DD287591A5 - DOSING BODY FOR RECEIVING MERCURY AND METHOD FOR PRODUCING THEREOF - Google Patents

Abstract

The invention relates to a Dosierkoerper for receiving mercury and a process for the preparation. The metering body serves to introduce a precisely metered amount of mercury into the discharge vessel or the electrode area of a discharge lamp, in particular a compact fluorescent lamp. A Dosierkoerper for the absorption of mercury consists of a skeleton material and mercury as Traenkwerkstoff. According to the invention, the skeletal material is a prealloyed powder consisting of several metals with the starting particle size between 0.05 and 0.5 mm, which form an alloy by a sintering process. The skeleton material contains as the main constituent of the alloy at least one of the metals zinc, antimony or iron and, as further alloy constituents, at least one of the metals aluminum, copper and nickel or their combination with iron. The skeleton material forms with the Traenkwerkstoff a metal-mercury-dressing. The Dosierkoerpers produced in 2 steps. First, the skeletal material is made by melting or sintering the alloy components. Thereafter, the skeletal material with the Traenkwerkstoff mercury is drowned and pressed simultaneously. {Discharge lamp; metering; Mercury; Skeletal material; pre-alloyed powder; Alloy components; Zinc; Antimony; Iron; Metal mercury-association; production}

Description

Field of application of the invention

The invention relates to a metering body for receiving mercury and a method for producing. The metering body is used to introduce a precisely metered amount of mercury into the discharge vessel or the electrode region of a discharge lamp, in particular a compact fluorescent lamp.

Characteristic of the known technical solutions

A prerequisite for the operation of almost all discharge lamps is the introduction of a precisely metered amount of mercury into the discharge vessel. During operation of the lamp, the mercury evaporates (in the case of high-pressure lamps completely). Thus, the operating pressure of the lamp is set by the introduced amount of mercury in connection with the filling pressure of the argon and the operating pressure and the electrical power via the operating pressure.

In the usual dosing the mercury is introduced in droplet form or in the form of halide compounds from a metering device via a pump nozzle or directly into the discharge vessel. When liquid mercury is used, it is not possible to guarantee precise dosing of very small quantities due to the surface tension. The discharge vessels are dosed with a larger amount of mercury, thereby the quality of the lamps, in particular with regard to the luminous flux and the Farbortos be reduced. Furthermore, there is an increased consumption of mercury and thus a greater workplace and environmental impact.

Furthermore, methods are known in which the liquid mercury is in closed containers. According to DE-AS 2511417, the liquid mercury is in a container which is arranged in the exhaust tube. In DE-OS 2340859, a capsule mounted within a lamp envelope contains the dosing material The capsule is opened from the outside by a jet of a laser device A disadvantage of this method is that a region of the discharge vessel is to be kept free of phosphor, DE-OS 2161024 is also known, in which case the mercury is again located in a closed capsule near the electrode, and the capsule is opened by induction. According to DE-AS 2410400, the mercury becomes known as mercury DE-OS 3545073 discloses a porous compact as a storage element for liquid mercury for dosing, and DE-OS 3545048 describes the method for producing the storage element a single metal whose melting point is above 250 ° C or a us at least two metals or a mixture forming an alloy. In its pores, the compact stores the

fixed amount of mercury, wherein the metal forming the compact or the mixture or alloy with the mercury is not alloyed. The production of the memory element is subject to a complex processing method. It takes place via an electrolysis process with subsequent tempering and a granulation process. When using a compact as a mercury storage element, however, a pollution of the environment by mercury can not be excluded because mercury can accumulate in the form of drops on the surface of the storage element.

Object of the invention

The aim of the invention is to enable a technically simple and accurate metering of mercury discharge lamp and to achieve a reduction in workplace and environmental pollution by mercury.

Explanation of the essence of the invention The invention is based on the object, a metering body for receiving mercury and a method for producing

to provide a precise dosage of a discharge lamp, in particular a compact fluorescent lamp, with a defined amount of mercury and at the same time reduces the workplace and environmental pollution by mercury.

According to the invention the object is achieved in that a dosing body for receiving mercury from a Skeleton material and a impregnating material consists. The skeletal material and the impregnation substance form a metal Mercury dressing while retaining the physical properties of mercury, which become a solid and

air-stable porous dosing is shaped. The skeleton material forms a prealloyed powder, which by melting or

Sintering of metals with a starting particle size between 0.05 and 0.5mm is formed. The resulting alloy

forms the skeletal material and is the basis for the absorption of a defined amount of the impregnating material. The

The impregnating material is mercury. As metals for the skeleton material are suitable elements of the 2nd, 3rd and 5th Hauptgri.ppe and Elements of the 1st, 2nd and 8th subgroup of the Periodic Table of the Elements. Particularly advantageous is as Main component of the alloy of at least one of the metals zinc, antimony or iron. Further alloy components

For example, the metals may be aluminum, copper and nickel as well as their compound with iron.

The following combinations of elements can be used: Zn-Co, Zn-Ni-Co, Zn-Fe-Co, Z. Cu, Zn-Cu-Co, Zn-Al, Zn-Al-Li, Zn-Al-Co, Zn-Ni, Zn-Al-Ni, Zn-Sb-Co, Zn-FeAl ₃ Co, SbCu, Sb- CuCo, FeAl ₃ -Cu, FeAl ₃ -Co. The skeletal material may contain one or more melt additives. As melting additives, lithium and / or cobalt

and / or copper are used.

Dio production of the dosing carried out by filling the alloying ingredient for the skeleton material with a Starting particle size of 0.05 to 0.5 mm in a crucible, then melting or sintering at a Temperature between 460 to 760 K under argon, cooling by zone melting at a cooling rate

between 20 to 60 K / min and crushing the resulting filter cake in a grinding process to powder.

The pre-alloyed powder is impregnated with the impregnating material and at the same time in a mold at a pressure until

10Mpcm " ^2. Then the dosing body is portioned.

Due to the controlled isostatic pressing process, the compaction and filling of the pore spaces of the aluminum materials takes place.

with a defined amount of liquid mercury, which leads to an uptake of 25Gew .-% mercury. To one

To ensure absorption capacity of the skeletal material for mercury, the particle size of the starting materials in Range of 0.05 to 0.5 mm. This achieves a porosity of 30 to 60%. Lithium, cobalt and copper can be used as Melt additives are used to improve the aging resistance, to reduce intergranular corrosion

and increase the strength properties.

The proposed mercury-containing dosing can easily be brought into a discharge process with the argon metering

become. After introduction of the dosing in the discharge lamp, a release of mercury during the

Ignition phase within the clear burning process and / or during the activation phase of the electrodes. embodiments The invention will be explained below with reference to exemplary embodiments. example 1 The alloying elements used were elemental zinc, copper and cobalt with the following weight ratio:

Zinc 75.0-98.5% by weight

Copper 24.0-1.0 wt% Cobalt 1.0-0.5 Gow%

Zinc and copper form the skeleton material. As a melting additive is added to reach 100Gew .-% cobalt. The metals used are brought to a temperature of 460 to 760 K at a dissolution rate of 5 to 20 K / min under argon atmosphere. The holding time is 2 to 10 minutes. The cooling rate under argon atmosphere is between 20 and 60 K / min.

The comminuted filter cake is placed in a mold with a specified amount of mercury, depending on the composition and preparation. By the pressing process, the dosing is made in the required shape and extent.

The particle size of the starting materials is between 0.05 and 0.30mr.i. Thus, taking into account the sintering or melting temperature, sintering time and subsequent pressing pressure up to a maximum of lOMPa / cm ^2, a porosity of 15 to 35% is achieved. The metering body is introduced into the discharge vessel with the argon metering stream.

Example 2

To produce a mercury-containing dosing is proceeded as in Example 1. The starting materials used are zinc, aluminum and cobalt with a particle size of 0.25 mm in the following ratio:

Zinc 75% by weight

Aluminum 20% by weight cobalt 5% by weight

The indicated metals are heated under argon atmosphere to a temperature of 460 to 760K. After a holding time of 2 to 10 minutes, the melt is cooled at 20 to 60 K / min under argon atmosphere. The resulting filter cake with a pore space of 25VoI .-% is placed in a mold with a predetermined amount of mercury and pressed at a pressure of 1 Mp / cm ² . In this case, a mercury uptake of 2.5% by weight is achieved. The metering body thus produced is introduced into the discharge vessel with the argon metering stream.

Claims (8)

1. metering body for receiving mercury, consisting of skeletal material and mercury as impregnating material, characterized in that the skeletal material is a prealloyed powder consisting of several metals with the starting particle size between 0.05 and 0.5 mm, by a melting or The sintering process consists of alloying and that the skeleton material with the impregnating material is a metal-mercury dressing. 2. dosing according to claim 1, characterized in that the skeletal material contains as the main constituent of the alloy at least one of the metals zinc, antimony or iron. 3. dosing according to claim 1 and 2, characterized in that the skeletal material contains as another alloying ingredient at least one of the metals aluminum, copper and nickel or their compound with iron. 4. Dosiorkörper according to claim 1, characterized in that Gdß the skeletal material contains a melt additive. 5. dosing according to claim 1 and 4, characterized in that the melt additive is lithium and / or cobalt and / or copper. 6. A method for producing a dosing body for receiving mercury according to claim 1, characterized by the following method steps - Filling the alloy components for the skeleton material with a starting particle size of 0.05 to 0.5 mm in a crucible, then melting or sintering at a temperature between 460 to 760 K under argon, cooling by zone melting at a cooling rate between 20 to 60 K / min and crushing the resulting filter cake in a grinding process to powder, - Impregnating the prealloyed powder with the impregnating material mercury and simultaneously pressing in a mold at a Proßdruck to 10Mpcm ~ ² and then portioning the dosing. 7. A process for the preparation of a dosing according to claim 6, characterized in that the alloy constituents, a melt additive is added. 8. A process for the preparation of a dosing according to claim 6 and 7, characterized in that is used as the melting additive lithium and / or cobalt and / or copper.