Experience sharing of some failures of the roller press
Date：2019-07-04 14:51 Source：未知Views:
(1) Description of abnormal situation of T company
The height of the vertical feeding pipe between the roller press and the weighing bin causes the working pressure of the roller press to be low, the function of the pressing is poor, the residual material of the grinding material is large, the fine powder is small, the system output is low, and the grinding power consumption is high;
T company grinding system configuration: using 120-50 roller press (material throughput 165t / h, main motor power 250kw-10kv-21A (rated current, the same below) × 2) +550/120 scattering classifier (treatment Capacity 140-175t/h, Dispersion + classification motor total power = 45kw + 30kw) + Φ3.2 × 13m three warehouse open circuit tube mill (main motor power 1600kw-10kv-110A (rated current, the same below), grinding body Loading capacity 127t, a warehouse length 3.25m, two warehouse length 2.50m, three warehouse length 6.50m + four circle height 550mm activation ring, mill barrel working speed 17.6r/min) + grinding tail dust collector composed of open circuit combined powder Grinding system
Production of P.O42.5 grade cement (product specific surface area ≥ 380 ± 10m2 / kg), system output 65t / h, grinding power consumption 35kwh / t;
Abnormal conditions and results: the R80μm sieve of the grinding material is 78.7% (<80μm fine powder is only 21.3%), and there are more coarse particles in the finished cement sieve residue, and the system capacity potential needs to be further exerted to reduce the grinding power consumption.
Technical diagnosis analysis: the height of the vertical feeding pipe between the receiving plane and the weighing bin of the roller press is less than 1.2m, the height is low, the pressure in the pipe is small, and the rod valve needs to be adjusted frequently. The weighing bin often produces segregation or collapse, and the production At the same time, the dust on the side of the roller press is more serious, the working pressure is only 6.0 MPa-6.5MPa, which directly affects the extrusion effect of the material, and the fine powder content of <80μm in the outlet material is low.
Technical measures and effects adopted: Using the opportunity of overhaul at the end of the year, increase the height of the hoisting machine and the weighing bin, and increase the height of the vertical feeding pipe to 2.5m at the same time; repair the side baffle of the roller press to reduce the leakage rate of the roller edge; In the process, the weighing position of the weighing bin is kept at 60%-70%, the segregation, the collapse of the material, the stable material pressure and the column are formed, and the sanitary condition of the working site is significantly improved; the working pressure of the roller press is 6.0 MPa- The 6.5MPa was adjusted to 7.2 MPa-7.5MPa, and the extrusion effect was significantly improved. The R80μm sieve material after classification by the grader was reduced from 78.7% to 49.8% (<80μm fine powder reached 50.2%). Before reducing the sieve residue by 28.9% (that is, the fine powder content in the milled material is increased by 28.9%), there is basically no coarse particles in the sieve residue, and the output of the P.O42.5 grade cement system is up to 79t/h, and the grinding power consumption is reduced. 26.4kwh/t.
Through transformation, according to the annual output of 600,000 tons, the annual energy saving can be 4.8 million degrees, and the power saving benefit is more than 2.8 million yuan.
(2) J company abnormal situation description
The feeding control from the weighing bin to the roller press is unstable, the roller press performs poor functional force, the main motor output is less, the fine powder of the grinding material is less, the output is low, and the system grinding power consumption is high;
J company grinding system configuration: using 170-100 roller press (material throughput 620t / h, main motor power 900kw-10kv-66A × 2) + Vx8820 powder separator + φ4.2 × 13m double warehouse tube mill ( Main motor power 3550kw-10kv-251A, grinding body loading 240t, final drive JS150B, speed ratio i=47.295:1, mill barrel working speed 15.6r/min, one bin length 3.75m, two bin length 8.75m+ Five circle height 900mm activation ring) +O-sepa, N-3500 powder separator (spindle motor power 160kw, feeding capacity 630t/h, powder selection capacity 210t/h, system fan air volume 245000m3/h, wind pressure 6000Pa, motor Double closed circuit combined grinding system composed of power 560kw) + grinding tail dust collector;
Abnormal conditions and results: production of P.O42.5 grade cement production 165t / h (finish fineness R45μm sieve residue 9.0 ± 1.0%), system grinding power consumption up to 44kwh / t;
Technical diagnostic analysis: the roller press is unstable, the extrusion function is poor, the main motor output is less, the running current is only 42%--45% (28A--30A/66A); the specific surface area of the grinding material is 160m2/kg about;
Technical measures and effects adopted: the patented technology of a certain technology company "roller type double-feed device", stable control of roller press feeding, main motor output 72% -78% (operating current 48A-52A / rated Current 66A); the internal structure of the mill is improved more to ensure the finished product content in the milled material; under the premise of a specific surface area of 170m2/kg and a specific surface area greater than 270m2/kg (8m2/kg/M); The output of P.O42.5 cement system reached 210t/h, the power consumption of grinding was reduced to 38.1kwh/t, the power saving was 5.9kwh/t, and the power saving range was 13.41%.
The O-sepa N-3500 finished product separator has been removed, and the sepax-4500 high-efficiency eddy current classifier developed by a mechanical equipment company has been used (feeding capacity 900t/h, powder selection capacity 260--300t/h) The finished product specific surface area adjustment range 360--480m2/kg, cage rotor diameter φ2800mm, rotor height h=1450mm), spindle motor power 90kw (frequency control) + system internal circulating fan power 400kw (frequency control) (R45μm selection The powder efficiency is >85%); after the improvement, the power of the separator system is reduced by 720kw-490kw=230kw compared with the past; at the same time, a 110kw dust collector is reduced in the system, and the total installed power of the system is reduced by 340kw;
After continuous improvement, the output of P.O42.5 cement system is ≥250t/h, the highest output is 270t/h, and the system grinding power consumption is further reduced to 25kwh/t.
(3) S company abnormal situation description
Fly ash, desulfurization gypsum, two materials with small particle size enter the weighing chamber together, and the desulfurized gypsum has a large water content, which causes the weighing chamber wall to be heavily viscous and becomes a feeding channel. The material pressure of the feeding tube is small, resulting in the output of the roller press. Less, extrusion, poor functional force, low system output, high power consumption for grinding;
S company grinding system configuration: using 120-50 roller press (material throughput 165t / h, main motor power 250kw-10kv-21A × 2) +550/120 scattering classifier (processing capacity 140-175t / h, Motor power 45kw + 30kw) + Φ3.2 × 13m three warehouse tube mill (main motor power 1600kw-10kv-119A, grinding body loading 140t, a warehouse length 2.75m, two warehouse length 3.0m, three warehouse length 6.50m + Open circuit combined grinding system consisting of four ring height 650mm activation ring) + grinding tail dust collector;
Grinding P.O42.5 grade cement production 65t / h (product specific surface area ≥ 360 ± 10m2 / kg), system grinding power consumption 33kwh / t.
Abnormal conditions and results: finer-grained fly ash and desulfurized gypsum together with other materials enter the weigh bin, the press capacity of the roller press is poor, the work is not good, the running current is low, and the graded grinding material R80μm Up to 65% or more (<80μm fine powder content is only about 35%);
Technical diagnosis and analysis: the powdery material affects the extrusion work of the roller press, the work roll of the roller press is small, and the running current is low; at the same time, the weighing wall is heavily adhered due to the large moisture of the material, which becomes the material passage and the blanking material. The pressure is small, which affects the extrusion effect of the roller press;
The technical measures and effects adopted: the fly ash and the desulfurized gypsum are directly metered into the tube mill, and the adherent material of the weighing chamber wall is cleaned, so that a stable material pressure is formed in the blanking tube, and the roller press realizes supersaturated feeding. Improve the effect of extrusion work; the R80μm sieve after the classification by the grader is 55% (<80μm fine powder content is 45%); P.O42.5 cement output is 75t/h (the finished specific surface area ≥360m2/ Kg), increased production 10t / h, an increase of 15.38%; grinding power consumption reduced to 30kwh / t, reduced 3kwh / t, power saving amplitude of 9.1%.