Study On The Online Monitor And Control Technology Of The VOCs In The Printing Process

VOCs(Volatile Organic Compounds), diffusing into the air can seriously affect the atmospheric environment and endanger human health. At present, VOCs control technology is mainly focused on source and terminal treatment.Study on the diffusion characteristics of VOCs in the printing process and monitoring program is proposed, by changing workshop environment condition to improve VOCs collection, providing basis for VOCs control in printing industry. Mainly including:(1)A computer fluid dynamics method(CFD) was used to simulate the laminar air conditioning system in the workshop. The VOCs flow and the control model were established under the coupling of temperature field and airflow field.The VOCs mainly distributed in the neighborhood of the printer. Most of the VOCs distributed around the printing unit.and the characteristics of uneven distribution was proposed.(2)According to the distribution characteristics, three kinds of VOCs monitoring methods, such as fixed point, uniformity and non-uniformity, were proposed. The VOCs emission was monitored by PID VOCs detector to verify the feasibility of the scheme, And at last, analysis the measurement uncertainty.(3)The ZigBee technology was applied to the gas concentration monitoring system, and the wireless sensor network with the topological structure as the mesh network was built. Completing that in the complex environment real-time monitoring of the VOCs for long time, unattended, multi-point monitoring and multi-alarming.(4)The VOCs capture efficiency of the terminal treatment facility in the printing industry is only 20-40%. By changing the environmental conditions of the workshop, the air supply angle is 45 °, which is beneficial to the concentration of VOCs in the workplace, effectively improving the collection rate of the gas gathering device.