Energy loss in fired brick and flue gases
Energy loss in fired brick and flue gases : The fired bricks coming out of the kiln are at a temperature higher than the ambient temperature and thus a part of the heat contained in fired bricks is lost. Similarly, the hot flue gases leaving the chimney also contain heat. The higher the temperature of the fired brick at the kiln exit, the higher the measurable heat loss in fired bricks would be. The flue gas loss depends both on the temperature and on the flow rate of ? ue gases. Thus the fired bricks and the flue gases coming out of the kiln should be at the lowest possible temperatures. Further, fired brick and flue gas temperatures depends on the efficiency and completion of heat transfer process between air and bricks inside the kiln.
VSBK has a very efficient counter-flow heat transfer arrangement. The key to this is the brick setting arrangement. Here, bricks do not touch each other and every brick has air passages on all the four sides. All the four sides of a brick thus come into contact with air, which results in a high heat transfer area per brick. In contrast, in BTKs the bricks are arranged in the form of solid columns and bricks set inside the column do not directly come into contact with air, resulting in lower heat transfer area per brick. The heat transfer process in a VSBK is so efficient that the flue gases coming out of the shaft are cooled down to around 100 oC , while the fired bricks at the bottom have temperatures in the range of 1000-150oC.