Liquid level detection device and water tank

Abstract

The utility model provides a liquid level detection device and a water tank. The liquid level detection device comprises a shell, a buoy and a sensing assembly, and the buoy is movably arranged in the shell; wherein the shell comprises a first shell, a connecting seat and a second shell which are sequentially and fixedly connected from top to bottom, and a through hole or a gap is formed in the side wall and / or the bottom of the second shell and allows liquid to pass through; the buoy comprises a rod part and a floating part, the floating part is arranged in the second shell, and the rod part penetrates through the connecting base and extends into the first shell; the sensing assembly comprises a signal unit and a sensing unit, the signal unit is arranged on the rod part, the sensing unit is arranged on the first shell, and the signal unit and the sensing unit are used for jointly determining the vertical position of the buoy. The water tank comprises a water tank body, a control system and the liquid level detection device. The liquid level detection device is installed on the top of the water tank body, and the control system is electrically connected with a sensing unit of the liquid level detection device. According to the liquid level detection device, the influence of the solution and pollutants on the sensing assembly on the liquid level detection device can be completely isolated.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a liquid level detection device and a water tank. Background Art

[0002] The semiconductor industry waste gas treatment equipment (Local Scrubber) is a device that treats a variety of mixed chemical waste gases discharged during the production process. Therefore, various chemical reactions and corrosion will inevitably occur in the water tank of the waste gas treatment equipment. Those water-soluble substances will also dye the process cooling water (PCW) water body, generate a variety of by-products in the water tank, and even some viscous floating objects. As the concentration of impurities increases, it often affects the sensitivity of the liquid level detector, resulting in the failure of the liquid level detector or false alarm. In addition, the ambient temperature of the wafer manufacturing plant is generally around 23℃~25℃, while the internal temperature of the water tank is usually between 30℃~45℃. Due to the temperature difference, a large amount of water vapor will be generated in the water tank, which will condense on the inner wall of the detection tube of the liquid level detector, affecting the liquid level detection.

[0003] In the prior art, there are roughly three types of liquid level detectors widely used in water tanks of waste gas treatment equipment: float type, connector type, and duckbill float type. However, they are all prone to jamming, failure, and failure to detect signals or false detection due to floating objects attached to the liquid level detector, which can cause equipment downtime. Similar interference situations occur in various wafer manufacturing plants, causing large-scale liquid leakage and abnormal equipment downtime in wafer manufacturing plants (FABs). Therefore, a liquid level detection device is needed to solve the false detection and frequent error reporting of liquid level detectors in the prior art. Utility Model Content

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a liquid level detection device and a water tank, which are used to solve the problem that the liquid level detector of the water tank in the prior art is prone to misdetection and frequent error reporting.

[0005] On the one hand, an embodiment of the present application provides a liquid level detection device, including a shell, a float and a sensor assembly, wherein the float is movably arranged in the shell; wherein the shell includes a first shell, a connecting seat and a second shell fixedly connected in sequence from top to bottom, and the side wall and / or the bottom of the second shell are provided with through holes or gaps for liquid to pass through; the float includes a rod portion and a floating portion, the floating portion is arranged in the second shell, and the rod portion passes through the connecting seat and extends into the first shell; the sensor assembly includes a signal unit and a sensing unit, the signal unit is arranged on the rod portion, and the sensing unit is arranged on the first shell, and the signal unit and the sensing unit are used to jointly determine the vertical position of the float.

[0006] In some embodiments, a connection seat through hole is configured at the center of the connection seat, the connection seat through hole wall is configured with internal threads, the first shell is configured with corresponding external threads, and the first shell and the connection seat are connected by threads.

[0007] In some embodiments, the second shell is fixedly connected to the connecting seat via a flange.

[0008] In some embodiments, the flange is provided with a rubber gasket.

[0009] In some embodiments, the signal unit is a magnet, the induction unit is a reed switch, the magnet is fixedly disposed at the top end of the rod, the number of the reed switches is several, and the several reed switches are vertically distributed on the outside of the first shell.

[0010] In some embodiments, the first shell is provided with a purge port, and the purge port is used to allow a purge gas to pass through.

[0011] In some embodiments, the second shell is a dirt shield.

[0012] In some embodiments, a plurality of exhaust holes are symmetrically arranged above the dirt shield for exhausting air.

[0013] In some embodiments, the second shell is a fence. On the other hand, the embodiment of the present application also provides a water tank, comprising a water tank body, a control system and the liquid level detection device described in the above embodiment; the liquid level detection device is installed on the top of the water tank body, the control system is electrically connected to the sensing unit of the liquid level detection device, and the control system is used to determine the liquid level according to the signal of the sensing unit and perform corresponding control.

[0014] As described above, the liquid level detection device and water tank of the present application have the following beneficial effects: when the liquid level detection device is working, when the float rises or falls with the liquid level, the float will not be hindered by any obstacles, and the shell controls the float so that it will not drift with the fluctuation of the liquid surface. The liquid level detection device of the present application is installed upright on the top of the water tank, wherein the sensor component, the float rod, the connecting seat and the first shell are all located on the water tank, and only the second shell and the floating part of the float contained in the second shell are immersed in the solution, so that the influence of the solution and pollutants on the sensor component can be isolated. Gas is connected from the top of the transparent first shell to purge the inside of the shell, which can effectively remove water vapor and dilute the harmful gas remaining in the shell. The liquid level detection device of the present application is suitable for use in narrow spaces, is easy to install on the water tank, can effectively reduce the space required for the device in the wafer manufacturing plant, and can completely isolate the influence of the solution and pollutants on the sensor component to avoid causing false detection of the sensor component. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The following figures describe in detail the exemplary embodiments disclosed in this application. The same reference numerals represent similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting, exemplary embodiments, and the drawings are only for the purpose of illustration and description, and are not intended to limit the scope of this application. Other embodiments may also accomplish the inventive intent in this application. It should be understood that the drawings are not drawn to scale.

[0016] in:

[0017] Figure 1 is a schematic diagram of a liquid level detection device according to some embodiments of the present application;

[0018] Figure 2 yes Figure 1 Schematic diagram of the explosion of the liquid level detection device;

[0019] Figure 3 is a schematic diagram of a water tank according to some embodiments of the present application;

[0020] Figure 4 is a schematic diagram of a liquid level detection device according to some other embodiments of the present application;

[0021] Figure 5 yes Figure 4 Schematic diagram of the connecting socket and the second shell of the liquid level detection device. DETAILED DESCRIPTION

[0022] The following description provides specific application scenarios and requirements of the present application, with the purpose of enabling those skilled in the art to make and use the content in the present application. It will be apparent to those skilled in the art that various local modifications to the disclosed embodiments are apparent, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present application. Therefore, the present application is not limited to the embodiments shown, but to the widest scope consistent with the claims.

[0023] An embodiment of the present application provides a liquid level detection device, including a shell, a float and a sensor assembly, wherein the float is movably arranged in the shell; wherein the shell includes a first shell, a connecting seat and a second shell fixedly connected in sequence from top to bottom, and the side wall and / or the bottom of the second shell is provided with through holes or gaps for liquid to pass through; the float includes a rod portion and a floating portion connected as one piece, the floating portion is arranged in the second shell, and the rod portion passes through the connecting seat and extends into the first shell; the sensor assembly includes a signal unit and a sensing unit, the signal unit is arranged on the rod portion, and the sensing unit is arranged on the first shell, and the signal unit and the sensing unit are used to jointly determine the vertical position of the float.

[0024] The technical solution of the present application is described in detail below with reference to the embodiments and drawings.

[0025] Embodiment 1:

[0026] Figure 1 is a schematic diagram of a liquid level detection device according to some embodiments of the present application. Figure 2 yes Figure 1 Schematic diagram of the explosion of the liquid level detection device.

[0027] refer to Figure 1 and Figure 4 As shown, in some embodiments, the liquid level detection device 100 includes a shell 1, a float 2 and a sensor assembly 3, and the float 2 is movably arranged in the shell 1. The shell 1 includes a first shell 11, a connecting seat 12 and a second shell 13 fixedly connected in sequence from top to bottom. The side wall and / or the bottom of the second shell 13 are provided with a through hole 131 or a gap 131' for liquid to pass through. The float 2 includes a rod 21 and a floating part 22 connected in one piece. The floating part 22 is arranged in the second shell 13, and the rod 21 passes through the connecting seat 12 and extends into the first shell 11. The sensor assembly 3 includes a signal unit 31 and a sensing unit 32. The signal unit 31 is arranged on the rod 21, and the sensing unit 32 is arranged on the first shell 11. The signal unit 31 and the sensing unit 32 are used to jointly determine the vertical position of the float 2. The float 2 is protected by the second shell 13 and will not drift with the fluctuation of the liquid level.

[0028] In some embodiments, the first shell 11 is made of a transparent material, which is transparent and visible for easy monitoring by staff. In some embodiments, the first shell 11 is made of a corrosion-resistant material, such as acrylic. The first shell 11 and the second shell 13 provide space for the buoy 2 to float up and down. The material of the connecting seat 12 can be copolymer polypropylene (PPR) or polyvinyl chloride (PVC). The second shell 13 is made of stainless steel (for example, 316L stainless steel). Because the buoy 2 is always soaked in the water tank solution, it must be corrosion-resistant, so the buoy 2 is made of a corrosion-resistant material (for example, polytetrafluoroethylene).

[0029] refer to Figure 2 As shown, in some embodiments, a connection seat through hole 121 is configured at the center of the connection seat 12, and the wall of the connection seat through hole 121 is configured with an internal thread. The first shell 11 is configured with a corresponding external thread 111. The first shell 11 and the connection seat 12 are connected by threads. The cross section of the floating portion 22 of the buoy 2 is larger than the connection seat through hole 121, and the cross section of the rod portion 21 is smaller than the connection seat through hole 121. The buoy 2 floats on the liquid surface, and the floating portion 22 can float up and down in the second shell 13, but cannot pass through the connection seat through hole 121 and be restricted in the second shell 13. The rod portion 21 passes through the connection seat through hole 121, which can keep the buoy 2 in an upright state, so that the rod portion 21 floats vertically up and down in the connection seat through hole 121.

[0030] refer to Figure 3 The embodiment of the present application also provides a water tank 4, including a water tank body 41, a control system (not shown) and the aforementioned liquid level detection device 100; the liquid level detection device 100 is installed on the top of the water tank body 41, and the control system is electrically connected to the sensing unit 32 of the liquid level detection device 100, and the control system is used to determine the liquid level according to the signal of the sensing unit 32 and perform corresponding control. The fish bladder-type float 2 is upright installed in the water tank 4, and the first shell 11 is made of transparent acrylic material, which is convenient for observing the internal situation of the first shell 11. An external thread is set at the bottom of the first shell 11, and an internal thread is set at the connecting seat through hole 121. The external thread of the first shell 11 is screwed into the internal thread of the connecting seat through hole 121, so that the first shell 11 and the connecting seat 12 are fixedly connected. The floating part 22 of the buoy 2 is placed in the second housing 13, and a connecting hole 133 is provided on the top of the second housing 13. The second housing 13 is installed on the back of the connecting seat 12 with screws (not shown) passing through the connecting hole 133, thus forming a cavity that can only accommodate the up and down movement of the buoy 2. When installing, only an opening (not shown) for installing the connecting seat 12 is provided on the water tank 4, and the liquid level detection device of the present application is installed upright and fastened with screws.

[0031] Specifically, in some embodiments, the signal unit 31 is a magnet, the induction unit 32 is a reed switch, and further, the magnet is a permanent magnet and a strong magnet, which is used to provide a magnetic field for the reed switch. The magnet is fixedly arranged at the top of the rod 21, and the number of the reed switches is several. The several reed switches are vertically distributed and arranged outside the first housing 11. Specifically, refer to Figure 3 In some embodiments, the reed switches are fixedly arranged at four different heights on the first shell 11. The four reed switches correspond to four liquid level heights HH, H, L, and LL, respectively, and are used to detect the high and low states of the liquid levels. The sensing unit 32 is installed outside the first shell 11 and does not contact the liquid, which can effectively avoid interference from the internal temperature, corrosion, water mist, floating objects, etc. of the water tank. In some embodiments, the magnet is attached or sleeved on the top of the rod 21, and the reed switch is attached or sleeved on the outside of the first shell 11.

[0032] In some embodiments, the connection base 12 is configured with fixing holes 122. For example, the fixing holes 122 are four through holes evenly distributed around the connection base through hole 121. The water tank 4 is provided with through holes (not shown) for fixing the connection base 12 on the water tank 4 at positions corresponding to the fixing holes 122. The connection base 12 can be fixed on the water tank 4 by passing bolts through the through holes.

[0033] In some embodiments, the sensing unit 32 of the sensor assembly 3 is electrically connected to the control system of the water tank 4, and the control system is used to determine the liquid level based on the signal of the sensing unit 32. A signal unit 31 is installed on the upper part of the buoy 2. When the buoy 2 rises or falls with the liquid level, the signal unit 31 will trigger the sensing units 32 at different positions outside the first shell 11. After receiving the corresponding signal, the control system can determine the current liquid level and take corresponding measures according to the liquid level. For example, when the liquid level reaches H, the liquid is discharged, and when the liquid level reaches L, the discharge is stopped. When the liquid level reaches HH, there is a risk of liquid overflow and the machine is shut down and an alarm is triggered. When the liquid level reaches LL, the liquid level is too low and the machine is shut down and an alarm is triggered.

[0034] In some embodiments, the first shell 11 is provided with a purge port 112 for introducing a purge gas. Specifically, the purge gas may be an inert gas, such as ordinary nitrogen (GN2). The introduction of nitrogen purge can effectively remove and dilute the harmful gas remaining in the first shell 11.

[0035] In some embodiments, the second housing 13 is a dirt shield that can block various byproducts, floating objects, and impurities generated in the water tank 4 .

[0036] In some embodiments, a plurality of exhaust holes 132 are symmetrically arranged above the dirt shield for exhausting gas. When the purge gas enters from the purge port 112, it is discharged from the exhaust holes 132 to balance the gas pressure.

[0037] Embodiment 2:

[0038] Figure 4 and Figure 5 It is a schematic diagram of a liquid level detection device according to some other embodiments of the present application.

[0039] In some embodiments, the second housing 13 ′ is a fence. Figure 4 and Figure 5 In the liquid level detection device shown, the first housing and the connecting seat have the same structure as in the first embodiment, and the fence of the second housing 13' is in the shape of a ring, which is only an example shown in the figure. It can also be in other forms of fences, such as vertical bars.

[0040] refer to Figure 5 As shown, in some embodiments, the second housing 13' is fixedly connected to the connecting seat 12' through a flange 23'. In some embodiments, the flange 23' is provided with a rubber gasket 231. The flange 23' is provided with a step: the O-type rubber gasket 231 is embedded when the second housing 13 and the connecting seat 12 are connected, so that the connection between the flange 23' and the second housing 13' is stable and reliable.

[0041] The beneficial effects that may be brought about by the embodiments of the present application include but are not limited to: when the float rises or falls with the liquid level, the liquid level detection device of the present application is upright and fixedly installed on the top of the water tank through the connecting seat, wherein the connecting seat and the first shell are located on the water tank, the second shell and the part of the float contained in the second shell are immersed in the solution, and the sensor component is installed and arranged at the position where the liquid level detection device is located on the water tank, which completely isolates the corrosion of the solution on the sensor component and the influence of pollutants on the sensor component. Not only will the float not be hindered by any obstacles, but the entire shell controls the float not to drift with the fluctuation of the solution level. Gas is connected from the top of the transparent first shell to purge the inside of the shell, which can effectively remove water vapor and dilute the harmful gas remaining in the shell. The liquid level detection device of the present application is suitable for use in narrow spaces, is easy to install, can effectively reduce the space required for the device in the wafer manufacturing plant, and can completely isolate the influence of the solution and pollutants on the sensor component, avoiding the phenomenon of false detection of the water tank liquid level and frequent error reporting.

[0042] It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other beneficial effects that may be obtained.

[0043] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this application. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this application.

[0044] It should be noted that in the description of this application, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", and "fix" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a rotating connection or a sliding connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood in combination with specific circumstances.

[0045] In addition, when terms such as "first", "second", and "third" are used in the specification of this application to describe various features, these terms are only used to distinguish these features and cannot be understood as indicating or implying the relationship between the features, the relative importance, or implicitly indicating the number of features indicated.

[0046] In addition, the present specification describes exemplary embodiments by reference to idealized exemplary cross-sectional views and / or plan views and / or stereograms. Therefore, differences from the illustrated shapes due to, for example, manufacturing techniques and / or tolerances are foreseeable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but should include deviations in shapes caused by, for example, manufacturing. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the actual shapes of the regions of the device nor to limit the scope of the exemplary embodiments.

[0047] At the same time, the present application uses specific words to describe the embodiments of this specification. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in the present application does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0048] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0049] Finally, it should be understood that the embodiments described in this application are only used to illustrate the principles of the embodiments of the present application. Other variations may also fall within the scope of the present application. Therefore, as an example and not a limitation, the alternative configurations of the embodiments of the present application may be considered to be consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments explicitly introduced and described in the present application.

Claims

1. A liquid level detection device, characterized in that: It comprises a housing, a buoy and a sensor assembly, wherein the buoy is movably arranged in the housing; wherein, The housing comprises a first housing, a connecting seat and a second housing which are fixedly connected in sequence from top to bottom, and the side wall and / or the bottom of the second housing are provided with through holes or gaps for liquid to pass through; The buoy comprises a rod portion and a floating portion, wherein the floating portion is arranged in the second shell, and the rod portion passes through the connecting seat and extends into the first shell; The sensor assembly includes a signal unit and a sensing unit. The signal unit is arranged on the rod portion, and the sensing unit is arranged on the first shell. The signal unit and the sensing unit are used to jointly determine the vertical position of the buoy.

2. The liquid level detection device according to claim 1, characterized in that: A connecting seat through hole is arranged at the center of the connecting seat, an internal thread is arranged on the wall of the connecting seat through hole, the first shell is arranged with a corresponding external thread, and the first shell and the connecting seat are connected by threads.

3. The liquid level detection device according to claim 1, characterized in that: The second shell is fixedly connected to the connecting seat via a flange.

4. The liquid level detection device according to claim 3, characterized in that: The flange is provided with a rubber gasket.

5. The liquid level detection device according to claim 1, characterized in that: The signal unit is a magnet, the induction unit is a reed switch, the magnet is fixedly arranged at the top end of the rod, the number of the reed switches is several, and the several reed switches are vertically distributed and arranged outside the first shell.

6. The liquid level detection device according to claim 1, characterized in that: The first shell is provided with a purge port, and the purge port is used to allow purge gas to pass through.

7. The liquid level detection device according to claim 1, characterized in that: The second shell is a dirt shield.

8. The liquid level detection device according to claim 7, characterized in that: A plurality of exhaust holes are symmetrically arranged above the dirt isolation cover for exhausting air.

9. The liquid level detection device according to claim 1, characterized in that: The second shell is a fence.

10. A water tank, characterized in that: It comprises a water tank body, a control system and a liquid level detection device as claimed in any one of claims 1 to 9; the liquid level detection device is installed on the top of the water tank body, the control system is electrically connected to the sensing unit of the liquid level detection device, and the control system is used to determine the liquid level according to the signal of the sensing unit and perform corresponding control.

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