DE1660629B2 - Device for heating up plastic threads - Google Patents

Description

The invention relates to a device for heating plastic threads in a false twisting machine with a plurality of threads, with double pipes running in the direction of the thread, through the space of which a heat transfer medium flows, and through the interior of which a thread runs a flow or return line for the heat transfer medium are connected. It is required of heating devices of the type mentioned that they always heat the individual thread to the same temperature as it passes through and keep it at this temperature for as long as possible, and that the heating of the various threads is kept as equal as possible.

It is therefore necessary to avoid dead spaces in the flow path of a heat transfer medium, in which impurities and / or air and water can collect when the system is filled and in which "standing lakes" of the heat transfer medium can form, and a flow that is as uniform and undisturbed as possible of the heat transfer medium through the system and in particular through the double pipes. Furthermore, it is necessary that the same amount of heat is supplied to all threads in the unit of time. Regardless of its distance from the heat source, the same amount of heat transfer medium at the same temperature must therefore flow through the double tube of each thread. Around 160 to 200 threads are treated in modern false twisting machines. This results in machine lengths of, for example, 12 to 15 m. Furthermore, the throughput speeds of the threads through these machines are relatively high. The lengths of modern machines and the relatively high throughput speeds of the threads therefore make it difficult in some circumstances to meet the requirements mentioned

In a known device according to Swiss patent specification 314606, the heat transfer medium in the area of the double tube already penetrated by the thread is fed in at a single point along the circumference and discharged again at a single, different point, with the narrowed cross-sections of the feed or discharge line form throttling points . With this type of supply or removal of the heat transfer medium, there is a considerable amount of dead space for the flow. DariiK also causes the throttling points to flow directly into those already interspersed with threads

ao pipes or double pipes both at the inlet aK also at the exit point significant disruptions di.s even flow, which also lead to dead spaces. As is well known in this "Standing" heat transfer medium cools down because it

»5 is not replaced by a permanent stream a uniform heating of the threads is not guaranteed in this known device.

The supply of the heat transfer medium is required for the device according to the Austrian patent

font 185 286 in the same way, so that 'lic same disadvantages with this known device available. In addition, because of the pressure and temperature drops in the pipes, it is one for everyone Threads with the same heating with the known arrangement according to the aforementioned Austrian Patent hardly achievable.

The present invention is therefore based on the object for the heat transfer medium heating up the threads To create a pipeline system in which none of the flow is not or only insufficiently interspersed dead spaces are present, and in which the uniform flow is as little as possible by deflections and changes in cross-section, at least in the area H: s thread passage, is disturbed. In addition, it should be ensured by the invention that each thread, independently of its relative position to the heat source, of the same. Amounts of heating medium is flushed around, if possible has largely the same temperature everywhere.

This object is achieved by the invention specified in claim 1. Refinements of the invention are described in claim 2.

The invention is described below using an exemplary embodiment in connection with Drawing explained in more detail.

F i g. 1 shows in a section I-I of FIG. 2 den Construction of a cell perpendicular to the frame plane of the cell;

F i g. 2 is section II-II of FIG. 1 and represents a radiator combining several cells, while

F i g. 3 schematically the structure of the radiator group of two machines with the associated conveyor system for the heat transfer medium.

Every two threads 1 pass through a cell 2 (FIG. 1) from top to bottom. As when heating the threads 1 are deposited from this binder, which is in the cooler areas of the heating

soy. i.e. near the thread entry point and the At the thread exit, each thread 1 is initially taken from an insert tube 3 in a known manner surrounded, which is pushed into the inner tubes 4 of the double tubes designed according to the invention. The insert tubes 3 consist, for. B. made of aluminum. They are fitted into the inner tubes 4 so that when the heating and expansion a good heat conducting connection with the inner wall of the tubes 4 results. The tubes 3 are replaced at certain time intervals when they are dirty.

The inner tubes 4 are surrounded at a certain distance from the outer tubes 5, so that a heat transfer medium, for. B. a synthetic high temperature oil can circulate. The selection of the oil depends on the desired heating temperature. Since its evaporation point must be above this temperature, it is advisable to choose oils. whose evaporation temperatures at atmospheric pressure are in the range "or 330 to 350" C '. Since the heat content of the oils is proportional to the specific gravity and the specific heat, it is advantageous if the calculation value specific gravity times specific heat is high so that only a smaller amount of oil has to be kept in um-knit.

The two double pipes 4, 5 are each connected to a connecting pipe at their upper and lower ends 6 and 7 connected to one another to form the frame-like cell 2, the outer tubes 5 according to the invention with the surfaces on the inside of the frame and the inner tubes with the outside of the frame Surfaces of the connecting pipes 6 and 7 are welded. Furthermore, according to the invention protrude beyond the connecting pipe pieces G and 7 the outer tubes S to both sides in the horizontal direction and are on their ends are closed by end caps 8.

In the middle between the two double pipes 4, 5 open into the connecting pipes 6 and 7 at their lowest or highest point 9 or 10 Robrstückr 11, which the cell 2 to the distribution line 12 and connect the collecting line 13 door to the heat transfer medium.

The formation of the connecting pipes 6 and 7 with horizontal E.iden, their described according to the invention Connection with the double pipes 4, 5 and the arrangement of the junctions of the pipe sections 11 at the highest or lowest point of the connecting pipes 6 and 7 serve the special task in which System in which the heat transfer oil circulates, Τι ι-rooms to avoid that, even after the system has been filled with the heat transfer medium, there are impurities, Water or air, can deposit. By the arrangement according to the invention, in which no pockets and Wells are present, the mentioned foreign stage, which an even circulation of the Disturb the heat transfer medium and an equally high heat transfer from the heat transfer medium to the pipe sections or cause steam hammer when filling the system through the bottom up if possible oil that rises and reaches every nook and cranny are washed out; because at the transition from a horizontal to a vertical part of the cell 2 and to the distribution or collecting line 12 and 13 it is ensured that the transition point is always in the highest or lowest point of the horizontal Parts lies.

The Rohrstücki 11, which are designed as throttle tubes, but can also consist of tubes of wider diameter with built-in throttling points, have the task of uniformly distributing the heat transfer medium to the individual cells? a radiator 14 (FIG. 2) without the need for special regulating organs. The high flow resistance of the pipe sections II ensures that there is equal pressure at all branches to the individual cells 2 of a heater 14 in the distribution line 12 and in the collecting line 13.

As can be seen from Fig. 2, the distribution line 12 and the collecting line 13 consist of horizontal tubes extending over the entire length of the radiator, which are closed at one end with a cap, while at the other end the connecting lines IS and 16 open out to the for the whole Mas <_, iine common flow and return line system 18,19 (Fig. 3) The lines 15 and 16, which are designed as throttle tubes for the radiator 14, Ληά to avoid any dead spaces eccentrically to the distribution or collecting line 12 or 13 connected.

The entire radiator 14 consists of several, connected to the same distribution or collecting line, cells 2 combined to form pairs and is provided with a common high-quality insulation 17. z. B. made of mineral wool, enclosed. The collecting line, which is partially embedded in its own insulation layer 13 can be used via brackets, not shown, the individual radiator 14 in the To fasten textile machine, then on the distribution line 12 also not shown guide elements are provided that prevent the suspended radiators 14 from swinging in the textile machine.

The scheme of FIG. 3 shows an example of how several, for example, all to two textile machines belonging radiator 14 combined into a group and ^ n the main line system 26,27, in which a heat source, not shown is arranged, can be connected.

Each radiator group forms a closed circulation system for the heat transfer medium !, whereby this from the feed pump 20 through the flow line 18, the individual heating elements 14, the return line 19 and leading to a mixer pipe 21 lying in the flow line 18, with a Non-return valve 22 provided branch line 23 is circulated. The delivery pressure in this system is depending on the extent of the system z. B. about 5 to 8 atü. The temperature of the flow 18 is controlled by a temperature sensor 24, on which a target value can be set, e.g. on a Temperature of 220 "C kept in such a way that from the return line 19 via a through the temperature sensor 24 influenced control valve 25 led away a relatively small amount from the machine circuit and to a heat source not shown, e.g. B. a boiler, leading return main line 26 is fed in, while at the same time the same portion from the flow line 27 with a temperature of about 280 to 290 ° C through a filter 28 and the mixing tube 21 to the machine circuit is newly supplied. The control valve 25 in the return line 19 is of the one with a manual control valve provided bypass line 30 bridged, so that the system in the event of malfunctions or failure of the regular

treatment can also be kept at the desired temperature by hand. Another bypass line 32 with the closure member 33, the filter 28 can short-circuit in order to clean it during to enable the operation from time to time.

A commercially available centrifugal pump with a mechanical seal is particularly suitable as the feed pump 20, because these pumps have very low leakage losses. A bi-metal element, for example, can be used as the temperature sensor24 to serve. Electro-pneumatically controlled organs are advantageously used for the regulation, because these take effect relatively quickly, i.e. without a major default.

The circulation system of the machine circuit, without the connections 18 and partly 19 to the Main lines 26, 27 are designed so that the amount of oil circulated per unit of time is about 20 times as large the amount supplied or withdrawn from the supply network is 27.26. Furthermore, the temperatures should of the heat transfer oil at the system inlet and at the system outlet not more than 2 ° C from each other differ.

As already mentioned, the selection of the heat transfer medium depends on the maximum temperature to be reached. Both the radiators 14 and all associated supply and discharge pipes are to produce from appropriately temperature-resistant pipes, with z. B. for temperatures below 300 ° C Pipes made of St. 35.29 and from 300 ° C to 400 ° C pipes from St. 35.8 should be used.

The structure according to the invention of the radiator 14 from individual frame-like cells 2, which in their parts traversed by the threads 1 are designed as double tubes 4, S, furthermore allows with

jo get by with a relatively small amount of heat transfer medium. Furthermore, the long way ensures the the threads 1 in the lying between the connecting tubes 6 and 7, in their entire length at almost the same temperature

cover ren4,5, an even temperature of the threads 1 over a long distance, which could not be achieved with previous arrangements. By installing the throttle tubes 11 between the lines 12 or 13 and the connecting tubes 6

ao and 7 guarantee a uniform pressure distribution in the distribution and collecting lines 12 and 13, which ensures that the individual cells 2 are ^{exposed to the same amount of heat without p} - special regulating elements being provided for this purpose

as must.

1 sheet of drawings

Claims (2)

Patent claims: 1. Device for heating plastic thread in a false twisting machine with a multitude of threads, with double tubes running in the thread direction, through the space between which a heat transfer medium flows, and through the interior of which a thread runs . Return line for the heat transfer medium are connected, characterized in that two double pipes (4, 5) are connected to one another by cross connections to form a frame-like cell (2), and that furthermore the cross connections αετ cell (2) as horizontal ·, via the outer pipes (5) protruding connecting tubes (6, 7) closed at both ends are formed, which at their lowest (S ¹ ) or highest (10) point via connections (11) each containing a throttle point with a distribution (12) or collecting line (13) connected s: .nd. 2. Device according to claim 1, characterized in that in each case a number of cells (2) are combined to form a heating element (14), the individual heating elements (14) each having their own distribution (12, 15) or collecting line (13 , 16) are connected in parallel to the Voi (18) or return line (19) for the heat transfer medium, and that ft.ner each radiator (14) with its distribution (12) and collecting line (13) is enclosed by its own insulation is.