CN1030862C - Explosion-suppressing method and apparatus for pressure cylinder by attaching plates to and winding wire around it - Google Patents

Abstract

The present invention relates to a method and a device for suppressing explosion by winding wires and attaching plates on a bearing cylinder. Attaching plates which are formed from a plurality of cambered laths are attached in the crack position of a cylinder body (or a pipeline) and distributed uniformly into a loop, and the inner diameter of the attaching plates is equal to the outer diameter of the cylinder body. After wound by wires, the attaching plates are attached with the cylinder body to generate friction force, and the attaching plates and the cylinder body keep in deformation coordination and form constraint stress. The present invention can reduce the amplitude value of the axial stress of the cylinder body, reduce the push force of crack expansion, raise the expansion resistance and have the functions of stopping cracks and suppressing explosion. Treatment can be carried out by the present invention when equipment is in the operating state and under the condition of welding without fire work. After the treatment of explosion suppression, the safety factor can be raised by more than 1.6 times, and the treating expense is low. The present invention has the functions of crack arrest, explosion suppression, high safety and long service life for pressure containers with super-standard defects.

Description

Explosion-suppressing method and apparatus for pressure cylinder by attaching plates to and winding wire around it

The present invention relates to the pressurized container flameproof apparatus.

Pressurized container is widely used in many essential industrys production department such as oil, chemical industry, oil refining, medicine, food, town gas, space technology and heat energy power station.Because a variety of causes in design and the manufacturing causes various birth defects, for example: the defective alive of the serious unreasonable generation of structure (stress corrosion and crackle), the inferior weld cracking that causes of welding quality; Or owing to as reasons such as high temperature, low temperature, high pressure, frequent pressure surge and strong corrosive medias, cause various acquired defects, for example creep that produces under the hot environment, embrittlement, the fatigue crack that the operation pressure frequent fluctuation causes, and the material failure that causes of various rugged environment etc.In case defective expands to threshold state, just will cause catastrophic accident, cause great personal injury and property loss.In order to prevent the generation of accident, domestic and international large quantities of scientific and technical personnel study from many aspects, and have obtained outstanding achievement, have advanced the development of pressure vessel safety engineering, but still have some problems:

1. strict steel smelt, rolling, forging and Structural Strength Design and welding, check and thermal treatment process technology, and it requires more height, and the cost of being paid is also big more;

2. the safety control in the strict using process with regularly open jar check and fracture tired with man-rate analyses such as reliability, a jar loss of checking is opened in its stopping production, along with production-scale expansion, its loss is also big more;

3. in multiple safety attachments such as development safety valve, preventing bursting cap, adopt explosion-proof frame, anti-explosion container, acoustic emission system for monitoring or the like anti-explosion alarming device that protects, these devices all will spend high cost, and its effect is also undesirable.

The datonation-inhibition major technique key of inservice pressure vessel and large-scale pipeline excessive defect is at present:

1. not only to consider axial, the circumferential crack of vessel shell, even the defective that produces at the nozzle opening position, these crackles or defective may be present in cylinder body outer wall, also may be present in cylinder inboard wall, the situation complexity;

2, these excessive defects of in-situ processing need not stop, be with sometimes to press under the operating conditions and carry out at equipment, often forbid getting angry the condition harshness in the processing procedure;

3, how to introduce the mechanism of the datonation-inhibition crack arrest of multilayer, the winding that is easy to implement is strengthened, and especially to large diameter pressurized container and pipeline, great difficulty is arranged technically.

As disclosed WO92/05383 patent document on April 2nd, 92, it designs a kind of back and forth staggered ribbon-like fibre winding mechanism, for pressure measuring cylinder volume defect position provides a kind of new reinforcement technology, but this technology is not only installed complexity, and the band fiber that is twined can only be limited to glass or plastic material adds epoxy resin again, because its intensity is lower, generally can only play and mend the expansion of stifled corrosion leak and prevent the effect that its boundary's matter is leaked, and can not be fundamentally the pipeline of the various steel pressurized containers that have a large capacity and a wide range be played crack arrest, especially datonation-inhibition effect, and can not be applied to the high temperature occasion especially.

The objective of the invention is: provide a kind of under equipment running status, can play the method and the device of crack arresting and burst arresting effect the pressure cylinder crackle.

Technological scheme of the present invention is: in pressure cylinder (or pipeline) cracks, stick the arc pasting board, pasting board is after prestressed wrapping wire twines, produce frictional force by the applying between pasting board and the cylindrical shell, and keep compatibility of deformation and form restraint stress with cylindrical shell, both can reduce the axial stress amplitude of cylindrical shell, reduce the crack propagation Driving force, can increase the expansion resistance again, thereby make the hoop, axial or oblique crack arrest, datonation-inhibition function arranged all of pressurized container.Its device is to comprise multi-turn multilayer prestressing force wrapping wire, and in the cracks of cylindrical shell, it is uniform to post hoop, the pasting board that the polylith arc lath that its internal diameter is identical with the cylindrical shell external diameter is formed, and multi-turn multilayer prestressing force wrapping wire, from coil to coil is wrapped on the pasting board layer by layer.

The present invention compares the useful effect that is had with background technique:

1. through the pressure cylinder of datonation-inhibition processing, no matter initial ring is to still axial crack expansion, and the consequence of failure of breaking blasting finally all can not take place, and safety coefficient can improve more than 1.6 times;

2. can under equipment running status, handle the repairing of to stop;

3. the welding of not getting angry can be because of not repairing the improper new defective that causes;

4. the expense of datonation-inhibition processing is low, and the Safety performance height.

This shows that the present invention has crack arrest, datonation-inhibition to the pressurized container of band excessive defect, the effect that safety is lengthened the life, it has important social benefit and economic benefit.

Below in conjunction with accompanying drawing the present invention is described in detail.

Fig. 1, has the pressure cylinder explosion suppression device schematic representation of crackle;

Fig. 2, faced board structure parameter schematic representation.

As shown in Figure 1, be attached to axial pasting board 2 on the crackle 4 by ring Form to uniform polylith arc lath, it is big that number is looked cylindrical shell 1 diameter Little and decide, the gap between the lath is generally about 2mm; Fit Face is made into has certain roughness, in order to binding face bigger rubbing is arranged Wipe coefficient. Pasting board 2 can directly be fitted the hoop wrapping wire with cylindrical shell 1 3 twine outside pasting board under the pre-tensile stress being subjected to.

The selection of pasting board and wrapping wire:

1. the material of pasting board generally should the identical material with cylindrical shell or pipeline of selection Material is made. If cylindrical shell or pipeline are precious metal, then mainly examine Consider and select to have good mechanical property and select coefficient of thermal expansion α (its In also comprise wrapping wire) be close with cylindrical shell or pipeline material coefficient of thermal expansion Material. But because the thickness of pasting board is general all less than cylindrical shell or pipeline Wall thickness, in the little situation of the temperature difference, not identical by coefficient of thermal expansion The impact that produces generally can not considered.

2. wrapping wire is selected standard compliant steel wire, its phosphorus content can Choose between (0.1～0.4) %, sulphur, phosphorus content 0.4% with Lower, guarantee preferably plasticity and good toughness, when preventing from stretching Fracture. Also can select other metal or nonmetal wire.

As shown in Figure 2, the meaning of each symbol:

L---the effective length of pasting board seal face, to general cylindrical shell or pipeline, for eliminating the edge stress impact, suggestion is got

Wherein R is cylindrical shell or pipeline outer radius, and S is cylindrical shell or pipeline wall thickness; Or Get datonation-inhibition desired minimized friction length, get both higher values;

The thickness of St-pasting board (comprising environmental corrosion nargin) is general Get 1/3～1/5 of cylindrical shell or duct thickness;

Dti-pasting board inner diameter, equal cylindrical shell or pipeline outside Directly;

The thickness of t-pasting board end convex shoulder (flange) generally gets 1～2 times of wrapping wire diameters also can require to arrange according to winding process;

The height of h-pasting board end convex shoulder requires to choose according to twining the number of plies;

D-wrapping wire diameter or rectangular cross section size.

Embodiment 1, certain high pressure pipe line 133 * 4.5mm, working pressure 10MPa, 200 ℃ of operating temperatures, poisonous medium; Detect and find to have the long 150mm of circumferential crack, dark 4mm, external crack; Known material is the 20# steel, yield σ y=260MPa, and intersity limitation σ u=420MPa, the prediction bursting pressure is 13.6MPa.When device of the present invention was handled, pasting board adopted 20# steel, L=80mm, St=2mm, 10 of wrapping wire d=2mm ^#Steel wire, yield σ _Cy=210MPa, intersity limitation σ _Cu=167MPa is 4 layers around layer, and the number of turns is 35 circles, and the bursting pressure after datonation-inhibition is 22.7MPa, and visible bursting pressure after datonation-inhibition is clean to improve 1.69 times.

Embodiment 2: certain floating tower valve, and design pressure 40MPa, 150 ℃ of design temperatures, physical dimension are 1400 * 48000 * 22mm; Material is 16MnR, yield σ _y=35MPa, intersity limitation σ _u=500MPa, wlding T507, intersity limitation σ _u=520MP; The circumferential weld place has one to be extended to surface crack along opening of external wall by incomplete fusion in the middle of detect finding, the long 1500mm of known crackle, and 19mm deeply, the prediction bursting pressure is 9.31MPa.Handle through device of the present invention, the pasting board material is 16MnR, L=580mm, St=4mm, 10 of wrapping wire d=2mm ^#Steel wire is 4 layers around layer, and the number of turns is 264 circles, wrapping wire top tensile stress 330N, and the bursting pressure after the processing can be brought up to 18.6MPa, and the bursting pressure after promptly datonation-inhibition is clean to improve 2 times.

Claims (3)

1. the crack arresting and burst arresting method of a pressure cylinder crackle is characterized in that:

1), sticks the arc pasting board in the cracks of pressure cylinder;

2) pasting board is outer after prestressed wrapping wire twines, and produces frictional force by the applying between pasting board and the cylindrical shell, and keeps compatibility of deformation and form restraint stress with cylindrical shell.

2. the crack arresting and burst arresting device of a pressure cylinder crackle, comprise multi-turn multilayer prestressing force wrapping wire (3), it is characterized in that: the crackle (4) in cylindrical shell (1) is located, it is uniform to post hoop, the pasting board (2) that the polylith arc lath that its internal diameter is identical with the cylindrical shell external diameter is formed, described multi-turn multilayer prestressing force wrapping wire (3), from coil to coil are wrapped on the pasting board (2) layer by layer.

3, explosion suppression device according to claim 2 is characterized in that: the length of pasting board (2) seal face $L=5\sqrt{\mathrm{RS}},$ Or get datonation-inhibition desired minimized friction length; The thickness St of pasting board (2) gets 1/3～1/5 of cylindrical shell, and wherein R is the cylindrical shell outer radius, and S is the cylindrical shell wall thickness.

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