CONDENSATE TRAP DEVICE

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to German Patent Application Number DE 10 2024 139 023.9, filed Dec. 19, 2024, the entire contents of which is hereby incorporated by reference.

FIELD OF DISCLOSURE

The disclosure relates to a condensate trap device and an air purification system comprising a condensate trap device.

BACKGROUND

Air purification systems with filters and/or condensate traps are common in various branches of industry.

Filters and condensate traps are used to at least partially remove unwanted contaminant from gas or vapour streams in order to increase the efficiency and/or service life of machines. In particular, the intention is to prevent damage that might be caused by the entrained contaminant (e.g. corrosion damage) or by the unwanted deposition of contaminant. Generally speaking, production and process rooms should be protected from contamination by the use of filters and condensate traps. Product quality should also be improved by at least partially removing contaminant from the gas or vapour stream.

Known filters and condensate traps often have a limited service life because they clog up quickly. Clogging may also prevent consistent removal of contaminant from gas or vapour streams, resulting, for example, in product quality decreasing with increasing operating time. Furthermore, the permeability of known filters and condensate traps decreases over time, making it impossible to provide a consistent airflow, for example, in air purification systems, or meaning that complex airflow control is required to compensate for the reduced permeability.

Furthermore, known filters and condensate traps need frequent servicing. This means that filter and/or condensation elements have to be replaced or cleaned. This often requires the corresponding industrial plant to be shut down, which can sometimes result in high downtime costs. There are also cleaning costs and the cost of replacing any filters.

The industrial use of condensate traps extends across various industries and covers numerous areas of application. In the petrochemical industry, for example, condensate traps are used to remove condensate from vapour streams before they are introduced into further processes. This not only contributes to improving machine efficiency but also increases the quality of the final products and minimizes corrosion damage to machine components. Similarly important is the use of condensate traps in food processing, where they help ensure the purity of steam that comes into direct contact with food. Condensate removal can prevent contamination which could compromise the quality and safety of the food.

Condensate traps are also used in vacuum technology to protect vacuum pumps from condensate. Condensate traps can also be used in polymer processing, particularly in polymer film production. During plastics processing, such as the production of polymer films, contaminant (for example monomers, oligomers, auxiliaries and/or additives and/or other substances) may migrate from the plastic. The presence of this contaminant may impair the quality and mechanical properties of the plastic products produced (in particular films) and/or damage the production equipment (for example a film stretching machine).

Despite their importance for various applications, conventional condensate traps often have limitations which restrict their performance and/or require high maintenance.

SUMMARY

The disclosure provides a condensate trap device and an air purification system which at least partially eliminate the aforementioned disadvantages.

According to the disclosure there is condensate trap device, an air purification system and a machine for producing a material web according to the independent claims. Further aspects of the disclosure are mentioned in the dependent claims and in the following description.

In particular, the problem is solved by a condensate trap device which can be used in particular for air purification in a film stretching machine or for purifying exhaust air. The condensate trap device can also be used in other branches of industry, such as food processing, the petrochemical industry, power generation and/or the like.

The condensate trap device comprises at least one movably mounted condensation element and at least one drive unit. The drive unit is assigned to the at least one condensation element and can drive the condensation element.

The one movably mounted condensation element is arranged in the condensate trap device so that it is flowed through and/or over by a contaminated airflow.

The movably mounted condensation element is set up so that contaminant which is carried by the second airflow at least partially condenses on the at least one condensation element. The contaminant can therefore be (at least partially) removed from the airflow.

Movement of the condensation element, which is initiated by the drive unit, results in condensate formed, i.e. condensed contaminant, being at least partially removed from the condensation element.

In the production of plastic films, the contaminant comprises, for example, monomers, oligomers and/or other volatile components which escape from the (still warm) plastic film or the melt. This contaminant can settle as what is referred to as a “white powder” in the stretching machine, in particular in a transverse stretching machine, and/or the ventilation system, and damage it. For example, openings can become clogged or moving components (such as air control valves) can become stiff or even blocked.

Product quality can also be compromised if the contaminant settles on the product (e.g. a plastic film).

Removing the settled condensate from the machine is also complex as it usually requires the stretching machine to be stopped and production to be interrupted. The condensate trap device now allows the contaminant to be specifically removed from the airflow before it settles. This enables product quality to be improved and the service life of a machine for producing plastic film to be increased and/or cleaning intervals to be extended. The condensate trap arrangement also significantly increases the service life of any filters.

In one aspect, the condensate trap device can be set up so that the movably mounted condensation element can be driven and therefore moved during operation of the machine. This allows the condensation element to be at least partially freed of condensate during operation. This allows downtimes to be avoided or at least significantly reduced.

In one aspect of the disclosure, the movably mounted condensation element is coupled to the drive unit in such a way that the at least one condensation element is driven substantially translationally. In particular, the at least one condensation element can be moved by the drive unit in one direction and in the opposite direction (for example up and down). This movement can be periodic.

This back-and-forth movement can be limited at least on one side by a stop so that the at least one condensation element is guided by the drive unit against the stop. The resulting impacts lead to an at least partial removal of settled condensate from the condensation element.

In one aspect, the condensation element is lifted by the drive unit from a first position and then falls back into this first position. The first position of the condensation element is defined, for example, by a first stop on which the condensation element rests in the first position. By hitting the first stop, the condensation element experiences a shock at the end of its downwards movement.

Alternatively or additionally, the condensation element can be actively guided towards a stop by the drive unit. For example, if the upwards movement of the condensation element is limited by a (further) second stop, the condensation element can experience a shock at the end of its upwards movement (by stopping at the stop).

The disclosure is obviously not limited to up and down movements, the condensation element instead being able to be moved translationally as desired in order to be at least partially freed of condensate.

In particular, the drive unit can be set up to translate a rotational movement into a translational movement of the condensation element. For this purpose, the drive unit can comprise at least one eccentric element.

The eccentric element may, for example, be a cam of a camshaft. The at least one cam of the camshaft can engage with the condensation element so that a rotation of the camshaft is translated into a translational movement (e.g. up and down) of the condensation element.

In a further aspect, the condensate trap device comprises at least one guide element. The movably mounted condensation element can also be a circulating condensation element and be guided in a circulating manner by the at least one guide element. The at least one guide element may, for example, be a roller or a wheel, in particular a gear.

A circulating condensation element makes it possible to provide a condensation element which extends further and, in particular, has a larger surface area than, for example, stationary condensation elements. In particular, the condensation element can pass through an area through which the airflows flow and also extend into an area which is not flowed through. By being guided in a circulating manner, for example, only a portion of the condensation element is ever in the flowed-through area, enabling the service life of the condensation element to be significantly extended. This results in less downtime due to maintenance of the condensate trap device.

In one aspect, the movably mounted condensation element is belt-shaped or plate-shaped. In particular, the circulating condensation element can be belt-shaped.

If a plurality of guide elements (such as rollers) are provided, the condensation element can be redirected so that the second airflow repeatedly flows through it. The efficiency of the condensate trap device can therefore be increased because the amount of contaminant separated can be increased. For example, the condensation element can be redirected so that the second airflow flows through the condensation element at least twice, or at least three times, or at least four times, or at least six times, or at least eight times. A plurality of condensation elements can likewise be connected in series. If provision is made for a plurality of condensation elements connected in series, their opening width or mesh size can decrease in the direction of flow.

A condensation element which is flowed through first can therefore be coarser than a subsequent condensation element. For example, the size of openings in the condensation element that is flowed through first can be in the range of 0.3 mm to 10 mm, or in the range of 0.5 mm to 8 mm, or in the range of 1 mm to 8 mm, or in the range of 3 mm to 5 mm (equivalent diameter). The size of the openings of the subsequent condensation element can be reduced, for example, by at least 10%, or at least 20% or at least 30%. The equivalent diameter indicates the size of the largest circle that can be inscribed in the opening. Plate-shaped condensation elements can be used in particular when the movably mounted condensation element is driven substantially translationally. Examples of plate-shaped condensation elements are condensation elements which comprise, for example, a stretched sheet, a perforated sheet, a metal mesh/wire mesh, a nonwoven mat, a ring mesh and/or the like.

The at least one plate-shaped condensation element can, for example, comprise a frame into which at least one air-permeable element (e.g. a nonwoven, a fabric or even a sheet metal structure) is clamped. This increases the stability of the condensation element. It is possible for a frame to support a plurality of air-permeable elements. The drive unit can comprise a drive element. This drive element can be set up to drive the condensation element indirectly or directly. For example, the drive element can directly drive a guide element, thus driving the condensation element. The drive element may, for example, be an electric motor or comprise an electric motor. It is also possible for the drive element to be manually operable and, for example, comprise a hand crank.

The drive unit can also be controlled. If a sensor detects that condensate has settled on the condensation element and/or that a desired flow rate is no longer being achieved, the drive unit can be started and the condensation element moved in order to at least partially remove the condensate. The drive unit can also be time-controlled and move the condensation element at defined times. If the drive element is manually operable, a corresponding instruction can be issued to the operators that the at least one condensation element has to be operated.

The condensation element can be removable for cleaning. Alternatively and/or additionally, the condensate trap device can comprise at least one cleaning element which is set up to remove condensate from the movably mounted condensation element. The cleaning element may be a mechanical cleaning element, a chemical cleaning element and/or a physical cleaning element.

For example, the cleaning element may comprise at least one brush and/or at least one scraper, the cleaning element being arranged so that the condensation element is guided past it. As it passes, the cleaning element can then remove condensate from the condensation element, in particular by wiping it off. The cleaning element can also apply a cleaning agent which removes the condensate or at least simplifies its removal. The cleaning element may also comprise a compressed air nozzle and/or a (water) jet nozzle which blows clean and/or rinses the condensation element as it is guided past.

In a further aspect, the cleaning element can be set up to vibrate the condensation element, at least in certain areas, so that the condensate that has formed is, so to speak, knocked off. This can be achieved using fixed or movable structures past which the condensation element is guided. It is also possible for the condensation element to be dried, in particular by being blown dry, after cleaning. The cleaning element allows the condensation element to be freed of condensate during ongoing operation.

The condensate trap device can also comprise a catching device set up to catch condensate. The condensate caught can be removed from the catching device continuously or at intervals. This can be done automatically or manually. The catching device may, for example, be a tub, a container and/or the like.

In one aspect, the condensate trap device comprises at least one air mixing device. The air mixing device is set up to mix a first airflow and a second, contaminated airflow in order to generate a mixed airflow. The mixed airflow can then be directed towards the at least one condensation element in order to flow over or through it.

It has been shown that very homogeneous mixed airflows can be achieved in this way. This leads to an increase in product quality, particularly when the mixed airflow is fed as incoming air to a machine for producing plastic films, for example, to a cooling zone of a stretching machine.

The first airflow has a first temperature here and the second airflow a second temperature, the second temperature preferably being higher than the first temperature. The mixed airflow is then at a temperature which is between the first and second temperatures and carries contaminant. This contaminant can then condense on the condensation element-partly due to the reduced temperature- and thus be separated. In one aspect, the air mixing device comprises at least one air mixing element. The at least one air mixing element is flowed through by the first airflow and the second airflow (which may already be partially mixed). This achieves a homogeneous mixing of the airflows and prevents the formation of what are referred to as streaks.

Undesirable streaking occurs when airflows of different temperatures meet and mix. The term “streaking” here describes the characteristic structure which results from incomplete mixing, i.e. air strands with different temperatures form. This is detrimental to the quality of the film. The air mixing element can reduce or even prevent streaking and improve the quality of the film. The at least one condensation element can also further reduce streaking.

The at least one air mixing element may, in particular, comprise a stretched sheet, a perforated sheet, a metal mesh, a wire mesh, a nonwoven mat, a ring mesh and/or the like. If a plurality of air mixing elements are provided, they can be connected in series, the opening width or mesh size thereof being able to decrease in the direction of flow.

An air mixing element which is flowed through first can therefore be coarser than a subsequent air mixing element. For example, the size of openings in the air mixing element that is flowed through first can be in the range of 0.3 mm to 10 mm, or in the range of 0.5 mm to 8 mm, or in the range of 1 mm to 8 mm, or in the range of 3 mm to 5 mm (equivalent diameter). The size of the openings of the subsequent air mixing element can be reduced, for example, by at least 10%, or at least 20% or at least 30%.

In a further aspect, the air mixing device can be set up so that the first airflow and the second airflow flow into the air mixing device in a co-current, a counter-current or a cross-current. In co-current operation, the first and second airflows are oriented in substantially the same direction. In counter-current operation, the first and second airflows are oriented in opposite directions. In cross-current operation, the first and second airflows are at an angle to each other, for example substantially orthogonal.

In a further aspect, the air mixing device may comprise at least one nozzle arrangement (for example a nozzle box). The nozzle arrangement is configured to direct the first and/or second airflow. For example, two types of nozzle arrangements may be provided, with a first type being able to be configured to direct the first airflow and a second type being able to be configured to direct the second airflow. At least one nozzle arrangement of each type may be part of the condensate trap device. By arranging the nozzle arrangements accordingly, a co-current, counter-current or cross-current can then be generated.

The nozzle arrangement comprises a plurality of outlet openings arranged so that the first airflow (or the second airflow) flows to the air mixing element or condensation element over substantially the entire width of the air mixing element and/or the entire width of the condensation element. The entire width of an air mixing element can therefore be used for further mixing of the airflow, or the entire width of the condensation element can be used for condensate formation. This increases the efficiency of the condensate trap device.

The condensate trap device may also comprise a temperature control element (for example a heating or cooling element) which is set up to control the temperature of the first airflow, the mixed airflow and/or an output airflow of the condensate trap device. By controlling the temperature of the first airflow or the mixed airflow, the at least one condensation element can be brought to a temperature which is below a condensation temperature of the contaminant. This promotes condensation.

By controlling the temperature of the output airflow, it can be brought to a process temperature (for example when the output airflow is recirculated into a production facility), or energy can be extracted from the output airflow before it is released into the environment.

In one aspect, the condensation element is a circulating metal belt. For example, the metal belt can comprise a metal mesh. It is also possible for the metal belt to be designed as a link belt, hinged belt, chain belt, rod mesh belt, wire eyelet link belt, spiral mesh belt and/or the like. If the condensation element is plate-shaped, the metal belt can be held in a frame of the condensation element. The metal belt may be permeable, allowing the airflow to pass through it. Depending on the application, a mesh size or link size can be selected which promotes good condensate formation while also providing good airflow.

When the metal belt is redirected (or strikes the condensation element), the individual links or mesh of the metal belt can move relative to each other so that separated condensate falls off the metal belt. The metal belt may therefore have a certain self-cleaning effect.

The metal belt may be made of steel, in particular a corrosion-resistant steel such as 1.4301 or 1.4571. Non-ferrous metals can also be used.

In particular, the condensation element can comprise a condensation section and at least one conveying section. For example, provision may also be made for two conveying sections, with the condensation section arranged in between.

The condensation section is connected to the conveying section. The condensation section is also set up to form condensate. The conveying section can interact with the drive unit to drive the condensation element. In one aspect, the conveying section comprises a chain which is attached (e.g. welded, riveted or the like) to the side of the condensation section, for example. The conveying section may likewise comprise a belt.

There is further an air purification system which comprises at least one condensate trap device of the type described above. The air purification system may, for example, be part of a film stretching machine and may, for example, supply incoming air and/or be used for degassing.

In addition to at least one condensate trap device, the air purification system comprises at least one airflow feed unit which is set up to provide a first airflow to the condensate trap device. In particular, this first airflow is provided to an air mixing device. The airflow feed unit may, for example, comprise a fan, particularly an adjustable fan.

The air purification system also comprises at least one exhaust air unit which is set up to extract exhaust air from a machine (such as a film stretching machine) and provide it to the condensate trap device as a second airflow. In particular, this second airflow is provided to the air mixing device. Since this second airflow is taken from the machine, it is typically contaminated. The exhaust air unit may, for example, comprise a fan, in particular an adjustable fan. Provision may also be made for a controllable or adjustable valve which allows only a portion of the extracted exhaust air from the condensate trap device to be provided as a second airflow.

As described above, the air mixing device is set up to mix the first airflow and the second, contaminated airflow in order to generate a mixed airflow. The mixed airflow can then be directed over or through a condensation element of the condensate trap device in order to separate contaminant from the mixed airflow.

The air purification system is further set up to provide the mixed airflow to the machine as incoming air after the condensate trap device. This allows contaminant to be removed from the machine and product quality to be increased.

The air purification system may further comprise at least one air distribution device. The air distribution device is set up to receive the second airflow from the exhaust air unit, disperse the airflow received and provide the dispersed airflow to the condensate trap device, in particular the air mixing device. This enables optimal use to be made of the surface area of the at least one air mixing element or condensation element.

The air purification system may further comprise a coarse filter arrangement. The coarse filter arrangement can filter contaminant which might pass through the condensate trap device from the airflow. The coarse filter arrangement can therefore be arranged downstream of the condensate trap device.

The coarse filter arrangement may comprise one or more coarse filters which comprise, for example, a metal mesh, a steel wire mesh, a filter fleece and/or the like. The coarse filter may be reusable (and accordingly cleanable) or designed for single use.

A heating element can also be arranged between the condensate trap device and the coarse filter arrangement. It is also possible to arrange a heating element downstream of the coarse filter arrangement.

The air purification system may also comprise at least one filter arrangement which comprises at least one filter that is typically finer than the coarse filter. This allows additional contaminant to be removed from the airflow. The filter arrangement is, for example, arranged downstream of the coarse filter arrangement.

In one aspect, the air purification system comprises a heating element. The at least one filter arrangement can be arranged upstream and/or downstream of the heating element in the direction of flow. In particular, a heating element can be arranged between the coarse filter arrangement and the filter arrangement and/or after the filter arrangement.

The air purification system can further be set up to release an airflow or a portion of the airflow leaving the condensate trap device (or the coarse filter arrangement or the filter arrangement) into the environment and/or recirculate it to the machine. The exhaust air can therefore as far as possible be freed of contaminants, allowing it to be reused.

Even further, there is a machine for producing a material web, in particular a film stretching machine, with at least one of the air purification systems described above.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure is explained in more detail below using, by way of example, the attached Figures.

FIG. 1A shows a schematic representation of a condensate trap device according to the disclosure.

FIG. 1B shows a further schematic representation of the condensate trap device according to the disclosure from FIG. 1.

FIG. 1C shows a detailed schematic representation of a condensation element.

FIG. 2A shows a detailed schematic representation of an air mixing device.

FIG. 2B shows a detailed schematic representation of a condensation element.

FIG. 2C shows a detailed schematic representation of a drive unit.

FIG. 3A shows a detailed schematic representation of an air purification system.

FIG. 3B shows a detailed schematic representation of a further air purification system.

FIG. 4 shows a schematic representation of a coarse filter arrangement.

FIG. 5 shows a schematic representation of a machine for producing a material web.

DETAILED DESCRIPTION

FIG. 1A shows a schematic representation of a condensate trap device 110 according to the disclosure. FIG. 1B shows the condensate trap device 110 according to the disclosure in a further view.

The condensate trap device 110 comprises a movably mounted condensation element 112, here a circulating one. In the embodiment shown, the condensation element 112 is designed to be belt-shaped, for example as a link belt (for example a round wire link belt).

The condensate trap device 110 also comprises at least one guide element 116. A plurality of guide elements 116 are provided here, these being designed as guide rollers. The condensation element 112 is guided over the guide rollers 116 and repeatedly redirected so that an airflow 212, 216 flows repeatedly (here four times) through the condensation element 112.

A drive unit 114 is provided to drive the condensation element 112 in a circulating manner. The drive unit comprises a drive element, such as an electric motor or a hand crank. As shown in FIG. 1B, the drive element of the drive unit 114 can drive a guide roller 116 which then drives the condensation element 112.

An air mixing device 109 is arranged upstream of the condensation element 112 in the direction of flow. This comprises a plurality of nozzle arrangements 113. Three nozzle arrangements 113 are shown here by way of example. In the embodiment shown, the nozzle arrangement 113 serves to direct a first airflow 212. The nozzle arrangement comprises a plurality of outlet openings 113a (see FIG. 1B) which are arranged so that the airflow 212 flows to the condensation element 112 over substantially the entire width of the condensation element 112. The openings could alternatively or additionally also be provided on the top and/or bottom of the nozzle arrangements, as shown, for example, in FIG. 2A.

A further, second airflow 216 can be routed between the nozzle arrangements 113. The first airflow 212 is at a first temperature T1. The second airflow 216 may be contaminated (that is to say may carry contaminant) and be at a second, higher temperature T2. The airflows 212, 216 are mixed by being guided. The mixed airflow is at a temperature between the temperatures T1 and T2. This promotes the condensation of the contaminant on the condensation element 112.

An air mixing element, for example in the form of a perforated plate (not shown here), can be arranged upstream of the condensation element 112. The air mixing element further mixes the two airflows 212, 216.

When this mixed, contaminated airflow hits the temperature-controlled condensation element 112, the carried contaminant can condense on the condensation element 112 and thus be removed from the airflow. In particular, the condensation element is indirectly temper-controlled so that the airflows meet here at different temperatures. Active temperature control is also possible.

After passing through the condensation element, the airflow can be fed into an industrial plant as incoming air or discharged into the environment. Depending on the degree of contamination, further filtration may be necessary beforehand.

The condensate adhering to the condensation element 112 can be removed by a cleaning element 118. The cleaning element may be a mechanical cleaning element, a chemical cleaning element and/or a physical cleaning element which cleans the condensation element 112 as it passes by.

A catching device 115 can also be provided to catch the condensate. The condensate caught can then be removed from the catching device 115 continuously or at intervals.

As shown in FIG. 1B, the condensation element 112 comprises a condensation section 112a. Condensate primarily condenses in this section. The condensation section 112a may, for example, comprise a wire mesh and/or similar material. A conveying section 112b is arranged on either side of the condensation section 112a. The conveying sections 112b are connected to the condensation section 112a and can interact with a drive unit 114.

As illustrated schematically in FIG. 1C, the conveying sections 112b can, for example, be designed as chains which can engage with a gear in order to drive the condensation element 112. The condensation section 112a is designed in FIG. 1C as a belt which comprises a plurality of belt links 112k, 112l, 112m. The belt links can be formed from wire 112q and connected via belt axles 112s.

If the condensation element 112 is redirected, the individual belt links 112k, 112l, 112m shift relative to one another, allowing separated condensate to fall off the condensation element 112. The condensation element 112 therefore has a certain self-cleaning effect.

FIG. 2A is a schematic representation of an air mixing device 109 which can be arranged upstream of a condensation element (see FIG. 2B) as part of a condensate trap device 110. The air mixing device 109 shown in FIG. 2A comprises a plurality of plate-shaped air mixing elements 109a, 109b, 109c. The plate-shaped air mixing elements 109a, 109b, 109c each comprise a perforated plate here which, in the example shown, has rectangular through-openings. The through-openings can obviously also be other shapes. For example, the through-openings can also be round or oval, or be any other shape. Combinations of different shapes are also possible.

As shown, the air mixing device can comprise a plurality of air mixing elements. In the representation shown, three air mixing elements 109a, 109b, 109c are arranged one after the other (in series) in the direction of flow. The hole size of the air mixing elements 109a, 109b, 109c can decrease in the direction of flow.

In the embodiment shown in FIG. 2A, the air mixing device 109 comprises four nozzle arrangements 113. These serve to direct an airflow 212. The nozzle arrangement comprises a plurality of outlet openings 113a which are provided on the top and/or bottom of the nozzle arrangements. Alternatively and/or additionally, the outlet openings can also be arranged as shown in FIG. 1B. The airflow 212 is directed over substantially the entire width of the air mixing element 109a via the nozzle arrangements 113. The airflow 212 may, for example, comprise fresh air or consist of fresh air and be at a first temperature T1.

Another airflow 216 can be directed to the air mixing elements 109a-c between the nozzle arrangements 113 (here in cross-current). The airflows 212, 216 are first mixed in the area of the nozzle arrangements. This mixing is enhanced by the air mixing elements 109a-c so that ultimately a substantially homogeneously mixed airflow 214 is generated.

The airflow 216 may be contaminated (that is to say may carry contaminant) and be at a second, higher temperature T2. The mixing leads to cooling, thus allowing contaminant to precipitate or condense when the contaminated, mixed airflow 214 hits the condensation element 112.

This is shown in FIG. 2B. The contaminated, mixed airflow 214 hits the condensation element 112. The contaminant condenses there. The mixed, purified airflow 214′ (that is to say after passing through the condensation element 112) can then be fed to an industrial plant as incoming air or discharged into the environment. Depending on the degree of contamination, further filtration may be necessary beforehand.

The condensate adhering to the condensation element 112 can be removed from the movably mounted condensation element 112 as shown in FIG. 2B.

For this purpose, the movably mounted condensation element 112 is coupled to a drive unit 114. The drive unit comprises a hand crank 114a. The shafts 119 can be driven in rotation by means of the hand crank 114a. Other drive elements, such as an electric motor, can obviously be used instead of the hand crank.

Eccentric elements 117 are arranged on the shaft 119. At least one condensation element 112 rests on these eccentric elements 117. Rotation of the shaft 119 therefore leads to a translational up-and-down movement of the condensation element (direction of movement Z). The translational movement is guided by the guide elements 116, here lateral guide rails. The movement sequence is shown again in FIG. 2C.

Catching devices 115 in the form of drawers are provided below the condensation elements 112. These catch the removed condensate.

FIG. 2C shows the drive unit, in particular the up-and-down movement of a condensation element 112, again in detail in a side view. As shown, an eccentric element 117 is arranged on a shaft 119. In the initial position (far left), the eccentric element 117 is in a first position. The condensation element 112 rests on the eccentric element 117 and is in a first position.

A rotation of the shaft 119 leads to a rotation of the eccentric element 117 and therefore to the lifting of the condensation element 112 (see FIG. 2C, second representation from the left). If the shaft 119 is rotated further, the condensation element 112 is also raised further (see FIG. 2C, third representation from the left).

In the representation shown, the eccentric element comprises a shoulder 117a. At this shoulder 117a, the distance from the outer contour of the eccentric element 117 to the centre of the shaft 119 changes abruptly. If the shoulder 117a is overstepped by the condensation element 112, as is the case from the third to the fourth representations in FIG. 2C, the condensation element 112 falls abruptly back to the first position. In doing so, it can hit the eccentric element 117 or a stop (not shown).

Upon returning to the first position, the condensation element 112 experiences a shock at the end of its downwards movement. This leads to an at least partial removal of settled condensate from the condensation element 112.

FIG. 3A shows a schematic representation of an air purification system 2. FIG. 3B shows another air purification system 2. The air purification system 2 may, for example, be part of a film stretching machine, as shown in FIG. 5, and may, for example, be used there to supply incoming air and/or for degassing.

The air purification system 2 comprises at least one condensate trap device 110, at least one airflow feed unit 140 and at least one exhaust air unit 200.

The airflow feed unit 140 is set up to provide a first airflow 212 to the condensate trap device 110. The airflow feed unit may, for example, comprise a fan, in particular an adjustable fan, which draws in ambient air (fresh air). The airflow feed unit 140 can also extract process air from a machine, such as a film stretching machine. In this case, it is preferable to draw in process air which has a low degree of contamination and/or is at a lower temperature than the second airflow 216. In film production, this is the case, for example, in the last cooling zone.

The exhaust air unit 200 is set up to extract exhaust air from a machine (for example a machine for producing plastic film) and provide it to the condensate trap device 110 as a second airflow 216.

The exhaust air unit 200 may, for example, comprise a fan 142, in particular an adjustable fan. Provision may also be made for a controllable or adjustable valve which allows only a portion 216 of the extracted exhaust air 200 to be provided to the condensate trap device 110. Another portion of the exhaust air 200 can be released into the environment. Filtering can be provided here to prevent pollutants from entering the environment. The fan 142 can be arranged downstream of a branch 141, as shown. Alternatively, the fan 142 (dotted representation) can also be arranged upstream of the branch 141.

The second airflow 216 can be directed via an air distribution device. The air distribution device 108 is set up to receive the second airflow 212 from the exhaust air unit 200, disperse the airflow received and provide the dispersed airflow to the condensate trap device 110, in particular an air mixing device 109. The airflow can therefore be guided over the entire width of an air mixing element.

The first and second airflows 212, 216 are directed through the air mixing device 109 of the condensate trap device 110 as described above. The mixed airflow 214 generated in this way is then directed onto or through a condensation element 112 so that contaminant is condensed and removed from the airflow. Finally, a mixed, purified airflow 214′ can exit the condensate trap device 110 and optionally be fed to a coarse filter arrangement 120 and/or at least one filter arrangement 130.

The airflow 214′ purified in this way can then be returned to the machine as incoming air 218 via additional fans 144.

Provision may also be made for a heating element 150 to control the temperature of the (partially) purified airflow. The heating element 150 may, for example, be arranged upstream of the filter arrangement 130, this arrangement being shown in FIG. 3A. The heating element 150 may likewise be arranged downstream of the filter arrangement 130, this arrangement being shown in FIG. 3B.

The air distribution device 108, the condensate trap device 110 (with optional air mixing device 109 and condensation element 112), the coarse filter arrangement 120 and/or the filter device 130 can form an air purification unit 100. The air purification system 2 may comprise a plurality of (at least two) such air purification units 100. A film stretching machine can likewise be assigned a plurality of air purification systems 2 which may in turn comprise at least one or more air purification units.

An air purification unit 100 can, for example, be assigned to a preheating zone 23, a stretching zone 24, an annealing zone 25 and/or a cooling zone 26 of a transverse stretching machine 22 in order to supply them with incoming air 218. The airflow of the incoming air 218 can be controlled or regulated via separate fans 144. It has been shown that use in the cooling zone 26 leads to particularly effective contaminant removal.

If the air purification system 2 is assigned, for example, to a cooling zone 26 of a stretching machine 20 (see FIG. 5), the incoming air 218 passes over the plastic film 10 in the cooling zone 26, absorbs any remaining contaminant and can be extracted again as exhaust air 210 by an exhaust air unit 200. The film is also cooled by the incoming air 218.

FIG. 4 shows a schematic representation of a coarse filter arrangement 120. The coarse filter arrangement 120 is flowed through by an airflow, such as a mixed airflow 214′. The coarse filter arrangement 120 comprises a plurality of coarse filters 124 (for example a metal mesh, a stretched sheet, a filter fleece and/or the like), which have been inserted into a corresponding filter frame 122. The coarse filters 124 may be reusable or replaced after use.

In another aspect, the coarse filter arrangement can be constructed similarly to the condensate trap device. For example, the coarse filter may similarly be a circulating or movably mounted coarse filter through which the airflow 214 flows. There is no need to control the temperature of the coarse filter here. In addition, provision may also be made for a cleaning element (for example a compressed air nozzle for blowing out the coarse filter, a scraper and/or a brush for mechanically cleaning the coarse filter and/or the like) which cleans the coarse filter as it is guided past the cleaning element.

FIG. 5 shows a highly schematic illustration of a machine 1 for producing a material web 10 which comprises a plurality of different machines and devices. In the example shown, the machine 1 is a film stretching machine, the disclosure being explained by way of example by reference thereto-without limiting the scope of protection.

In this case, the material web 10 is a plastic film. In the example shown, the machine 1 has an extrusion machine 12, a casting roller machine 14, at least one stretching machine 20—such as a longitudinal stretching machine 21 (MDO, “Machine Direction Orienter”) and/or a transverse stretching machine 22 (TDO, “Transverse Direction Orienter”)—a drawing roller machine 16, and a winding machine 18.

The film produced is, for example, a biaxially stretched film, such as polypropylene film (BO-PP), polyethylene terephthalate film (BO-PET), polyamide film (BO-PA), polyethylene film (BO-PE), polylactide film (BO-PLA), capacitor film (BOPP-C) or battery separator film (BSF).

To produce the plastic film 10, a film is generated on the cooling roller of a casting roller machine 14 using the extrusion machine 12. For this purpose, the extrusion machine 12 generates a melt from starting materials, such as granules, which is applied to the cooling roller, thereby generating the film.

This film is conveyed as a material web 10 from the casting roller machine 14 to the longitudinal stretching machine 21 which is part of a stretching machine 20. In the longitudinal stretching machine 21, the film is stretched longitudinally to produce a film.

In the longitudinal stretching machine 21, the film runs over a plurality of heated rollers in order to bring the film to the desired temperature. The film can also be stretched longitudinally over the rollers.

Stretching takes place in the longitudinal direction, i.e. in the take-off direction, between at least two of the rollers present in the longitudinal stretching machine 21 so that the cast film becomes a monoaxially stretched film.

The film obtained is conveyed from the longitudinal stretching machine 21 to the transverse stretching machine 22 where it is stretched transversely.

The transverse stretching machine 22 has an oven 32 with various zones for treating the film along the take-off direction A of the machine 10.

The film is heated in the first zone, also called the preheating zone 23. In the subsequent second zone 24 (“stretching zone”), the film is stretched in the transverse direction so that it is wider and less thick at the end of the second zone than at the beginning.

After stretching, the film then passes through the third and further zones 25 (called the “heat treatment zone”, “further heating zone” and/or “annealing zone”), where, for example, the film can be relaxed at high temperatures.

The film then passes through a further zone 26 (“cooling zone”), the film being cooled in the last zone.

A further zone is called the neutral zone and serves to separate zones. The neutral zone is, for example, an empty space without ventilation.

The zones of the transverse stretching machines 22 can also be divided differently and/or designed differently in terms of their length. For example, fewer or shorter neutral zones can be provided, or the neutral zones can be arranged, even additionally, in other locations. Changes to the remaining zones are also conceivable.

After the transverse stretching machine 22, the now biaxially (longitudinally and transversely) stretched film 10 now passes through the drawing roller machine 16 and is wound up by the winding machine 18.

It is also conceivable for the machine 10 to be designed in a different way, for example as a stretching machine having a simultaneous stretching machine with an oven as an alternative to or in addition to the longitudinal stretching machine 21 and/or the transverse stretching machine 22.

The transverse stretching machine 22 or its oven and in particular the preheating zone 23, the stretching zone 24, the at least one annealing zone 25 and/or the at least one cooling zone 26 can be ventilated or vented via the air purification system 2 described. FIGS. 3A and 3B schematically show such an air purification system which can be used to ventilate or vent the cooling zone 26. The condensate trap device 110 serves here to reduce the contaminant concentration in the oven air and thus improve the quality of the film 10 and/or increase the service life of the machine 1.