The experimental study on different combinations of connected vessels in airtight explosion process

The experiment was conducted on airtight explosion process of methane-air mixture in sphere- vessels linked by pipes. The impact of the length of pipes on the explosion pressure inside the vessels is analyzed through experiments by linking airtight vessels with pipes in different length. It can be concluded that when the single-sphere links the pipes, both values of the maximum explosion pressure and the rising rate of maximum pressure inside the spherical vessel, big or small, follow the trend of decreasing step by step. Meanwhile, the rising rate of maximum pressure and the volume of the vessel meet the cube root law. When the small spherical vessel connects the pipes, pressure inside the pipes is on the increase first, then decreases, after that increase again. While the big spherical vessel links the pipes, the pressure inside the pipes is on the decrease first, then increases, after that increase again. The rising rate of maximum pressure in the connecting set-up consisting of big and small spherical vessel is far higher than that in the single vessels. And the rising rate in the initiating vessel is slower than that in the secondary vessel. Given the growing length of pipes in the connecting set-up consisting of big and small spherical vessel, the values of maximum explosion pressure in secondary vessels gradually grows, despite gas is ignited in the big or small vessels; however, as regards to the pressure in the initiating vessels, the values of pressure in the big spherical vessel is on the decrease step by step and finally reaches a static figure, if gas is ignited in the big one. While the values of pressure in the small spherical vessel follow the trend of decreasing first, then increasing, finally declining to a static figure. As the devices of the connecting set-up are on the increase, the speed-decline of the pressure in the vessels accelerates. The experimental study on different connecting ways during airtight explosion process provides technical support and the scientific basis for safe design of engineering equipments.