CN101502826A - Large-sized oil conduit anti-corrosive coating curing oven - Google Patents

Abstract

A large oil pipe anticorrosion coating curing furnace is used to solve the curing problem of downhole oil pipe anticorrosion paint. Its technical solution is: the composition includes a combustion chamber, a heat exchanger connected with the chimney of the combustion chamber and a curing furnace, the curing furnace is provided with a conveying device for conveying workpieces, and the curing furnace is divided into multiple temperature chambers along the conveying direction of the workpieces. There are partitions between adjacent temperature rise areas, and the bottom of each temperature rise area is evenly distributed with air distribution pipes, and the air distribution pipes are evenly distributed with air holes, and the air inlets pass through The circulating fan is connected to the exhaust port on the top of the curing furnace, and heat-conducting oil pipes are evenly distributed above the air distribution pipe. The heat-conducting oil pipes form a circulating oil circuit through the oil pump and the oil pipe in the heat exchanger. The invention can not only realize stepwise heating and uniform heating, effectively ensure the quality of the paint film, but also not discharge toxic gas and meet the requirements of environmental protection.

Description

A large oil pipe anti-corrosion coating curing furnace

technical field

The invention relates to a large-scale curing furnace for curing the anticorrosion coating of downhole oil pipes in oil fields, and belongs to the technical field of furnaces or kilns.

Background technique

After spraying anti-corrosion paint on the surface of downhole tubing in the oil field, it is generally dried in a curing oven. The drying process directly affects the adhesion of the anti-corrosion paint and is a key factor determining the service life of the tubing.

At present, there are many types of curing furnaces used at home and abroad to cure the anti-corrosion coating of downhole tubing in oil fields, such as the vertical circular coil heating and curing furnace and the horizontal circular coil heating and curing furnace designed by Italy Ggarioni&Naval Company, The four-pass vertical circular coil heating and curing furnace produced by Fulton Company of the United States, the tube frame oil curing heating furnace produced by GMBH Company of Germany, the Fifth Design and Research Institute of Machinery Industry and the Shengli Petroleum Administration Engineering Construction Company jointly developed Horizontal chain curing furnace, etc. However, none of the existing curing furnaces can achieve stepwise temperature rise, and the pipes are placed in a high-temperature environment after entering the furnace, which greatly affects the adhesion of the paint. Since the downhole pipe is generally long (more than 10 meters) and thicker (more than 100mm in diameter), the uniformity of heating in the existing curing furnace is not ideal, and it cannot meet the requirement that the temperature difference along the length and radial direction of the pipe is less than 3°C. In addition, none of the existing curing furnaces can handle various toxic gases released from the spray paint during the drying process, which cannot meet the environmental protection requirements. A separate environmental protection device needs to be installed, which increases the production cost.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a large oil pipe anticorrosion coating curing furnace that can realize stepwise temperature rise, uniform heating and no toxic gas discharge.

Problem described in the present invention is realized with following technical scheme:

A large oil pipe anti-corrosion coating curing furnace, which consists of a combustion chamber, a heat exchanger connected to the chimney of the combustion chamber, and a curing furnace. The curing furnace is equipped with a conveying device for transporting workpieces. The conveying device along the workpiece in the curing furnace The direction is divided into multiple temperature rise areas, and there are partitions between adjacent temperature rise areas. The bottom of each temperature rise area is evenly distributed with air distribution pipes. The air distribution pipes are evenly distributed with air holes, and the The tuyere is connected to the exhaust outlet on the top of the curing furnace through the circulating fan outside the curing furnace, and evenly distributed heat-conducting oil pipes are arranged above the air distribution pipe, and the heat-conducting oil pipes pass through the oil pump and the oil pipe in the heat exchanger to form a circulating oil circuit.

The above-mentioned large oil pipe anti-corrosion coating curing furnace also includes an air distribution plate in the composition, and the air distribution plate is placed horizontally above the heat conduction oil pipe, and ventilation holes are evenly distributed on it.

The above-mentioned large-scale oil pipe anti-corrosion coating curing furnace is additionally equipped with a burner pipe, one end of which is connected to the circulating air pipe between the circulating fan and the exhaust port on the top of the curing furnace, and the other end is connected to the combustion chamber.

In the above-mentioned large oil pipe anticorrosion coating curing furnace, an oil inlet solenoid valve is installed in the oil passage of the heat conduction oil pipe in each temperature rise zone, and the control terminal of the oil inlet solenoid valve is connected to a control circuit.

The above-mentioned large-scale oil pipe anti-corrosion coating curing furnace is equipped with an air distribution plate on the top of the curing furnace.

In the above-mentioned large oil pipe anticorrosion coating curing furnace, the temperature rise zone is divided into a low temperature rise zone, a medium temperature rise zone and a constant temperature rise zone.

The above-mentioned large-scale oil pipe anti-corrosion coating curing furnace is equipped with an oil inlet solenoid valve in the oil passage of the heat conduction oil pipe in each temperature rise area, and an air inlet solenoid valve is installed at the air inlet of the air distribution pipe in each temperature rise area. The control terminal of the valve is connected with the control circuit.

The invention adopts a continuous production method, the heat generated by the combustion of fuel in the combustion chamber is transferred to the heat transfer oil through the heat exchanger, and the heat transfer oil enters the curing furnace through the circulating oil circuit, and releases heat under the action of the circulating air, so that the temperature in the curing furnace rises. High, to heat the workpiece that is introduced into the curing furnace. The curing furnace is divided into multiple temperature rise zones arranged along the conveying direction of the workpiece. The oil inlet solenoid valve is used to roughly adjust the temperature of each temperature rise zone, and the air inlet solenoid valve is used to finely adjust the temperature of each temperature rise zone. The workpiece is transferred from the low-rise zone to the high-rise zone, thereby realizing step heating. The function of the partition is to prevent the lateral flow of air, which is beneficial to the division of the temperature rise area. The circulating air adopts the method of secondary air equalization, the air distribution pipe is the first air equalization, and the air distribution plate is the second air equalization, which effectively reduces the lateral temperature difference of the workpiece, and the air equalization plate has the auxiliary air equalization effect. Using a high-temperature fan for flue gas circulation and increasing the flue gas velocity on the surface of the workpiece can reduce the longitudinal temperature difference of the workpiece and improve the heat transfer efficiency between the workpiece and the flue gas to meet the requirements of the production cycle. The function of the burnback pipe is to make the irritating gas generated in the curing furnace enter the combustion chamber for combustion, and to generate a slight negative pressure in the curing furnace to prevent toxic gas from entering the workshop. The invention can not only realize stepwise heating and uniform heating, effectively ensure the quality of the paint film, but also not discharge toxic gas and meet the requirements of environmental protection. The field trial also shows that the transverse temperature difference of the 10m tubing basically does not exist, and the longitudinal temperature difference is less than 3°C. Measured by the environmental protection department, the control of pollutants in the flue gas complies with the national "industrial organic waste gas catalytic purification device (HJ/T 389-2007)" emission standard, and the purification efficiency is 98%.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing.

Fig. 1 is a structural representation of the present invention;

Figure 2 is a top view of the layout of the air distribution duct;

Fig. 3 is a top view of the arrangement of heat-conducting oil pipes;

Fig. 4 is a schematic diagram of the flow direction of circulating air;

Fig. 5 is a top view of the transmission device.

The labels in the figure are: 1. Drying furnace, 2. Air distribution plate, 3. Heat conduction oil pipe, 4. Air distribution pipe, 5. Burner, 6. Backfire pipe, 7. Heat exchanger, 8. Oil delivery pipe, 9. Chimney, 10. Circulating air duct, 11. Evening plate, 12. Circulating fan in low temperature rising zone, 13. Circulating fan in medium temperature rising zone, 14. Circulating fan in constant temperature rising zone, 15. Baffle, 16. Low temperature rising zone Zone, 17, medium temperature rise zone, 18, constant temperature rise zone, 19, air inlet solenoid valve in low temperature rise zone, 20, air inlet solenoid valve in medium temperature rise zone, 21, constant temperature rise zone air intake solenoid valve, 22, oil pump, 23. Oil inlet solenoid valve in low temperature rise area, 24. Conveyor chain, 25. Transmission sprocket, 26. Reducer, 27. Feed inlet, 28. Transmission device, 29. Oil inlet solenoid valve in constant temperature rise area, 30, Average Air hole, 31, the combustion chamber, 32, the oil inlet solenoid valve in the middle temperature rise zone, 33, the workpiece to be baked.

Detailed ways

Referring to Fig. 1, the burner 5 among the present invention is positioned at the bottom of the burn-back pipe 6 and is connected with the combustion chamber 31, the bottom of the chimney 9 is connected with the heat exchanger 7, and the circulating air pipe 10 is connected from the top of the curing furnace 1, and from the curing furnace 1 From top to bottom are the air equalizing plate 11, the air distribution plate 2, the heat conducting oil pipe 3, and the air distributing pipe 4. The heat conducting oil pipe 3 forms a circulating oil circuit through the oil pump 22 and the oil pipe in the heat exchanger 7.

Referring to Fig. 2, there are two dividing plates 15, and the curing furnace is divided into three temperature rise zones, namely a low temperature rise zone 16, a middle temperature rise zone 17 and a constant temperature rise zone 18 (the number of temperature rise zones can be adjusted). The circulating air is sent into the low temperature rise zone 16, the medium temperature rise zone 17 and the constant temperature rise zone 18 respectively by the circulation fan 12 in the low temperature rise zone, the circulation fan 13 in the medium temperature rise zone and the constant temperature rise zone 14, and then flows into the air distribution pipe 4, Then flow out through the uniform air hole 30 on the air distribution pipe 4, and then flow through the heat-conducting oil pipe with heat-conducting oil inside, so that the circulating air is heated. Since the number of air distribution pipes 4 arranged in the three temperature rise zones is different and the apertures of the air equalization holes 30 are different, and the partition plate 15 is supplemented, three temperature rise zones with different temperatures are formed. A circulating air duct is connected to the top of the curing furnace so that the flow field in the furnace can be circulated. The computer automatically adjusts the opening of the air inlet solenoid valve 19 in the low temperature rise area, the air inlet solenoid valve 20 in the middle temperature rise area, and the air inlet solenoid valve 21 in the constant temperature rise area to control the flow and velocity of the circulating air, thereby controlling the temperature in the three temperature rise areas. fine-tuning of the temperature field.

Referring to Fig. 3, the heat transfer oil pipe 3 in Fig. 3 is arranged on the top of the air distribution pipe 4 in Fig. 2, and the oil pump 22 sends the heat transfer oil heated by the heat exchanger 7 into the heat transfer oil pipe 3 in three temperature rise zones in three ways , the temperature fields of the three temperature rise zones are coarsely fed through the oil inlet solenoid valve 23 in the low temperature rise zone, the oil inlet solenoid valve 32 in the medium temperature rise zone, and the oil inlet solenoid valve 29 in the constant temperature rise zone, so that the oil enters along the direction indicated by the arrow. The workpiece 33 to be baked in the curing furnace 1 passes through three temperature rise zones in sequence, so as to realize stepwise temperature rise.

Referring to Figure 4, the circulating air enters the curing furnace 1 through the uniform air hole on the air distribution pipe 4, and then passes through the heat transfer oil pipe 3 with heat transfer oil inside, and the heated circulating air flows upward through the air distribution plate 2, and its direction is as follows: indicated by the arrow. The hot blast is circulated through the circulating air duct 10 at the top of the curing oven 1 and three circulating blowers 12, 13, 14. After the hot air (with exhaust gas) coming out from the top of the curing furnace 1 enters the circulating air duct 10, part of it flows back to the combustion chamber 31 through the combustion return pipe 6, and is exhausted into the atmosphere by the chimney 9 after being fully burned, so there is no need to separately install an environmental protection unit. The device can make the exhaust gas discharge meet the environmental protection standard, and make full use of the combustible components in the exhaust gas, and improve the thermal efficiency of the curing furnace. Simultaneously, this design can form a negative pressure in the curing furnace 1 to ensure that the irritating gas produced by the baking paint tube will not overflow into the workshop and endanger human health. The rest of the hot air enters the circulating fan again and flows back into the curing furnace 1, which can minimize the heat loss of the exhaust gas and improve the thermal efficiency.

Fig. 5 is a top view of the transmission device 28, the transmission chain 24 drives the transmission sprocket 25 to run, and the speed reducer 26 is controlled by a frequency converter, which can realize stepless speed adjustment and meet the production cycle requirements of oil pipes with different diameters.

Claims (6)

1, a kind of large-sized oil conduit anti-corrosive coating curing oven, it is characterized in that, comprise combustion chamber (31) in the formation, heat exchanger (7) that is communicated with combustion chamber chimney (9) and curing oven (1), be provided with the conveyer (28) that is used for conveying workpieces in the described curing oven (1), direction of transfer along workpiece in the curing oven (1) is divided into a plurality of temperature rises district, be provided with dividing plate (15) between the adjacent temperature rise district, the uniform wind-distributing pipe in the bottom in each temperature rise district (4), described wind-distributing pipe (4) is gone up uniform equal wind hole (30), and its air inlet connects the exhaust outlet at curing oven (1) top through the outside circulating fan of curing oven (1), in wind-distributing pipe (4) top equally distributed heat-conducting oil pipes (3) is set, the oil pipe of described heat-conducting oil pipes (3) in oil pump (22) and heat exchanger (7) constitutes circulating oil path.

2, according to the described large-sized oil conduit anti-corrosive coating curing oven of claim 1, it is characterized in that, also comprise the pipe (6) that strile-backs in the formation, the circulation airduct (10) between the exhaust outlet at described strile-back pipe (6) one termination circulating fans and curing oven (1) top, a termination combustion chamber (31).

3, according to claim 1 or 2 described large-sized oil conduit anti-corrosive coating curing ovens, it is characterized in that, also comprise air distribution plate (2) in the formation, described air distribution plate lies in a horizontal plane in heat-conducting oil pipes (3) top, uniform air vent on it.

4, large-sized oil conduit anti-corrosive coating curing oven according to claim 3 is characterized in that, also is included in the homogenating plate (11) that curing oven (1) inner top is provided with in the formation.

5, large-sized oil conduit anti-corrosive coating curing oven according to claim 4 is characterized in that, described temperature rise is divided into low temperature rise district, middle temperature rise district and constant temperature and risen the district.

6, according to the described large-sized oil conduit anti-corrosive coating curing oven of claim 5, it is characterized in that, also be included in the oil-feed magnetic valve that is provided with in heat-conducting oil pipes (3) oil circuit in each temperature rise district in the formation, the air intake magnetic valve that wind-distributing pipe (4) air inlet in each temperature rise district is provided with, the control end connection control circuit of described each magnetic valve.

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