DE102017125833B4 - UV lamp consisting of a UV tube with a rod-shaped cladding tube and a base with electrical connections and a reflector - Google Patents

Abstract

UV lamp (1), consisting of a UV tube (2) with a rod-shaped enveloping tube (5) and a base (3) with electrical connections (4), a reflector (8) made of polytetrafluoroethylene being provided, and the UV lamp (1) comprises a base support (6) which is arranged in the area of the base (3) of the UV lamp (1), characterized in that the reflector (8) is arranged on part of the outer peripheral surface of the cladding tube (5). and the cladding tube (5) and the reflector (8) are completely surrounded by a shrink tube (11) in such a way that the base support (6) has a groove (10) pointing towards the cladding tube (5) for receiving the reflector (8) on the end face and the shrink tube (11) extends over this base support (6).

Description

technical field

The invention relates to a UV lamp consisting of a UV tube with a rod-shaped enveloping tube and a base with electrical connections, with a reflector made of polytetrafluoroethylene being provided.

definitions

In relation to this application, UV means ultraviolet and is used to designate a defined wavelength range.

Ultraviolet rays (UV) form part of the natural spectrum of sunlight. Short-wave ultraviolet rays belong to the group of optical rays. Yet they are invisible to the human eye. The UV rays from the so-called C band (hence the name UVC) have a strong germicidal effect around 260 nm (nanometers). The killing rate is subject to the dose-response principle; Therefore, technical characteristics of the tube performance and the description duration for functionally reliable UVC disinfection are decisive.

The germicidal effect is particularly effective on bacteria, viruses, yeasts and moulds. These microorganisms are effectively inactivated by so-called UV disinfection of air, water or surfaces. The UV sterilization technology does not use any chemicals or toxic compounds and does not lead to the development of mutation-related resistance. The unwanted microorganisms become inactive in a matter of seconds, while the product properties of the irradiated product remain almost unchanged. UV disinfection is used in particular in areas where there are high demands on consumer protection and the requirements of the HACCP concept.

Ultraviolet radiation is very energetic and upon absorption of the radiation triggers photochemical reactions in the respective nucleic acids of the exposed cell. When two thymines are next to each other in the DNA strand, they react and form a dimer that is useless for duplication and transcription. If there is multiple damage, the cell is no longer able to regenerate. It loses the ability to divide and multiply and dies.

From an economic point of view, germ reduction of up to 5-log level is possible. The exact UV dose that leads to the inactivation of the microorganisms varies depending on the type. While the majority of bacteria and viruses become inactive with a relatively low dose, yeast, mold, fungi and spores require a correspondingly higher dose.

The short-wave UVC radiation can be shielded by ordinary window glass, transparent plastic such as Makrolon ^® or acrylic glass and all practically opaque materials.

State of the art

UVC disinfection is used particularly in the food processing industry. Due to the environment in which the radiation sources are used, special requirements are placed on the UC source. It must at least meet the IP52 standard.

The UVC source is usually surrounded by a cladding tube. This cladding consists of a quartz glass that surrounds the radiation source. The cladding tube with the UV source and the corresponding connections forms the tube. If a UVC source is provided, one also speaks of a UVC tube. The electrical connections, i.e. the connection from the UVC source to a power connection, is formed by a base that has the appropriate electrical contacts, preferably pins. These are plugged into a receptacle in the manner of a plug in order to establish an electrical contact. The UVC source together with the cladding tube, the base, the electrical connections and the control element form the UVC lamp.

In order to protect the cladding tube from rupture and to prevent splinters from being scattered in the event of a rupture, it is provided that a protective tube surrounds the cladding tube. This protective tube consists of a preferably rotationally symmetrical base body made of stainless steel or aluminum and is dimensioned in such a way that this base body surrounds the cladding tube at a distance.

In addition, a viewing window is provided on the peripheral surface, from which the radiation emitted by the radiation source emerges. This viewing window is usually milled or lasered.

The inner wall of the protective tube has a reflector such that the emitted radiation passes through the viewing window in an at least partially concentrated manner. This reflector usually consists of a layer of aluminum or an aluminum alloy such as aluminium-manganese.

From the DE 699 12 253 T2 a highly efficient illumination source and illumination system with improved emitted irradiance is known. In the embodiments described, an elongated UV light source is proposed as the radiation source, which is surrounded by an extremely highly reflective casing. This cladding is a plastic tube which has an aperture opening. The size of this aperture opening is defined. The casing is designed in such a way that its walls are thin so that the non-reflected radiation, which is converted into heat, can exit directly from the casing, since this has a negative effect on the performance of the UV source.

From the DE 10 2015 105 362 A1 a beam source is known which has an increased reflectivity and at the same time the cladding tube is encased in a Teflon tube. There is also an intention to use polytetrafluoroethylene (PTFE, sometimes also polytetrafluoroethene) as a reflector material. Colloquially, this plastic is often identified by the trade name Teflon ^® . This achieves a high level of consistency in the performance of the UV source. One reason for using polytetrafluoroethylene as a reflective material is that the material has a thermally insulating effect. This means that the heat generated by the UV lamp, in particular the UVC source, remains in the protective tube. This creates a closed environment for the UV lamp that is almost independent of the outside temperature. This makes it possible to use the UV lamp in areas where it was not previously stable and reacted in a temperature-sensitive manner. The UV lamp can also be used in a cold or changing temperature environment, resulting in a wide range of applications with high power efficiency.

From the US2006/0186573A1 discloses an apparatus and method for heat-shrinking a sleeve of heat-shrinkable jacket material into circumferential and longitudinal conformity with a substrate product encased by the jacket material. In particular, this method and the device are used for the production of UV lamps. The present invention provides a sleeve handle/holding tool and table member combination used during a defined shrinking process to allow for the tensioning and positioning of a heat shrinkable sleeve during the heat application process.

The DE 10 2014 102 309 A1 refers to a device for forming a radiation source according to at least one of the standards IP52 to IP 68 Standard consisting of at least one tubular body, which comprises an emitting light source with electrical connections, at least one socket support for accommodating the electrical connections of the tubular body, an electrical connector for Transmission of electrical energy via the socket carrier to the tube body. It is provided to provide a kit in connection with the device, which allows a variety of arrangement and application options.

In the DE 10 2009 055 137 A1 describes a high pressure discharge lamp. This high-pressure discharge lamp has a ceramic discharge vessel which is accommodated in an outer bulb, the outer bulb also being surrounded by a splinter guard which fits snugly against the outer bulb. In particular, the splinter protection is a shrink tube.

The DE 10 2015 011 482 A1 shows a device for treating a medium with UV radiation, having a treatment space, a space-forming structure and an LED UV radiation source, wherein the medium can be accommodated in the treatment space and UV radiation can be provided by the LED UV radiation source. The space-forming structure has a stiffening base structure with at least one penetration and a UV-radiation-permeable film, the arrangement of which is determined by the base structure. This space-forming structure separates the treatment space from the LED UV radiation source, with the UV radiation being able to be introduced into the treatment space through the space-forming structure.

Disadvantages of the Prior Art

From a technical point of view, it is very complex to use these UV lamps, which have been known from the prior art, in a harsh environment.

Rough environments are understood to mean, for example, those that prevail in food production, in particular in meat production. Here, pieces fall onto the UV lamps and the lamps are exposed to high mechanical pressure from high-pressure cleaners, especially during the cleaning process. As a result, in particular the base screw connections known from the prior art, which are used to hold the UV tube and its base that can be contacted electrically, must be fluid-tight. The screw connections can loosen or the reflectors can also be misaligned as a result of shaking movements, for example due to the conveyor belts or the cleaning process.

Therefore, as a rule, only constant checks can ensure that there is complete tightness.

object of the invention

The object of the invention is to design a UVC tube in such a way that it can still fully provide the power with reduced control even in a harsh environment.

solution of the task

The basic idea is to provide a UV lamp which has high reflectivity and can perform reliably under severe conditions in a harsh environment. The solution to the problem is represented by the features of claim 1.

This solution consists of using polytetrafluoroethylene (abbreviation PTFE, occasionally also polytetrafluoroethene) as the reflector material for the reflector. Colloquially, this plastic is often identified by the trade name Teflon ^® . This achieves a high level of consistency in the performance of the UV source. A special embodiment provides white polytetrafluoroethylene (oPTFE) as the reflection material.

So that this reflector is fixed to the cladding tube, the cladding tube is covered with a transparent Teflon tube, which encloses the cladding tube together with the reflector. This is a heat-shrinkable tube that shrinks as a result of temperature and thus presses the reflector against the outer wall of the cladding tube.

A surrounding clear hose also protects the cladding tube and reflector. The transmission capability is only slightly influenced by the choice of material for the protective hose.

Advantages of the Invention

The UV lamp has an integrated reflector made of oPTFE. Integration is achieved by simply shrinking the surrounding heat shrink tubing.

In order to achieve an exact position of the reflector on the cladding tube, a cylindrical base support is provided. On the one hand, this base support surrounds the base of the UV source with the electrical connections and at the same time protects the electrical connections by providing a cavity. The cavity has the property that encapsulation material can be inserted in order to encapsulate the electrical contacts in a fluid-tight manner as soon as they are connected by cables.

On its side facing the cladding tube, the base support has a groove into which the front side of the reflector can be pushed before it is fixed by the shrink tubing.

Advantageously, the shrink tube extends not only over the enveloping tube, but preferably also over the base support and ends in the area of the cavity of the base support. This has the advantage that the seal between the enveloping tube and the base support does not have to be absolutely tight, because the shrink tube completely covers the opening in terms of fluid.

If the cladding tube, which is made of glass, breaks, the shards collect inside the shrink tube and cannot get into the environment. This is particularly important if such UV lamps are used in the food industry, for example, in order to offer appropriate safety here.

Further advantageous configurations can be found in the following description, the claims and the drawings.

character list

• 1 eine exemplarische perspektivische Ansicht auf die UV-Lampe mit elektrischer Anschlussleitung;
• 2 eine perspektivische Ansicht die UV-Lampe gemäss 1, jedoch in Explosionsdarstellung;
• 3 eine perspektivische Ansicht auf ein Teil der UV-Lampe gemäss 1, nämlich den Sockelträger mit Reflektor.

It shows:

• 1 an exemplary perspective view of the UV lamp with electrical connection line;
• 2 a perspective view of the UV lamp according to FIG 1 , but in an exploded view;
• 3 a perspective view of part of the UV lamp according to FIG 1 , namely the base support with reflector.

Description of an embodiment

In 1 a UV lamp 1 is shown. This UV lamp 1 consists of a UV tube 2 which in turn includes a base 3 with an electrical connection 4 . A UV source, which is not shown in detail in the drawing, is coupled to the base 3 . The UV source is surrounded by a rod-shaped cladding tube 5 . The cladding tube 5 is usually made of quartz glass. A base support 6 is provided in the area of the base 3 . This is also intended to accommodate one or more seals 7 . A reflector 8 is arranged on the cladding tube 5 . In order to operate the UV lamp 1 electrically, a cable 9 provided, which is coupled to the electrical connection 4 of the base 3 of the UV lamp 1.

To assemble the UV lamp 1, the cable 9 is connected to the electrical connection 4. The two sealing rings 7 are placed in the base support 6 and then the base support 6 is guided over the cladding tube 5 to the base 3. The electrical unit is sealed by casting a sealing compound through the cavity now formed in the base support 6.

In a further step, the reflector 8 is now to be assembled. As in 3 shown, this is formed onto the cladding tube 5 and then pushed into a groove 10 formed in the base support 6 in the direction of the arrow 11 . As a result, the reflector 8 is fixed to the round circumference of the cladding tube 5 . In a last step, a Teflon shrink tube 11 is pulled over the UV tube 2 from the free end to the base support 6 ( 2 ) across the base support 6. The end of the UV tube 2 opposite the base support 6 is welded so that this end is completely closed. The Teflon shrink tubing 11 is now heated and as a result it lies against the cladding tube 5 or the reflector 8 and presses the reflector 8 against the cladding tube 5. The other end of the Teflon shrink tubing 11 is in the area of the base support 6 on the side separated to the cable 9.

A UV lamp 1 with a reflector 8 is thus provided, which provides a constant UV steel quality and output in relation to the environment almost independently of the area of application. The UV lamp can be used in particular in harsh environments. This lamp is also characterized by the simple assembly and the small number of components.

Reference List

1

UV lamp

2

tube

3

base

4

Connection

5

cladding tube

6

base support

7

sealing rings

8th

reflector

9

Cable

10

groove

11

Arrow

Claims (3)

UV lamp (1), consisting of a UV tube (2) with a rod-shaped cladding tube (5) and a base (3) with electrical connections (4), a reflector (8) made of polytetrafluoroethylene being provided, and the UV lamp (1) comprises a base support (6) which is arranged in the area of the base (3) of the UV lamp (1), characterized in that the reflector (8) is arranged on part of the outer peripheral surface of the cladding tube (5). and the cladding tube (5) and the reflector (8) are completely surrounded by a shrink tube (11) in such a way that the base support (6) has a groove (10) pointing towards the cladding tube (5) for receiving the reflector (8) on the end face and the shrink tube (11) extends over this base support (6). protective tube claim 1 , characterized in that the shrink tube (11) consists of polytetrafluoroethylene. Protective tube according to one of the preceding claims, characterized in that the UV lamp (1) comprises a UVC source.

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