JPS6342760A - Blow device blowing treating medium against beltlike product moving in longitudinal direction - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a web-shaped product which is moved longitudinally by means of nozzle passages which are arranged at right angles to the upper and lower sides of the web-shaped product and are provided with blow nozzles. This invention relates to a blowing device for blowing a treatment medium.

[Prior Art] In such blowing devices, a gaseous treatment medium is generally introduced into the nozzle passage from one side by a blower and is blown onto the surface of the product through a slit-like nozzle opening extending across the width of the product strip. .

A device for heat-treating strip products with a stream of air is described, for example, in German Patent Application No. 1 Ql 1020. In this case, the air flow is conducted through a ventilation box or nozzle box, which is provided with slot-like or slot-like air outlet nozzles on the upper or lower side. The airflow supply to the nozzle box takes place from one end face thereof and is controlled by a regulating flapper. The cross-sectional area of the nozzle box is either the same from the air population to the free end of the nozzle box, or is reduced for a given purpose. In the case of such ventilation boxes or nozzle boxes with the same cross-sectional area, an adjusting flap is provided in each box, which divides the internal chamber of the nozzle channel into an upper and a lower partial chamber. The upper partial chamber has an upwardly directed air outlet nozzle, and the lower partial chamber has a downwardly directed air outlet nozzle. The adjusting flapper can be pivoted about a pivot axis which extends parallel to the product strip approximately in the center of the nozzle channel. In this way, depending on the position of the adjusting flapper, the treatment medium is blown upwardly or downwardly from the same ventilation box or nozzle box.

When the adjusting flapper is in an intermediate position approximately parallel to the plane of the web, it forms an intermediate wall for the nozzle passage, with half of the airflow directed to the L-oriented air outlet nozzle and the other half directed downwardly. The air is guided to the outflow nozzle. The nozzle passage formed in this way is
The air stream is selectively used to treat the web extending from below on the first side, from below the web extending below the nozzle passageway, or from both simultaneously.

However, such nozzle channels, for example nozzle fingers which are supplied with gaseous treatment medium from one side, do not flow uniformly out of the nozzle opening over the length of the slit of the blow nozzle. This undesirable characteristic also occurs if the nozzle passage has a slope, ie the cross-sectional area of the nozzle passage becomes smaller and smaller when viewed from the inlet side of the treatment medium. Depending on the flow into the nozzle box or nozzle finger,
Further disturbances of the outlet velocity distribution in the nozzle occur due to the horizontally incoming gas flow, due to the jet action, and also due to the formation of swirls.

In order to eliminate this drawback and to ensure a uniform distribution of the outflow velocity from the nozzle, a braid, for example a perforated plate, is installed in the nozzle passage.
Guide plates or dams are provided. However, this improvement measure had to be individually tailored to the nozzle structure or nozzle schedule.

For this purpose, for example, German Patent No. 300 775
No. 2 discloses dividing the nozzle finger into two dam chambers located one above the other in order to improve the flow characteristics.

A corrugated cover is then provided over the slotted nozzle, the edges of which are partially covered on the upper and lower sides by partitions. The flow conditions between the upper and lower dam chambers are stabilized by both dam chambers located above and below and by several diversions of the gas flow before leaving the nozzle, so that the flow from the nozzle is The outflow of the treatment medium is made very uniform.

A disadvantage of this known device is that the structure inside the nozzle finger is very complex. Furthermore, as mentioned above, the known devices always have to be adapted to the facts or conditions of the current application situation. In that case, the outflow situation can only be corrected within a narrow range.

[Problem that the invention seeks to solve]

The object of the invention is to provide a side-fed system which does not require any special braiding and is such that the velocity distribution of the exiting gas stream is as uniform as possible along the slit nozzle, regardless of the dimensions or construction of the nozzle. An object of the present invention is to provide a blowing device using a nozzle box.

[Means for solving problems]

According to the invention, this object is achieved by the measures specified in the characterizing part of claim 1. Advantageous embodiments of the invention are described in the claims.

[Effect]

By forming an overflow passage, approximately ±6%
It was possible to reduce the velocity distribution to approximately ±1.7%, ie to a very small value, and to a substantially uniform value. The invention can be employed, for example, in nozzle passages of arbitrary dimensions in length and width, and in structures and devices of different geometries, in particular in each nozzle finger, located one behind the other in the direction of product conveyance. It can be used just as well as a nozzle box that has multiple nozzle gaps that extend to . The intermediate wall, which forms a special overflow passage in the nozzle box, can extend along the outer wall of the nozzle box, and in the nozzle passage from the inlet side of the treatment medium (possibly via a slit cover) the intermediate wall can be extended. It is only important that the flow to the blow nozzle occurs without the need for penetration. The intermediate wall, with its balancing opening, serves only to balance the local pressure differences in the main channel caused by different exit velocities of the processing medium from the slit nozzle. Due to this balance, the outflow velocity from the blow nozzle is also uniformly distributed. Since the different outflow velocities for the treatment medium mainly occur only in the start and end areas of the nozzle passage, the balancing openings do not have to be uniformly distributed over the entire length of the intermediate wall, but are often located in the nozzle box. It is sufficient to provide the balancing openings in the intermediate wall in the starting region on the inlet side and in the opposite end region. There is a closed intermediate wall section between both regions with especially uniformly distributed balancing openings. The distribution of the balancing openings can then be different in both ranges.

〔Example〕

Embodiments of the present invention will now be described in detail with reference to the drawings.

The drawing shows a nozzle finger 1 with a ceiling wall 2 and two side walls 3 as boundary walls. A slit nozzle 6 is arranged on the bottom wall 4 of the nozzle finger 1, and corrugated slit covers 4a, which are known per se, are arranged at the starting and ending ends of the slit nozzle 6. In the following, the term "slit nozzle" also includes a number of single nozzles in series. The supply of treatment medium to the nozzle finger 1 takes place from the left side, as indicated by the three arrows E. Circulation of the treatment medium is effected in a known manner by means of a circulation fan (not shown). The processing medium introduced into the nozzle finger 1 flows out from the slit nozzle 6 in a direction,
In that case, it collides with the strip-shaped product 9 shown by the dashed line. The conveyance direction of the latent product 9 is indicated by an arrow T. The flow rate of the processing medium from the nozzle 6 is represented by an arrow and its length. The nozzle finger 1 in this embodiment has a slope, ie the cross-sectional area gradually decreases from the inlet side E.

An intermediate wall 5 is arranged inside the nozzle finger 1 along the wall of the nozzle finger 1, in particular along the ceiling wall 2. The ceiling wall 2 forms a stationary overflow passage 10 together with the intermediate wall 5 and parts of the side walls 3 on both sides. In this embodiment, the intermediate wall 5 is preferably provided with balancing openings distributed uniformly. The total opening area of all balancing openings in the intermediate wall 5 must be equal to or somewhat larger than the total opening area of all nozzle openings. For example, a perforated plate is used as the intermediate wall. intermediate wall 5
Alternatively, the balance opening in the perforated plate may be the intermediate wall 5.
Balance the pressure between the space of the overflow passage located on the 1- side of the nozzle finger 1 and the remaining space of the nozzle finger 1 located below the intermediate wall 5. The end face of the overflow channel 10 at the inlet point E is then closed off by a wall 7 in order to prevent the processing medium from flowing out directly to the outside. Similarly, the opposite end of the overflow channel 10 is closed off by a wall 8.

This arrangement structure is suitable for gas containers with uniform static pressure.
It is based on the idea that flow occurs only when the pressure changes at any given point. Flow then occurs towards points of lower pressure. By inserting the intermediate wall 5 into the nozzle finger 1, a structure is created which acts as a stationary overflow passage in a dual sense.

As is customary during operation, the nozzle passage is fed from the artificial side E and is flowed through. The introduced treatment medium flows out through the nozzle 6 towards the -C strip product 9. 1 - the stationary overflow passage mentioned above] 0 is separated by an intermediate wall 5 from the actual nozzle which is dynamically flushed. In accordance with the principle of "action-reaction", a location with a large outflow velocity in the nozzle passage produces a larger static pressure than a location with a small ME exit velocity. Due to the somewhat lower velocity of the medium exiting at a location, a small pressure difference Δp1<Δp2 with respect to the surroundings occurs, in which case the balancing opening in the intermediate wall 5 causes a pressure difference as indicated by the arrow in the intermediate wall 5. The balance is done.

Compensation of speed differences or static pressure differences therefore takes place in the overflow channel. The static pressure is equalized and converted to dynamic pressure, and thus velocity, at the nozzle.

The incorporation of the intermediate wall 5 in the form of the stationary overflow channel 10 is simple and quick in all cases. In that case, the geometric 1=j law analogy for the intermediate wall is that the distance from the ceiling wall 2 or the area of the balancing opening comparable to the cross-sectional area of the nozzle opening are not particularly strict, and a large play is allowed with respect to the structure. It will be done. That is, it is conceivable that the overflow passage has a uniform cross-sectional area, for example, or that the cross-sectional area of the overflow passage decreases along its extent, without significantly reducing the effectiveness of the invention. .

Different embodiments are shown in FIGS. 3 and 4. These figures show that the invention is not only suitable for simple nozzle passages, but also for nozzle passages of different constructions.

The basic structure is the same as that shown in FIGS. 1 and 2. In FIGS. 3 and 4, a nozzle box 16 with a number of parallel slit nozzles is shown in longitudinal and cross-sectional views, respectively.

. : ; )-shaped product 9 is indicated by a dash-dot line, in which case the transport direction is also indicated by an arrow T in FIG. 4 . As is clear from FIG.
It has a uniform cross-sectional area up to the end at the end face wall 8. The ceiling wall and side walls of the nozzle box] 6 are again designated by numerals 2 and 3. The nozzle box is open on the inlet side E for feeding the treatment medium indicated by the arrow.

Viewed in the transport direction T, the nozzle box 16 has a number of consecutive nozzles 6.6a, 6b, which are formed by the inclined wall 4 and are slit nozzles. The actual nozzle channel through which the main flow of the treatment medium flows is designated by the reference numeral 11. An intermediate wall 5 is provided along the ceiling wall 2, and the intermediate wall 5 forms an overflow passage 10 by the ceiling wall 2 and a portion of both side walls 3. This overflow channel 10 is closed off at both end faces by walls 7, 8, so that no treatment medium can flow directly into the overflow channel 10 from the inlet or exit again.

The embodiments shown in FIGS. 3 and 4 are based on the recognition that there is a difference in the flow rate of the treatment medium from the nozzle mainly in the start and end regions of the nozzle box, and that the difference is small in the central region. . Therefore, in many cases it is sufficient for a balance flow to occur in both of these outer regions. For this reason, in FIGS. 3 and 4 the intermediate wall 5 is divided into three parts 5a, 5b, 5c.

The section 5a on the artificial side E and the section 5b at the opposite end of the nozzle box 11 are provided with balancing openings. Between these parts 5a, 5b is located an intermediate wall part 5C which does not have a balancing opening. In FIG. 3, the different outflow velocities from the nozzle 6 are indicated by arrows of different lengths in the three intermediate wall sections, labeled vl, v2. The corresponding pressure differences are designated Δp1 and Δp2, in which case Δpl<Δp2 and therefore vl<
A v2 relationship also arises. A balance flow therefore occurs in the direction of the arrow from the range Δp2 through the balancing opening in the intermediate wall section 5a and the overflow passage 10 to the balancing opening in the intermediate wall section 5b. This pressure balance balances the velocity distribution along the width of the slit nozzle 6.

It should be noted that the dimensions of the two intermediate wall portions 5a, 5b do not necessarily have to be the same, and the distribution of the outflow openings can also be different within these ranges.

The total area of all the balancing openings in the parts 5a, 5b need not be related to the total opening area of the nozzle, but may be approximately the same as the total area of the nozzle openings in the starting end range or the ending range affected by the balance of the nozzle box. This allows it to be made somewhat larger. Balancing takes place not only along the width of the slit nozzles, but also between successive nozzles 6.6a, 6b in the transport direction T of the strip product.

5, 6 and 7 show further advantageous embodiments employing the invention in many ways. In this case, FIG. 5 is a sectional view taken along line A-A in FIG. 6, and FIG.
It is a sectional view along the BB line in a figure. Band-shaped product 9
is indicated by a dashed line, and its transport direction is indicated by an arrow T. In FIG. 7, the strip-shaped product 9 is shown in broken lines. This embodiment is based on the above-mentioned German Patent No. 30
The starting point is a nozzle finger 15 as described in JP-A-47752. The ceiling and side walls of the nozzle finger 15 are labeled 2°3. A horizontal partition 12.13 is arranged in the lower part of the side wall 3, between which a corrugated cover 4a is located. The side walls 3 are followed by inclined outer walls 14 below the horizontal partition 13, which side walls 14 form nozzle gaps 6 at their ends. The corrugations of the cover 4a extend perpendicularly to the direction of the nozzle gap 6.

The nozzle finger is connected to the upper dam chamber 11a and the dam chamber 11 located in front of the nozzle 6 by the cover 4a.
It is divided into b. An intermediate wall 5 is arranged between the inner free end of the horizontal partition 13 and the inclined outer wall 14 associated therewith, which extends approximately vertically and is oriented toward the nozzle gap 6. facing parallel. The intermediate wall 5 extends from the inlet side of the nozzle finger to its end. The intermediate wall 5, the partition wall 13, and the outer wall 14 form an overflow passage 10 having a triangular cross section on the left and right sides of the nozzle gap 6. The intermediate wall 5 is divided into parts with and without a balancing opening. The overflow channel] 0 is closed by a wall 7 on the inlet side E of the nozzle finger and by a wall 8 on the opposite side, so that a direct inflow or outflow of the treatment medium into the overflow channel 10 is prevented. In FIG. 7, the starting end range 5a and the ending end range 5b of the intermediate wall 5
is equipped with an opening for balance flow through. Between these areas 5a and 5b there is an intermediate wall portion that does not have a balancing opening. The differential pressures Δp1 and Δp2 and the corresponding different outflow velocities vl, v2 are shown. In this case, the relationship Δpl<Δp2 or vl<v2 occurs. In FIG. 7, the balance flow flowing from the range Δp2 through the overflow passage 10 to the range Δp] is indicated by an arrow. Of course, an intermediate wall with balancing openings along the entire length can also be used.

In the embodiments described above, it is immaterial whether the nozzle finger has a decreasing or constant cross-sectional area over its entire length (as shown in FIG. 5). If the intermediate wall 5 is provided with balancing openings locally or in its entirety, in which case these openings are approximately uniformly distributed in the area in question, then the balancing openings, which are comparable to the nozzle opening area, are The condition regarding total area is automatically satisfied.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a nozzle finger with a slope, Figure 2 is a cross-sectional view of the nozzle finger in Figure 1, Figure 3 is a vertical cross-sectional view of a nozzle box with many nozzle slits, and Figure 4 is a vertical cross-sectional view of a nozzle box with many nozzle slits. The figure is a cross-sectional view of the nozzle box in Figure 3.
The figure is a longitudinal cross-sectional view of different embodiments of the nozzle finger (a cross-sectional view taken along line A-A in Figure 6).
A cross-sectional view of the nozzle finger in the figure, FIG.
It is a sectional view along the BB line in a figure. DESCRIPTION OF SYMBOLS 1... Nozzle passage, 2... Side wall, 3... Side wall, 5... Intermediate wall, 6... Nozzle, 7... End wall, 8...
... End wall, 1 [] ... Overflow passage, 13.
... Partition wall, 14 ... Outer wall, 15 ... Nozzle passage,
16... Nozzle box. Applicant's representative Sato-Yu FIG, 5 A←--゛FIG, 6

Claims (1)

[Claims] 1. Blow nozzles are arranged at right angles to the upper and lower sides of the strip-shaped product, and the processing medium is applied to the strip-shaped product moving in the longitudinal direction by a nozzle passageway into which the processing medium is supplied from one side. In a blowing device for blowing, especially for film tentering, a nozzle opening (6
), an intermediate wall (5) is arranged along the wall (e.g. ceiling wall 2) which, together with the outer walls (2, 3) of the nozzle passage (1), forms an overflow passage (10); (5) is provided with balancing openings distributed at least in a first region (5a) on the inlet side (E) of the treatment medium and in a second region (5b) on the opposite side, in which case the overflow passage ( 10) A blowing device for blowing a treatment medium onto a longitudinally moving strip-like product, characterized in that the blowing device 10) is closed at both end faces thereof to prevent direct passage of the treatment medium. 2. Device according to claim 1, characterized in that the intermediate wall (5) is provided with balancing openings over its entire length. 3. Claim characterized in that the overflow channels (10) are arranged with approximately the same cross-sectional area along the wall (2) located opposite the blow nozzle (6) of the nozzle channel (1) The device according to item 1 or 2. 4. The total area of the balance opening in the intermediate wall (5) is
4. Device according to claim 1, characterized in that the total opening area of the nozzle (6) affected by the balance flow is equal to or larger than the total opening area of the nozzle (6). 5. A nozzle box (1
6). Device according to any one of claims 1 to 4, characterized in that: 6) is used. 6. The device according to any one of claims 1 to 4, characterized in that a nozzle finger (1) with a slit-shaped blow nozzle (6) is used. 7. The nozzle finger is divided into an upper dam chamber and a lower dam chamber by a corrugated cover placed on the horizontal partition wall, and the lower dam chamber on the side of the slit-shaped blow nozzle continues to the partition wall and blows. In a blowing device which is laterally bounded by an outer wall extending obliquely to the nozzle, there is a substantially perpendicular 7. Device according to claim 6, characterized in that an intermediate wall (5) is arranged extending parallel to the blow nozzle (6). 8. The nozzle passages (1, 15) are connected to the processing medium inlet side (E
8. Device according to claim 1, characterized in that the cross-sectional area decreases starting from ).