DE102012010738B4 - valve assembly - Google Patents

Abstract

Valve arrangement comprising a housing (7, 20, 21), with a valve seat (8) fixed to the housing and with a movable valve closure part (12) cooperating with the latter, having a heating device (2, 3, 7), the housing (7, 20 , 21) is at least partially made of thermally conductive material and / or formed with a smooth heat conducting surface, characterized in that the housing (7, 20, 21) at least partially engages in a cavity (4) containing a heating medium.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a valve according to the preamble of claim 1.

Such valve arrangements are z. As used in autoclaves, which serve to sterilize surgical instruments or other items. In such autoclaves, the germs / pathogens are killed by coming into contact with water vapor at a temperature above 100 ° C (eg, 134 ° C) for an extended period of time (typically longer than 3 minutes).

In order to be able to safely reach any point in the sterilization of complex hollow bodies, a class B autoclave is required. This is characterized by the fact that it works with saturated steam and fractionated vacuum. A method is z. B. specified in DIN 0.

• Beim Aufbauen eines Vakuums bei Anwesenheit von Restflüssigkeiten mit hohem spezifischem Dampfdruck bildet sich Dampf bereits bei niedriger Temperatur. Durch das Verdampfen wird aus der verbleibenden Restflüssigkeit Wärme entzogen. Dadurch sinkt die Temperatur der Restflüssigkeiten in Anbauteilen des Autoklaven wie Ventilen, Leitungen oder anderen Wassersäcken. Die kalte Restflüssigkeit verdunstet bei niedrigem Druck und
• erschwert den Aufbau eines Vakuums in den Fraktionier- oder Spülzyklen, die jeweils ein Evakuieren der Behandlungskammer und ein anschließendes Füllen derselben mit Dampf umfassen und dazu dienen, den Gehalt der Kammeratmosphäre an Luft stark herabzusetzen.

In a valve arrangement serving to control the steam, condensate or residual liquid can form. This affects the work of the autoclave:

• When building up a vacuum in the presence of high specific vapor pressure residual liquids, steam already forms at low temperature. Evaporation removes heat from the remaining liquid. As a result, the temperature of the residual liquids sinks in attachments of the autoclave such as valves, pipes or other water bags. The cold residual liquid evaporates at low pressure and
• complicates the build up of a vacuum in the fractionating or rinsing cycles, each comprising evacuating the treatment chamber and then filling it with steam and serving to greatly reduce the content of the chamber atmosphere in air.

In known solutions, the valve assemblies are connected via screw connections and lines to the chamber. Even with a chamber with double jacket the valves remain cold and residual liquids evaporate at low or at least decreasing (heat extraction by evaporation) temperature. Many sealing points on relatively cold valves mean low operational safety because of difficult to evacuate water bags and potential leaks.

Another known solution is for example in DE 1 106 572 A disclosed. There, a shut-off device is described, which is particularly suitable for liquids that have a high tendency to crystallize. The obturator has, in order to counteract the crystallization tendency of the liquids, a closure piece, which is heated from the inside by a liquid, vapor or gaseous medium.

Further are DE 40 25 732 A1 and DE 10 2007 051 814 A1 heated valves can be seen, which each have a heating element in the interior of its housing, by means of which the housing or a fluid flowing through the valve can be heated.

DE 29 49 692 A1 discloses a column head for chemical laboratory work in which a valve seat projects into a vapor space. In addition, in DE 19 37 743 A a steam sterilizing autoclave described.

It is therefore the object to provide improved valve arrangements available in which the disadvantages caused by residual liquids are reduced.

This object is achieved by the valve arrangement according to claim 1.

The valve assembly according to the invention is characterized in that its housing is well thermally coupled to the container controlled by it, so that the valve arrangement has approximately the temperature of the container.

The autoclave containers are usually heated to avoid condensation of vapor on the chamber wall. If the valve assembly is thermally coupled to the container, the valve is also heated. As a result, the residual liquids in the valves also have a higher temperature and evaporate faster, since the cooling occurring during evaporation is compensated by the heating of the valve elements from the container.

Due to the higher vapor pressure and the associated higher steam temperature, the condenser performance is increased and a lower vacuum can be achieved in a shorter time. This can shorten the fractionation cycles.

The shortened cycle times and the accelerated vacuum build-up also reduce the problem of micro-leaks, for example on the door of the autoclave.

Advantageous developments of the invention are specified in subclaims.

Particularly effective, the valve assembly can be heated when one of the container of the Autoclave arranged heating device with its housing detected

Particularly effective in terms of design is a solution in which the heating device comprises a cavity. This can be formed by half pipes or panels, which are flowed through by a heating medium, for example steam.

The valve arrangement can be heated in a particularly simple and effective manner if the housing at least partially extends into such a cavity and is directly exposed directly to the heating medium.

Particularly effective double jacketed containers are to be heated. In this case, the cavity between an inner container and an outer shell, the z. B. is charged with steam, as a heater. A housing passing through the outer casing is heated particularly effectively.

If the corresponding housing section is welded to the inner and / or outer jacket container, a particularly good heat transfer is ensured by the intimate metallic coupling. At the same time, the risk of leakage decreases.

Within the valve assembly, the heat transfer can be improved and the risk of leakage can be reduced if the valve seat and / or a fitting are also welded to the housing.

In order to improve the sealing and leakage problem of the movable valve closure part, there are versions in which this runs in a guide channel, which in turn is thermally coupled to the housing.

In addition, this improves the thermal coupling of valve closure part and housing.

Embodiments in which the valve arrangement is arranged within an insulation surrounding the container are also advantageous. As a result, a particularly effective heating of the valve arrangement is obtained.

• 1 einen schematischen Aufbau eines Autoklaven;
• 2 eine Schnittdarstellung eines hinteren Abschnittes eines Druckbehälters des Autoklaven mit einer erfindungsgemäßen Ventilanordnung;
• 3 eine vergrößerte Darstellung der Ventilanordnung aus 2; und
• 4 bis 7 Darstellungen weitere Ventilanordnungen mit abgewandelten Heizeinrichtungen.

An embodiment of the invention will be explained below with reference to the drawing. It shows:

• 1 a schematic structure of an autoclave;
• 2 a sectional view of a rear portion of a pressure vessel of the autoclave with a valve assembly according to the invention;
• 3 an enlarged view of the valve assembly 2 ; and
• 4 to 7 Representations further valve arrangements with modified heaters.

1 schematically shows the typical structure of an autoclave. A pressure vessel 105 encloses a chamber 107 of the autoclave. The chamber can via a chamber valve 104 fed with steam and by opening a valve 109 as well as a valve 112 through a suction pump 115 be evacuated.

The valve 109 is in practice in the wall of a capacitor 110 integrated and is surrounded by insulation there.

A steam generator 106 heats the chamber 107 with water vapor generated from fresh water from a water pump 102 from a fresh water tank 101 via a fresh water valve 103 provided.

Between the vacuum pump 115 and the chamber 107 is the capacitor 110 switched, under which a collecting container 111 is located for condensate. Condensate is produced by means of a condensate pump 114 via a valve 113 from the collection container 111 deducted.

The chamber atmosphere can be via a valve 116 and a filter 117 be discharged to the circulating air.

At the bottom of the chamber 107 accumulating condensate can via a valve 108 by the pressure on his mirror in one of the pumps 114 and 115 loaded collection container 119 be directed.

The material to be sterilized is placed on a tray 122 arranged. This or more trays are introduced through an opening such as a door in the chamber (the pressure vessel) of the autoclave.

After closing the autoclave, the following process steps take place: evacuation and pressure build-up (fractionation, in several fractionating cycles), sterilization, drying, aeration. After these sub-processes, the sterile product can be removed with the tray. The devices, instruments or objects are then sterile and can be safely used.

Fractionation removes non-condensable potentially germ-laden gases from the sterilization chamber. It is several times pure steam from an internal or introduced external steam generator in the sterilization chamber and then sucked off again via the valve assembly. The non-condensable gases are removed by dilution.

Also aerosols are not easy to remove, since they can not be compressed in a vacuum pump without condense contained vapors. Whenever the vacuum pump is supposed to suck it in, it evaporates again.

In addition, when the vacuum builds up in the chamber, residual liquids evaporate, and the vapor thus generated occupies a larger volume. Because of this, the capacitor is 110 intended. The aerosol or the saturated vapor can rain out in the condenser and the condensate is collected there or discharged therefrom.

When building up a vacuum in the presence of high specific vapor pressure residual liquids, steam already forms at low temperature. Evaporation removes heat from the remaining liquid. As a result, the temperature of the residual liquids sinks in attachments such as valves, pipes and other water bags. The cold residual liquids evaporate at low pressure and make it more difficult to build up a vacuum in the fractionating cycles.

The following with reference to the 2 and 3 described chamber valve prevents the above-mentioned difficulties with residual fluid.

2 shows a double-walled pressure vessel 1 with an inner jacket 2 which is at a distance from an outer jacket 3 is surrounded. Between outer and inner sheath 2 . 3 there is a cavity 4 in which there is a good heat-conducting heat transfer fluid, z. As water vapor.

The pressure vessel 1 is from an insulation 5 surround. This could be partially or completely formed by an outer poor heat conductive jacket of the autoclave wall, in the illustrated embodiment, for. B. by a third coat, the coat 3 surrounds, with the gap then evacuated (Dewar).

At the rear end of the pressure vessel 1 is a chamber valve 6 intended.

It comprises a housing main part 7 that with a container-side end section 7a in a suitable opening 2a of the inner jacket 2 is tightly welded in stages. It penetrates the outer jacket 3 and is on its outer circumference with a matching opening 3a of the outer jacket 3 welded.

Alternatively, the chamber valve 6 also in the housing main body 7 be gas-tight screwed or cohesively connected to this gas-tight.

Thus, the cavity surrounds 4 the cylindrical smooth outside of the end portion 7a ,

The housing main body 7 carries inside a valve seat 8th , which is connected via a thread with the housing body and against this by means of a seal 9 is sealed. The seal 9 and the valve seat 8th are interchangeable.

In another embodiment, the valve seat 8th also in the case main body 7 be welded.

Between the container-side end of the housing main part 7 and the inner jacket 2 runs a weld 10 , Between the outer circumference of the connection socket 7 and the outer jacket 3 runs a weld 11 ,

The chamber is made of stainless steel, preferably 1.-stainless steel. The welds are very hygienic reasons and preferably refinished to good surface quality, eg. B. pickled or electropolished.

An at the same time serving as an armature of an electromagnet valve closure part 12 runs in sliding play inside a tubular guide part 13 which has a thread 14 with the end of the housing main part facing away from the container 7 screwed. It is there with a seal 15 sealed. Alternatively, other tight and removable connectivity options may be considered.

The valve closure part 12 is about a spring 16 , attached to a paragraph of the leadership part 13 supports, with its sealing surface 17 against the valve seat 8th pressed.

An anchor forming portion of the valve closure member 12 is from an armature winding 18 surrounded, which under electrical tension the valve closure part 12 from the valve seat 8th takes off and the passage to a side connector 19 releases.

The connecting piece 19 is also with the case main body 7 screwed or welded in another version with this.

An isolation 5 surrounds the housing body 7 and partly the connection piece 19 that with the vacuum pump 114 or the capacitor 110 connected is.

In the drawing, the reference number 20 for a cup-shaped end portion of the guide member 12 defining a spring chamber and the controlling end portion of the valve closure member 12 surrounds. He is close in the left in the drawing open end of the housing main body 7 used.

With 21 is a housing of the solenoid of the electromagnet designated.

In operation, the autoclave passes through the chamber valve 6 evacuated. The cavity 4 is traversed by hot steam, which in turn the housing main body 7 and with it all the others with the case main body 7 coupled components of the chamber valve 6 heated. The heating effect is improved by the fact that the insulation 5 the chamber valve 6 almost completely surrounds.

2 shows an enlarged view of the valve assembly 1 ,

The parts of the Kammmerventiles are made of a material with good heat conduction to vaporize residual fluid inside the chamber valve well. The same applies to the material of the welds 10 and 11 ,

In terms of good heat transfer, the cooperating surfaces of the casing are the main body 7 and inner container 2 as well as outer container 3 worked on a good flat fit.

In the embodiments of the 4 to 7 are components referring to the 1 to 3 have already been described, again provided with the same reference numerals. They need not be described again below.

At the valve after 4 has the housing main body 7 an integrated heat exchanger 40 that's over wires 42 . 44 with an external heat source 46 communicates.

The housing main body 7 to 5 is made of a material with high eddy current losses and is located in the alternating field of a magnetic coil 50 that by an RF generator 52 is fed.

At the valve after 6 becomes the case main body 7 by an annular IR radiator arrangement 60 heated, whose radiation from the outer surface of the housing main body 7 is absorbed.

At the valve after 7 is in the housing main body a heating resistor 70 embedded by a power supply 72 is fed.

Also with the valves after the 4 to 7 Condensation in the valve is avoided.

Claims (12)

Valve arrangement comprising a housing (7, 20, 21), with a valve seat (8) fixed to the housing and with a movable valve closure part (12) cooperating with the latter, having a heating device (2, 3, 7), the housing (7, 20 , 21) is at least partially made of thermally conductive material and / or formed with a smooth heat conducting surface, characterized in that the housing (7, 20, 21) at least partially engages in a cavity (4) containing a heating medium. Valve arrangement after Claim 1 , characterized in that the heating medium is steam. Valve arrangement after Claim 1 or 2 , characterized in that the cavity (4) can be flowed through by the heating medium. Valve arrangement according to one of Claims 1 to 3 , characterized in that the cavity (4) an inner shell (2) and a the inner shell (2) at a distance surrounding the outer jacket (3) of a container is limited. Valve arrangement after Claim 4 , characterized in that the housing (7, 20, 21) the outer shell (3) and the inner shell (2) passes through tightly. Valve arrangement after Claim 4 or 5 , characterized in that the housing (7, 20, 21) at least with the inner shell (2) or with the outer jacket (2) is integrally connected. Valve arrangement according to one of the preceding claims, characterized in that the valve seat (8) with the housing (7, 20, 21) is connected in a gas-tight manner cohesively or positively. Valve arrangement according to one of the preceding claims, characterized in that a coupling portion (7a) of the housing (7, 20, 21) is integrally formed with a housing main part or welded or glued thereto. Valve arrangement according to one of the preceding claims, characterized in that the valve closure part (12) in a guide channel (13) of the housing (7, 20, 21) runs. Valve arrangement according to one of the preceding claims, characterized in that the valve closure part (12) by a servo motor, an electromagnet (13), a pneumatic Cylinder or a hydraulic cylinder is adjustable. Valve arrangement according to one of the preceding claims, characterized in that the housing (7, 20, 21) is at least partially surrounded by an insulation (5). Valve arrangement after Claim 11 , characterized in that the insulation is at least partially formed by an insulating Dewar jacket part.

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