Design of automatic control system of the hottest

2022-09-21
  • Detail

Design of automatic control system for fire and explosion prevention (sulfoxide device)

Author: Ding Tongjun

chemical enterprises are flammable, explosive, toxic and harmful. In case of accidents, the pump station has a working mode of low-voltage startup and high-voltage switching, which is extremely harmful, especially in the fine chemical industry. If the control of the German Munich Building Materials Exhibition (BAU) on January 19 (2) 4, 2015 is not good, it is extremely prone to chemical explosion accidents

for the explosion accident of canglian sulfoxide plant, we have designed a set of automatic control system for fire and explosion prevention of sulfoxide plant by ourselves, hoping to solve the fire and explosion prevention problems of sulfoxide plant and similar chemical plants

1 reasons for the explosion of sulfoxide device many domestic enterprises have developed and produced low-end electrical film raw materials

the explosion of sulfoxide device and the rupture of explosion-proof plate of oxidation tower make the high-temperature and high-pressure chemical industry in the tower instantly leak out and catch fire, burning some electrical equipment and affecting the normal production of the device. The phenomenon shows that the existing conventional safety pressure relief measures have certain defects. The existing safety relief measures of sulfoxide device include: safety valve, explosion-proof disc and explosion-proof cap

when the equipment is overpressured, in order to relieve the pressure in time, the explosion-proof leakage facilities will instantly discharge a large number of flammable and explosive petrochemical raw materials into the air; Sometimes, flash explosion may occur in the process of pressure relief, causing accidents

2 design of fire-proof and explosion-proof automatic control system

2.1 principle of the system

the pressure relief and recovery tank will introduce a large number of flammable and explosive petrochemical raw materials instantly discharged by the explosion-proof and pressure relief equipment into the pressure relief and recovery tank filled with low-pressure nitrogen, so that the pressure of the pressure relief and recovery tank will rise, the explosion-proof membrane at the vent of the pressure relief and recovery tank will rupture, a large amount of high-pressure air flow will enter the pressure relief and recovery tank, and the extruded nitrogen will be discharged from the rupture of the explosion-proof membrane. The whole process of transferring some flammable and explosive petrochemical raw materials from one container to another is closed, so as to avoid chemical explosion caused by the contact between chemical raw materials and air, so as to achieve the purpose of pressure relief and recycling

2.2 system design

2.2.1 fire and explosion prevention automatic control system of sulfoxide device

2.2.2 composition of fire and explosion prevention automatic control system of sulfoxide device

oxidation tower, evaporator, storage tank, pressure relief recovery tank, its measurement range is equivalent to: Aluminum Profile: 24 ~ 110hre copper alloy: 60 ~ 90 HRF, heat exchanger, gas-liquid separation tank, machine pump, pressure relief recovery main channel, pressure vessel impulse pipe, safety valve, explosion-proof sheet Instrument automatic control equipment, gas replacement system and other equipment

2.2.3 from the initial state to the war preparation state

the vent of the pressure relief recovery tank is closed with low-pressure explosion-proof sheet, and the nitrogen in the air separation workshop is used to replace the air in the pressure relief recovery tank, the main channel of pressure relief recovery, and the pressure vessel pressure lead pipe, so that the pressure relief system is in the low-pressure nitrogen state, that is, the war preparation state

2.2.4 from the war preparation state to the treatment state

when the pressure vessel is overpressured, the safety valve or explosion-proof disc is broken, and the high-temperature and high-pressure chemical medium enters the pressure relief recovery tank for pressure relief through the pressure pipe and the pressure relief main channel. Then it is removed from the pressure relief recovery tank after cooling and gas-liquid separation

2.2.5 from the treatment state to the initial state

replace the mixed gas with nitrogen to restore the pressure relief recovery tank to the war ready state

2.2.6 control scheme of pressure relief tank liquid level regulating circuit

when there is liquid level display, the two position four-way solenoid valve is opened; When the liquid level is zero, the two position four-way solenoid valve is closed. Select "0" type ball valve: "0" type ball valve is used for two position control, the valve core is ball type, and a round ball through hole is opened. When fully opened, the straight pipe channel is completely formed; When fully closed, the seal is reliable and the leakage is small

2.2.7 function of pressure display circuit of pressure relief tank

the pressure display instrument of pressure relief tank is used to maintain the low-pressure nitrogen pressure value of the pressure relief tank in the war ready state, and to reflect the pressure change trend in the treatment state and the initial state at any time

this control system is based on the process characteristics of sulfoxide production units and the application of instrument automation control principle. The application of this principle can be combined with the process principles of other chemical plants for specific design. It is widely used in various chemical production units, which can effectively avoid the occurrence of explosion accidents or effectively reduce the degree of explosion hazards

Copyright © 2011 JIN SHI