Production process and control of furnace tube temperature for coking accessorie

<1>Production process of coking coke oven equipment

Ordinary coking enterprises all have the problem of high energy consumption and heavy pollution.At the same time,the coke oven equipment in the coking plant has abundant waste heat resources during the production process.Most of the waste heat resources are not only unused,but also consume a large amount of energy for treatment,which not only causes energy waste but also increases environmental pollution,forming pressure for energy conservation,consumption reduction,and emission reduction in coking enterprises.However,energy conservation and efficiency enhancement also have enormous potential.

Coking accessories have a large amount of waste heat resources in the coke oven heating system,raw gas discharge system,coke oven body,quenching and other links of the coking section.After heat exchange in the coke oven regenerator,the combustion waste gas discharged from the coke oven still has a temperature of 200-400℃.The raw gas discharged from the coke oven through the rising pipe is not less than 800℃,and the red hot coke just released from the carbonization chamber is about 1000℃.These solid and gas substances have a large quantity,complex production and treatment processes,and contain a large amount of waste heat resources,which have recycling value.However,recycling is difficult,and most enterprises currently do not recycle them.

In chemical production,there are also a large number of scattered low-quality waste heat resources in the process of gas cooling,transportation,washing and purification,and chemical product recovery.The mixture of tar and ammonia water from the gas suction pipeline,the circulating cooling water of the horizontal tube primary cooler,the waste water from ammonia distillation,as well as various process media in various sections such as gas desulfurization,ammonia washing,final cooling benzene washing,and crude benzene distillation,contain a lot of scattered and low-grade waste heat resources.Some of the waste heat has been recycled,but some of it is not only not recycled,but also consumes a large amount of water and electricity resources for treatment,resulting in high energy consumption.

At present,the country has put forward high requirements for energy utilization in the steel industry.We should adhere to the core of resource utilization and circular economy,adhere to the principles of"reduction,reuse,and resource utilization",and feature low consumption,low emissions,and high efficiency.We should fully recycle and utilize waste heat,pressure,gas,wastewater,and waste materials,and basically achieve zero emissions,so that the new steel plant can achieve steel production,energy conversion Urban solid waste disposal and providing resources for related industries have become environmentally friendly,service-oriented,and resource-saving green factories.

In order to actively respond to the overall plan of Chongqing's"retreat from two to three"and solve the long-term environmental pollution problem that restricts the development of Chongqing Iron and Steel,Chongqing Iron and Steel will carry out environmental relocation,which is a good opportunity for Chongqing Iron and Steel to rise again.New Chongqing Iron and Steel will inevitably improve its technology,product capacity,cost,energy consumption,pollution control,and other aspects,which puts forward high requirements for energy utilization efficiency.

The Chongqing Iron and Steel Environmental Protection Relocation Coking Project will build a coking plant with an annual output of 2.4 million tons of coke.Therefore,research on the recovery and utilization process technology of coking waste heat will provide technical support for energy conservation and emission reduction of the coking plant,in line with the practical needs of Chongqing Iron and Steel Environmental Protection Relocation and the long-term development trend of the coking industry.

<2>Control appropriate furnace tube temperature for coke oven accessories

The temperature control index of the coking heating furnace tube is a key process index of the coke oven accessory device.During normal production operation,strengthen the adjustment of the heating furnace flame,control the combustion situation of the heating furnace,and do a good job in monitoring to control the temperature change of the furnace within a reasonable range to avoid partial burning.In case of emergency situations such as local overheating of the furnace tube,it is necessary to increase the steam injection rate of the heating furnace tube in a timely manner and adjust the combustion situation of the heating furnace nozzle in a timely manner,The temperature of the heating furnace tube of the coking coke oven equipment does not exceed the process indicators.

At the same time,the maintenance and upkeep of measuring and control instruments should also be strengthened.Each instrument should be accurate,and the automatic control instrument can be adjusted according to the setting instructions,so that the temperature of the heating furnace tube can be accurately monitored and controlled.

In order to prevent coking of the central furnace tube in the heating furnace,it is necessary to strictly control the temperature of each part of the furnace tube and adjust the gas injection rate of the heating furnace tube.To slow down the coking of the heating furnace tube,it is generally required that the oil in the heating furnace tube should be strictly controlled at a temperature greater than 426℃,and the residence time of the oil in the furnace tube should not exceed 30 seconds.This requires the residual oil in the heating furnace tube to increase the flow rate at a suitable steam injection rate,The oil passes through the heating furnace tube where the critical decomposition section is located in a strong turbulent state.To ensure that the oil product exists in a turbulent state and passes through the heating furnace tube at a high speed within the critical decomposition temperature range,control the temperature and pressure of the furnace tube.Injecting too much steam into the furnace tube will correspondingly reduce the oil partial pressure inside the furnace tube,and the gasification rate will increase with the increase of steam injection amount,resulting in an increase in the density of high-temperature medium in the liquid and gas phases.On the contrary,it will cause instability and coking of the oil medium inside the furnace tube,and the increase of steam injection amount will also correspondingly increase the heat load of the heating furnace.Therefore,the design of the delayed coking heating furnace adopts the"three point steam injection"technology,with a steam injection rate of 1-3%of the oil medium being appropriate.