Blast Furnace Pulverized Coal Injection

Blast furnace pulverized coal injection technology has become a main measure for coke saving, iron increasing and improving smelting effect and facilitating blast furnace operation smoothly, also has become blast furnace smelting technological progress and main method in today's world  
Blast furnace pulverized coal injection replaces heat provided by carbon inside coke, enriches reductive gas inside furnace and improves indirect reduction. Due to cooling effect to furnace hearth, temperature along with the hearth radium direction distributed evenly which has provided the condition for blast furnace receiving blast temperature and improved pig iron quality.  
During blast furnace pulverized coal injection, it must ensure that coal injection should be safely, reliable and continuously in order to reduce iron-making cost. Therefore, realizing of continuously automatic injection is a main problem that needs to be considered under the condition of control safety and reliability has been guaranteed.

Technical Significance

Blast furnace pulverized coal injection has a revolutionary significance to blast furnace iron-making technology, which is a key technology to decide whether blast furnace could compete with other iron making methods and to continuous survival and development, thereby the significance is specified as below:

(1) By using low cost pulverized coal to replace expensive and gradually scarce metallurgical coke that will reduce blast furnace iron-making coke ratio and pig iron cost.

(2) Coal injection is effective means to adjust furnace condition heat system.

(3) Pulverized Coal injection can improve working condition of blast furnace hearth and make blast furnace operate smoothly.

(4) The injected pulverized coal is gasified and burnt before tuyere that will reduce the theoretical combustion temperature, in order to maintain the necessary T theory of blast furnace smelting; it needs compensation, which has created a condition for blast furnace using high blast temperature and oxygen enrichment blast blowing.

(5) More hydrogen emitted than coke during the process of coal injection gasification, which improved gas reducing capacity and penetration diffusivity capacity, and will be in favour of ore reduction and improved blast furnace operation index.

(6) Partial metallurgical coke is replaced by coal injection that will mitigate the requirement of coking coal, reduce coking facilities and save construction investment, especially for partial coking furnace that had been operated 30 years and required overhaul, quantity demanded of coke will be reduced due to coke replaced by pulverized coal, the coking furnace that required to be overhaul should shut down and abandon.

(7) Coke replaced by injected pulverized coal will reduce coking furnace quantity and coke yield, thus, it will also lower the environment pollutions caused by coking.

Our Advantages

1. According to different requirements and characteristics of user, it can achieve personalized customization of process proposal, including single series paratactic double tanks, single series paratactic three tanks, single and double series chain tanks, double series five tanks, paratactic six tanks, one set of injection tank corresponding with two blast furnaces and other coal injection processes.

2. Strict Process Control Proposal

2.1 Technological process and control requires the blast furnace pulverized coal injection system mainly including raw coal storage and transportation system, coal pulverizing system, drying system and injection system.

2.2 The raw coal storage and transportation system, the raw coal is conveyed through belt conveyor to soft coal bunker and anthracite bunker，according to total coal feeding quantity and soft coal and anthracite proportion to set and achieve automatic coal blending in coal pulverizing workshop. Technical process control requirement of raw coal storage and transportation system: to achieve automatic coal blending as per technical process control requirement.

2.3 The coal pulverizing system drying agent is absorbed into medium-speed mill through negative pressure formed by main exhaust blower, the raw coal will be evenly added into medium-speed mill through weighing coal feeder, after the raw coal is crushed and dried, qualified pulverized coal will be entered into bag-type powder collector through pulverized coal piping, it will be stored in pulverized coal bunker after collecting. Technical process control requirement of coal pulverizing system: to achieve automatic regulation for medium-speed mill inlet pressure, system air volume and temperature.  

2.4 The drying agent in drying system is a mixture gas of high temperature flue gas in flue gas furnace and low temperature flue gas in blast furnace and hot blast heater. Technical process control requirement of drying system: to achieve automatic regulation for air and gas volume proportion required when flue gas furnace combusting.

2.5 Injection system adopts high pressure juxtaposition type injection tank to convey pulverized coal for blast furnace. Technical process control requirement of injection system: to achieve automatic injection as per coal injection volume required by blast furnace.  

3. Advanced Automatic Control

The reliable operating high pressure and low pressure drive system, advanced and open computer control system, excellent and smooth man-machine interaction interface. As per the requirements of user, it can use software that user acquainted to control program and design technical process display.

● Steady, advanced, reliable operating high pressure and low pressure drive system
● Electric, instrument and computer “Three electrical”integrated to be one control mode.
● Abundant technical parameter, all sort of operating and controlling measures are equipped ,real time dynamical man-machine interaction interface.
● Safe and reliable, all inspected security interlock and alerting system
● A combination operating mode between integrated interlock control and local control   maintenance.
● Standard and orderly cable laying.

4. Comprehensive Service

We can design coal injection system to customer.

We can provide whole set of all mechanical equipments, electric equipments, and automatic control and production tools in coal injection workshop to customer.

We can provide EPC contract to customer: including whole sets of workshop design, civil construction, equipment manufacture and whole sets of equipment installation, commissioning, trial run and production operation service.