The 100000 ton ultra-high power graphite electrode project is equipped with three production lines for mixing and molding.

Production Line 1: Equipped with 1 asphalt high-level tank, 1 asphalt batching scale, 1 stearic acid melting tank, 1 stearic acid scale, 1 dry material heater, 2 4000L kneading machines, 2 4000L cooling machines, 1 paste conveyor, 1 3500t extrusion molding machine, and 1 waste hopper.

Production Line 2: Equipped with 1 asphalt high-level tank, 1 asphalt batching scale, 1 stearic acid melting tank, 1 stearic acid scale, 1 dry material heater, 2 3000L kneading machines, 2 3000L cooling machines, 1 paste conveyor, 1 2500t extrusion molding machine, and 1 waste hopper.

Production line 3: equipped with 1 asphalt high-level tank, 1 asphalt batching scale, 1 stearic acid melting tank, 1 stearic acid scale, 1 Elixu mixing and cooling machine Q=4T/pot, 1 disc feeder, 1 4000t extrusion molding machine, and 1 waste hopper. The asphalt flue gas purification system is responsible for the collection, exhaust, and purification treatment of equipment and workstations that emit asphalt flue gas during process production. The process production flowchart is as follows

2.2. Quantity and installation location of flue gas purification systems

According to the process flow of mixing and molding, a total of 3 sets of flue gas purification systems are configured. Each set of asphalt flue gas purification system corresponds to purifying the asphalt flue gas generated by a mixing and molding production line.

The asphalt flue gas purification system is used to purify asphalt flue gas generated from high-level storage tanks, asphalt scales, stearic acid melting tanks, stearic acid scales, mixing pots, cooling pots, mixing cooling machines, disc feeders, paste belts, and extrusion molding stations. In addition, all three sets of asphalt flue gas purification systems have the ability to purify the asphalt flue gas generated by their respective waste paste hoppers.

Three sets of asphalt flue gas purification system dust collectors and exhaust fans are planned to be installed on the roof of the forming workshop at an elevation of 38000.

2.3 Design parameters of asphalt flue gas purification system

(1) The design parameters of purification systems 1 #, 2 #, and 3 # are the same

Design smoke exhaust capacity: 27000 m3/h

Dust collector filtration area: ≥ 550m2

Smoke exhaust fan: 9-28No.10D Q=30053m3/h, H=5531Pa

Attached electric motor: N=75KW

Requirements for dust collector purification filter material: oil proof, waterproof, and film coated for asphalt flue gas, with a service life of not less than 3 years.

(2) Purification system equipment and workstations emit asphalt smoke concentration

Asphalt high-level tank and asphalt scale: 900~1500mg/m3

Ailixu mixing and cooling machine: 1200-1500mg/m3

Mixing pot and cooling pot: 2000~3500mg/m3

Paste conveyor: 1000~1500mg/m3

Extrusion molding machine production station: 1000~1500mg/m3

Waste paste hopper: 800~1000mg/Nm3

Technical requirements for asphalt flue gas purification system

(1) The asphalt flue gas purification system adopts the "black method" purification technology of carbon powder adsorption.

(2) The purification system uses charcoal powder to process the petroleum coke batching powder. A new silo is built in the purification system to store the petroleum coke batching powder, with a capacity of 30m3. After purification, the petroleum coke powder is returned to the process batching silo to participate in process production. (The number and capacity of silos can be adjusted according to actual needs, but silos should ensure at least one shift's production capacity is met.)

(3) The design inclination angle of the exhaust pipe before adding carbon powder to the asphalt flue gas purification system shall not be less than 30 °, and the setting of the exhaust pipe and exhaust hood shall be easy to disassemble and clean.

(4) The asphalt flue gas purification system is equipped with pressure and temperature detection instruments (with remote transmission function) at the inlet, outlet, and necessary positions of the dust collector.

(5) The asphalt flue gas purification system's extrusion molding station and waste paste discharge station automatically switch valves (pneumatic valves) according to actual production usage. During normal production, the purification system can collect and purify the flue gas generated by the extrusion molding station or waste paste discharge station through automatic switching.

(6) The exhaust pipe of the purification system shall be equipped with regulating valves, and quick opening observation ports shall be set at necessary positions. Quick opening inspection ports must be set at the mixing position of the carbon powder added to the exhaust pipe.

(7) The exhaust pipe of the asphalt flue gas purification system must meet the requirement of non clogging, ensuring that the purification effect does not deteriorate within five years of operation, and there is no need to dismantle the exhaust pipe for cleaning; The carbon powder conveying pipeline for purification adopts wear-resistant treatment, and the service life of the conveying system elbows and key components is not less than 2 years.

(8) The production mode of the purification system Ailixu mixing and cooling machine (also used for water spray forced cooling) process is: about 15 minutes to produce a pot of paste, and the total time for adding asphalt and wet mixing is about 7 minutes; After wet mixing, spray water to cool, stir and evaporate for 5-6 minutes, then remove from the pot. That is to say, there are 4 times per hour, and each time, the steam generated by~150kg of water needs to be discharged within 5-6 minutes.

The purification system needs to specially consider the large amount of water vapor emitted in a short period of time, and the preparation of hot air should consider using thermal oil to prepare hot air. The processed flue gas must ensure that there is no condensation in the exhaust pipe and dust removal equipment.

(9) The asphalt high-level tank, asphalt scale, stearic acid melting tank, and stearic acid scale exhaust pipe must be connected to the nearest exhaust main pipe. The exhaust pipe must have a horizontal inclination angle of not less than 45 °, and the exhaust branch pipe must be insulated with a 50mm silicate+0.5mm galvanized iron sheet insulation layer.

(10) The amount of carbon powder added to the asphalt flue gas purification system can be adjusted. Request to record the historical trend of adding charcoal powder to the system.

(11) The control system of the asphalt flue gas purification system adopts remote control operation by industrial computer. The purification system supports intelligent operation requirements such as one key start, one key stop, automatic shutdown and alarm in case of accidents. The purification system can automatically shut down and ensure that the purified powder does not leak in case of accidents or power outages. The industrial computer is installed in the control room of the molding workshop, and the control system needs to monitor, alarm, and record necessary parameters of the purification system (temperature, pressure, equipment operation, amount of carbon powder added, etc.).

(12) Before bidding, the bidding unit shall provide a purification system flowchart, core equipment parameters, a brief introduction to the purification system process flow, and measures to ensure performance.

(14) The noise standard for the operation of the purification system must meet the requirements of the relevant provisions of the "Design Code for Noise Control of Industrial Enterprises" (GB/T50087-2013).

(15) The components of the purification system and the outer surface of the pipelines shall be coated with two coats of iron red phenolic anti rust primer, followed by two coats of phenolic topcoat. The color shall be selected according to the requirements of Party A.

(16) After purification by the purification system, the petroleum coke powder is returned to the process formulation batching warehouse.

2.5 Technical performance indicators of asphalt flue gas purification system

(1) Chimney outlet

Asphalt smoke:< 10mg/Nm3

Particulate matter:< 10mg/Nm3

(2) The hygiene conditions of production positions must meet the "Hygiene Standards for the Design of Industrial Enterprises" (GBZ 1-2010).