CN218435911U

CN218435911U - Barrel for double-screw extruder

Info

Publication number: CN218435911U
Application number: CN202222015800.3U
Authority: CN
Inventors: 李朝明
Original assignee: Shanghai Liyuan Environmental Technology Co ltd; Nanjing Lingfeng Intelligent Technology Co ltd
Current assignee: Shanghai Liyuan Environmental Technology Co ltd; Nanjing Lingfeng Intelligent Technology Co ltd
Priority date: 2022-08-02
Filing date: 2022-08-02
Publication date: 2023-02-03
Anticipated expiration: 2032-08-02

Abstract

The utility model relates to a barrel for double screw extruder, be the barrel body of rectangle including the appearance. The utility model discloses a barrel body, including barrel body, barrel body center and base plate, the barrel body center is equipped with "8" font inside lining, "8" font inside lining is formed by two relative concatenations of "3" font inside lining, the base member material of "8" font inside lining is high chromium cast iron, the internal surface of "8" font inside lining has prepared in proper order from inside to outside that hardness is the metal nitriding layer that the gradient increases, from the fusible alloy spraying layer, nickel base tungsten carbide alloy spraying layer. The utility model provides an extruder barrel is the surface coating that the gradient increases through preparing the three-layer hardness on the body, improves surface coating's cohesion to make inside lining surface one deck have higher hardness, wearability and corrosivity, its life improves more than 4 times than pure high chromium cast iron barrel. In addition, during maintenance, only one of the two 3-shaped linings can be replaced according to the abrasion condition of the lining, so that the replacement cost of the lining during maintenance is reduced.

Description

Barrel for double-screw extruder

Technical Field

The utility model belongs to the technical field of screw extruder, in particular to a cylinder body for a double-screw extruder.

Background

The screw extruder is a mechanical production device widely applied to industries such as plastic, food and feed processing, and the like, and the working principle of the screw extruder is that pressure and shearing force are generated through rotation of a screw, so that materials are subjected to physical or chemical changes after the actions of mixing, extruding, shearing and the like, and finally, a finished product is extruded at the terminal of the device.

With the rapid development of polymer industry, various novel filling, reinforcing, modifying and functional polymer materials are emerging continuously, and are widely applied to various high-strength reinforced plastics. In order to reduce the manufacturing cost of plastic products and to improve certain properties thereof, various reinforcing fillers, such as talc and calcium carbonate, are generally added to the plastic products. Due to the addition of the auxiliary agent, various corrosive media (such as chlorides, bromides, sulfides and the like) can be generated under the action of various physical and chemical properties in the extrusion production process. The barrel liner is corroded or worn, or both, by the additives during the plastic processing.

In the production process, the barrel of the extruder is in a severe high-pressure high-temperature environment and bears huge friction force and shearing force, and the abrasion condition of the inner surface of the barrel is serious. The abrasion of the barrel liner affects the compression and shearing of the twin screw extruder to the material, resulting in a reduction in product quality. On the other hand, the frequent replacement of the worn and failed barrel liner increases the cost, delays the production plan and reduces the production efficiency, so that the abrasion of the barrel is reduced, the working life of the barrel is prolonged, the maintenance cost of the equipment is greatly reduced, the quality of the product is ensured, and higher economic benefit is brought to enterprises. Many researches for improving the wear resistance of mechanical parts at home and abroad exist, but the working environment of the barrel of the extruder is special, the friction is not common between metal and metal, but between metal and high molecular polymer, crop products and other soft abrasive materials, and the soft abrasive materials are often corroded by various corrosive media under higher temperature and contact stress, the friction and wear mechanism of the type is very complex, and the industry urgently needs to develop a special protection measure for enhancing the inner surface of the barrel.

At present, the conventional heat treatment has little significance for improving the service performance of the barrel lining material, the whole heat treatment technology cannot fully utilize the material, and various defects exist. For example, hot-dip coating, the range of selecting materials by carburizing is narrow, and the wear resistance of the prepared coating is not enough; the use of high strength alloy materials to integrally manufacture the liner for the can is costly.

High Velocity Oxygen (HVOF) is a high temperature, high velocity combustion flame stream generated by combustion of a hydrocarbon fuel gas such as propane or propylene, or hydrogen and high pressure oxygen in a combustion chamber or in a special nozzle. The supersonic flame spraying has moderate heat input, high spraying speed, difficult crystallization of the coating and compact structure, and is the preferred technology for preparing the coating on the inner surface of the cylinder. However, the coating has high hardness, which generally has a difference of over 1200HV (HRc 70) and the hardness (HRc 60-62) of the cylinder body, and the service life of the coating cannot be exerted to the maximum extent in the high-temperature working process.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a barrel for double screw extruder is provided, its surface hardness, wearability and corrosion resistance improve to reduce the replacement cost and improve production efficiency and life.

The utility model provides a technical scheme that its technical problem adopted is: a barrel for a twin-screw extruder is provided, comprising a barrel body having a rectangular outer shape. The utility model discloses a barrel body, including barrel body, barrel body center and base plate, the barrel body center is equipped with "8" font inside lining, "8" font inside lining is formed by two relative concatenations of "3" font inside lining, the base member material of "8" font inside lining is high chromium cast iron, the internal surface of "8" font inside lining has prepared in proper order from inside to outside that hardness is the metal nitriding layer that the gradient increases, from the fusible alloy spraying layer, nickel base tungsten carbide alloy spraying layer.

The both ends of "3" font inside lining are equipped with the joint groove that the symmetry matches, "8" font inside lining is passed through by two "3" font inside linings the joint groove interlock concatenation forms.

The thickness of the metal nitriding layer is 0.2-0.3 mm, and the hardness of the metal nitriding layer is 750-850 HV.

The thickness of the self-fluxing alloy spray welding layer is 1.5-2.0 mm, and the hardness is 900-1000 HV.

The thickness of the nickel-based tungsten carbide alloy spraying layer is 0.3-0.5 mm, and the hardness of the nickel-based tungsten carbide alloy spraying layer is more than 1200HV.

Advantageous effects

The utility model provides an extruder barrel is the surface coating that the gradient increases through preparing the three-layer hardness on the body, improves surface coating's cohesion to make inside lining surface one deck have higher hardness, wearability and corrosivity, its life improves more than 4 times than pure high chromium cast iron barrel.

In addition, during maintenance, only one of the two 3-shaped linings can be replaced according to the abrasion condition of the lining, so that the replacement cost of the lining during maintenance is reduced, and the lining maintenance device has good cost performance.

Drawings

FIG. 1 is a front view of a barrel for a twin screw extruder.

FIG. 2 is a cross-sectional view of a barrel for a twin-screw extruder.

Wherein, 100-cylinder body; 200- "8" shaped lining; 201- "3" shaped inner lining; 202-a metallic nitrided layer; 203-self-fluxing alloy spray welding layer; 204-nickel base tungsten carbide alloy spray coating; 205-snap groove.

Like reference symbols in the various drawings indicate like elements.

Detailed Description

The present invention will be further described with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that various changes and modifications of the present invention may be made by those skilled in the art after reading the teachings of the present invention, and these equivalents also fall within the scope of the appended claims.

As shown in fig. 1 and 2, the utility model provides a cylinder for a twin-screw extruder, which comprises a cylinder body 100 with a rectangular shape. The cylinder body 100 center is equipped with "8" font inside lining 200, "8" font inside lining 200 is formed by two "3" font inside linings 201 relatively concatenation, the base member material of "8" font inside lining 200 is high chromium cast iron, the internal surface of "8" font inside lining 200 is equipped with the metal nitriding layer 202, the self-fluxing alloy spouts the welding layer 203, nickel base tungsten carbide alloy spraying layer 204 that hardness is the gradient and increases from inside to outside in proper order.

As a preferred embodiment of the utility model, on the basis of above-mentioned technical scheme, the both ends of "3" font inside lining 201 are equipped with the joint groove 205 that the symmetry matches, "8" font inside lining 200 is passed through by two "3" font inside linings 201 the joint groove 205 interlock concatenation forms. The depth and width of the groove of the clamping groove 205 are both 2-4 mm.

As an optimized embodiment of the utility model, on the basis of the above technical scheme, the intersecting line edge of "3" font inside lining 201 carries out radius passivation treatment, and radius is 3 ~ 10mm, can reach the reinforcing coating cohesion, prevents the destruction of coating because of stress concentration leads to.

In a preferred embodiment of the present invention, based on the above technical solution, the 3-shaped lining 201 is heat-treated after being machined, and the heat-treated hardness is HRc 58-60.

As a preferred embodiment of the present invention, on the basis of the above technical solution, the heat-treated 3-shaped liner 201 is nitrided to form a metal nitrided layer 202 having a thickness of 0.2 to 0.3mm and a hardness of 750 to 850HV.

As a preferred embodiment of the present invention, on the basis of the above technical solution, a layer of self-fluxing alloy is spray-welded on the inner surface of the 3-shaped liner 201 after the nitriding treatment, the thickness of the formed self-fluxing alloy spray-welding layer 203 is 1.5-2.0 mm, and the hardness thereof is 900-1000 HV. The self-fluxing alloy comprises the following components in percentage by weight: c:0.7 to 1.1, B:3.0 to 4.0, si:3.5 to 5.0, cr:15 to 17, fe:2 to 5 percent, and the balance being Ni. The self-fluxing alloy spray welding layer 203 is metallurgically bonded with the cylinder body 100, has high density, and has excellent corrosion resistance and wear resistance.

As a preferred embodiment of the present invention, on the basis of the above technical solution, the inner surface of the "3" shaped liner 201 is sandblasted and roughened, then supersonic flame spraying method is adopted, nickel-based tungsten carbide alloy powder is directly sprayed to the inner surface of the liner by a spray gun to obtain a nickel-based tungsten carbide alloy spraying layer 204, and then the spray gun repeatedly sprays the nickel-based tungsten carbide alloy spraying layer 204 back and forth above the inner surface of the "3" shaped liner 201, so that the nickel-based tungsten carbide alloy spraying layer 204 is stacked layer by layer, the thickness of each nickel-based tungsten carbide alloy spraying layer 204 is 50-100 μm, and the total thickness of the stacked nickel-based tungsten carbide alloy spraying layer 204 is 0.3-0.5 mm; when the supersonic flame spraying is carried out, the flame flow speed of the supersonic flame spraying is more than 2000m/s, the speed of sprayed particles is 400-500m/s, the temperature of the inner surface of the lining is less than 100 ℃ when the supersonic flame spraying is carried out, the oxygen flow is 200-250L/min, the powder feeding rate is 25-35g/min, and the distance between a spray gun and the surface of the 3-shaped lining 201 is 200-275mm when the supersonic flame spraying is carried out. The granularity range of the nickel-based tungsten carbide alloy powder is 100-150 mu m, and the mass percentage content ratio of tungsten carbide to nickel is 40% -50% to 50% -60%.

As an optimal embodiment of the utility model, on the basis of the above technical scheme, the hot spraying process after "3" font inside lining 201 splice into complete "8" font inside lining 200 through joint groove 205, install the complete inside lining after splicing into barrel 100 through hot mosaic technology interference fit, barrel 100 heating temperature is 250 ~ 400 ℃ when hot is inlayed.

The utility model provides an extruder barrel inside lining has high rigidity, high wear resistance, corrosion resistance, and its life improves more than 4 times than pure high chromium cast iron barrel to when overhauing, can only change one in two "3" font inside linings 201 according to the inside lining wearing and tearing condition, thereby inside lining replacement cost when reducing the maintenance has good price/performance ratio.

Claims

1. The utility model provides a barrel for double screw extruder, includes that the appearance is barrel body (100) of rectangle, its characterized in that, barrel body (100) center is equipped with "8" font inside lining (200), "8" font inside lining (200) are formed by two "3" font inside linings (201) splice relatively, the base member material of "8" font inside lining (200) is high chromium cast iron, the internal surface of "8" font inside lining (200) has prepared in proper order from inside to outside that hardness is metal nitriding layer (202), self-fluxing alloy spray welding layer (203), nickel base tungsten carbide alloy spraying layer (204) that the gradient increases.

2. The barrel for the double-screw extruder as claimed in claim 1, wherein the two ends of the 3-shaped lining (201) are provided with symmetrically matched clamping grooves (205), and the 8-shaped lining (200) is formed by splicing two 3-shaped linings (201) through the clamping grooves (205) in an occlusion way.

3. Barrel for a twin-screw extruder according to claim 1, characterised in that the metal nitriding layer (202) has a thickness of 0.2-0.3 mm and a hardness of 750-850 HV.

4. Barrel for a twin-screw extruder according to claim 1, characterised in that the thickness of the self-fluxing alloy spray layer (203) is 1.5-2.0 mm and the hardness is 900-1000 HV.

5. Barrel for a twin-screw extruder according to claim 1, characterised in that the sprayed layer (204) of nickel-based tungsten carbide alloy has a thickness of 0.3-0.5 mm and a hardness of more than 1200HV.