approved agencies reserve the right to verify the date of manufacturing from the records at vendor’s manufacturing premises also. Each piece shall be clearly marked and identified. Codes shall also be marked on part list and erection drawing.
It is a common practice that such cargoes are unloaded from containers and sent by open truck/ trailer during the last leg of journey. In India, most such operations are done in the evening or late hours and this exposes cargo to handling damages, wet damages in inclement weather, shortages and sometimes loss of total volume too.
It is thus prudent to employ external surveyors during such operations to supervise the transhipment and following scopes can be given to surveyors for attendance: Check the cargo condition at the time of door opening of containers Ensure that cargo handling equipments such as forklifts and their handlers are well versed and ensure physical condition of truck/trailer, condition of tyres, tyre pressures and documentation Ensure adequate quantity and quality of lashing material is available with truck/ trailer/transporter Ensure safe unloading of cargo from container Ensure safe loading method on truck/trailereach unitised cargo is adequately stowed on truck/trailer bed Ensure that cargo is duly covered for prevention rom water/ external damages Ensure that proper protest letter is submitted to the respective party or conveyed. (The views expressed are solely of the author. The publication may or may not subscribe to the same.)