Background of the invention

The invention relates to a tempering device by which the temperature of a tempering target can be influenced .

Furthermore the invention relates to a method for tempering a target .

The obj ect of the invention is described in more detail in the preambles of independent claims of the application .

In various research and process apparatuses it is necessary to use temperature-regulated piping for example to keep the examined substances fluid or to adj ust initial temperature of a reaction temperature . In the current solutions , some drawbacks have however been observed, such as the di f ficulty to build the heating system as well as challenges related to accurate adj usting of the temperature and reaching a suf ficient temperature .

Brief description of the invention

The idea of the invention is to provide a new and improved device and method for tempering desired targets .

The characteristic features of the device according to the invention are presented in a characteri zing part of the independent device claim .

The characteristic features of the method according to the invention are presented in a characteri zing part of the independent method claim .

The idea of the solution as disclosed is to use a tempering device for tempering, i . e . heating, cooling or maintaining a current temperature , of a selected target .

A tempering device for influencing temperature of a tempering target comprises at least one elongated prof ile element that is made of elastic thermal ly conductive material . A cross-section of the profile element comprises at least one tempering space that is arranged to receive means for influencing the temperature . Additionally, the profile element has at least one thermal trans fer surface that i s arrangeable against the tempering target .

Thereby temperature-regulated piping can be built , or already existing piping can be converted to temperature- regulated piping by installing in connection with one or more piping components of the piping a profile element presented in this document with its equipment .

By means of tempering, for example a substance inside a tempering target can be kept fluid or initial temperature of a reagent can be adj usted .

The elastic material facilitates installing of the profile element . Because of good thermal conductivity, the thermal trans fer can be achieved uni formly without thermal point loads .

The tempering target may be an element , a component or a piping component of piping, a process apparatus or a corresponding system or device . The tempering targets may be for example the following : pipe ; process pipe ; pipe o f a research apparatus ; valve ; elbow fitting; branch piece , such as T-piece or Y-piece ; container; expansion tank; pressure accumulator ; filter .

The idea o f one embodiment is that the profile element is formed by cutting from a long profile preform . The profile preform may be a bar-type piece , or it may be a wound or rolled preform from which a profile preform in a desired length for a particular purpose can be cut . The advantage of this embodiment is that the profile elements can be formed easily and in a flexible manner . Making the profile preform in industrial production is af fordable in terms of costs . Cutting the elastic profile element to a suitable length is easy and quick by normal hand tools .

The idea o f one embodiment is that the profile element has a target space in which the tempering target is intended to be arranged . This target space may be si zed so that it is suitable for receiving several targets of di fferent si zes . Additionally, because of the elastic material , however, the target space may settle snugly against the target and thus ensure good thermal trans fer . Also this feature i s advantageous in terms of operation and a factor increasing functional flexibility .

The idea of one embodiment is that said at least one tempering space extends from a first end of the profile element to its opposite second end .

The idea of one embodiment is that the profi le element comprises several tempering spaces .

The idea of one embodiment is that the cross-section of the profile element comprises at least one sensor space for arranging at least one temperature sensor .

The idea of one embodiment is that said at least one sensor space extends from a first end of the profile element to its second end .

The idea of one embodiment is that the sensor space is at an equal distance from the thermal trans fer surface to the tempering space .

The idea of one embodiment is that said at least one tempering space is equipped with at least one temperature element .

The idea of one embodiment is that the cross-sectional profile includes at least two tempering spaces extending from one end of the profile element to the other and both being equipped with temperature elements connected to each other at one end of the profile element .

The idea of one embodiment is that said at least one temperature element is a heating element .

The idea o f one embodiment is that the heating element is an electric heating element .

The idea o f one embodiment is that the heating element is a liquid-circulation heating element .

The idea of one embodiment is that said at least one temperature element is a cooling element .

The idea o f one embodiment is that the cooling element is a liquid-circulation cooling element . The idea of one embodiment is that said at least one tempering space is arranged to operate as a flow channel that is delimited by inner surfaces of the tempering space, and the opposite outermost ends o f which flow channel are equipped with connectors for coupling the tempering space to liquid circulation to influence the temperature of the tempering space and of the profile element .

The idea of one embodiment i s that the material of the profile element comprises silicone as a base material and at least one thermally conductive additional material .

The additional material has good thermal conductivity and silicone as the base material provides good elastic properties to the profile element .

The idea of one embodiment is that the base material of the profile element is s ilicone and the thermally conductive additional material is zinc oxide .

The idea of one embodiment is that the base material of the profile element is heat-resisting silicone .

The idea of one embodiment is that the base material of the profile element is rubber or rubber-based material .

The idea of one embodiment is that the base material of the profile element is elastic and resilient material .

The idea o f one embodiment is that the profile element is made by extrusion through an extrusion tool .

The idea of one embodiment is that the base material of the profile element is arranged to operate as an electrical insulation material , whereby it is arranged to protect the electrical temperature element . Thereby the durability and reliability of the temperature element may be improved . Additionally, electrical safety may al so be improved .

The idea of one embodiment is that the base material of the profile element has good chemical resistance properties , whereby it is arranged to operate as protection against chemical leaks . The idea o f one embodiment is that the profile element is equipped with a colour-code system, whereby profile elements in di f ferent colours may define for example a pipe si ze and type . Furthermore the colour-code may indicate whether the tempering o f the pro file element is cooling or heating, as well what type or power the tempering arrangement therein is . In addition, the colour of the profile element facilitates detection of a tempered pipeline in systems in which there are many di f ferent pipes and pipe elements .

The idea of one embodiment is that mutually di f ferent profile elements may be coupled to each other . This way, various combinations can be formed of di f ferent profile elements and of the temperature elements provided therein .

The idea of one embodiment is that the cross-section of the profile element comprises an outer surface and an inner surface , whereby the inner surface is arranged to operate as said thermal trans fer surface and is arranged to delimit a target space arranged to receive the tempering target .

The idea of one embodiment is that the cross-section of the profile element is annular and comprises an outer circumference and an inner circumference , whereby the inner circumference is arranged to operate as said thermal transfer surface and is arranged to delimit a target space arranged to receive the tempering target .

The idea of one embodiment is that the cross-section of the profile element comprises a cut in a longitudinal direction of the profile element extending from the outer surface of the profile element to the target space , whereby opposite branches are arranged to be formed in the crosssection, which branches are stretchable away from each other to form a gap between ends of the branches .

In other words , the cross-section is not a closed shape as said longitudinal cut disconnects the inner and the outer surface . Because of the elastic material the profile element is arrangeable around the tempering target without the need to remove the tempering target for installation . The profile element can be pressed to its place in a transverse direction of the tempering target in such a way that the tempering target is positioned in the target space .

The cut thus enables an openable or a stretchable installation opening to be formed in the profile element . As the material of the profile element is elastic, it tends to return to its initial shape after installation, whereby the installation opening closes automatically .

The idea o f one embodiment is that the profile element may have corresponding longitudinal cuts and openable installation openings for arranging the temperature elements to the tempering spaces . This makes it easier to arrange the temperature elements to their places . Additionally, the temperature elements are easily removable , replaceable and re-installable .

The idea o f one embodiment is that the profile element may have corresponding longitudinal cuts and openable installation openings for arranging the sensors to the sensor spaces .

The idea of one embodiment is that the cross-section of the profile element is rectangular-shaped comprising opposite longer sides and opposite shorter sides , and wherein one of the longer sides is the thermal trans fer surface .

The idea o f one embodiment is that the ends of the profile element having the shorter sides are equipped with coupling members , whereby rectangular-shaped profile elements equipped with matching coupling members are connectable to each other .

The idea of one embodiment is that the coupling members comprise at a first end of the profile element a male connector, the outermost end of which is arranged to correspond to a cross-sectional shape of the tempering space closest to a second end of the profile element , whereby said tempering space is arranged to operate as a female connector and is arranged to receive said male connector . In this embodiment , one tempering space of the profile element or a space corresponding thereto is utili zed as a connector component . One or more other tempering spaces of the prof ile element operate as heating or cooling channels .

The idea of one embodiment is that the coupling members enable a connection both between aligned profile elements , and between transverse profile elements . This is enabled because it is possible to cut a connection between the outer surface and the tempering space situated at the end either in a longitudinal direction or in a transverse direction of the profi le element , whereby two profile elements are connectable to each other in al ignment one after the other or transversely to each other .

The idea o f one embodiment is that the profile element comprises several tempering spaces that are at an equal distance from the thermal trans fer surface .

The idea o f one embodiment is that the profile element comprises at an opposite surface relative to the thermal trans fer surface at least one insulation layer that is an integral part of the profile element and is made of an insulation material that di f fers from the base material of the profile element .

The idea of one embodiment i s that the solution as disclosed is related to a method for tempering a piping element , in which method : a tempering device is arranged against the piping element ; and heat is trans ferred between the piping element and the tempering device . Additionally, in the method a tempering device comprising at least one profile element made of elastic thermally conductive material i s used; and heat is trans ferred by means of temperature elements provided within the profile element or by means of liquid circulation . The idea of one embodiment is that the prof ile element is arranged around the piping element without removing said tempering target from the piping .

The idea o f one embodiment is that the profile element is arranged against an outer surface of the piping element , which piping element is one of the following : pipe ; proces s pipe containing flowing liquid; pipe of a research apparatus ; valve ; elbow fitting; branch piece , such as T- piece or Y-piece ; container ; expansion tank; pressure accumulator ; filter .

Further, it can be stated that the system as disclosed enables the tempering and trace heating of piping precisely to a desired temperature . The benefits include uni form thermal distribution in all parts of the piping . An elastic profile or profile element made of high-thermal conductivity material operates as the core of the system, which profile or profile element is installed over readymade piping . For example electric resistances or water circulation may be used as a thermal source inside the profile .

The trace heating system as disclosed is based on a thermally conductive elastic profile element to be installed around a pipe , or a corresponding target element , inside which profile element a thermal element as well as a necessary number of temperature sensors are installed . The profile element distributes the heat produced by the thermal element uni formly around the pipe, and does not cause thermal point loads . The temperature sensor can be placed in the profile element such that the temperatures experienced by it are the same with the pipe , which enables accurate temperature adj ustment . The length of the profile to be installed may correspond to the length of the piping, which facilitates the evaluation of length of the thermal elements needed . The system may further include components made from the same material , by means of which the heating can continue seamlessly over other parts of the piping, such as valves , T-pieces and extension pieces . One obj ective in developing the solution was an easily installable product enabling accurate and reliable adj ustment of temperature , and not causing thermal point loads in the piping, while providing a suf ficiently high operating temperature . A further obj ective was that the solution works with pipes of di f ferent si zes , and that it is also possible to be operated under chemically challenging conditions .

The above embodiments and the features presented therein may be combined to provide desired configurations .

Brief description of the figures

Some embodiments of the solution as disclosed are illustrated in more detail in the following figures , in which

Fig . 1 and 2 schematically illustrate , as a longitudinal cross-section seen from the side , some tempering devices arranged around tempering targets ,

Fig . 3 and 4 schematically illustrate annular crosssections of some profile elements as seen in a longitudinal direction;

Fig . 5 schematically il lustrates a substantially rectangular-shaped cross-section o f one profile element and connection members provided at edges as seen in a longitudinal direction,

Fig . 6 schematically illustrates modes of connection o f the pro file element illustrated in Fig . 5 in order to form a box-shaped structure as seen in a longitudinal direction, and

Fig . 7 schematically illustrates one profile elements intended to be arranged around an elbow fitting or an angular piece .

For the purpose of clarity, some embodiments of the solutions as disclosed are illustrated in the figures in a simpli fied form . In the figures the same reference numbers are used to refer to the same elements and features . Detailed description of some embodiments

Fig . 1 il lustrates one tempering device 1 arranged around a tempering target 2 . In this case the tempering target 2 is a pipe in which a liquid, gas or other fluid substance may flow . The tempering device 1 comprises at least one elongated profile element 3 , which is made of elastic thermally conductive material . The profile element 3 illustrated in Fig . 1 comprises two longitudinal tempering spaces 4 that are equipped with temperature elements 5 operating as means 6 for influencing temperature of the tempering target 2 . The temperature elements 5 may be for example electric heating cables 6 . The temperature elements 5 may be connected to each other by a separate coupling part or they may turn at the opposite end of the profile element 3 , as i llustrated and indicated by re ference number 7 . The profile element 3 is made of high-thermal trans fer material , whereby heat is trans ferred ef ficiently between the temperature element 5 and the tempering target 2 . The profile element 3 has a thermal trans fer surface 8 against the tempering target 2 .

The tempering device 1 illustrated in Fig . 2 di f fers from that illustrated in Fig . 1 in that no separate element is arranged inside the tempering spaces 4 , but the tempering spaces 4 may operate as flow channels 9 for a heating or cooling liquid flow . At the ends of the tempering spaces 4 there are connectors 10 for coupling the liquid circulation and at one end of the profile element 3 there is a connecting channel 11 , such as a hose , by which the flow channels 9 may be coupled to each other .

As an alternative to the solution o f Fig . 2 , separate pipes or channels may be arranged to the tempering spaces for the liquid flow .

Fig . 3 illustrates a cross-section of one profile element 3 . The cross-section of the profile element 3 is annular comprising an outer surface 12 and an inner surface 13 . The inner surface 13 delimits a device space 14 to which the tempering target 2 may be arranged . The inner surface 13 also operates as the thermal trans fer surface 8 . Between the outer surface 12 and the inner surface 13 there may be a cut 15 to facilitate installation of the profile element 3 around the tempering target . The cut 15 and the elastic material together make it possible that the structure can be stretched during installation . Further, the outer surface 12 may have a recess 16 at the cut 15 to facilitate the installation . The recess 16 may have conical surfaces also facilitating the installation . The profile element 3 of Fig . 3 has two tempering spaces 4 arranged on opposite sides of the device space 14 . Further, the profile element has a sensor space 17 for arranging one or more sensors . In connection with the tempering spaces 4 there may be cuts 18 and in connection with the sensor space 17 there may be cuts 19 to facilitate installation of the devices . Further, the outer surface 12 may have recesses 20 and 21 in connection with the cuts 18 and 19 also to facilitate the installation . The shape and si ze of the recesses 16, 20 and 21 may di ffer from each other, such that on that basis it is easy to see whether the installation channel leads to the device space 14 , to the tempering space 4 or to the sensor space 17 .

It should be mentioned that in the cross-section of the profile element 3 the shape of the outer surface 12 and of the inner surface 13 may be also other than round . The shape of the inner surface 13 may correspond to the shape of the outer surface of the tempering target and may be for example a rectangle . Further, the shape of the outer surface may be for example a rectangle .

Fig . 4 illustrates a cross-section of another profile element 3 dif fering from that illustrated in Fig . 3 in that there are six tempering spaces 4 and they are located at regular intervals to each other to provide uniform thermal distribution . There are or there are no cuts in connection with the tempering spaces 4 and with the sensor space 17 . Further, there may be recesses at the outer surface 12 , or alternatively there are no recesses .

Around the prof ile element 3 there may be an insulation layer 22 that is made of material having a high insulating capacity .

Fig . 5 illustrates a profile element 3 that has a substantially rectangular-shaped cross-sectional profile including several tempering spaces 4 . Further, there may be a sensor space 17 . The profile element has opposite longer sides 23 and opposite shorter sides 24 , and wherein one of the longer sides 23 is the thermal trans fer surface 8 . The ends of the profile element 3 having the shorter sides 24 are equipped with coupling members 25 . Thereby rectangularshaped profile elements 3 equipped with matching coupling members are connectable to each other, as can be seen in Fig . 6 . On the right side in Fig . 5 there is a proj ection with a round head 26 fitting in a space 27 having a round cross-section on the opposite side . The webs 28 may be cut open, which enables the profile elements to be installed in alignment one after the other or transversely to each other . Both of these modes of installation are shown in Fig . 6 .

Prof ile elements 3 as i llustrated in Fig . 5 may be arranged around the tempering target without coupling any connecting members , whereby separate attachment clamps or corresponding fixing members may be used .

Further it is possible that a profile element as illustrated in Fig . 5 may be cut narrower, whereby a new connecting element may be formed at the left side thereof from the tempering space 4 to which a fixing proj ection having a round head 26 can be coupled .

Further the cross-sectional profile as in Fig . 5 may be entirely without the coupling members 25 , whereby fixing of the profile element 3 and holding it against the tempering target is arranged by other means .

Fig . 7 and 8 il lustrate one profile element 3 that is shaped so as to be arranged over an elbow fitting of piping . The device space 14 is thereby shaped according to the shape of the piping component . The cut 15 and elastic material facilitate installation of the profile element 3 in its place . Further because of the cuts 18 it i s easy to install the temperature elements to the tempering spaces 4 .

General description of the solution

The following provides a more general description of the solution, its features and characteristics that may be applied in the solution .

The operation of the tempering device is based on thermal trans fer through an elastic prof ile or profile element operating as a thermal conductor to a pipe or corresponding tempering target enclosed within the profile . By means of the profile , heat can be trans ferred uni formly to the walls of the pipe , so that no thermal point loads are able to occur . At the same time , equal temperatures at all points of the pipe can be ensured and the emergence of cold points is prevented, at which cold points for example crystalli zation or local condensation could take place . Thermal elements located in the tempering space or pocket may operate as the thermal source , which thermal elements may be for example electric resi stances . The heat supplied to the profile is distributed uni formly around these elements , being conducted uni formly in all directions . In the heating of smaller pipes a uni form thermal load to the pipe is achieved when two thermal elements are installed to the profile , which thermal elements are placed at both sides of the profile as in Fig . 3 . By increasing the number, the heating ef ficiency can be raised as well as more uni form thermal distribution achieved around the pipe . The s igni ficance in this is increased especially when the diameter of the pipe to be heated is signi ficantly larger than the diameter of the thermal elements . One example of this kind of situation is illustrated in Fig . 4 . The system may also be operated with one thermal element , but then the thermal load is applied rather to one side of the pipe .

For ef f icient thermal trans fer, it is advantageous that the thermal elements as well as the pipe are in contact to the profile along a surface area that is as large as possible . This is easy to achieve by si zing the diameters of internal features of the profile slightly smaller than their counterparts . To improve ef ficiency of the system, an insulation can be installed to the outer surface to keep most of the heat inside the profile .

Often in heated piping it is advantageous i f the temperature of the system is known precisely and can be adj usted reliably . The piping can be assumed to be consistent in physical properties along the entire piping, when the pipe is empty or the substance flowing therein is sufficiently homogeneous . In this case the thermal conditions are similar at all points of the piping and for reliable measurements it is suf ficient that the temperature is known at a few points . For this purpose , the profile is equipped with a sensor space to which a thermal sensor having a suitable thickness can be installed . Fig . 3 illustrates one possible location in the cross-section of the profile where the sensor may be placed . In the profile , the sensor is located at an equal distance from both thermal elements , whereby the temperature is distributed uni formly on both sides of the midline of the profile . In case it is to be ensured that the sensor experiences the same temperatures with the pipe , it must be located at the same distance from the thermal element with the pipe . An example of this implementation is illustrated in Fig . 4 . The temperature sensor pocket extends through the length of the profile , so it enables installation of the sensor to any point . Furthermore , it enables the use of several sensors as well as taking veri fication measurements at desired points . The temperature sensor can be installed in its place at the same time with the thermal elements . Retrofitting it in an existing heated line can also be easily done .

By means of the temperature sensor, temperature control can be implemented for example by a PLC, whereby the temperature in the piping can be kept very consistent . Achieving a consistent temperature is facilitated by sufficient thermal storage capacity of the profile . Especially when using electric resistances , this shows as ability to balance the thermal point load supplied by the resistances before it is conducted to the walls of the pipe .

The heating profile can be installed over an existing piping . In connection with installation, thermal elements having the necessary e f ficiency are placed inside the profile . The installation can be performed manually or by using a suitable tool that speeds up the installation work . When using an electrical resistance wire , it i s easiest to si ze the length of the wire two times the length of the pipeline to be heated or some multiple thereof . Thereby the start of the resistance wire is at one end of the pipeline, from where it extends along one thermal element channel to the other end of the pipe and returns along another one . This way the supply of electricity can be implemented at only one point of the pipe . I f more power is needed, the wire can be circulated through several loops in a simi lar way . When the resistance has been installed inside the profile , installing the profile over the pipe is easy . The installation groove of the pipe i s stretched open and the profile is pressed around the pipe one section at a time .

Other methods may also be used as a thermal source . When using for example water circulation, a thermally conductive element is installed in thermal pockets , inside which element a liquid flows . Alternatives are for example a copper pipe or a hose made of thermally conductive material . Heating provided by this type of arrangement al so enables the profile to be used in ATEX zones . When provided with liquid circulation, it is also possible to use the profile for cooling . When using the liquid-circulation heating, it is advantageous to make the pockets intended for the heater slightly larger in order to keep flow resistance in the long lines reasonable . It is also possible to provide liquid circulation by running the liquid to be heated directly along the heating element channels of the profile . In this case it is advantageous to keep the wall strength slightly thicker .

The heating profile is made o f elastic material , whereby it easily bends through angles in the piping . In addition, the profile may be rotated about its axis at di f ferent points of the piping, which may be useful for example when several sharp bends are located close to each other . In case the piping contains T-pieces , extensions , valves and other such pipe parts , heating over them may be provided by components made of the same material fitting over the components . One example of a heater fitting over an elbow fitting is illustrated in Fig . 7 and 8 . In terms of operation it is essential that the heater is in contact with the fitting along the largest possible area . In addition, it must be equipped with a pocket suitable for the resistance wire .

I f the diameter of the pipe to be heated is large or the geometry of the piece to be heated is other than a cylinder, profiles fitting better over the shape may be made by the same operating principle . Their operating principle is similar to the cylindrical profiles described above . The heating profi le may be for example rectangular-shaped . One possible manner of implementing this is illustrated in Fig . 5 . The heating target is placed against one surface o f the profile that operates as a thermal trans fer surface . The thermal elements are placed in pockets within the profile or in tempering spaces , the number of which may vary . The number of the thermal elements may be adj usted for example according to the need of heating power . A temperature sensor may be placed in one of the internal sensor spaces o f the profile . To achieve the most representative result , it is advantageous to choose the point of installation from a pocket adj acent to the thermal element . The profile il lustrated in Fig . 5 is also equipped with an option to j oin two or more profiles together, whereby the same profile may be utili zed with pieces in as many si zes and shapes as possible . Joining is made by means of male geometry arranged in the profile . Joining can be achieved to an end of another profile by cutting open a face on a female geometry' s connection surface side . Using the same principle , j oining can also be achieved to any free pocket of the profi le by cutting a desired pocket open in a longitudinal direction . This way, heating can be provided for example for square-shaped pieces . One possible implementation of connection possibilities is illustrated in Fig . 6 . The profile can be cut in two in a longitudinal direction in case there is no use for the whole width . This is particularly useful when heating is provided for a larger pipe of a diameter not matching the width of the profile . By cutting the profiles to a suitable width, they can be connected from both ends so as to create a closed structure .

I f the thermal elements are to be protected from possible leaks coming from the pipe , the structure of the profile must be chosen such that the thermal elements are installed in their places from the outer edge of the profile as in Diagram A. Thus , possible leaks are not immediately in contact with the elements . This provides particular advantage when there are chemically aggressive substances flowing in the piping, which may break the resistance elements . I f the profile is made of electrically non-conductive material and electrical resistance wires operate as thermal elements , the piping and the thermal elements can be insulated from each other . Thus , possible electri fication of the piping i s avoided, in case a res istance wire breaks up and grounding occurs to the surrounding material . To achieve additional protection the ends of the heating profile may be protected by plugs made of the same material , in the middle of which plugs a hole is cut for introducing the pipe . This way, for example a flow taken out at a sampl ing point or vapours rising therefrom will not be able to contact the heating elements .

For the operation of the profile the essential factors are its elasticity and good thermal conductivity . One material choice found to be working is silicone to which zinc oxide is added . By choosing the silicone grade the thermal resistance and maximum operating temperatures o f the profile may be influenced . A heat resistant grade provides a maximum temperature of up to 350 ° C . By adj usting the proportion of zinc oxide the thermal conductivity and thermal storage capacity of the material may be influenced .

One preferred use for the profile is in maintenance heating, but it may also be used as a heater or cooler installed over a pipe .

Examples of tests performed on the device

To ensure the functioning of the invention, the profile was subj ected to various test arrangements , in which its properties and behaviour in di f ferent situations were examined .

A profile made for a 6mm thick pipe was chosen to be used in the tests .

In the tests , bending of the profile around dif ferent shapes was examined . The profile was arranged at a turn of 180 degrees with a radius of 15mm. Resistance wires were installed inside the profile . By rotating the profile around its axis during the turn, the resistance wires could be held well in their places and the incisions made for the pockets were kept closed . The profile bends over sharp turns without problems . Additionally, bending of the profile at an angle without axial rotation was tested .

The ef ficiency and precision of heating were tested by an arrangement in which a heating prof ile was installed around a 50cm long 6mm thick pipe , which heating profile was equipped with a Im long electric resistance cable of 100W . The cable ran along one thermal element groove of the profile to one end of the pipe and returned along another one . For adj usting the temperature , a k-type sensor was installed in a thermal sensor groove of the profile . The supply of electricity to the resistance was provided through an SSR coupled to a PLC . The same logic received temperature data from an internal sensor of the profile . The internal temperature of the pipe was measured by a separate sensor, the reading of which was used in evaluating the temperature adj ustment . At the beginning of the test , the temperature of al l parts was approx . 20 ° C . The target temperature was set to 80 ° C . The temperatures inside the pipe and heating profile had settled very close to the target temperature of 80 °C when 3 minutes had passed from the beginning of heating . During the test , neither of the temperatures rose over 85 ° C . The result demonstrates functioning of the profile excellently when using electric resistances as a thermal source . The test was continued with di f ferent temperatures , and the results were consistent .

Behaviour of the profi le under a water-circulation heating source was studied by a test arrangement in which 4mm thick copper pipes were installed in thermal element grooves inside the profile . At one end the pipe ends were connected to each other by a silicone hose . At the opposite end, inlet and outlet hoses were installed to the pipes . The outlet ran from the pipe end directly to a thermal bath . The inlet side was connected to the thermal bath via a peristaltic pump . In the test the thermal bath was heated to a temperature of 80 ° C and was kept unchanged . By means of the pump , water at constant temperature was fed through the copper pipes installed to the heating profile . The temperature was monitored by means of thermal sensors installed inside the profile as well as to the pipe to be heated . The measurement results as the temperatures had settled after operation of about 5 minutes showed that the temperature inside the pipe was about 2.5°C lower than the water bath. The difference remained stable through the remainder of the test. This means that the target temperature of 80°C would have been reached by raising the temperature of the bath by 2.5°C. A temperature difference of 3.5 degrees at the measurement points between the profile and the pipe is explained by the structure of the profile, in which the location of the temperature sensor from the thermal element is farther away than the surface of the pipe to be heated.

Some advantages and features of the solution:

- Uniform thermal distribution along the entire piping .

- Simple installation.

- Thermal cables are protected from chemicals.

- Possible breaking of the cable does not cause an electric shock hazard.

- Enables accurate measurement of external temperature of the pipe to be heated.

- Possible to easily make for all sizes of pipes.

- Enables trace heating up to 350 degrees.

- The structure of the profile distributes heat produced by the thermal elements uniformly around a pipe to be heated. Traditional trace heating by an electric cable causes a thermal load in the piping at individual points.

- The structure of the profile that is open from one side enables the heater to be installed in its place without a need to turn thermal elements around the pipe. The length of the thermal element needed is the same as the length of the pipe to be heated, so it is easy to order suitable heating cables.

- The material used for the profile is silicone that withstands different chemicals well. The process pipe and the heating elements are located in di fferent parts of the profile, so they are not able to contact each other .

- The known solution in which an electrical heating cable i s wound around a metall ic pipe may cause an electric shock hazard . This occurs particularly easily in the vicinity of sampling valves , i f for example an acid or solvent runs in the pipe to be heated . The profile presented in this document is made of electrically non-conductive material , so possible damaging of the electric heater does not conduct electricity out from the structure .

- The temperature sensor i s located in the profile at a point where the temperature conditions are as close as possible to the conditions experienced by the pipe . Traditional ly, the sensor is placed onto the pipe and the temperature it measures depends strongly on how close to it the heating element i s located .

- The profile is easily scalable for di f ferent-si zed pipes .

- High-temperature silicone withstands heat up to 350 degrees .

- Installation of the profile as disclosed is quick, and uni form trace heating conditions are achieved by means o f it . The pro file operates as a good insulation between the heater and the pipe to be heated . At the same time , it protects the heating elements from chemicals etc . other factors possibly stressing the heater .

- Building trace heating for small pipes ( diameter under 50mm) is demanding by current means . The profile according to the solution as disclosed can be sold by meter for all in need thereof . Making of the product can be outsourced to a suitable company manufacturing silicone profiles and it can be produced in unlimited amounts as ordered .

- The solution may also comprise a product family that includes connection parts for example for t- pieces , valves and other actuators .

The figures and their description are intended only to illustrate the idea of the invention . The scope of protection of the invention, however, is defined in the claims of the application .