EP1215457A2 - Device for easier defrosting of refrigerating apparatuses, particularly of air coolers - Google Patents

Abstract

The system is designed with a rotary joint (11), which has a central axis (20) of rotation connected rotation proof with one (12) of the lever arms, which is rotatable by means of a servo motor (21) fixed at the other lever arm (13) in such a manner. That the full adjusting power of the servo motor is transmittable on both lever arms (12,13), over the entire opening range of the knee lever (10).

Description

The invention relates to a device for easier defrosting of refrigeration Apparatus, in particular of air coolers, according to the preamble of claim 1 such a device is known for example from DE 31 18 600 A1.

Air coolers are often used in rooms with temperatures below 0 ° C. During the Operating such air coolers leads to ice accumulation on the heat transfer surfaces of the Heat exchanger. This ice formation has a negative effect on the heat transfer or Heat transfer coefficient, so that the overall heat transfer is deteriorated. Therefore, it is common practice to use the heat transfer surfaces, i.e. the heat exchanger surfaces, at predetermined intervals, for example by supplying electrical energy, gas or Warm water to thereby heat the ice formed on the heat transfer surfaces melt down. The fans are switched off during such a defrost phase. Despite If the fans come to a standstill, larger amounts of heat are applied during the defrosting phase given the environment. There is air circulation between the heat exchanger and the indoor air as well as inside the air cooler. The air circulation is particularly formed intensely on the side of the air cooler on which the one heated during the defrost phase Heat exchanger block is ultimately located in such an operation in High energy losses due to the unused amount of heat. It can also cause steam vapor formation and to a frosting in the immediate vicinity of the air cooler and on the air cooler come yourself.

To avoid these disadvantages, a device from DE 196 41 258 A1 known in which the defrost flap, called the door, the air cooler during the Defrost phase on the open side of the heat exchanger closes. In this known However, the device is the defrost flap with the knee lever in the manner of a door closer connected, i.e. the drive axis of the servomotor is at the end of one Lever arm of the knee lever, which is why the defrost flap can be closed, but on Because of the almost congruent parallelism of the two lever arms of the toggle lever in the Closing state not or not readily in the flow cross section of the Heat exchanger releasing operating position, i.e. Open position, is pivotable, because the torque that can be transmitted from the servomotor to the toggle lever is in the closed position the knee lever is too small. This disadvantage is counterbalanced compensated for that on the side of the axis of rotation opposite the defrost flap arranged and attached to the latter. With the defrost flap in the closed position The counterweight therefore does not protrude above the top of the heat exchanger inconsiderable dimension and is approximately at a right angle to it. It is therefore disadvantageous that such a device is not only a relatively large one Has space requirements, but is also structurally quite complex.

The invention is therefore based on the object of an input device to create the type mentioned, which is easier and more economical to handle and can be produced.

According to the invention, this object is achieved by a device with the features of Claim 1 solved.

Advantageous further developments are the subject of the subclaims.

Thereafter, the lever arms can have cross sections which are designed such that the one lever arm can be arranged within the other lever arm. On the one hand, this is the Lever mechanism strength increased. In addition, the lever arms guide the Adjusting the defrost flap against each other so that tilting of the lever arms is impossible is. Furthermore, the axis of rotation on two, opposite legs of the Cross-section be stored. This results in turning the axis of rotation and thus the one Lever arms relative to the other lever arm a good and safe power transmission. On Moving the axis of rotation is prevented as well as overstressing the bearings of the Rotary joint. One of the lever arms can be an extension projecting beyond the swivel joint have as a mutual stop of the lever arms in the operating position of the lever mechanism. So that is the lever mechanism in the operating position of the defrost flap on one which releases the flow cross section Sagging prevented On the one hand, by designing the extension as a stop, there is one Limitation of the opening angle of the lever mechanism to 180 ° possible, on the other hand can the lever mechanism can be arranged and designed with the aid of the stop so that the entire device is kept statically stable even in the operating position without the Actuator in the operating position to transmit forces to the lever arms.

According to an advantageous development of the invention, a lever mechanism is / are in each case on both sides next to the defrost flap or several lever mechanisms in the area of the defrost flap provided, wherein only one of the lever mechanisms has a servomotor and the Lever mechanisms are rotatably connected to each other via a linkage. The linkage prevents in particular bending the defrosting flap in all positions of the flap, except for the resting position. The linkage also enables a uniform opening and Close the defrost flap as it is held on both sides by a lever mechanism and can be operated. Even if the servomotor is arranged on one side, this is the same Applying the torque to both lever mechanisms, i.e. Toggle, possible.

According to another development of the invention, the linkage has a square tube that is attached to the defrost flap using brackets with round holes. Such a connection between the linkage and the defrost flap prevents freezing in a simple way, because the linkage is only in a few places on the bracket, so that even if this Contact points should be covered with ice or frost, the servomotor with its torque is still able to make such frozen connections between the above Elements to solve. This is the case with flat systems, for example with a peripheral one Surface contact, such as with a round tube in a round holder, is not always guaranteed.

Fig. 1

eine schematische teilweise Seitenansicht einer Vorrichtung zum leichteren Abtauen von kältetechnischen Apparaten, insbesondere von Luftkühlern, in der Ruhestellung sowie in der Betriebsstellung;

Fig. 2

eine schematische teilweise Seitenansicht der Vorrichtung in der Ruhestellung;

Fig. 3

eine schematische Seitenansicht der Vorrichtung in einer Zwischenstellung;

Fig. 4

eine schematische, perspektivische, teilweise Ansicht der Vorrichtung;

Fig. 5

eine schematische, perspektivische Detailansicht eines Hebelmechanismus der Vorrichtung; und

Fig. 6

eine schematische, teilweise geschnittene Vorderansicht einer Halterung der Vorrichtung.

Exemplary embodiments of the subject matter of the invention are explained in more detail below with reference to the drawing, in which:

Fig. 1

is a schematic partial side view of a device for easier defrosting refrigeration apparatus, in particular air coolers, in the rest position and in the operating position;

Fig. 2

a schematic partial side view of the device in the rest position;

Fig. 3

a schematic side view of the device in an intermediate position;

Fig. 4

a schematic, perspective, partial view of the device;

Fig. 5

a schematic, perspective detailed view of a lever mechanism of the device; and

Fig. 6

is a schematic, partially sectioned front view of a holder of the device.

A device 1 for easier defrosting of refrigeration apparatus, not shown in detail 2, in particular of air coolers, is schematic in a partial side view in FIG. 1 shown. The device 1 has a so-called defrost flap 3, which is transverse to the direction of flow of a flow cross section of the refrigeration apparatus 2 Medium, e.g. Gas or air.

The device 1 also has an adjusting device 4 which serves to defrost the flap 3 from its operating position which releases the flow cross-section, which is dashed in FIG. 1 is shown in its rest position closing the flow cross-section, which in FIG. 1 is shown in solid lines, and vice versa.

According to the invention, the adjusting device 4 has a lever mechanism 5, which on the one hand on the defrost flap 3 and on the other hand at least partially on the flow cross section surrounding housing part 6 is attached. The lever mechanism is in Fig. 1 with respect to the Rest position of the defrost flap 3 omitted for the sake of clarity and only in In relation to the operating position shown in dashed lines.

The defrost flap 3 is preferably made of insulated plastic and / or a composite material manufactured. The low density of the material used allows adjustment of the Defrost flap with as little effort as possible. The insulated design of the flap prevents ice build-up during and between defrosting phases.

The defrost flap 3 shown in its rest position in solid lines in FIG. 1 is on their upper end pivotally mounted about a horizontal axis of rotation 7.

According to a first embodiment of the invention, the lever mechanism 5 has a laterally next to the defrost flap 3 arranged toggle lever 10, which two over one Swivel joint 11 interconnected lever arms 12, 13 has. The free end 14 of one Lever arm 12 is articulated near the free end 15 of the defrost flap 3. The free end 16 of the other lever arm 13 is articulated in the lower half of the housing part 6. Unlike in Fig. 1, the free end 16 of the other lever arm 13 can also be close to the lower end of the Housing part 6 be articulated.

This means that the device according to the invention can also be used in existing refrigeration systems or devices can be retrofitted with relatively little effort. The articulation of the free end 14 of a lever arm 12 at the free end 15 of the defrost flap 3, that the plane going through the upper housing part 17 by the articulation is little or no is not towered over.

2 shows the device 1 in a partial side view in the rest position, the defrost flap is omitted for the sake of clarity.

3 the device according to the invention is indicated schematically in an intermediate position, in which the defrost flap 3 the flow cross section of the refrigeration not shown Apparatus 2 partially closed.

According to the perspective, schematic partial view of the toggle lever 10 in the area 5, the swivel 11 has a rotationally fixed with the one lever arm 12 connected axis of rotation 20. The lever arms 12, 13 have a U-shaped cross section. The U-shaped cross sections of the lever arms 12, 13 are designed such that one lever arm 12 can be arranged within the other lever arm 13, as shown in FIG. 5. The axis of rotation 20 is rotatably supported in legs of the U-shaped profile of the other lever arm 13 and rotatable by means of a servomotor 21 attached to the other lever arm 13. The Rotary motor 21 is indicated schematically in FIGS. 1 to 4 and, for example, via a Abutment 22 (see FIG. 5) firmly connected to the other lever arm 13. Not closer Shown axis of rotation of the servomotor 21 is non-rotatably on the axis of rotation 20.

3 and 5, the other lever arm 13 has a hinge 11 projecting above Extension 23, which acts as a mutual stop for the lever arms 12, 13 in the operating position of the lever mechanism 5 acts.

According to a second embodiment of the invention, there is a lever mechanism 5 in each case on both sides, d. H. provided on both sides, next to the defrost flap 3, whereby according to one preferred embodiment, only one of the lever mechanisms 5 has a servomotor 21 has and the lever mechanisms 5 rotatably connected to each other via a linkage 24 are. It is generally possible to use several lever mechanisms (5) in the area of the defrost flap (3) to be provided, which can also be constructed from a plurality of partial flaps arranged side by side can. Such an arrangement is shown schematically by way of example in FIG. 4, in the two together connected defrost flaps are shown. It is also possible, preferably in Dependence of the structure of the housing part, also between individual ones spaced apart Defrost flaps to provide one or more lever mechanisms. The linkage 24 connects the lever arms 12 of each lever mechanism 5 in a rotationally fixed manner, the Linkage is connected via brackets 25 to the outside 26 of the defrost flaps 3. each Bracket 25 is, according to the illustrated embodiment, an angle profile or according to a Not shown embodiment, a U-profile, the one leg of the angle profile on the outside 26 of each defrost flap 3 rests and the other with one leg connected legs of the angle profile approximately vertically from the outside 26 of each defrost flap projects. The vertically protruding leg of each bracket 25 has a through hole 27, through which the linkage 24 passes and in which it is rotatably mounted.

According to a particularly preferred embodiment of the invention, the linkage 24 is a Square tube 30, each in the through bores 27 formed as round bores Bracket 25 sits. A front view of such an arrangement is schematic and partial shown in section in Fig. 6. According to this figure, only the outer four are located Corner points 31 on the round through bore 27 of the holder 25. So that takes place in only few areas a point contact between the linkage 24 and the through hole 27 each bracket 25 instead, which between the linkage 24 and the brackets 25 existing friction is reduced. Such an arrangement also has the advantage that it generally does not freeze, which has a favorable effect on the operational safety of the invention Device affects. Fig. 6 shows that the square tube 30 has a square Cross section.

The outer ends of the linkage 24 can fit into a square hole at the free end 14 of each Lever arm 12 inserted or otherwise rotatably with the relevant lever arm be connected.

According to the schematic side view of part of the device in Fig. 2 are the lever arms 12, 13 of each toggle lever 10 are designed and arranged such that they are in the rest position of the lever mechanism 5 are approximately parallel to each other. This may require to build up the holder 25 sitting on the defrost flap higher than that on the housing part 6 attached bracket 32. In this case, dimension a according to FIG. 3 is larger than dimension b, from which it follows that the distance between the articulation of the lever arm 12 and the outside 26 of the defrost flap is greater than the distance between the articulation of the lever arm 13 and the outer, d. H. edge of the housing part 6 pointing towards the device 1.

It is also possible to provide the brackets 25 and 32 at different heights in such a way that, for example, the bracket 32 in the rest position of the lever mechanism above the Bracket 25 is arranged. Such an arrangement would result if the defrost flap 3 in Fig. 3 in the direction of arrow A is pivoted into the rest position, so that the Bracket 25 finally the dash-dotted position on the front edge of the housing part 6 accepts. In this case, the outer end 14 of the lever arm 12 projects in the rest position of the Lever mechanism 5 through the outer or lower end 16 of the lever arm 13 through below, so that the lever arms in the rest position a completely parallel position can take and thereby a complete closure of the flow cross section of the Refrigeration apparatus 2, not shown in more detail, is ensured by the defrost flap 3.

According to the exemplary embodiments shown, the device according to the invention is located 1 completely in the cold area of the system and is therefore a relatively constant temperature exposed. Furthermore, the device according to the invention is also in the operating position of its Lever mechanism not in full airflow, which is beneficial to the flow conditions and affects the operational safety of the device according to the invention. To that extent is the invention Device not in the aforementioned defrost phase of the air cooler Exposed to warm air.

As indicated in Fig. 2, the adjusting device 4 according to the invention, i. H. the lever mechanism 5, designed such that each toggle lever 10 in the idle state of the defrost flap saves space on the housing part 6 or on the refrigeration apparatus 2. When complete When the defrost flap is open, each extended toggle lever 10 according to FIG. 1 forms a stable diagonal Bracing between the process or refrigeration apparatus, for example that Air cooler, or its housing part 6 and the defrost flap 3.

The attachment and operation of each toggle lever 10 is chosen such that the leverage the static load when opening the defrost flap, d. H. when transferring the defrost flap in the operating position. The further the defrost flap opens, the larger it becomes the weight at the point of application of the lever arms, namely on the brackets 25 and 32. Je the further each toggle lever 10 opens, the greater the lever ratio is related to the positioning force of the servomotor 21.

As previously mentioned, the lever mechanism is in the rest position, in which the Defrost flap closes the flow cross section of the refrigeration apparatus 2, all movable elements of the device according to the invention outside the heated area. This also ensures that there is no steam on these elements can condense and the movable elements against freezing due to frost or Ice deposits are protected.

The device according to the invention works as follows.

The defrost flap 3 is usually located in the flow cross section of the refrigeration Apparatus 2 releasing operating position, which is shown in dashed lines in Fig. 1 is. As a result, the defrost flap 3 is approximately parallel to the direction of flow of the medium, such as. the air, according to arrow B in Fig. 1. The lever arms 12 and 13 of the toggle lever 10 are aligned with each other so that the toggle lever is maximum, i.e. H. is opened by 180 °. The servomotor 21 is in switched off this position.

For transferring the defrost flap from its operating position that releases the flow cross-section 1 into its rest position closing the flow cross section according to FIG Fig. 1 or 2, the servomotor 21 is actuated such that this the toggle lever 10 slowly closes and pivots the lever arms 12 and 13 to each other about the pivot 11, an intermediate position is shown in Fig. 3. Another actuation of the servomotor 21 has the consequence that this the defrost flap further in the direction of arrow A in Fig. 3 in the direction pivoted on the housing part 6 until finally the defrost flap the flow cross-section closes the apparatus and the lever mechanism its rest position shown in Fig. 2 occupies in which the lever arms 12 and 13 completely or at least partially into each other or folded together.

The engine can be switched off in the rest position as well as in the operating position of the defrost flap his. So the motor would only be under voltage if the Defrost flap is transferred from its operating position to its rest position or vice versa.

After the defrost phase is complete, the servomotor 21 is actuated again in such a way that the Lever arms 12, 13 of the toggle lever 11 by a pivoting movement of the lever arms around the Swivel joint 11 are pressed apart again, so that the lever mechanism finally again assumes its operating position shown in dashed lines in FIG. 1, in which the defrost flap 3 is again arranged parallel to the direction of flow B of the air.

According to an advantageous, not shown development of the invention is the lever mechanism 5 with a return spring, for example with a torsion spring around the swivel joint 11, provided which the defrost flap 3 automatically in the event of a power failure of the servomotor 21 transferred to the operating position. The lever arms 12, 13 of the toggle lever 10 can isosceles, d. H. the same length, for example 500 mm, but also with different Length. The device according to the invention can be used in different Flow cross-sections or flap sizes are used almost unchanged. The device can be in the immediate vicinity of or from the refrigeration apparatus spaced apart. In this respect, the housing part can itself be part of the refrigeration technology Apparatus or part of a flow channel for the flowing medium.

This is a device for easier defrosting of refrigeration equipment, in particular of air coolers, which is easier and more economical to use.

Claims (7)

Device for easier defrosting of refrigeration equipment (2), in particular air coolers,
with a defrosting flap (3) which is mounted transversely to the flow direction of the medium acting on a flow cross section of the refrigeration apparatus (2), and
with an adjustment device (4), with the aid of which the defrost flap (3) can be transferred from its operating position, which releases the flow cross section, to its rest position, which closes the flow cross section, and vice versa,
The adjusting device (4) has a lever mechanism (5) fastened on the one hand to the defrost flap (3) and on the other hand to a housing part (6) which at least partially surrounds the flow cross section and which has at least one toggle lever (10) arranged to the side of the defrost flap (3). of two lever arms (12, 13) connected to each other via a swivel joint (11), of which the free end (14) of one lever arm (12) at the free end (15) of the defrosting flap (3) and the free end (16 ) of the other lever arm (13) are articulated on the housing part (6), characterized in that the swivel joint (11) has a central axis of rotation (20) which is non-rotatably connected to the one lever arm (12) and which is connected to the other lever arm ( 13) attached servomotor (21) can be rotated such that the full positioning force of the servomotor (21) can be transmitted to both lever arms (12, 13) over the entire opening area of the toggle lever (10). Device according to claim 1, characterized in that the lever arms (12, 13) are designed such that one lever arm (12) can be arranged within the other lever arm (13) and an extension (23) projecting beyond the swivel joint (11) as a mutual Has stop of the lever arms in the operating position of the lever mechanism (5). Device according to claim 1 or 2, characterized in that the lever arms (12, 13) have a U-shaped cross section. Device according to one of claims 1-3, characterized in that a lever mechanism (5) is provided on both sides next to the defrosting flap (3). Device according to one of claims 1-3, characterized in that a plurality of lever mechanisms (5) are provided in the region of the defrost flap (3). Apparatus according to claim 5, characterized in that only one of the lever mechanisms (5) has a servomotor (21) and the lever mechanisms (5) are connected to one another in a rotationally fixed manner via a linkage (24). Apparatus according to claim 6, characterized in that the linkage (24) has a square tube (30) which is fastened to the defrost flap (3) by means of brackets (25) with round through bores (27).

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