Chinese researchers have recently developed and put into use a high-efficiency submersible pump, a move to improve safety in the nation' s coal mines, researchers said on Thursday.

Jointly developed by Hefei University of Technology and Sanyi Jianghai Pump Co., Ltd. of Hefei City in east China's Anhui Province, the 4,000 kilowatt pump is believed to be the most powerful in the world.

Submersible pumps are used to drain coal mines, both during daily production and coal mine flooding. The newly developed pump will greatly improve rescue work when a mine is flooding, said Li Gang, a researcher from Hefei University of Technology.

"An ordinary submersible pump can only drain off about 100 cubic meters per hour, while this high-efficiency pump can drain off up to 1450 cubic meters per hour, significantly shortening rescue times," Li said.