The Distribute Control System Of Phosphorusgypsum Production Iine In Jiyuan City Henan Province

Phosphogypsum is mainly byproducts to produce wet process phosphoric acid plant,detergent plant, phosphorus chemical plants. Most are currently centralized approach to opendumps, so easily through the wind and rain to its harmful substances into the air and soilpollution of the surrounding environment. The State shall encourage and promote the full use ofphosphogypsum, currently mainly used for the production of gypsum cement retarder,construction gypsum, fertilizer and so on. In terms of domestic production control most of thephosphorus gypsum powder production line control automation have been achieved, there arethree main methods of control: programmable logic controller (PLC), distributed controlsystems (DCS) and fieldbus technology (FCS). In the process of production, before using arotary kiln calcination, but its temperature is difficult to control, waste heat and workloadshortcomings make it significantly reduces the efficiency of enterprises. Currently newer iscalcined gypsum FC-compartment technology solves some relative disadvantages of the above,the enhanced recycling of heat and automatic operation. Saves fuel and labor costs, improve theefficiency of enterprises.Paper combines phosphogypsum production line distributed control system of HenanJiyuan projects into the production process of raw materials, heating, drying and pre-dedustingsystem, calcined, finished five section.Integration of the various section describes the processfor each section in the internal rules of operation of equipment, precautions and missionobjectives. According to the design and implementation of control requirements based on lowermachine CBM, PC IFIX the distributed control system. Lower machine to achieve the reversestart motor between each device group and sequence stops. When some electrical equipmentfailure, an alarm signal at the same time according to the established sequence stop thisequipment. Host realized: the motor control interface displays device status; temperature,pressure, velocity feedback inverter analog input display; drive speed reference and otheranalog outputs given and displayed.Gypsum powder production process is a multivariable control, the main control variablesof temperature, pressure, and volume of feed valve opening, in order to produce qualifiedgypsum powder will need to coordinate and control these variables. Temperature control concentrated in the pre-drying and calcining section. In the pre-drying and dust removalsystem section of the main tasks is to use the heating section of the hot flue gas, the raw materialproduction of gypsum section is not attached to the water by removing most of the pre-dryingsystem, by reducing powder and dust collection devices to pre-the hot warehouse for finishedfiring with the next section. In this section you want to control the export of pre-dryingtemperature, variable control of the volume of feed with pre-drying, heat transfer damper valveopening and boiling furnace temperature. The heat from the boiling calcined in two parts. Afterthe system is stable calciner exhaust temperature is generally stable at around150℃, hightemperature by adjusting the damper tune the size of the valve opening control how much pre-boiling furnace heat into the dryer. When the temperature adjusting damper valve openingconstant boiling hearth furnace temperature, the higher the pre-drying inlet temperature; Whenboiling hearth furnace temperature is constant, the lower the temperature adjusting dampervalves, the higher the pre-drying inlet temperature. When a certain amount of pre-drying thefeed, the pre-drying inlet temperature, the higher the pre-drying outlet temperature; When thepre-drying outlet temperature is constant, the greater the volume of feed pre-drying, the morepre-drying outlet temperature low. The main task is to go through the calcination section afterdrying gypsum powder calcined at FC interior compartment into hemihydrate gypsum powder.In this section is to be controlled in the calcination furnace outlet temperature, the controlvariable has a boiling temperature of the furnace chamber, heat transfer damper valve openingamount and the calciner feed. The section of the heat from the boiling furnace, high temperatureby adjusting the damper adjusting the size of the valve opening control how much heat into thecalciner.When the high temperature adjustment damper valve opening is constant, the higherboiling furnace temperature, the higher the calciner inlet temperature.When the fluidized bedtemperature is constant, the bigger damper valve, the higher inlet temperature of calcinationfurnace. When the calciner inlet temperature is constant, the volume of feed calciner, thehigher the calciner outlet temperature. When a certain amount of the calciner feed, the inlettemperature of the calciner, the higher the calcining furnace outlet temperature. Regulating thetemperature control system is coupled multivariable process, combined with the experience ofoperating data and excellent site operator by summing the outlet temperature of the pre-dryingand calcining furnace outlet temperature change amount of the pre-drying the feed, the feed amount of the calciner, coordinated control temperature adjustment damper valve opening andboiling hearth furnace temperature variables.Phosphogypsum production line distributed control system of Henan Jiyuan has beencompleted on-site commissioning, and put into operation. The actual operation shows thesystem, DCS security paper design, reliable, efficient, and achieved good economic and socialbenefits.