6, 00000 tons of push-pull type pickling line

Project name: 6, 00000 tons of push-pull type pickling line

Customer name: shandong east ding steel rolling co., LTD

The nature of the project: new project

Undertake: Beijing JieRui general contracting

A time: on May 7, 2011

Production: under construction

Operation: good

A, pickling process description

The pickling for push-pull type pickling line, adopts the more advanced shallow slot turbulent pickling technology, provides the process equipment and technology, is proved by production practice, reliable, advanced, mature, stable production and can meet the buyer long-term operation of complete sets of equipment and technology. The technology has the equipment structure is reasonable, high efficiency, low production cost, convenient operation, less equipment operation fault etc.

Designed by pickling line, steel strip pickling process from open book to all coiling process are completed online. In the entrance of the unit is equipped with a feeding trolley, coil with a crane on the bench, and then feeding the small car will be transported to the pre open book to roll coil for pre decoiling (including straightening and cutting head and cutting Angle head), followed by feeding the small car will coil to the uncoiler barrel center position. Uncoiling unit adopts the cantilever uncoiler, uncoiler volume increases by Jane set on one side of the drum spindle hydraulic cylinder drive, uncoiler rack driven by hydraulic cylinder can be mobile on the stand, to adjust the center of the coil during uncoiling. To ensure the straightness, when the steel belt wear belt in the entrance of the unit is equipped with a straightening machine.

Steel strip after entering pickling tank, steel strip surface and groove in hydrochloric acid solution directly on chemical reactions as follows:

Fecl3 Fe203 hci + 6 = = = 2 + 3 h2o

Fe304 hci + 8 = = = 2 fecl3 + FeCl2 + 4 h2o

Fe0 hci + 2 = = = FeCl2 + H2O

Fe 2 + HCL = = = FeCl2 + H2

Pickling tank is divided into five segments, tub, for carbon steel lined with neoprene and double article granite. This structure can avoid maintenance replacement granite lining and sometimes does not destroy lined with rubber layer. Between paragraphs slot with acid squeeze dry rubber roller and acid isolation room, drain and squeeze dry rubber roller lining granite roller surface in the same plane, in the steel belt running the upper plane is equipped with glass fiber reinforced plastic tank cover, and through the water seal tank sealing. Squeeze roller frequency conversion driving, and can be worn by the change of the motor current detection process to take the lead position, avoid overlapping accumulation within steel strip to acid tank. In each period of acid tank set up a set of acid circulation heating system, heat acid using vertical heating graphite heat exchanger, acid with the help of tub structure at the same time, in the form of turbulent flow fast flow, thus greatly improve the pickling speed. New acid from 5 # acid circulation can add, at the same time through acid circulation tank liquid level control system, step by step forward, and finally collected by 1 # tank platoon to waste acid tank. Due to the isolated paragraphs pickling tank, independent circulation, therefore, can effectively control the paragraphs acid trough concentration gradient. First paragraph separate cleaning cleaning trough, flushing water discharge to match acid tank. The rest of the 4 paragraph by circulating spray irrigation (condensate), add clear water is rinsed by the fifth slot into, flush water tank at the bottom of the tank cleaning set flow from level 4 step by step to paragraph 2, the last paragraph 2 by the overflow mouth to the rinse water collecting tank. The pickling tank and cleaning tank to slightly negative pressure control, by setting the paragraphs import and export of acid mist smoke duct to waste acid regeneration scrubber stand acid mist, the spray washing the back vent outside factory. Steel belt drying with hot air dryer, hot air heating with steam heat exchanger. Steel strip trimming the cantilever rotary shears, set up the entrance of the disc shears a pinch on the machine (CPC), control cutting edge of the removal of waste by waste while coiler will waste into waste while pellets. Coiler using cantilever tension reel, coiling tension through the three-roll machine set up. Winding with EPC control winding side roll. Export volume is equipped with hydraulic drive discharge coil car coil to unloading platform.

Electrical control system consists of power distribution system, ac frequency conversion motor drive unit, ac motor control unit, PLC control system, the total work station operation, points of work station, an open-book industrial monitoring system. The operation of the system controlled by PLC programmable controller is completed, the operating system also includes pickling auxiliary process chain control system

Second, the design basis

Raw materials for hot rolling of carbon-steel, deep drawing steel, low alloy steel

Steel grade Q195, Q215, Q235, 08 f, CQ, DQ, DDQ, etc

600000 tons/year production plans

Project 7200 hours

Max26000Kg raw material weight/volume

610 mm diameter Φ, Φ 762 mm

Outside diameter Φ 2100 MRN

800-1300 - mm wide

The thickness of 1.8-4. Omm

The finished weight Max 26000 kg/roll

610 mm diameter Φ, Φ 508 mm

Φ outer diameter 2100 mm

800-1250 - mm wide

The thickness of 1.8-4. Omm

The biggest uncoiling tension 18 kn

The biggest coiling tension 60 kn

Process method Push-pull type shallow slot turbulent hydrochloric acid pickling

Acid trough the total length of about 68 m

Pickling medium of hydrochloric acid (31%) or higher

Acid concentration in 8 ~ 18%

The pickling time min 26 s

Pickling temperature 65 ~ 85 ℃

Acid concentration Max 200 g/L HC1

Fe2 + 120 g/L

In time an open-book section Max: 2. Omin winding period of Max: 1.5 min

Product form volume to the volume

Unit drive for ac drive, frequency conversion speed regulation

Production line arrangement Look from the operation side line from left to right

The energy of water, electricity, steam

The unit rate

The pickling process speed Max 150 m/min

He wears l0-80 - m/min

Looping reserves

No entrance

Export 30 m

Three, the technological process

Early open book to stand: by loading to roll to roll up the car, uncoiler to strap to send three roller straightening machine, corner cut to hydraulic shears, cut waste bucket (features: reduce the time to prepare an open-book section, effective use of the pickling line). Pickling line: decoiler (with roller, reverse bending roll) to open book scraper, turned to the pinch roll - guide roller - with pinch roll straightening machine and transverse shear to guide roller, pre cleaning trough (900 mm, squeeze roller 2) - > 5 hydrochloric acid pickling tank (5 x13. 5 = 67. 5 m) - water tank level 5 (including the pre-cleaning section) - blowing edge finder - hot air dryer - 2 # pinch roll - loop (two looping swing stations) to guide roller, pinch on the machine to cut disc (configuration waste edge coiling machine), three roller to transverse shear, tension roller guide roller - to pinch roll - reel to discharge coil car, the loading area