Hot air pipeline expansion joint

Abstract

The invention discloses a hot air pipeline expansion joint which is characterized in that a corrugated pipe of the expansion joint adopts a heat insulation layer consisting of high-temperature-resistant and high-strength ceramic fiber folding blocks to prevent hot air from contacting with the corrugated pipe, an anti-scouring and high-temperature-resistant silicon-containing hardening agent is sprayed on the surface of the heat insulation layer, and the heat insulation layer replaces original ceramic fiber cotton and can extend and retract along with the expansion joint. The corrugated pipe is thoroughly isolated from hot air, and the hardening layer protects the heat insulation layer from being scoured by high-temperature air flow.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon black industry, and specifically relates to a pipe expansion joint connecting a high-temperature air outlet of a high-temperature air preheater (hereinafter referred to as: preheater) and a burner in a vertical direction. Background Art

[0002] The preheater on the carbon black production line heats the cold air and then enters the hot air pipe from the hot air outlet and returns to the reactor burner for combustion, achieving the purpose of energy saving. The air temperature of the preheater currently in use has reached 950°C. The reactor outlet is connected to the preheater base and parallel to the hot air pipe. The hot air enters the burner vertically downward through the elbow. The vertical section of the pipe is equipped with a pipe expansion joint. The shell of the hot air pipe is equipped with an insulation layer and a fire-resistant layer. The ceramic fiber wool and stainless steel baffle are used to form an insulation layer in the bellows of the pipe expansion joint. The expansion joint is in a pre-compression state before installation. The existing problems are: 1. The expansion joint bellows are filled with ceramic fiber cotton, with small compression, large number of waves, long bellows and poor stability of the pipe expansion joint; 2. Under high temperature, as the expansion joint bellows elongate, the ceramic fiber cotton in the bellows becomes looser and the thermal insulation effect is poor, and the strength of the bellows decreases or it is burned through after being heated; 3. Under high temperature, the stainless steel baffle is severely deformed, and the ceramic fiber cotton leaks out of the expansion gap of the baffle into the hot air flow and then into the burner, blocking the burner gas port; 4. After the hot air containing ceramic fiber cotton enters the reactor, the carbon black exhaust contains impurities, and the produced carbon black is of poor quality or unqualified; 5. The bellows and the cylinder are overlapped with welds, the thermal insulation effect of the bellows is poor, and the weld strength is low and easy to crack. Therefore, the heat insulation of the bellows is very important, which directly affects the service life of the expansion joint. The current heat insulation method has poor effect and high damage rate of bellows. Our company has launched a bellows insulation layer technology after research, which can effectively isolate the adverse effects of hot air on the bellows and ensure that no impurities are mixed in the hot air. Butt welds are used between the bellows and the connecting cylinder to solve the problem of weld cracking. Summary of the invention

[0003] The present invention introduces a hot air duct expansion joint. The bellows of the expansion joint adopts an insulation layer composed of high-temperature resistant and high-strength ceramic fiber folded blocks to prevent hot air from contacting the bellows. An erosion-resistant and high-temperature resistant silicon-containing hardener is sprayed on the surface of the insulation layer. The insulation layer replaces the original ceramic fiber cotton and can expand and contract with the expansion joint, so that the bellows is completely isolated from the hot air. The hardened layer protects the insulation layer from being eroded by the high-temperature air flow.

[0004] The invention discloses a hot air duct expansion joint, comprising: a support plate, a rain cover, a pull rod, a flange cylinder, a fixing pin, a bellows, an intermediate cylinder, a connecting pin, a heat insulation block I, a heat insulation block II, a heat preservation layer, a fire-resistant layer, a blocking plate, and a hardener. The invention is characterized in that: the duct expansion joint is mainly composed of an upper and lower flange cylinder, an intermediate cylinder and a bellows, and a blocking plate is provided at the mutual connection; the heat insulation layer of the flange cylinder and the intermediate cylinder is composed of a heat preservation layer and a fire-resistant layer; the heat insulation layer of the bellows is composed of a concave heat insulation ring and a convex heat insulation ring matched up and down, and the surface is sprayed with a hardener; the concave heat insulation ring It is composed of several insulation blocks II connected together by connecting pins; the convex insulation ring is composed of several insulation blocks I connected together by connecting pins; the insulation block I is a convex ceramic fiber stacked block; the insulation block II is a concave ceramic fiber folded block; the bellows insulation layer is fixed to the connected cylinder with fixing pins after being connected to the blocking plate, and the two ends are connected to the flange cylinder and the middle cylinder by butt welding; the rain cover is welded to the shell of the upper flange cylinder and the middle cylinder, and is located above the bellows; support plates are welded to the flange cylinder and the middle cylinder, and the pipe expansion joint is adjusted and fixed by a pull rod.

[0005] The design points of the present invention are:

[0006] The heat insulation layer is not affected by the expansion and contraction of the bellows, thereby enhancing the welding strength of the connection between the bellows and the cylinder.

[0007] The beneficial effects of the present invention are:

[0008] 1. The ceramic fiber folded block insulation layer solves the problem of the bellows' strength reduction and deformation after being exposed to high temperature, reduces the number of corrugations and increases the overall stability of the pipe expansion joint;

[0009] 2. After the strength of the bellows is improved, the welding strength with the cylinder is improved, eliminating the hidden danger of weld cracking;

[0010] 3. It increases the service life of the pipeline expansion joint, reduces the number of shutdowns for maintenance, and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Schematic diagram of the present invention

[0012] Figure 2 The present invention Figure 1 Ⅰ Enlarged image

[0013] Figure 3 The present invention Figure 1 Markings in the AA section schematic diagram: 1-support plate, 2-rain cover, 3-pull rod, 4-flange cylinder, 5-fixing pin, 6-bellows, 7-intermediate cylinder, 8-connecting pin, 9-insulation block I, 10-insulation block II, 11-insulation layer, 12-refractory layer, 13-blocking plate, yh-hardener. DETAILED DESCRIPTION

[0014] A hot air duct expansion joint comprises: a support plate 1, a rain cover 2, a pull rod 3, a flange cylinder 4, a fixing pin 5, a bellows 6, an intermediate cylinder 7, a connecting pin 8, a heat insulation block I9, a heat insulation block II10, a heat preservation layer 11, a fireproof layer 12, a blocking plate 13, and a hardener YH.

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Specific implementation process:

[0016] 1. Make the outer shell of the upper and lower flange cylinders 4 and the middle cylinder 7 and weld the anchor nails, process the step at the connection between the cylinder and the bellows 6, drill holes at the cylinder installation fixing pins 5, install the insulation layer 11, and make the refractory layer 12;

[0017] 2. Make a support plate 1, a rain cover 2, a pull rod 3, and a blocking plate 13;

[0018] 3. Outsourced bellows 6, insulation block Ⅰ9, insulation block Ⅱ10, outsourced hardener yh, nuts;

[0019] 4. Use the connecting pin 8 to connect several heat-insulating blocks I9 together to form a convex heat-insulating ring, and connect several heat-insulating blocks II10 together to form a concave heat-insulating ring;

[0020] 5. The concave and convex heat insulation rings are installed on the flange cylinder 4 and the plugging plate 13 of the intermediate cylinder 7 according to the positions shown in the figure, fixed with the fixing pin 5 and then welded to the cylinder, and the hardener yh is sprayed on the surface of the heat insulation layer;

[0021] 6. Connect the flange cylinder 4 and the intermediate cylinder 7 through the bellows 6, and the concave and convex insulation rings should be matched together;

[0022] 7. After the expansion joint composed of the flange cylinder 4, the intermediate cylinder 7 and the bellows 6 is aligned, weld the two ends of the bellows 6 to the steps of the connected cylinder;

[0023] 8. Weld support plate 1 and rain cover 2;

[0024] 9. The pull rod 3 passes through the three support plates 1, and is adjusted with nuts to make the corrugations of the bellows 6 in a pre-stressed state and fixed with locking nuts;

[0025] 10. Factory inspection, packaging and delivery.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A hot air duct expansion joint, comprising: A support plate (1), a rain cover (2), a pull rod (3), a flange cylinder (4), a fixing pin (5), a bellows (6), an intermediate cylinder (7), a connecting pin (8), an insulation block I (9), an insulation block II (10), a thermal insulation layer (11), a fire-resistant layer (12), a plugging plate (13), and a hardener (yh), characterized in that: the pipeline expansion joint is mainly composed of an upper and lower flange cylinder (4), an intermediate cylinder (7) and a bellows (6), and a plugging plate (13) is provided at the interconnection; the thermal insulation layer of the flange cylinder (4) and the intermediate cylinder (7) is composed of a thermal insulation layer (11) and a fire-resistant layer (12); the thermal insulation layer of the bellows (6) is composed of a concave thermal insulation ring and a convex thermal insulation ring matched up and down The concave heat-insulating ring is composed of a plurality of heat-insulating blocks II (10) inserted together through a connecting pin (8); the convex heat-insulating ring is composed of a plurality of heat-insulating blocks I (9) inserted together through a connecting pin (8); the heat-insulating layer of the bellows (6) is butt-jointed with the blocking plate (13) and then fixed to the connected cylinder with a fixing pin (5), and the two ends are butt-welded to the flange cylinder (4) and the intermediate cylinder (7); the rain cover (2) is welded to the shell of the upper flange cylinder (4) and the intermediate cylinder (7), and is located above the bellows (6); a support plate (1) is welded to the flange cylinder (4) and the intermediate cylinder (7), and the pipe expansion joint is adjusted and fixed by a pull rod (3).

2. A hot air duct expansion joint according to claim 1, characterized in that: The heat insulation block I (9) is a convex ceramic fiber stacked block; the heat insulation block II (10) is a concave ceramic fiber folded block.

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