We constructed a novel sonochemical reactor for heterogeneous solid fluid reactions which uses high intensity ultrasound from a concentrator horn It can be shown that the concept of a conical funnel fits the demands for a nearly perfect radiation effectiveness and a good reaction management. Theoretical investigations concerning the sound field in both the sonotrode and the reactor for different cases give some insight in the fundamental relationship between consumed electrical power, converted mechanical energy in the transducer and radiated sound energy. The main energy conversion paths in the liquid are presented as well. A Grignard reaction was investigated in the reactor and showed extreme reaction rate enhancements which are due to a mechano chemical reaction kinetic caused by imploding bubbles and the thereby generated shock waves and microjets. A simulation of the particle size distribution during simultaneous reaction and fragmentation in an ultrasonic loop reactor was developed to correlate measured size distributions with model equations.