Patent Description:
Because ultraviolet rays can effectively inactivate bacteria and viruses, it has become a common sterilization method. In recent years, ultraviolet Light Emitting Diodes (LEDs) based on AlGaN materials have developed rapidly. Compared with traditional mercury lamps, ultraviolet LED lamps have many advantages, such as small size, no mercury, fast response speed, low-voltage light source and so on, so that ultraviolet LED lamps are widely used in the fields of surface sterilization, liquid sterilization, air sterilization and so on.

<CIT> discloses a device for disinfecting of gases and/or liquids, includes a tube of UV-transparent glass having a hollow interior space and a tube wall with a tube inside wall and a tube outside wall, as well as at least one UV-light source. The UV-transparent glass tube has an indentation extending into the interior space on at least one location and in the at least one indentation at least one UV-light source is arranged. The geometry causes the UV-light sources to be closer to the medium to be disinfected, so that a large portion of the UV-light reaches the interior space on a direct path through the glass, thus allowing fbr a low-loss transfer of the UV-light.

<CIT> discloses an UV light disinfecting system where UV light is distributed along the walls of a highly reflective tube. In some embodiments, the UV light disinfecting system is flexible. In at least one embodiment, the UV light disinfecting system includes at least one UV-LED positioned external to a highly reflective tube. In exemplary embodiments, the reflective tube includes a plurality of openings that are arranged so as to position each opening adjacent to a corresponding UV-LED such that UV light generated by the corresponding UV-LED is able to pass through the opening and into the reflective tube. The UV light is scattered along the length of the reflective tube to prevent or eliminate the presence of biofilms as well s to disinfect, sterilize, and purify and pathogens within the tube. Methods to mitigate the growth of biofilms in a water conduit is also provided.

<CIT> discloses a water purification apparatus. In the water purification apparatus, a light source irradiates the water, passing through the flow passage, with ultraviolet light. The light source has a light emitting diode that emits the ultraviolet light whose wavelength is contained in a bandwidth of <NUM> or above to less than <NUM>, and the optical output in this wavelength bandwidth is in a range of <NUM> W to <NUM> W. The flow passage passes the water at a flow rate of <NUM>/second to <NUM>/second. The flow passage is formed by a wall surface having a tubular shape. A window through which the ultraviolet light is passed is provided in at least part of the wall surface.

<CIT> discloses a fluid sterilizing device which includes barrel portion having a channel where fluid to be sterilized flows; inlet formed on one end portion side of the barrel portion; outlet formed on the other end portion side of the barrel portion; a light source that emits ultraviolet light toward the fluid; and a rectifier mounted inside the channel and having a cylindrical through hole.

One of the existing devices for ultraviolet sterilization of liquid is provided with a liquid storage tank, and the liquid in the liquid storage tank is sterilized by long-term ultraviolet irradiation. The sterilization device can achieve the sterilization rate of <NUM>%, and the sterilization device is cheap and relatively mature in technology. However, under the long-term ultraviolet irradiation, the above ultraviolet sterilization device will cause yellowing of the plastic of the tank body of the liquid storage tank and even result in powdering in severe cases. Therefore, in the prior art, a flow-through sterilization device is proposed. When the liquid flows through the sterilization cavity, it can achieve <NUM>% of sterilization at a flow rate of several liters/minute.

However, in order to achieve the sterilization ability, the above flow-through sterilization devices generally use ultraviolet LED light sources with higher ultraviolet power. At the same time, the flow-through sterilization device needs to be designed with a more complex heat dissipation structure and a liquid flow structure, which is large in volume and high in cost, and brings difficulties to large-scale popularization.

The embodiment of the present invention provides an ultraviolet sterilization device according to claim <NUM>. The ultraviolet sterilization device of the invention is simple in structure, low in cost, and suitable for popularization and use in scenes such as household water dispensers, faucets, pet water dispensers, humidifiers, smart toilets and the like.

Preferred features of the invention as recited in the dependent claims.

<NUM>-ultraviolet sterilization device; <NUM>-liquid passing pipe assembly; <NUM>-shell; <NUM>-outer wall surface; <NUM>-inner wall surface; <NUM>-hollow pipe; <NUM>-liquid inlet end; <NUM>-liquid outlet end; <NUM>-accommodating groove; <NUM>-upper cover; <NUM>-second light transmitting hole; <NUM>-reflective film; <NUM><NUM>-first light transmitting hole; <NUM>-ultraviolet light source; <NUM>-LED lamp; <NUM>-substrate; <NUM>-joint.

Because ultraviolet rays can inactivate bacteria and viruses, ultraviolet sterilization has become a common sterilization method. There are mainly two types of existing liquid sterilization devices. One liquid sterilization device is provided with a liquid storage tank to sterilize the liquid in the liquid storage tank by using ultraviolet rays, but this method easily causes yellowing of the tank body of the liquid storage tank. Based on this problem, the prior art also proposes a flow-through sterilization device, which sterilizes the liquid by external irradiation of the sterilization cavity when the liquid flows through the sterilization cavity. However, the existing flow-through sterilization devices generally use light sources with high ultraviolet power, and are correspondingly provided with a complex heat dissipation structure and a liquid flow structure, which are bulky and costly, and are not conducive to large-scale popularization and application.

Embodiments of the present invention will be described with reference to the accompanying drawings hereinafter.

The present invention provides an ultraviolet sterilization device <NUM>, as shown in <FIG>, which includes a liquid passing pipe assembly <NUM> and an ultraviolet light source <NUM>. The liquid passing pipe assembly <NUM> includes a shell <NUM> and a transparent hollow pipe <NUM>, the shell <NUM> is sleeved on the hollow pipe <NUM>, the shell <NUM> is provided with an accommodating groove <NUM>, and the ultraviolet light source <NUM> is provided in the accommodating groove <NUM>. One end of the hollow pipe <NUM> is provided as a liquid inlet end <NUM>, and the other end thereof is provided as a liquid outlet end <NUM>, and the hollow pipe <NUM> is used for circulating liquid. The wall surface of the hollow pipe <NUM> is covered with a reflective film <NUM>, the reflective film <NUM> is provided with first light transmitting holes <NUM> at the position corresponding to the ultraviolet light source <NUM>, the first light transmitting holes <NUM> are communicated with the accommodating groove <NUM>, so that the ultraviolet light emitted by the ultraviolet light source <NUM> is incident into the hollow pipe <NUM> and sterilizes the liquid circulating in the hollow pipe <NUM>, and the reflective film <NUM> is used for scattering the ultraviolet light in different areas in the hollow pipe <NUM>.

It should be noted that the ultraviolet light source <NUM> is provided in the accommodating groove <NUM> provided on the shell <NUM>. The transparent hollow pipe <NUM> is used for the liquid to be sterilized to flow. The wall of the hollow pipe <NUM> is covered with the reflective film <NUM>. Ultraviolet light enters the hollow pipe <NUM> and irradiates on the wall surface of the hollow pipe <NUM>, and the light ray is reflected by the reflective film <NUM> covered on the wall surface. Under the action of the reflective film <NUM>, ultraviolet rays are scattered to various areas in the hollow pipe <NUM>, such as the vicinity of the liquid inlet end <NUM>, the middle area of the hollow pipe <NUM> and the vicinity of the liquid outlet end <NUM>, so as to sterilize the water in various areas in the hollow pipe <NUM> and obtain a good sterilization effect. Since the reflective film <NUM> is an opaque or partially transparent film layer, it is necessary to provide the first light transmitting holes <NUM> in the reflective film <NUM> so that the ultraviolet light emitted by the ultraviolet light source <NUM> can enter the hollow pipe <NUM> through the first light transmitting holes <NUM>.

In this embodiment, the reflective film <NUM> is covered on the hollow pipe <NUM>, and the ultraviolet light source <NUM> is scattered to different areas in the hollow pipe <NUM>, so as to realize the sterilization and disinfection function of the liquid flowing through the hollow pipe <NUM>. The device is simple in structure and low in cost, and can be widely applied to scenes such as household water dispensers, faucets, pet water dispensers, humidifiers, smart toilets and the like.

In a possible embodiment, there are two groups of ultraviolet light sources <NUM>, and the two groups of ultraviolet light sources <NUM> are provided on the opposite sides of the circumferential outer wall of the shell <NUM>, respectively.

It can be understood that if the ultraviolet light source <NUM> is only provided at one side of the circumferential outer wall of the shell <NUM>, although the ultraviolet rays are scattered by the reflective film <NUM>, the illumination (i.e., the illumination intensity) of the ultraviolet light on the opposite sides of the circumferential outer wall of the hollow pipe <NUM> may not be uniform enough, and the illumination on the side where the ultraviolet light source <NUM> is provided is stronger, which will lead to the uneven sterilization degree of each area of the flowing liquid. Therefore, one group of ultraviolet light sources <NUM> is provided on each of the opposite sides of the circumferential outer wall of the shell <NUM>, respectively. On the one hand, the illumination of ultraviolet light can be improved, and on the other hand, the uniformity of the illumination of ultraviolet light on the opposite sides of the circumferential outer wall of the hollow pipe <NUM> can be ensured, thereby ensuring the consistency of sterilization degree of all areas of the water.

In an alternative embodiment, as shown in <FIG> and <FIG>, the ultraviolet light source <NUM> includes LED lamps <NUM>, and LED lamps <NUM> in each group of ultraviolet light sources <NUM> include one or two LED lamps.

The ultraviolet light source <NUM> is formed by welding an LED lamp <NUM> capable of emitting ultraviolet light on a ceramic or metal substrate <NUM>. A circuit is preset on the ceramic or metal substrate <NUM>. The circuit is used to control turning on or off the LED lamp <NUM>.

It should be noted that there may be a single LED lamp or a plurality of LED lamps <NUM>, but because the reflective film <NUM> is opaque or not completely transparent, in order to make the ultraviolet light emitted by the ultraviolet light source <NUM> enter the hollow pipe <NUM> through the reflective film <NUM>, it is necessary to provide the first light transmitting holes <NUM> on the reflective film <NUM>. It can be understood that the larger the number of LED lamps <NUM> is, the larger the area of the first light transmitting holes <NUM> is and the more incomplete the reflective film <NUM>. Moreover, because there is more than one group of ultraviolet light sources <NUM>, the area of the first light transmitting holes <NUM> is larger. The incompleteness of the reflective film <NUM> will affect its reflection effect on ultraviolet light. In order to protect the integrity of the reflective film <NUM>, it is necessary to limit the number of LED lamps <NUM> of each group of ultraviolet light sources <NUM>, and then control the number and area of the first light transmitting holes <NUM>.

In this embodiment, by limiting the number of LED lamps <NUM>, under the condition of meeting the irradiation intensity of ultraviolet light, the area of the first light transmitting hole <NUM> is reduced as much as possible, so as to ensure the integrity of the reflective film <NUM>, thereby ensuring the better reflection effect of the reflective film <NUM> on light.

In some embodiments, as shown in <FIG>, the LED lamps <NUM> are correspondingly provided in the middle of the hollow pipe <NUM>.

It should be noted that the LED lamp <NUM> can be provided at any position of the circumferential outer wall of the hollow pipe <NUM>. However, when the LED lamp is provided in the middle of the hollow pipe <NUM>, the ultraviolet light emitted by the LED lamp <NUM> can be uniformly distributed on both ends of the hollow pipe <NUM> under the action of the reflective film <NUM>. It can be understood that the LED lamp <NUM> directly irradiates the middle of the hollow pipe <NUM>. Therefore, the intensity of ultraviolet light is the strongest. The ultraviolet light at both ends of the hollow pipe <NUM> is obtained by reflecting the ultraviolet light in the middle of the hollow pipe <NUM> through the reflective film <NUM>, so that the intensity of ultraviolet light at both ends of the hollow pipe <NUM> is weak. However, in this arrangement mode, because the distance between each area of the areas at both ends of the hollow pipe <NUM> and the middle area is the same and not far away, the intensity of ultraviolet light on both ends symmetrical along the middle of the hollow pipe <NUM> is basically the same, and the intensity of ultraviolet light in the areas at both ends is not too weak. The areas at both ends also have certain sterilization ability. When the liquid flows into the hollow pipe <NUM> from the liquid inlet end <NUM>, the ultraviolet light at the liquid inlet end <NUM> first preliminarily sterilizes the liquid. When the liquid flows into the middle area of the hollow pipe <NUM>, because of the strong intensity of ultraviolet light here, the liquid can be thoroughly sterilized. When the liquid flows to the liquid outlet end <NUM> through the middle area of the hollow tube <NUM>, the ultraviolet light at the liquid outlet end <NUM> can further sterilize the liquid. In this way, in the whole process of liquid flowing through the hollow pipe <NUM>, the liquid is sterilized by ultraviolet light with a certain intensity, thus ensuring that the ultraviolet sterilization device <NUM> has a good sterilization effect.

On the other hand, the LED lamp <NUM> is correspondingly provided in the middle of the hollow pipe <NUM>, so that the LED lamp <NUM> is as far away from the liquid inlet end <NUM> and the liquid outlet end <NUM> as possible, which can prevent ultraviolet light from being reflected to the outside of the hollow pipe <NUM> as much as possible, thereby avoiding the lost energy of ultraviolet light, and the harm caused by ultraviolet light leakage.

In addition, in order to prevent ultraviolet light from being emitted from both ends of the hollow pipe <NUM> to the outside of the hollow pipe <NUM>, it is not necessary to provide reflective films <NUM> in the areas near the liquid inlet end <NUM> and the liquid outlet end <NUM> of the hollow pipe <NUM>, so that the ultraviolet light cannot be reflected at the ends of the hollow pipe <NUM>, thereby further ensuring that the ultraviolet light remains in the ultraviolet sterilization device <NUM> without leakage.

In some embodiments, the radial size of the LED lamp <NUM> is less than or equal to <NUM>.

The radial size of the LED lamp <NUM> should be selected according to the demand for the power of the LED lamp <NUM>. Generally speaking, the larger the power of the LED lamp <NUM> is, the larger the size is, and the stronger the intensity of ultraviolet light is. However, in this embodiment, since the radial size of the LED lamp <NUM> will affect the size of the first light transmitting hole <NUM> provided in the reflective film <NUM>, the larger the radial size of the LED lamp <NUM> is, the larger the first light transmitting hole <NUM> is. In order to ensure the integrity of the reflective film as much as possible, the radial size of the LED lamp <NUM> needs to be selected in an appropriate range. In this embodiment, according to the application scenario of the ultraviolet sterilization device <NUM> provided by the present invention, the radial size of the LED lamp <NUM> can be selected to be less than or equal to <NUM> to meet the demand. For example, the size of the LED lamp <NUM> can be a lamp bead with a size of ≤5mmX5mm, and a smaller lamp bead with a size of ≤<NUM> mmX3. <NUM> can be selected.

Accordingly, the radial size of the first light transmitting hole <NUM> is greater than or equal to one time the size of the LED lamp <NUM> in the radial direction and less than or equal to three times the size of the LED lamp <NUM> in the radial direction.

It can be understood that the radial size of the first light transmitting hole <NUM> is not less than the size of the LED lamp <NUM> in the radial direction, so as to ensure that all the ultraviolet light emitted by the LED lamp <NUM> passes through the first light transmitting hole <NUM> and irradiates into the hollow pipe <NUM>, thus making full use of the light energy of the ultraviolet light. The radial size of the first light transmitting hole <NUM> is less than or equal to three times the size of the LED lamp <NUM> in the radial direction. For example, the radial size of the first light transmitting hole <NUM> can be set to twice the size of the LED lamp <NUM> in the radial direction, so as to maintain the integrity of the reflective film <NUM> while ensuring that the ultraviolet light passes through the first light transmitting hole <NUM> as much as possible.

As for the specific arrangement position and arrangement mode of the ultraviolet light source <NUM>, the ultraviolet light source <NUM> is provided in the accommodating groove <NUM> of the shell.

As shown in <FIG>, the accommodating groove <NUM> is provided on the outer wall surface <NUM> of the shell <NUM>. The opening of the accommodating groove <NUM> is away from the hollow pipe <NUM>. The bottom of the accommodating groove <NUM> is provided with a second light transmitting hole <NUM> at the position corresponding to the first light transmitting hole <NUM>. The second light transmitting hole <NUM> is communicated with the first light transmitting hole <NUM>, so that the ultraviolet light emitted by the ultraviolet light source <NUM> is incident into hollow pipe <NUM> after passing through the second light transmitting hole <NUM> and the first light transmitting hole <NUM>. For the specific arrangement mode of the second light transmitting holes <NUM>, for example, the second light transmitting holes <NUM> are provided at the bottom of the accommodating groove <NUM> at the position corresponding to the LED lamps <NUM> of the ultraviolet light source <NUM>. The number of the second light transmitting holes <NUM> is the same as that of the LED lamps <NUM>, and a plurality of second light transmitting holes <NUM> are provided at intervals. The purpose of this arrangement is to ensure the integrity of the shell <NUM> as much as possible. Of course, an integral second light transmitting hole <NUM> can also be directly provided at the bottom of the accommodating groove <NUM>, so that the ultraviolet light emitted by each LED lamp <NUM> can pass through the second light transmitting hole <NUM>, which is not particularly limited here.

As shown in <FIG> and <FIG>, an upper cover <NUM> is provided at the opening of the accommodating groove <NUM>, and the upper cover <NUM> is used for protecting the ultraviolet light source <NUM>.

In another embodiment out of the invention, as shown in <FIG>, the accommodating groove <NUM> is provided on the inner wall surface <NUM> of the shell <NUM>, the opening of the accommodating groove <NUM> faces the hollow pipe <NUM>, and the ultraviolet light emitted by the ultraviolet light source <NUM> is incident into the hollow pipe <NUM> through the first light transmitting hole <NUM>. At this time, because the accommodating groove <NUM> is provided inside the shell <NUM>, and the opening of the accommodating groove <NUM> faces the hollow pipe <NUM>, the accommodating groove <NUM> does not need to be provided with the second light transmitting hole <NUM>. The ultraviolet light can directly enter the first light transmitting hole <NUM> through the opening of the accommodating groove <NUM>, and then be incident into the hollow pipe <NUM> from the first light transmitting hole <NUM>. It can be understood that this arrangement mode makes the ultraviolet light source <NUM> closer to the hollow pipe <NUM>, and the liquid circulating in the hollow pipe <NUM> can play a good cooling role to keep the excellent performance of the ultraviolet light source <NUM>.

In an alternative embodiment, the wavelength range of ultraviolet light emitted by the LED lamp <NUM> is <NUM>-<NUM>. Ultraviolet light in this wavelength range is referred to as deep ultraviolet light. Because bacteria have wavelength selectivity, ultraviolet light in this wavelength range generally has a better sterilization effect. Therefore, selecting the ultraviolet light source <NUM> in this wavelength range can effectively improve the sterilization effect of the ultraviolet sterilization device <NUM>.

Accordingly, the reflective film <NUM> is made of any one of inorganic material coating with diffuse reflectivity higher than <NUM>%, fluorine-based organic material film with diffuse reflectivity higher than <NUM>% or reflective medium film with specular reflectivity higher than <NUM>%. Specifically, from the view of difficulty and cost of the process, the expanded polytetrafluoroethylene film with diffuse reflectivity higher than <NUM>% is generally selected, which is relatively cheap and easy to process. However, if a better sterilization ability and a smaller size are required, the dielectric film of a distributed Bragg reflector with specular reflectivity greater than <NUM>% can be selected.

For example, as shown in <FIG> and <FIG>, the reflective film <NUM> is provided on the outer wall surface of the hollow pipe <NUM>. In fact, the reflective film <NUM> can also be provided on the inner wall surface <NUM> of the hollow pipe <NUM>. However, in actual process, since it is difficult to provide the reflective film <NUM> on the inner wall surface <NUM> of the hollow pipe <NUM>, and the liquid flowing in the hollow pipe <NUM> may chemically react with the reflective film <NUM>, the reflective film <NUM> can generally be provided on the outer wall surface of the hollow pipe <NUM>.

In order to prevent ultraviolet rays from escaping from the liquid inlet end <NUM> or the liquid outlet end <NUM> of the hollow pipe, the length of the hollow pipe <NUM> generally ranges from <NUM> to <NUM>. The inner diameter of the hollow pipe <NUM> ranges from <NUM> to <NUM>. The light emitting angle of the LED lamp <NUM> is less than or equal to <NUM> degrees. It can be understood that the length of the hollow pipe <NUM>, the inner diameter of the hollow pipe <NUM> and the light emitting angle of the LED lamp <NUM> should be selected based on comprehensive consideration, so as to prevent the ultraviolet light emitted by the LED lamp <NUM> from escaping as much as possible, thereby making full use of the energy of the LED lamp <NUM> to sterilize the liquid flowing through the hollow pipe <NUM>.

It should be noted that the length of the hollow pipe <NUM> can be <NUM> to <NUM> according to the light emitting angle of the LED light source and the reflectivity of the reflective film <NUM>. When the length of the hollow pipe <NUM> is below <NUM>, although the sterilization device for flowing water can be made smaller, the cumulative ultraviolet dose when the water flows through the hollow straight pipe is low, which will affect the sterilization rate. When the length of the hollow pipe <NUM> is above <NUM>, the size of the sterilization device for flowing water will also be significantly increased, but the cumulative ultraviolet dose does not significantly increase, which does not improve the sterilization effect obviously.

In addition, when the inner diameter of the hollow pipe <NUM> is larger than <NUM>, because the ultraviolet light will easily escape from both ends of the hollow pipe <NUM> due to the long path of each reflection of the ultraviolet light, it is possible to consider selecting the LED lamp <NUM> with a small light emitting angle. For example, the LED lamp <NUM> with a light emitting angle less than <NUM> degrees is selected, so as to restrict excessive ultraviolet light from escaping from both ends of the hollow pipe <NUM>. On the contrary, when the diameter of the hollow pipe <NUM> is smaller than <NUM>, the path of each reflection of ultraviolet light is short, and it is not easy for ultraviolet light to escape from both ends of the hollow pipe <NUM>. Therefore, the LED lamp <NUM> with a large light emitting angle can be selected. For example, the LED lamp <NUM> with a light emitting angle greater than <NUM> degrees can be selected to ensure that the energy of ultraviolet light can be fully utilized, so as to obtain ultraviolet light irradiation with higher intensity when the liquid flows through the hollow pipe <NUM>.

In addition, it should be noted that the ultraviolet light source <NUM> can also be provided at both ends of the hollow pipe <NUM>, that is, the liquid inlet end or the liquid outlet end. However, since there is liquid flowing through both ends, it is necessary to provide a waterproof structure to separate the ultraviolet light source <NUM> from the liquid. At this time, if the inner diameter of the hollow pipe <NUM> is relatively small, the space at the end of the hollow pipe is relatively small, so that it is generally difficult to provide the ultraviolet light source <NUM> at the end. When the inner diameter of the hollow pipe <NUM> is relatively large, the ultraviolet light source <NUM> can be provided at the end of the hollow pipe because the space at the end of the hollow pipe <NUM> is relatively large at this time. When the inner diameter is large, it is generally required to process liquid with a large flow rate, and the power of the ultraviolet light source <NUM> used at this time is relatively high. However, when the ultraviolet light source <NUM> is provided at the end, the liquid circulating in the hollow pipe <NUM> cannot cool the ultraviolet light source <NUM>, so that it is necessary to additionally provide a heat dissipation base to dissipate heat from the ultraviolet light source <NUM>, thus obtaining better optical characteristics. The smaller the inner diameter is, the more delicate the ultraviolet sterilization device <NUM> can be, but the corresponding flow rate that can be processed is also smaller. Generally, considering the sterilization ability and space requirements of the ultraviolet sterilization device <NUM> in practical application scenarios, the inner diameter range of the hollow pipe <NUM> can be set to <NUM> to <NUM>.

The ultraviolet sterilization device <NUM> provided in this embodiment has certain advantages in sterilizing flowing water with a small flow rate of <NUM>/min or less because of its small size.

In some embodiments, the hollow pipe <NUM> is made of any one of quartz, alumina or fluorine-based organic ultraviolet transparent material. It can be understood that in order to make the light of the ultraviolet light source <NUM> incident into the hollow pipe <NUM> to sterilize the water body flowing in the hollow pipe <NUM>, the hollow pipe <NUM> should be made of transparent materials, and all the above materials can be used to make the transparent hollow pipe <NUM>. Because the process of manufacturing the hollow pipe <NUM> of quartz is more mature and the cost is lower, a quartz hollow pipe <NUM> can generally be used.

In order to facilitate the connection of the hollow pipe <NUM> to a liquid source, such as a faucet, the liquid inlet end <NUM> of the hollow pipe <NUM> is provided with a detachable joint <NUM>. As shown in <FIG> and <FIG>, the end of the joint <NUM> is provided with an external thread, the end of the shell <NUM> corresponding to the liquid inlet end <NUM> is correspondingly provided with an internal thread, and the end of the joint <NUM> is screwed and fixed to the shell <NUM>. With this arrangement, it is convenient to replace the joint <NUM> according to the model of the liquid source, so that the ultraviolet sterilization device <NUM> provided by the present invention can be used more flexibly and is suitable for a wider range of application scenarios.

In addition, in order to facilitate the manufacturing of the shell <NUM>, the shell <NUM> can be made of heat shrinkable material. The heat shrinkable material has a memory function and covers the outer surface of the hollow pipe <NUM> after being heated and shrunk, and can play the roles of insulation, moisture protection, sealing and protection. Especially when the accommodating groove <NUM> is provided on the inner wall surface <NUM> of the shell <NUM>, the ultraviolet light source <NUM> is provided between the hollow pipe <NUM> and the shell <NUM>, and with the heat shrinkable material, it is easier to fix the ultraviolet light source <NUM>. In addition, the shell <NUM> can also be made of other metals, plastics and other materials, and it is generally considered to select materials that are not easy to yellow under irradiation of ultraviolet light.

Therefore, the ultraviolet sterilization device <NUM> provided by the present invention is modulated, with the selected length and inner diameter of the hollow pipe <NUM>, by the light emitting angle of the ultraviolet light source <NUM> and the reflectivity of the reflective film <NUM>. The ultraviolet light emitted by the ultraviolet light source <NUM> is irradiated into the hollow pipe <NUM> through the first light transmitting hole <NUM> on the reflective film <NUM>, and is reflected by the reflective film <NUM> for many times, so that the illuminance of the ultraviolet light in the hollow pipe <NUM> is greatly enhanced, and in the straight pipe the illuminance in the middle is high and the illuminance at both ends is low. At this time, the area with the strongest ultraviolet illumination is concentrated in the center of the hollow pipe <NUM>, and the illumination at both ends of the hollow pipe <NUM> is relatively weak. It can be understood that after the ultraviolet light is reflected by the reflective film <NUM>, the superposition of the ultraviolet light may occur, thus enhancing the illumination of the ultraviolet light in the hollow pipe <NUM> to a certain extent.

The specific size of the ultraviolet sterilization device <NUM> provided by the present invention will be illustrated by three specific examples hereinafter.

In a first example, as shown in <FIG>, the hollow pipe <NUM> of the ultraviolet sterilization device <NUM> is made of quartz. The quartz pipe has a length of <NUM>, an inner diameter of <NUM>, and a wall thickness of <NUM>. The reflective film <NUM> is an expanded polytetrafluoroethylene film with diffuse reflectivity of <NUM>% in the ultraviolet wavelength range of <NUM>-<NUM>. The film thickness of the reflective film <NUM> is <NUM>, and the reflective film <NUM> is provided with first light transmitting holes <NUM> with a size of 1mmX1mm. The ultraviolet light source <NUM> contains two LED lamps <NUM>. The distance between two LED lamps <NUM> is <NUM>, the bead size of the LED lamp <NUM> is <NUM>. <NUM>, the radiation power of the LED lamp <NUM> is 15mW, and the light emitting angle is <NUM> degrees. The substrate <NUM> is an aluminum substrate <NUM>. The outer shell <NUM> uses a plastic injection molding process to fix and protect the inner structure.

It should be noted that another function of the reflective film <NUM> is to fill the gap between the shell <NUM> and the hollow pipe <NUM>, so that the thickness of the reflective film <NUM> can be selected according to the actual structural requirements.

The distribution of ultraviolet illumination in the hollow pipe <NUM> of the ultraviolet sterilization device <NUM> provided in this example is analyzed hereinafter, and the actual sterilization test is carried out on the manufactured sample.

As shown in <FIG>, it can be seen from the figure that the area with the strongest ultraviolet illuminance is in the middle of the quartz pipe. The illuminance at this position reaches about 100mW/cm<NUM> (the two dark areas in the middle of the figure correspond to two LED lamps), and the illuminance decreases gradually towards both ends, and drops to about 5mW/cm<NUM> within the range of <NUM> from each end of the quartz pipe. Considering that the sterilization effect is the accumulation effect of illumination and time, the average illumination in the quartz pipe can be used as one of the important performance indexes to measure the sterilization ability. The average illuminance in the quartz pipe of this embodiment is about <NUM>. 6mW/cm<NUM>. It should be noted that, compared with the numerical values shown in <FIG>, the above illuminance values need to be converted into units.

In order to show the actual sterilization effect, the actual sterilization rate of the ultraviolet sterilization device <NUM> provided in this example is tested. This sterilization rate test is to use Escherichia coli <NUM> solution with a concentration of <NUM>×<NUM><NUM> cfu/ml (the unit of the number of colonies is cfu/ml). The solution flows in from the liquid inlet end <NUM> of the quartz pipe at a flow rate of <NUM>/min, and then flows out from the liquid outlet end <NUM> of the quartz pipe after sterilization in the cavity. In addition, the Escherichia coli <NUM> solution which does not flow through the sterilization device is taken as the positive control solution. 100uL of sterilized solution (i.e. experimental samples) and 100ul of positive control solution are taken and are put into a constant temperature incubator at <NUM> for culture after being smeared uniformly on the surface of eosin methylene blue agar. After <NUM> to <NUM> hours, the number of colonies of sterilized solution and positive control solution samples are observed and calculated. The sterilization rate can be calculated in at least two ways:.

After the experiment, the results are as follows (the unit of number of colonies is cfu/ml):
The number of colonies of the positive control solution is <NUM>×<NUM><NUM>, while the number of colonies of the sterilized solution is <NUM>. According to the above first formula, the sterilization rate can reach <NUM>%. According to the above first formula, the LRV value can reach <NUM>.

According to the above sterilization experiment data, it can be seen that the ultraviolet sterilization device <NUM> provided by this example can effectively sterilize the flowing water of <NUM>/min.

In the second example, as shown in <FIG>, the hollow pipe <NUM> of the ultraviolet sterilization device <NUM> is made of quartz. The quartz pipe has a length of <NUM>, an inner diameter of <NUM>, and a wall thickness of <NUM>. The reflective film <NUM> is an expanded polytetrafluoroethylene film with diffuse reflectivity of <NUM>% in the ultraviolet wavelength range of <NUM>-<NUM>. The film thickness of the reflective film <NUM> is <NUM>, and the reflective film <NUM> is provided with first light transmitting holes <NUM> with a size of 2mmX2mm. The ultraviolet light source <NUM> contains two LED lamps <NUM>. The bead size of the LED lamp <NUM> is <NUM>. <NUM>, the radiation power of the LED lamp <NUM> is 30mW, and the light emitting angle is <NUM> degrees. The substrate <NUM> is a copper substrate <NUM>. The main body of the shell <NUM> is made of aviation aluminum, and the joint at both ends of the shell <NUM> is made of plastic. Considering the thick wall thickness of the quartz pipe in this example, although the reflection of the reflective film <NUM> can make the whole quartz pipe have higher ultraviolet illumination, because the thickness range of the wall surface of the quartz pipe is not an effective sterilization space, in this embodiment the reflective film <NUM> preferably is attached to the inner wall of the quartz pipe, so that ultraviolet light can be reflected without passing through the side wall of the quartz pipe, avoiding the consumption of ultraviolet light energy, and thus ensuring a better reflection effect.

As shown in <FIG>, it can be seen from the figure that the area with the strongest ultraviolet illumination is in the middle of the quartz pipe, where the illumination reaches about 40mW/cm<NUM>, and the illumination decreases gradually towards both ends, and drops to about 3mW/cm<NUM> within the range of <NUM> from each end of the quartz pipe. The average illumination in the quartz pipe is about <NUM>/cm<NUM>. Although compared with the first example, the average illuminance in the cavity is reduced, but the sterilization space in the quartz pipe is increased, that is, the quartz pipe becomes thicker, and the flow rate of the liquid in the quartz pipe will slow down, that is, the irradiation time when the liquid flows into the ultraviolet sterilization device <NUM> will be increased. Actually, the test is also conducted at a flow rate of <NUM>/min, and the irradiation dose (illumination multiplied by time) of water flowing into the ultraviolet sterilization device <NUM> in this example is nearly twice that of the first example. That is to say, the larger the effective sterilization space is, the longer the corresponding sterilization time is, and the higher the corresponding processing capacity is.

In the third example, as shown in <FIG>, the hollow pipe <NUM> of the ultraviolet sterilization device <NUM> is made of quartz, and the length of the quartz pipe is <NUM>. The quartz pipe is a square pipe with the inner dimension of 8mmX8mm and the wall thickness of <NUM>. The reflective film <NUM> is formed by evaporating distributed Bragg reflection (DBR) on the outer wall of the quartz pipe by optical coating. The reflective film <NUM> is formed by alternating <NUM> pairs of MgO layers and ZrO<NUM> layers, and has a reflectivity of <NUM>% for ultraviolet light in the wavelength range of <NUM>-<NUM>. The reflective film <NUM> is provided with first through holes <NUM> with a size of <NUM>. The ultraviolet light source <NUM> contains two LED lamps <NUM>. The bead size of the LED lamp <NUM> is <NUM>. <NUM>, the radiation power of the LED lamps <NUM> is 15mW, and the light emitting angle is <NUM> degrees. The substrate <NUM> is an aluminum substrate <NUM>. The main body of the shell <NUM> is made of heat shrinkable sleeve, and the joint at both ends of the shell <NUM> is made of plastic.

In this example, DBR is used as the reflective film <NUM>. Although the manufacturing process is relatively complicated, the specular reflectivity of DBR is close to <NUM>%, and higher ultraviolet illumination is obtained inside the quartz pipe. As shown in <FIG>, the average illumination inside the quartz pipe reaches about 100mW/cm<NUM>, thus obtaining a better sterilization effect.

Claim 1:
An ultraviolet sterilization device (<NUM>), comprising a liquid passing pipe assembly (<NUM>) and an ultraviolet light source (<NUM>), wherein the liquid passing pipe assembly (<NUM>) comprises a shell (<NUM>) and a transparent hollow pipe (<NUM>), the shell (<NUM>) is sleeved on the hollow pipe (<NUM>) and an accommodating groove (<NUM>) is provided on an outer wall surface of the shell (<NUM>), and the ultraviolet light source (<NUM>) is provided in the accommodating groove (<NUM>); wherein an opening of the accommodating groove (<NUM>) is away from the hollow pipe (<NUM>) and an upper cover (<NUM>) is provided at the opening of the accommodating groove (<NUM>), wherein the hollow pipe (<NUM>) has an end configured as a liquid inlet end (<NUM>) and another end configured as a liquid outlet end (<NUM>), and the hollow pipe (<NUM>) is configured for circulating liquid; a wall surface of the hollow pipe (<NUM>) is covered with a reflective film (<NUM>), the reflective film (<NUM>) is provided with first light transmitting holes (<NUM>) at a position corresponding to the ultraviolet light source (<NUM>), the first light transmitting holes (<NUM>) are communicated with the accommodating groove (<NUM>), a bottom of the accommodating groove (<NUM>) is provided with second light transmitting holes (<NUM>) at positions corresponding to the first light transmitting holes (<NUM>), and the second light transmitting holes (<NUM>) are communicated with the first light transmitting holes (<NUM>) so that ultraviolet light emitted by the ultraviolet light source (<NUM>) is incident into the hollow pipe (<NUM>) after passing through the second light transmitting holes (<NUM>) and the first light transmitting holes (<NUM>) and sterilizes the liquid circulating in the hollow pipe (<NUM>), and the reflective film (<NUM>) is used for scattering the ultraviolet light in different areas in the hollow pipe (<NUM>).