No water cooling measures such as water pouring, spraying or water injection should be used to cool Chain Grate Stoker Bars when the boiler is running or immediately after shutdown at high temperatures. This wrong operation must be avoided in boiler maintenance, because it is an important cause of rapid damage and premature scrapping of Chain Grate Stoker Bars, seriously endangering structural integrity and service life.
Chain Grate Stoker Bars operate continuously at furnace temperatures of hundreds of degrees Celsius. After sustained combustion, these metal components stay in a thermally expanded state with sufficient structural tension, and their material toughness and internal stress fully adapt to high-temperature working environments. Direct contact with cold water will lead to an abrupt temperature drop on the bar surface, while the interior remains at a high temperature, forming a huge temperature gradient inside the component. Such an extreme temperature difference makes the outer layer contract sharply while the inner part remains expanded. Reverse internal force occurs instantly, producing thermal shock stress far beyond the component' s tolerance limit.
Even a single instance of water cooling at high temperatures will create numerous invisible microcracks on the bar surface, destroying the structural integrity and toughness of the metal. Repeated improper cooling enables microcracks to spread and connect, resulting in serious failures such as extensive cracking, spalling and fracture. In addition, drastic alternating hot and cold conditions will change the material properties of Chain Grate Stoker Bars and lead to embrittlement and hardening. The original high-temperature resistance and wear resistance drop sharply, making deformation, accelerated abrasion and jamming breakage very likely during subsequent normal operation.
Apart from component damage, water cooling at high temperatures generates massive hot steam that disturbs the combustion conditions inside the furnace. Residual vapor adheres to gaps and surfaces of Chain Grate Stoker Bars, absorbs dust and slag after cooling, and accelerates the accumulation of ash and clinker. This will lead to operational jamming and uneven heating of the grate in later operation. Natural cooling is the correct method. Keep proper ventilation in the furnace after shutdown for steady heat dissipation. Allow Chain Grate Stoker Bars to cool slowly together with the furnace temperature to release internal stress, maximally protecting the bar structure and extending the service life.
