CN217845522U - Set up in inside device of preventing leakage harm of cold box - Google Patents

Abstract

The utility model discloses a set up in inside device that prevents to leak harm of cold box. The cold box is enclosed by the cold box panel, and the leakage risk points inside the cold box are judged in advance, and one or a plurality of adjacent leakage risk points are enclosed to be provided with the leakage prevention device. The leakage-proof device comprises a liquid guide piece arranged below the leakage risk point and a separator connected with the liquid guide piece, at least one end of the liquid guide piece and the separator is fixed on the inner wall of the cold box panel and forms a surrounding, the leakage-proof space of the leakage risk point is enclosed, and the liquid guide piece has the gradient of guiding leakage liquid generated by the leakage risk point to the cold box panel. The leakage-proof space can be filled with mineral wool.

Description

Set up in inside device of preventing leakage harm of cold box

Technical Field

The invention belongs to the field of low-temperature equipment, and particularly relates to an anti-leakage device arranged in a cold box.

Background

The cold box is a self-supporting structure used for isolating environmental heat and ensuring normal operation of low-temperature equipment under a cryogenic condition, and has wide application in the fields of petrochemical industry, air separation and the like. To reduce the loss of cooling capacity, the interior of the cold box is often filled with a large amount of cold-insulating material. Taking a cold box commonly used in cryogenic air separation as an example, along with the enlargement of an air separation device, the air separation cold box is enlarged and raised, and the capacity of cold insulation materials filled in the cold box is increased when the volume of the air separation cold box is up to 60 m. The pearlite sand in the cold insulating material, also called swelling pearlite, is made up by breaking and high-temp. baking of vitreous mountain rock. Because the pearlite sand has excellent heat insulation performance, the pearlite sand is widely applied to the heat insulation of air separation and refrigeration equipment cold boxes.

When the pipeline and the container in the air separation cold box leak, especially the low-temperature liquid leaks, the liquid is stored in the pearlite. These liquids can persist in the pearlife for long periods of time without being discovered. Once these liquids are vaporized by heat exchange or friction during sand discharge, they expand rapidly, raising the gas pressure and even causing the cold box to explode. Therefore, whether the pearlife is dry or not is also the key for long-term safe operation of the cold box.

In the prior art, a thermometer (arranged on a bottom structure of a cold box or in a cold box foundation) at the bottom of the cold box is used for monitoring the leakage of low-temperature liquid in the pearlite heat insulation cold box. This design has the following disadvantages: there is a monitoring delay, if the leakage point is more than 30m above the bottom of the cold box, the leaked liquid may be absorbed by the pearlife until the limit point of detonating the cold box is exceeded; the difficulty of troubleshooting is high, for example, the position of a leakage point cannot be directly determined, and the leakage point can be maintained only by unloading sand; and limited protection for the parts of the cold box that are susceptible to cold shortness.

In view of the above, a problem to be solved by those skilled in the art is how to design a new device for preventing the running risk of the cold box caused by the leakage of the cryogenic liquid so as to eliminate the above-mentioned defects and shortcomings in the prior art.

SUMMERY OF THE UTILITY MODEL

Cryogenic equipment and piping contained in the cold box typically have large amounts of cryogenic liquid (below-100 c) passing through it. In order to prevent leakage, flanges or threads are reduced as far as possible between the rectifying tower and the pipeline and between the pipeline and the pipeline in the air separation cold box, but the pipelines connected with rotary equipment or the liquid storage container cannot completely avoid the use of the flanges, so that the possibility of leakage of high-pressure low-temperature liquid is caused. Leakage of cryogenic liquid in the cold box poses many risks, including cold brittleness of the metal caused by the contact of the cryogenic liquid with the carbon steel structure, and the possibility of explosion of the cold box caused by the accumulation of the cryogenic liquid in the pearlite. If stainless steel is used instead of carbon steel, or low temperature resistant steel (carbon steel or stainless steel containing more than 9% of nickel) is laid on carbon steel, the problem of metal cold shortness can be solved, but the manufacturing cost is greatly increased.

In order to overcome the above-mentioned technical problem among the prior art, the utility model discloses a set up in inside anti-leakage device of cold box, when the cold box by the cold box panel enclose and inside have the leakage risk point, anti-leakage device contains the baffle that sets up in the drain below the leakage risk point and links to each other with the drain, the at least one end of drain and baffle is fixed on the inner wall of cold box panel to constitute with a part of cold box panel and surround the anti-leakage space of leakage risk point, the drain has the slope of the leakage liquid direction cold box panel that will leak the risk point and produce. The leakage risk points comprise flange interfaces and/or threaded interfaces and/or butt-welded joints.

In one aspect, the liquid guide is made of a stainless steel plate, and the partition is made of a plate structure, a mesh structure, or a combination thereof.

In another aspect, the liquid guide member comprises a liquid accumulation part at one end close to the cold box panel.

In a further aspect, the liquid accumulation portion is provided with a temperature probe and/or a liquid drain port for draining leaked liquid accumulated on the liquid accumulation portion out of the cold box via a liquid drain pipe and optionally a liquid drain valve.

In yet another aspect, a baffle is disposed between the drain of the liquid accumulation portion and the cold box panel.

In yet another aspect, the cold insulation material in the cold box cannot enter the leakage-proof space, the cold insulation material in the cold box comprises pearlife, and the cold insulation material in the leakage-proof space comprises slag wool. The leakage prevention means encloses more than one leakage risk point.

Compared with the prior art, the utility model provides a technical scheme has following advantage:

1. the leakage of the low-temperature liquid is limited in the leakage-proof device, and the low-temperature liquid cannot contact a truss steel structure in the cold box and cause the truss steel structure to be cold-brittle, so that the steel structure can adopt carbon steel, and the manufacturing cost caused by laying low-temperature-resistant steel is prevented from being greatly increased;

2. the panel of the cold box is made of stainless steel, so that the cold box can be frozen when contacting low-temperature liquid, but cannot be cold and brittle, and operators can be reminded of the occurrence of leakage and the position of a leakage point in time;

3. the leakage-proof device and part of the cold box panel form a complete three-dimensional leakage-proof space around the leakage risk point, and the cold box outside the leakage-proof space can use the pearlife, so that the economy and the high efficiency of the pearlife as a cold insulation material are kept;

4. cold insulation materials such as slag wool and the like are used in the anti-leakage space, so that the explosion risk caused by infiltrating the pearlife with low-temperature liquid is avoided, once leakage occurs, the slag wool is removed more safely, and the maintenance is convenient;

5. the temperature detector is arranged on the liquid accumulating part of the liquid guide piece, so that the detection of the leaked liquid is more timely and accurate;

6. the design of leakage fluid dram and baffle has further protected cold box steel construction and cold box panel, and when using the baffle, the cold box panel also can use the carbon steel.

Drawings

The advantages and spirit of the present invention can be further understood by the following detailed description and accompanying drawings, and those skilled in the art will understand that the accompanying drawings and examples do not limit the present invention. Like reference symbols in the various drawings indicate like or equivalent elements.

FIG. 1 is a side sectional view of the leakage preventing means in the embodiment;

FIG. 2 is a sectional top view of the leakage preventing means in the embodiment;

FIG. 3 is a side sectional view of the leakage preventing means in the embodiment;

fig. 4 is a side sectional view of the leakage preventing means in the embodiment.

In the figure: 1-a leakage prevention device; 2-leakage risk points; 3-a liquid guiding member; a 3' -pooling part; 4-a separator; 5-cold box panel; 6-leakage prevention space; 7-a pipeline; 8-a through hole; 9-a temperature detector; 10-a liquid discharge port, 11-a liquid discharge pipe and 12-a liquid discharge valve; 13-a baffle; 14-cold box steel construction.

Detailed Description

To make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present application. All other embodiments obtained by a person skilled in the art without making creative efforts based on the examples in the present application belong to the protection scope of the present application.

In the description of the present application, it is to be noted that the terms "mounted," "connected," and "connected" are to be construed broadly unless otherwise explicitly specified or limited. "fixedly connected" or "fixed" or "non-movably connected" means that the connection between two or more structural members is not configured to provide relative movement. Examples of fixed connections include welded joints, flanged joints or bolted joints.

Furthermore, the use of any reference herein to "a" or "an" does not denote a limitation of quantity, but rather denotes the presence of technical features not previously mentioned. Similarly, unless a specific number of a claim recitation is intended to cover both the singular and the plural, and embodiments may include a single feature or a plurality of features.

It should be understood that, in this application, "at least one" means one or more, "a plurality" means two or more. "and/or" is used to describe the association relationship of the associated objects, meaning that there may be three relationships, for example, "a and/or B" may mean: only A, only B and both A and B are present, wherein A and B may be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single item(s) or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.

The terms "up", "down", "above" and "below" are made with respect to a horizontal plane passing through the leak. The terms "upwardly", "above" refer to above the horizontal plane; "downward" and "below" are to be understood as being below the horizontal plane.

The cold box is a hollow structure which mainly comprises a surrounding truss steel structure and a cold box panel enclosed on the surrounding truss steel structure. The cold box is generally cylindrical or rectangular. Taking a cuboid cold box as an example, the truss steel structure can be made of carbon steel or stainless steel and comprises rectangular cold box columns at four corners, a plurality of cold box cross beams which are sequentially fixed on the cold box columns at two sides from top to bottom, and a plurality of groups of two inclined struts which are fixed on the adjacent three cold box cross beams in a crossed manner and take the middle of the middle cold box cross beam as a cross point. And cold box panels used for wrapping the whole cold box are respectively welded on the truss steel structure in a sealing manner to form a closed box body. Before the air separation cold box is put into operation, the cold box is required to be filled with the pearl sand for cold insulation of a container and a pipeline, and the pearl sand in the cold box body is in a full state under normal conditions.

The cold box houses various equipment and piping. The tubing to tubing and tubing to equipment interfaces, and certain equipment, such as the heat exchanger itself, can age, crack, and leak fluid transported therein over extended periods of use. Those skilled in the art can determine which interfaces or devices are more susceptible to leakage based on experience and expertise, and thus determine them as "leakage risk points". The gist of the present application is to predict the above-mentioned "leakage risk point" and construct a leakage prevention device around it when the equipment in the cold box is not in operation before filling with the pearlite. One leakage prevention means may surround one leakage risk point or may surround a plurality of adjacent leakage risk points. The anti-leakage device can be provided with a through hole for the pipeline to pass through, and sealing measures are taken between the through hole and the pipeline to prevent the pearlife outside the device from entering the anti-leakage device.

The leakage-proof device and the connected partial cold box panels form a complete three-dimensional leakage-proof space around the leakage risk point, and the pearlife filled in the cold box and outside the leakage-proof space can not fall into the space. The leakage-proof device mainly comprises a liquid guide member and a partition member connected with the liquid guide member. The liquid guide is arranged below the leakage risk point, has a size sufficient to catch and convey the falling leaked cryogenic liquid, is free from cold brittle materials, preferably stainless steel, and is fixed at one end to the inner wall of the panel of the cold box, for example by welding. The liquid guide may be a flat plate or a groove, and the edge may be a straight line, a broken line or a curved line, and guides the cryogenic liquid from the end that catches the leaked cryogenic liquid to the end that is connected to the cold box panel along a substantially downward slope. The slope is an acute angle formed by the straight line intersecting the horizontal plane along the direction in which the liquid guide members are arranged. The smaller the acute angle, the smaller the gradient. Since the liquid-conducting element is connected to the panel of the cold box, it inevitably transfers the ambient heat to the cold box, so that it is arranged at a distance from the equipment, pipes and points of risk of leakage in the cold box, in order to avoid loss of cooling capacity in the latter.

The partition is attached to the liquid-conducting member, preferably completely attached to the edge of the liquid-conducting member, and has at least one end fixed to the inner wall of the cold box panel. The leakage-proof device can be a box structure, the liquid guide part forms the bottom surface of the box, the separating part forms the side surface and the top surface of the box, and the panel of the cold box also forms one side surface. The leakage-proof device can also be a structure similar to a Mongolian yurt with a liquid guide as a bottom, and the separating piece is a continuous cambered surface. The separator is not in direct contact with the low-temperature liquid, so that the separator can be made of carbon steel besides stainless steel. The main function of the separator is to form a leakage-proof space and to keep the pearlite sand out of the leakage-proof device, so that part or all of it can be a plate structure, a net structure with a mesh smaller than the pearlite sand, or a combination of the two. In the leakage-proof space, a cold-insulating material which is not easy to store liquid, such as slag wool, can be used to enhance the heat insulation of the space.

The liquid guide part can be formed by connecting parts or sections with different gradients. Preferably, a liquid trap portion is formed at an end connected to the cold box panel, and the slope of the liquid trap portion is smaller than that of the other portion of the liquid guide member, or is nearly horizontal, so that leaked cryogenic liquid is slightly accumulated there. A temperature probe, optionally a resistance thermometer, may be provided at the liquid accumulation portion, with a probe inside the cold box, through the stainless steel plate via a hot trap. Resistance thermometers, also known as Resistance Temperature Detectors (RTDs), are temperature sensors made using materials whose resistance changes with temperature. The most common resistance thermometers are temperature sensing elements made of wound metal wires, mainly including platinum resistance thermometers and copper resistance thermometers, the precision platinum resistance thermometers are the most accurate thermometers, and the temperature coverage range is about 14-903K, so that the thermometer is suitable for the condition of low-temperature liquid in a cold box. When the cryogenic liquids contact the temperature detector, the temperature detector reads a temperature that is lower than the no-leakage condition, thereby alerting the operator to the occurrence of leakage.

On the hydrops portion, still can set up a leakage fluid dram between temperature probe and the cold box panel, the low temperature liquid direct discharge cold box that the leakage fluid dram will leak through flowing back valve and fluid-discharge tube has reduced the possibility of more liquid and cold box panel contact, and the low temperature liquid of discharge cold box can be collected in low temperature liquid collection device.

When the truss steel structures of the cold box, including cold box columns, beams or diagonal braces, are present near the junction of the liquid guide and the cold box panel, leaked cryogenic liquid may come into contact with these steel structures. If the steel structure is made of a material that is cold brittle, such as carbon steel, contact with cryogenic liquids will damage the steel structure of the cold box. On the hydrops portion, set up the baffle between leakage fluid dram and the cold box steel construction, can protect the steel construction not receive the erosion of cryogenic liquids. The baffle is made of a material that does not cold-crack, such as stainless steel.

Fig. 1 is a sectional view of a side view of the leakage preventing device 1. The leakage risk point 2 is a flange. The liquid guide 3 is a stainless steel plate, which is arranged below the leakage risk point 2 and is inclined downwards. The anti-leakage device 1 is of a box structure, the liquid guide piece 3 is quadrilateral, one side of the liquid guide piece is connected with the cold box panel 5 in a welding mode, the other three sides of the liquid guide piece are respectively connected with three side surfaces of the separating piece 4, and the connecting mode can adopt L-shaped angle steel welding. The partition 4 also forms the top surface of the leakage-proof space, and the top surface and two side surfaces of the partition 4 are fixed with the cold box panel 5 to form a complete leakage-proof space 6. The leakage-proof space 6 can be filled with a cold-insulating material (not shown in the figure) containing slag wool. When the low temperature liquid leakage happens to the leakage risk point, the leakage liquid flows to the cold box panel along the liquid guide piece, and the cold box panel is hung ice. The operator observing this phenomenon can immediately open the corresponding cold box panel, remove the mineral wool and repair the site of the leak.

Fig. 2 is a sectional view of the leakage preventing device 1 in fig. 1 in a top view, and it can be seen that a flange of the leakage risk point 2 is mounted on the pipe 7, which passes out of the leakage preventing device 1 through the through hole 8.

Fig. 3 is a modification of fig. 1, and is more suitable for the case of large leakage liquid flow. Wherein, the liquid guide member 3 is composed of two sections with different gradients. The section below the risk leak 2, which section is more steeply sloped and connected to the cold box panel 5 is called the liquid trap 3', which slopes less steeply, even more or less horizontally, so that the leaking liquid is accumulated in a small amount there, is in full contact with the thermometer 9 and can be drained out of the cold box via a drain 10 via a drain pipe 11, optionally via a drain valve 12. And the operator judges the occurrence of leakage through the reading of the temperature detector or the liquid discharge of the liquid discharge pipe and takes corresponding maintenance measures.

When the leakage-proof space 6 includes a truss steel structure of the cold box and the connection of the liquid guide 3 and the cold box panel 5 is located near the cold box steel structure 14, the structure of fig. 4 may be adopted in order to prevent the leaked cryogenic liquid from damaging the cold box steel structure 14. In comparison to fig. 3, fig. 4 adds a baffle 13 between the drain 10 and the cold box steel structure 14. When a leak occurs, the leaking liquid cannot bypass the baffle and is all drained out of the cold box through the drain 10.

The embodiments described in the specification are only preferred embodiments of the present invention, and the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the present invention. Unless clearly indicated to the contrary, each aspect or embodiment defined herein may be combined with any other aspect or embodiments or embodiment or embodiments. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature indicated as being preferred or advantageous. Those skilled in the art can obtain technical solutions through logical analysis, reasoning or limited experiments according to the concepts of the present invention, and all such technical solutions are within the scope of the present invention.

Claims (10)

1. The utility model provides a set up inside device that prevents leakage harm of cold box which characterized in that: the cold box is enclosed by cold box panel (5), and cold box inside has leakage risk point (2), prevents leaking device (1) and contains and set up in leading liquid spare (3) of leakage risk point (2) below and with lead separator (4) that liquid spare (3) link to each other, the at least one end of leading liquid spare (3) and separator (4) is fixed on the inner wall of cold box panel (5) to constitute the encirclement together with cold box panel (5) leak preventing of risk point (2) and let out space (6), it has the slope of leaking liquid direction cold box panel (5) that will leak risk point (2) production to lead liquid spare (3).

2. A leak damage prevention apparatus as defined in claim 1, wherein: the leakage risk points (2) comprise flange joints and/or screw joints and/or butt-welded joints.

3. A leak damage prevention apparatus as defined in claim 1, wherein: the liquid guide member (3) is made of a stainless steel plate, and the partition member is made of a plate structure, a net structure or a combination of the plate structure and the net structure.

4. A leak damage prevention apparatus as defined in claim 2, wherein: one end of the liquid guide piece (3) close to the panel of the cold box comprises a section of liquid accumulation part (3').

5. The leakage damage prevention apparatus of claim 4, wherein: the liquid collecting part (3') is provided with a temperature detector (9).

6. The leakage damage prevention apparatus of claim 4, wherein: the liquid accumulation part (3 ') is provided with a liquid discharge port (10), and the liquid discharge port (10) discharges the leakage liquid accumulated on the liquid accumulation part (3') out of the cold box through a liquid discharge pipe (11) and a liquid discharge valve (12).

7. The leak damage prevention apparatus as recited in claim 6, wherein: a baffle plate (13) is provided between the liquid discharge port (10) of the liquid accumulation section (3') and the cold box panel (5).

8. A leak damage prevention apparatus as defined in claim 1, wherein: the cold insulation material in the cold box cannot enter the leakage-proof space (6).

9. The leak damage prevention apparatus as recited in claim 8, wherein: the cold insulation material in the cold box comprises pearlife, and the cold insulation material in the leakage-proof space (6) comprises slag wool.

10. A leak damage prevention apparatus as defined in claim 1, wherein: the leakage prevention device (1) encloses more than one leakage risk point (2).

Images