RU2281850C1 - Self-propelled route machine for shot cleaning of tubes of oil and gas pipelines - Google Patents

Abstract

FIELD: equipment for making and restoring oil and gas pipelines, namely shot blasting of tubes before applying insulation coating onto them.

SUBSTANCE: apparatus includes detachable shot cleaning chamber, mechanism for rocking cleaning nozzles, shot blasting high and low pressure apparatuses, apparatus for automatically leveling machine. Low-pressure shot blasting apparatus are combined to cascades with high pressure shot blasting apparatuses in the form of cleaning nozzles with ejectors. Apparatus for automatically leveling machine includes inclination angle pickup and balancing weights in the form of reduction gears. Balancing weights are mounted with possibility of matched motion from electromechanical servo drives along inclined guides. Said guides are mounted in frame of machine at its both sides.

EFFECT: simplified design, enhanced efficiency, improved operational reliability of machine and cleaning degree of tubes.

2 dwg

Description

The invention relates to equipment for the production and restoration (repair) of oil and gas pipelines, and more particularly for shot blasting of pipes before applying an insulating coating to them.

Known machines are firms "CRC-EVANS" (USA), Van Voskaylen (Netherlands), JSC "Techtransmash" (Ukraine) and others, which use abrasive blasting of pipes with river sand. Their widespread use is limited for several reasons:

the need to prepare an abrasive (drying, dispersion by fractions, packaging);

delivery to the place of restoration work and constant replenishment of the stock of abrasive;

the possibility of abrasive getting onto a freshly primed pipeline surface;

the negative impact of the dry cleaning process on the health of staff.

A series of machines for cleaning the inner surfaces of pipes (Airblast company), universal machines (BLACTRAC company) have been created for shot processing. However, their use for processing external surfaces when performing restoration work on oil and gas pipelines is not possible.

Closer to the invention in terms of functionality and the achieved effect is the MTD-1420 bead-blasting machine designed, manufactured and tested at Surgutgazprom LLC, Kurganmashzavodom OJSC (17, Mashinostroiteley av., 17, 640631, Kurgan) .

The machine is a self-propelled unit, controlled by the operator from the edge of the trench through a remote control of an automated control system built on the basis of an industrial controller and frequency-controlled drives of the company "HITACHI" (Japan). The machine is equipped with a split shot-cleaning chamber with a nozzle swing mechanism; shot blasting machines equipped with shot batchers and mixing chambers; abrasive (shot) regeneration system, which includes screw conveyors, shot elevators in storage bins, a fan and a cyclone for separating cleaning products from large particles of the shot.

Tests of the MTD-1420 prototype showed the possibility of obtaining the degree of cleaning of the outer surface of the pipeline to class 2 according to BCH 008-88 with a roughness of the order of Rz = 40 ... 80 μm.

The disadvantages of the machine MTD-1420 are the design complexity and low reliability. Due to the considerable dimensions, the assembled machine is not transportable, and it is difficult to assemble it locally. A number of elements, such as hoses supplying shots to nozzles, moving parts of elevators and screw augers, have an extremely limited service life and require frequent periodic replacement, and therefore, a mobile spare parts warehouse and a team of workers are needed to restore the machine to work. In addition, the structure of the machine with the fractions (feeders) mounted on it and the considerable size led to a large mass, which makes it difficult to install it on the pipeline, and to the risk of deflection of the processed pipe.

The machine does not have its own device for eliminating deviations from the vertical position (inclinations). To maintain the vertical position, the machine is connected by a special rod to a power plant moving behind the trench parallel to the pipe, which introduces additional inconvenience to the operation of the entire complex.

The technical result of the invention is to simplify the design, increase reliability, productivity and quality of processing - is achieved by the fact that the machine contains a detachable shot blasting chamber and a swing mechanism of the cleaning nozzles, and the working speed of the abrasive is provided using a system of high-pressure jet devices in the form of nozzles with ejectors arranged in cascades with a system of low-pressure apparatuses, ensuring the transportation of shot to high-pressure apparatuses, with the presence of an automatic device about aligning a machine containing a tilt angle sensor and movable balancing masses in the form of reducers installed with the possibility of coordinated movement by means of tracking electromechanical drives along inclined guides mounted on the machine frame symmetrically on both sides of it.

The use of this technical solution can dramatically reduce the size and weight of the machine, eliminating high-pressure feeders, elevators, screws from it, which increases the continuity of the machine, increases the service life, significantly reduces its initial cost and operating costs.

The automatic vertical alignment device proposed in the invention also increases its performance and reliability.

In Fig.1 shows a view of the machine from the side of the pipe end, in Fig.2 a side view of the machine (along arrow A in Fig.1), Fig.3 installation diagram of the high-pressure jet apparatus.

The highway machine for cleaning fractions of oil and gas pipelines contains a frame (body) 1, on which are mounted: a detachable cleaning chamber 2, a circular oscillation (swing) mechanism 3 of the inkjet apparatus, a chassis 4 with a drive for moving the machine along the pipe, a device for automatically aligning the machine 5 vertically, ventilation installation 6 with cyclone 7, electrical cabinet 8 with machine control panel 9.

The frame 1 of the machine is made in the form of a welded structure of two arches, an upper power plate and two side ties.

The cleaning chamber 2 is detachable from 2 halves with the possibility of installation on the pipe with subsequent assembly and flange fastening to the upper plate of the frame 1. A collection collector 10 of the fraction with dispensers 11 and feeders 12, which are low-pressure jet devices, is fixed to the lower part of the chamber (1st stage) transporting shots to high pressure apparatuses. Above the cleaning chamber 2, a hatch 13 is installed on the upper plate of the frame 1 through which the shot is filled.

On the right side of the chamber 2 (figure 2), a window is made for accommodating the rotary part 14 of the rocking mechanism 3 with several (for example, 6th) cleaning nozzles equally spaced around the circumference — high pressure jet devices 15 (2nd stage), installation which are shown in figure 3. Compressed air intake to the devices of the 1st and 2nd stages is carried out from the collectors 16, mounted on both sides of the frame 1 on the couplers of its arches. The basis of the rotary part 14 is a detachable (for assembly on the pipe) gear 17 with internal gearing, through which the rotary part is connected with a reversible swing drive 18, equipped with an alternating current electric motor with adjustable frequency to change the angular velocity of the nozzles (jet devices) 15. The rotary part of the swing mechanism is equipped with a flexible protective ring 19 (figure 3), which prevents the shot from the chamber 2 from colliding with the surface of the pipe. The rotary part 14 of the rocking mechanism 3 of the nozzles 15 is installed by the outer surfaces (cheeks) of the wheel 17 on the support-centering rollers 20, which are held by brackets mounted on the frame 1.

For centering on the pipeline and moving along it, the machine is equipped with a chassis 4 mounted on the frame 1. It has two pairs of rollers 21, one of which is equipped with a drive 22 with a frequency-controlled AC motor to change the speed of movement of the machine through the pipe. For greater stability of the machine on the pipe in the lower part of the frame 1 has two pairs of freely rotating rollers 23.

To prevent lateral rolls, the machine is equipped with a device 5 for automatically leveling it in a vertical position. The device has an inclined guide 24 located on both sides of the machine. On guides with the possibility of coordinated movement, balancing masses are placed - gearboxes 25 provided with spindle nuts mating with fixed spindle screws 26, relative to which the gearboxes 25 are moved along guides 24. A well-known sensor type ILM-01 is used to monitor the vertical position of the machine (ZAO LIMAKO g .Tula), measuring the angle of inclination of the machine in both directions with an accuracy of 0.1 ° or similar, included in the automated control system of the machine (the sensor is not shown in the diagrams).

To separate the fraction from the cleaning products and ensure the environmental friendliness of the machine, a ventilation unit 6 with a cyclone 7 is mounted on the upper plate of the frame 1, connected by air ducts to the cleaning chamber 2.

The machine is controlled by a distributed automated control system (ACS), part of which is located directly on the machine in the form of a cabinet with electrical equipment 8 and a control panel 9, which is duplicated for an operator located at a distance from the machine, for example, on the edge of the trench. The control system also includes a machine speed sensor along the pipe (tachometer), nozzle rocking speed sensor (rocking cycle counter), fractional level sensors in the drive, machine vertical position sensor (sensors are not shown in the diagrams). The second part of the ACS is located on a power plant that supplies the machine with electricity and compressed air. The power plant moves parallel to the pipeline by means of a tractor (tractor).

ACS provides the machine in two modes - automatic under the supervision of an operator equipped with a remote control panel, and a setting mode in which any of the mechanisms and devices can be turned on when debugging and selecting modes that provide the specified quality of the pipeline surface treatment.

During restoration work on the pipeline, the route shot cleaning machine for the pipe works as follows. The start-up of a debugged and refueled machine in automatic mode is carried out by turning on the drive 18 of the mechanism 3 for swinging the jet devices 15 at an angle of 2π / n (n is the number of high-pressure jet devices), which ensures the speed of processing the annular section of the pipe surface with the jet of a fraction jet (Fig. 3) and by turning on the drive 22 for moving the machine through the pipe, providing the feed rate obtained by swinging, oscillating in the rotation of the flow of shot. Thus, these two coordinated movements determine the main indicators of the machine - its productivity and cleaning quality with a given roughness, for example, Rz = 40 ... 80.

The fraction is circulated in this case by means of the energy of compressed air coming from a compressor installed on a power plant moving in parallel with the machine. Initially, a portion of the shot is poured through the hatch 13 located on the top plate of the frame 1, and fills the collection tank 10 to the required level (volume) of the shot, controlled by the sensors. From the accumulator 10, the fraction through the dispensers 11 with the help of air flows enters the feeders 12, which are the 1st stage jet devices and provide the supply (transportation) of the fraction to the 2nd stage jet devices 15 located in the rotary part 14 of the swing mechanism 3. These the devices accelerate the fraction to a working speed (over 90 m / s). The parameters b, c and a of the installation of inkjet apparatuses are determined by known calculation methods and experiments in order to obtain the optimal "shot torch" (size a along the axis of the pipeline) (figure 3).

In this process, cleaning the surface of the pipeline from corrosion and the remnants of the previous coating more efficiently occurs with crushed shot with sharp edges. To obtain the best surface-hardening effect, steel balls are added to the crushed shot, when they hit the pipe surface at speeds above 90 m / s in the contact zone, the temperature reaches 1000 ... 1200 ° C (according to known data), which creates an environment corresponding to the region temperatures of phase transitions - hardening of the surface layer of the cleaned pipe occurs.

The spent fraction along the walls of the cleaning chamber 2 is rolled into a storage tank 10, mounted in the lower part of the chamber, and then reused according to the scheme described above. When fractions wear, the cleaning efficiency decreases, which leads to a decrease in the feed rate, and then to its replacement with a new portion.

The cleaning products of the processed pipeline are separated from the shot and removed from the cleaning chamber 2 by means of a ventilation unit 6 mounted on the top plate of the frame 1. By means of air ducts, the installation 6 is connected to a cyclone 7, by which the cleaning products are discharged into a collector or on a special flooring, and then together with flooring sent for recycling.

During the operation of the machine, its equilibrium state with respect to the vertical plane of symmetry of the pipeline is constantly monitored. The roll is eliminated by the automatic leveling device 5 (Fig. 1), equipped with an inclination angle type sensor ILM-01 (3AO LIMACO, Tula), by coordinated movement of moving balancing masses in the form of reducers 23 with follower electromechanical drives along inclined guides 22 s fixed on them fixed lead screws 24. Coordinated (synchronous) movement of the gearboxes is carried out in the opposite direction to the roll. So when the machine roll to the right, the right gearbox (Fig. 1) moves to the left (up). The left also moves to the left (down). With a left roll, the movement of the gears is reversed. The sensor included in the automatic control system of the machine constantly monitors the tilt, trying to keep it in a zero state through the control system.

Claims (1)

A self-propelled traction machine for cleaning oil and gas pipelines with a shot, containing a detachable shot blasting chamber and a pump nozzle swing mechanism, characterized in that the machine further comprises low pressure shot blasting apparatuses arranged in cascades with high pressure shot blasting apparatus made in the form of cleaning nozzles with ejectors, an automatic device leveling machine, containing a tilt angle sensor and balancing masses in the form of gears installed with the possibility voiced by tracking movement of electromechanical actuators on ramps attached to the machine frame symmetrically on either side.

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