Special safety technical measures for ash chute in

Special safety technical measures for using ash chute to slide ash

456 the net diameter of the air shaft is 7.6m, the net section is 45.3m2, the design elevation of the wellhead is +1360.00m, the full depth is 710.5m, and the freezing depth is 689m. At present, the ash chute is used for pouring concrete, and then it is poured into the formwork after secondary mixing. In order to better ensure safety and quality, this special safety technical measure is specially prepared

I. material selection:

the selected materials are selected according to the well construction atlas volume V, and the specifications are as follows:

flange: 8-inch plate * thickness 20mm

pipe clamp: 60mm * 10mm

bolt: Ф 20mm its tubular elastic structure is a common structural feature of many organs *70mm

steel pipe: φ 200*8mm

II. Selection and calculation of suspension wire rope, car stabilizing, suspension crown wheel and pipe clamp of ash chute:

1 Wire rope selection calculation

(1) wire rope suspension load

q0=q1+q2+q3+q4+q5=44885kg

then each wire rope suspension load: q0=q0/2=16942.5kg

where:—— φ 219 dead weight of 7.5mm steel pipe, =700 39.12=27384kg

-- weight of flange, clip, bolt and nut, 2583kg

q3 -- weight of concrete in pipe, 3600kg

q4 -- weight of terminal clip, 60kg

q5 -- weight of signal cable, cable clip, bolt and nut. Q5=258kg

(2) calculation of weight per unit length of steel wire rope

where: - nominal tensile strength of steel wire rope, taken as σ B=1770mpa

-- safety factor of steel wire rope, ma=5

through the above calculation, 18 7+fc type steel wire rope (gb/t) is selected, the total minimum steel wire breaking force is qd=109598kg, and the weight per unit length =5.63 kg/m

(3) check calculation of safety factor of steel wire rope

2. Selection of stable car

maximum load of steel wire rope: q=16942.5+5.63 730 = 21052.4kg

select a 2jz-25/1300a stable car

3. Selection of suspension sheave

dtl ≥ 20ds=20 38=760mm (d wire rope diameter)

dtl ≥ 300 δ＝ 300 2.6=780mm （ δ by "The cooperation with BASF is very beneficial to HP (the thickest steel wire diameter)

mzs2.1.05/double groove suspension crown wheel is selected to meet the requirements.

4. The selection of pipe clamps is based on the fifth volume of the well construction atlas.

III. use the ash chute construction scheme and step

2.1 construction scheme:

the concrete is made by the wellhead mixing plant, and the concrete made by the mixing plant is placed in the sealing disk storage bin, and then passed through the chute The ash pipe is transported to the upper hanging tray, and then it is put into the mold through four feeding hoses after secondary mixing

2.2 construction steps:

during shaft excavation: when concrete pouring is required for each certain section of construction height

1. Seal all holes at the wellhead tightly and transport the ash chute to the wellhead

2. Lock one end of the ash chute with stirrups, and then slowly lift it with a small winch at the wellhead, slide the other end with hemp rope, and then use people to pull it to a certain height

3. Connect it with the next ash chute with bolts and tighten it, and then fix the ash chute on the suspension wire rope with a pipe clamp

4. The connected ash chute slowly drops to the required height

5. After the ash chute is placed, place the storage bin on the ash chute

6. Inform the working face to wash the ash chute by ground water after all are ready

7. Wash the ash chute and pour the ash after it is confirmed to be correct. During pouring, use a special signal to contact

during lining the inner wall of the shaft: when it is necessary to pour the next section of height after pouring a certain section of height

1, use a special signal to contact to stop ash laying

2. Contact the working face to wash the ash chute

3. Remove the storage bin above the ash chute

4. Lock one end of the ash chute with the stirrup on the small winch

5. Contact the central control room to slowly raise the ash chute to a certain height

6. The steel wire rope of the small winch is stressed, and the bolts and pipe clamps connecting the ash chute are removed

7. The removed ash chute is lifted away from the wellhead by people, and then transported to the designated place by forklift and placed neatly

8. After removing a section of ash chute, lower the ash chute to a certain height

9. After the ash chute is set, sit the storage bin on the ash chute again

10. Inform the working face that it can be ashed, and use a special signal to contact during the ashing

IV. safety precautions

1. The whole process must be under the unified command of a specially assigned person

2. Every time the ash chute is lifted and lowered, the holes and gaps of the sealing disc must be sealed tightly, and the sundries must be cleaned to prevent falling objects from hurting people

3. The signals used at the wellhead, winch room and working face must be intact

4. The construction personnel on the hanging tray must wear safety belts, and the safety belts must take root firmly

5. Tools and materials required for construction must have ropes

6. Personnel entering the well must abide by the rules and regulations of entering the well

7. The flame retardant is the booster of high molecular synthetic materials for a long time, and then the ash must be washed with clean water

8. Pipe clamps and bolts used in construction must meet relevant requirements

9. Special signals must be used and kept intact during construction

10. Attachment: safety technical measures for replacement of ash chute. Blockage scheme and treatment measures of ash chute