Flange type high pressure sight glass

Abstract

The application relates to the technical field of industrial sight glasses, in particular to a flange type high-pressure sight glass. The sight glass body is internally formed with an installation cavity, the installation cavity is internally installed with a window glass assembly, the outer end of the sight glass body is installed with a compression ring for limiting the position of the window glass assembly through screws, high-pressure gaskets are arranged between the window glass assembly and the compression ring, and the side, away from the compression ring, of the window glass assembly is also provided with the high-pressure gaskets. High-pressure gaskets are arranged between the window glass assembly and an electronic endoscope and on the other side of the window glass assembly, and undertake the main sealing task; meanwhile, auxiliary sealing pieces are additionally arranged between the two sides of the window glass assembly and the high-pressure gaskets. The main and auxiliary sealing pieces are combined, can effectively cope with the coupling effect of possible slight deformation and medium corrosion under high pressure, greatly improve the sealing reliability during long-term use, and meet the strict requirement of zero leakage under super-high-pressure working conditions.

Description

Technical Field

[0001] This invention relates to the field of industrial sight glass technology, and in particular to a flange-type high-pressure sight glass. Background Technology

[0002] In modern chemical engineering, petroleum refining, supercritical fluid technology, and high-pressure synthesis, the operating pressure of reaction equipment is increasing. Units with pressure ratings of 20 MPa (approximately 200 bar) and above are becoming increasingly common. To ensure process safety and monitor reaction progress (such as phase changes, catalyst state, and fluid mixing), reliable observation windows, i.e., high-pressure sight glasses, must be installed on the pressure-bearing housing of the equipment.

[0003] Compared to traditional low-pressure sight glasses, 20MPa high-pressure sight glasses face extreme challenges:

[0004] 1. Extremely high structural strength requirements: The window glass and its clamping structure must withstand huge uniformly distributed loads to prevent them from shattering.

[0005] 2. High sealing difficulty: Under the combined effects of high pressure and possible temperature and media corrosion, a long-term zero-leakage seal must be achieved.

[0006] 3. Significant safety risks: If it fails, it may cause high-pressure media to be ejected, resulting in a serious safety accident.

[0007] 4. Preservation of optical performance: Under high pressure, glass will undergo slight deformation, and it is necessary to ensure that this does not affect the clarity of observation.

[0008] Currently, there is relatively limited standardized design and public research on ultra-high pressure sight glasses above 10MPa, especially those at 20MPa. To address the need for real-time observation of internal reaction states in ultra-high pressure (20MPa level) environments in industrial processes such as chemical, petroleum, and supercritical water oxidation, a high-strength, high-safety flange-type high-pressure sight glass has been designed.

[0009] Application content

[0010] The present invention proposes a flange-type high-pressure sight glass to solve the above-mentioned problems.

[0011] The technical solution of this invention is implemented as follows:

[0012] A flange-type high-pressure sight glass includes a sight glass body with an internally formed mounting cavity. A viewing glass assembly is installed inside the mounting cavity. A pressure ring that restricts the position of the viewing glass assembly is installed on the outer end of the sight glass body by screws. A high-pressure gasket is provided between the viewing glass assembly and the pressure ring. The high-pressure gasket is also provided on the side of the viewing glass assembly away from the pressure ring.

[0013] Furthermore, the viewing glass assembly includes a pressure-bearing layer, and protective layers are fixed on both sides of the pressure-bearing layer. The thickness of the viewing glass assembly is not less than 55mm, and the thickness of the pressure-bearing layer is not less than 25mm.

[0014] Furthermore, the pressure-bearing layer is made of high-strength chemically tempered glass or sapphire glass, and the protective layer is made of optical-grade quartz glass.

[0015] Furthermore, the high-pressure gasket is a metal toothed gasket or a flexible graphite spiral wound gasket.

[0016] Furthermore, the mounting cavity includes an outer mounting portion, a lens portion, and a media channel that are connected sequentially from the outside to the inside. The diameters of the outer mounting portion, the lens portion, and the media channel decrease sequentially. The window glass assembly and the high-pressure gasket are installed inside the lens portion.

[0017] Furthermore, auxiliary sealing elements, which are fluororubber O-rings, are installed between the two sides of the viewing glass assembly and the high-pressure gasket.

[0018] Furthermore, an electronic endoscope is provided on the outside of the viewing window glass assembly, and the electronic endoscope is fixed in the external mounting part by the pressure ring.

[0019] By adopting the above technical solution, the beneficial effects of the present invention are as follows:

[0020] 1. The mounting cavity adopts a stepped structure with the diameter decreasing from the outside to the inside (outer mounting part, lens part, media channel). This design allows the window glass assembly to be securely installed in the smaller diameter lens part, while the clamping structure (pressure ring) acts on the outer mounting part. This stepped pressure-bearing structure can effectively transfer the huge uniform load borne by the glass to the main body of the sight glass, avoiding stress concentration, thereby ensuring the overall stability of the window glass assembly and its clamping structure under ultra-high pressure.

[0021] 2. High-pressure gaskets are installed between the viewing window assembly and the electronic endoscope, as well as on the other side of the viewing window assembly, to perform the main sealing task. Simultaneously, auxiliary seals are added between the viewing window assembly and the high-pressure gaskets on both sides. This combination of main and auxiliary seals effectively addresses the potential for minute deformations under high pressure and the coupling effect of media corrosion, greatly improving the sealing reliability for long-term use and meeting the stringent requirements for zero leakage under ultra-high pressure conditions.

[0022] 3. The window glass assembly itself is composed of a pressure-bearing layer and protective layers on both sides. This "sandwich" structure not only ensures the main pressure-bearing capacity, but more importantly, even if the pressure-bearing layer fails under extreme conditions, the inner and outer protective layers can play a key barrier role, preventing the high-pressure medium from being sprayed out instantly. This provides a critical last line of defense for operators and equipment, significantly reducing the possibility and consequences of safety accidents.

[0023] 4. The pressure-bearing layer uses high-strength glass to ensure sufficient mechanical strength to resist minor deformations under high pressure, while the protective layers on both sides use optical-grade quartz glass with excellent optical properties to ensure that the clarity of light transmission is not affected, allowing for clear monitoring of the reaction process even under ultra-high pressure. Simultaneously, this design integrates an electronic endoscope into the main body of the endoscope, securing it with a pressure ring and using high-pressure gaskets to achieve a pressure seal between it and the viewing window glass assembly. This achieves a fusion of real-time observation and ultra-high pressure bearing capabilities, facilitating continuous monitoring of the internal reaction state of the equipment (such as phase changes and catalyst state). Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a main sectional view of Embodiment 1 of the present invention;

[0026] Figure 2 This is a main sectional view of Embodiment 2 of the present invention;

[0027] Figure 3 This is a front view of Embodiment 2 of the present invention;

[0028] Figure 4 This is a perspective view of Embodiment 2 of the present invention;

[0029] Figure 5 This is a simplified structural diagram of the window glass assembly of the present invention;

[0030] Figure 6 This is a cross-sectional view of the main body of the sight glass of the present invention.

[0031] The annotations in the attached figures are explained as follows:

[0032] 1. Sight mirror body; 2. Mounting cavity; 21. Lens section; 22. Media channel; 23. External mounting section; 3. Window glass assembly; 31. Pressure bearing layer; 32. Protective layer; 4. High-pressure gasket; 5. Auxiliary sealing component; 6. Electronic endoscope; 7. Pressure ring. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1:

[0035] like Figure 1 , Figures 5-6 As shown, a flange-type high-pressure sight glass includes a sight glass body 1 as the pressure-bearing body and a pressure ring 7 disposed opposite to the sight glass body 1. Both the sight glass body 1 and the pressure ring 7 are forged from high-strength alloy steel (e.g., 34CrNi3MoA). The two are fastened together by multiple high-strength bolts evenly distributed along the circumference to form a clamp-type structure.

[0036] At the central axis of the sight glass body 1, a mounting cavity 2 is machined, extending through the thickness direction of the sight glass body 1. The mounting cavity 2 includes an outer mounting portion 23, a lens portion 21, and a media channel 22 connected sequentially from the outside to the inside. The diameters of the outer mounting portion 23, the lens portion 21, and the media channel 22 decrease sequentially. Each stepped surface of the mounting cavity 2 is a plane parallel to the end face of the sight glass body 1 and is precision machined with a surface roughness Ra≤0.8μm to form a good sealing reference surface. The lens portion 21 is used to accommodate the window glass assembly 3.

[0037] The viewing glass assembly 3 is a three-layer composite structure, specifically including a load-bearing layer 31 as the main load-bearing component, and protective layers 32 attached to both sides of the load-bearing layer 31. The load-bearing layer 31 is made of aluminosilicate chemically tempered glass with a thickness of not less than 25mm to provide sufficient bending strength to withstand an internal pressure of 20MPa. The protective layers 32 on both sides are made of JGS2 optical grade quartz glass, the thickness of which can be determined according to the overall design requirements, mainly to provide excellent corrosion resistance and light transmission. The load-bearing layer 31 and the protective layers 32 are bonded together without stress using optical grade adhesive to form an integral optical unit. The viewing glass assembly 3 requires stress-free bonding, and the edges are finely ground and chamfered to prevent stress concentration. The total thickness of the viewing glass assembly 3 is designed to be not less than 55mm, and its outer diameter matches the inner diameter of the lens section 21 inside the viewing mirror body 1 to ensure that it can be inserted into the lens section 21.

[0038] The method for calculating the thickness of the viewing window glass is as follows:

[0039] Based on the thin-plate theory of elasticity, the circular window glass is considered as a circular plate rigidly clamped at the periphery, subjected to a uniformly distributed pressure P. Its maximum stress at the center is σ. max and the maximum deflection at the center ω max It can be estimated using the following formula:

[0040]

[0041] in, In the formula: P = 20MPa, R is the aperture radius (taken as 30 mm), t is the total thickness of the glass, E is the elastic modulus (~70GPa), and v is Poisson's ratio (~0.22).

[0042] To ensure safety, the following must be met: Where [σ] is the allowable bending strength of the glass (tempered glass can reach over 300MPa), and S is the safety factor (taken as ≥4). Based on calculations and considering the composite structure, the thickness of the single-layer pressure-bearing glass is preliminarily determined to be no less than 25mm, and the total component thickness is approximately 60mm.

[0043] A high-pressure gasket 4, serving as the primary seal, is installed between the viewing glass assembly 3 and the mounting step end face of the mounting cavity 2. The high-pressure gasket 4 is annular and can be either a toothed metal gasket or a flexible graphite spiral wound gasket. In this example, a 316L stainless steel flexible graphite spiral wound gasket with a clamp is preferred, and its pressure rating must be at least 25 MPa. Under preload, the high-pressure gasket 4 undergoes plastic deformation, filling the microscopic unevenness of the sealing surface and forming the first seal.

[0044] On the side of the viewing glass assembly 3 away from the inner cavity of the tank, that is, the side facing the pressure ring 7, a high-pressure gasket 4 is also provided, which contacts the other side surface of the viewing glass assembly 3.

[0045] The center of the pressure ring 7 has an observation hole with a diameter greater than or equal to the effective light transmission diameter of the window glass assembly 3. The stepped end face of the pressure ring 7 facing the mounting cavity 2 is also machined with an annular boss or flat surface corresponding to the position of the outer mounting part 23, for pressing the outer high pressure gasket 4.

[0046] To further improve the reliability of the seal, an auxiliary sealing element 5, which is a fluororubber (FKM) O-ring, can be added between the two side surfaces of the window glass assembly 3 and the high-pressure gasket 4. Shallow grooves for accommodating the O-ring can be made on the two side surfaces of the window glass assembly 3 or at corresponding positions on the high-pressure gasket 4 to prevent the O-ring from shifting during installation.

[0047] During installation, firstly, weld the sight glass body 1 to the mounting hole on the high-pressure vessel shell, ensuring the weld quality meets the pressure requirements. Then, sequentially place one high-pressure gasket 4 (optionally, an auxiliary seal 5 is first placed on its outer surface), the sight glass assembly 3, and another high-pressure gasket 4 (optionally, another auxiliary seal 5 is placed on its inner surface) into the mounting cavity 2 of the sight glass body 1. Next, align the pressure ring 7 and place it on top. Finally, insert and tighten the high-strength bolts. The tightening process requires the use of a hydraulic torque wrench, applying the specified preload torque gradually in 2 to 3 steps in a symmetrical cross-shaped sequence to ensure uniform preload on each bolt and to give the high-pressure gasket 4 the required initial sealing pressure.

[0048] During operation, the 20MPa medium pressure inside the high-pressure vessel acts on the inner surface of the sight glass assembly 3. This pressure is transmitted through the sight glass assembly 3 to the high-pressure gaskets 4 and pressure rings 7 on both sides, and the sight glass body 1. Because the high-pressure gaskets 4 have good resilience, the contact pressure on the gaskets can still remain higher than the medium pressure under the action of the medium pressure, thereby achieving zero-leakage sealing. At the same time, the auxiliary sealing element 5 can act as a secondary barrier in extreme cases.

[0049] In this embodiment, the high-strength bolts are made of 42CrMo material. Their quantity and specifications are calculated in detail according to the design pressure of 20MPa and the gasket tightening force requirements, based on the relevant formulas in GB / T 150 "Pressure Vessels" standard. This ensures that the stress on each bolt is within a safe range and that the total preload is sufficient to maintain the seal. After heat treatment, the tensile strength of all metal parts is not less than 980MPa to ensure the overall structural strength and safety.

[0050] Example 2:

[0051] like Figures 2-4 As shown, this embodiment is basically the same as embodiment 1. The difference is that, in order to integrate the online monitoring function, an electronic endoscope 6 can be embedded in the observation hole of the pressure ring 7. The lens of the electronic endoscope 6 is aimed at the viewing window glass assembly 3 for real-time acquisition and transmission of images inside the high-pressure vessel. At this time, the setting of the high-pressure gasket 4 and the auxiliary sealing component 5 remains unchanged, which can still ensure a reliable seal at the viewing window glass assembly 3, thereby providing a safe and clear optical path for the electronic endoscope 6.

[0052] Components not described in detail in this article are existing technologies.

[0053] 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, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flange-type high-voltage sight glass, characterized in that: The device includes a viewing mirror body (1), which has an internally formed mounting cavity (2). A viewing window glass assembly (3) is installed inside the mounting cavity (2). A pressure ring (7) is installed on the outer end of the viewing mirror body (1) by screws to restrict the position of the viewing window glass assembly (3). A high-pressure gasket (4) is provided between the viewing window glass assembly (3) and the pressure ring (7). The high-pressure gasket (4) is also provided on the side of the viewing window glass assembly (3) away from the pressure ring (7).

2. The flange-type high-voltage sight glass according to claim 1, characterized in that: The window glass assembly (3) includes a pressure-bearing layer (31), and protective layers (32) are fixed on both sides of the pressure-bearing layer (31). The thickness of the window glass assembly (3) is not less than 55 mm, and the thickness of the pressure-bearing layer (31) is not less than 25 mm.

3. A flange-type high-pressure sight glass according to claim 2, characterized in that: The pressure-bearing layer (31) is made of high-strength chemically tempered glass or sapphire glass, and the protective layer (32) is made of optical-grade quartz glass.

4. A flange-type high-voltage sight glass according to claim 1, characterized in that: The high-pressure gasket (4) is a metal toothed gasket or a flexible graphite spiral wound gasket.

5. A flange-type high-pressure sight glass according to claim 1, characterized in that: The mounting cavity (2) includes an outer mounting part (23), a lens part (21) and a medium channel (22) connected sequentially from the outside to the inside. The diameters of the outer mounting part (23), the lens part (21) and the medium channel (22) decrease sequentially. The window glass assembly (3) and the high-pressure gasket (4) are installed in the lens part (21).

6. A flange-type high-voltage sight glass according to claim 1, characterized in that: An auxiliary sealing element (5) is installed between the two sides of the window glass assembly (3) and the high-pressure gasket (4), and the auxiliary sealing element (5) is a fluororubber O-ring.

7. A flange-type high-voltage sight glass according to claim 1, characterized in that: An electronic endoscope (6) is provided on the outside of the viewing window glass assembly (3), and the electronic endoscope (6) is installed inside the external mounting part (23).

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