The invention relates to a 
tryptophan TVR (Thermal Vapor Recompressor) 
evaporation, concentration and 
crystallization system, and a method for concentrating and crystallizing by using the 
system, which belong to the field of 
biotechnology manufacturing. A first effect 
evaporator and a first effect 
circulating pump form a circulation path through a pipeline; the first effect 
evaporator and a firsteffect separator are communicated through a pipeline; the first effect separator and a second effect 
evaporator are communicated; the second effect evaporator and a second effect separator are communicated; the second effect separator is connected with a second effect 
circulating pump through a pipeline; the second effect 
circulating pump is communicated with the second effect evaporator through apipeline; an 
evaporation and 
crystallization device and a circulation 
discharge pump form a circulation path through a pipeline; the 
evaporation and 
crystallization device is also communicated with asurface condenser; the 
surface condenser is connected with a vacuum condensation water tank through a pipeline; the vacuum condensation water tank is connected with a vacuum condensation water pump.According to the 
tryptophan TVR evaporation, concentration and crystallization 
system, and the method for concentrating and crystallizing by using the system provided by the invention, through ingenious and effective combination of an evaporation and concentration technology, a TVR technology, a multiple-effect evaporation technology, and an evaporation and crystallization technology, heat energyin various parts in the system are fully utilized, so that vapor and materials fully exchange heat to achieve 
heat balance, so that the whole system is stable in temperature, steady, and easy to control.