Single effect evaporator The single-effect external circulation evaporator completes most of the gas-liquid separation in the separation chamber. Therefore, the external circulation evaporator can be more easy to mist entrainment and even run away. The separation chamber must have sufficient separation volume. In addition to the tangential way of the inlet, a foam trap must be installed in the separation chamber. The secondary steam should be discharged at the top of the separation chamber, and the secondary steam pipe should be inserted into a section of the separation chamber. The length of this section is generally between 150-250mm that can play the role of swirling flow, which is conducive to the further separation of gas and liquid. In order to better recover the material liquid entrained in the secondary steam, it is also possible to install a baffle-type or cyclone-type suds catching device between the separation pipe and the condenser pipe in the discharge pipe.