Described herein in one embodiment is a plant for the continuous solution polymerization of one or more monomers in a solvent, e.g., a hydrocarbon solvent. In one aspect, the plant comprises a high pressure pump and at least one heat exchanger downstream of the pump. In another aspect a feed is cooled by three heat exchangers which are refrigerated by means of a common three stage compressor. In another aspect, the plant comprises a primary reactor and a secondary reactor arranged to operate in parallel, in which the ratio of volume of the primary reactor to the secondary reactor is in the range of 60:40 to 95:5. In another aspect, a method of defouling a heat exchanger is provided in which the level of liquid refrigerant in the heat exchanger is temporarily lowered.