Heat Pump Evaporation Crystallization Technology of Salt-containing Phenol Wastewater

Xiantao Zhou,Longwei Ran,Fei Wang,Yun Chen,Tong Yang,Xiaoqing Chen

doi:10.11648/j.ajwse.20190503.13

Abstract

China is a large country in the production and use of pesticides, and the production and use of pesticides are among the highest in the world. According to statistics, the ratio of wastewater from pesticide production to wastewater discharged is about 1:100. Arbitrary discharge of a large amount of pesticide wastewater has caused serious environmental problems. The main way of pesticide wastewater treatment is to optimize emission reduction and control emissions. At present, treatment is the main way. There are many kinds of pesticide wastewater, which need targeted treatment, greatly increasing the difficulty of treatment. This paper takes the salty waste phenol wastewater discharged from a pesticide factory as the carrier, through basic physical property analysis, thermal property detection, crystallization kinetics research, basic small test, pilot scale amplification, research and development for the evaporation of this wastewater, crystallization processing equipment. In order to optimize the process route, it is preferable to use MVR compressor technology in comparison with multi-effects. Under the conditions of evaporation temperature 75°C to 90°C, compare the parameters of compressor power, cooling water volume, total energy consumption of evaporation crystallization device, total area, etc., and determine the evaporation temperature to be 90°C. In order to improve the energy utilization rate, the heat such as condensed water, crystal slurry output, and mother liquor reflux is rationally utilized. The multi-stage plate preheater and plate evaporator are used in the equipment design. The separator and condensed water vapor-liquid separation device adopt the patented structure to improve the operation efficiency.

Highlights

China country has more than 1400 pesticide factories and the second largest pesticide output in the world, with about400,000 tons
The heat source of the preheater adopts the evaporated condensed water, and the other part comes from the excess steam after the compression and the fresh steam; In order to ensure that the steam and fresh steam at the outlet of the compressor do not affect each other, it is best to set it to two sections)
The water spray cooling device designed for the compressor outlet usually has a large amount of water spray, and the design of the condensed water and excess cooling water collecting and discharging device here is more important

Summary

Introduction

China country has more than 1400 pesticide factories and the second largest pesticide output in the world, with about. The solution to the problem of wastewater pollution lies in the development and use of new production processes that can reduce the generation and discharge of pollutants. The basic physical properties of wastewater were studied and the evaporative crystallization and chemical characteristics of saline wastewater containing phenol were obtained by means of experiments [5]. The MSMPR model was used to carry out the related experiments on the crystallization kinetics of wastewater, the Xiantao Zhou et al.: Heat Pump Evaporation Crystallization Technology of Salt-containing Phenol Wastewater experimental measurement of the crystallization nucleation rate and the grain growth rate, and the MVR evaporation and crystallization device were designed for the process, equipment and foundation. 2. Study on Characteristics and Crystallization Kinetics of Salinated Phenol Wastewater

Determination of Basic Parameters of Physical Properties

Process Design

Industrial Operation Results and Analysis

Conclusion