A DEVICE FOR MEASURING OF THE WET TEMPERATURE OF A GASEOUS MEDIUM

Abstract: A device for measuring of the wet temperature of a gaseous medium such as damp air. The air is passed through channels in the device, whereupon a portion of the moisture is adapted to condensate against a cooled surface (5) and be collected in a container (9). The damp air is forced to flow through the collected water, which receives the wet temperature of the air. A thermometer (4) records the temperature of the water in the container. The device is provided with a cleaning system (26, 27) for cleaning or rinsing of the container, preferably intermittently. The cleaning and rinsing system is operated manually or automatically.

Description: A DEVICE FOR MEASURING OF THE WET TEMPERATURE OF A GASEOUS MEDIUM Techn cal Field The present invention relates to a device for measuring of the wet temperature of a gaseous medium, such as damp air. In the industries of papers, cellulose and tree the water is. evapor- ated by absorbation of the water in the air in the processes, whereupon the air is evacuated to the surroundings e.g. by means of fans. The heat con¬ tent of the evacuated air is recovered at different efficiencies for reuse in any way, for example in the drying process or for supplying the local heating. In order to control the process one try to maintain a given wet temperature of the evacuated air. Often this given wet temperature should be as high as possible without causing inconvenience, such as detonated cli¬ mate for the working people. Several different devices have previously been constructed for measur¬ ing of the wet temperature. Mostly of such previously known devices operates with filling of water in a container where a temperature sensor " s posi¬ tioned, which filling of water is performed by means of a valve and a floating body, which are adapted to maintain the water level at a sub¬ stantially constant level. However, such a construction is "y/er sensitive for disturbances, especially if fibre particles or dust accompany the damp air, whereupon the system can be stopped up. Operation disturbances will easily occur if the device is not cleaned and even fungus may occur. The maintenance is not difficult to perform but is often forgotten, whereupon the temperature measuring device does not operate satisfactory. The present invention relates to a new and improved temperature meter for the wet temperature, which is self providing of water and at the same time to a certain degree is self cleaning. Moreoyer, the deyice is provided with a cleaning and rinsing system so that the device can be cleaned. This cleaning can also be done fully automatically. Disclosure of the Invention According to the invention, the exhausted damp air is cooled so that the moisture is condensed, and this condensate is used for filling the container where the measuring probe is placed. The excess, water flows out through a spillway and dust particles are carried out together with the out¬ flow. The cleaning and rinsing system is preferably adapted to generate a whirlpool in the container, thereby forcing the fibres and dust particles to leaye the container through the same outlet as the condensed water leayes the device. According to the invention there is provided a device for measuring of the wet temperature of a gaseous medium, preferably damp air. The device comprises an outer tube having air flowing channels, and a temperature probe. The air flows through a first tube which is cooled, whereby the water is condensed on the surface of the tube. This water is coMected in a container. The damp air is passed through the water collected in the container. Preferably the device according to the invention comprises an outer tube, which is provided with a first, upper, inner tube and a second, lower, inner tube. The incoming damp air is conducted downwards inside the second tube to the condensated water in the container, and thence upwards in the space between the second tube and the outer tube and to the in-, terior of the first tube. The surrounding air is forced to cool. the outer surface of the first tube, whereby the moisture of the damp air is con¬ densed and flow to the bottom of the outer tube, which constitutes said container. Finally, the air is delivered to the surroundings by means of a fan member. The fan member is dimensioned so as to such the air -through the water collected in the container. The temperature probe is adapted to measure the temperature of the collected water, which will have the same temperature as the wet temperature of the air flowing past and beyond the temperature probe. .In order to give off the excess of the condensed water, an outlet tube is arranged at a certain height over the bottom of the outer tube. Moreoyer, there is a rinsing tube for supplying of water. The rinsing tube preferably opens to the outer tube substantially tangentially, where¬ by a whirlpool is generated in the lower portion of the tube. The water supplied and the released contamineπts are flowing gut through the outlet tube. In this way an efficient cleaning and rinsing device is obtained, whi-ch can be actiyated manually or automatically. The temperature measur¬ ing device has a certain continuous self-cleaning operation, since all the time the excess of the condensed water is given off through the outlet tube. The lower rim of the second tube is provided with indentations for providing an irregular lower rim. In this way the air flow is distributed over the ; whole periphery of the second tube at the lower rim. Between the outer tube and the first inner tube a space is provided. The air of the surroundings is sucked inside this space through holes in the outer tube. In this way the air in said space cools the outer surface of the first tube, whereby the moisture of the air inside the first tube condensates against its surface and is collected at the bottom of the outer tube. Brief Description of the Drawings A preferred embodiment of the invention is described below by reference to the appended drawings. Fig. 1 shows a longitudinal cross section through the measuring device according to the invention. Fig. 2 is a side view corresponding to Fig. 1 of a modified embodiment of the measuring device. Fig. 3 is a cross section taken according to the lines 3-3 of Fig. 1. Best Mode for Carrying Out the Inven tion--.and Industrial Applicability The measuring device 1 according to the invention comprises a sub¬ stantially vertical outer tube 2, which at its upper end is provided with a fan member 3 and at its lower end comprises- at temperature probe 4. Inside the outer tube 2 there is an upper, first inner tube 5 and a second, lower, inner tube 6. Close to the middle portion of the outer tube 2 there is a connection portion 7 having a connection flange 8. The connection portion 7 is connected to the upper portion of the inner tube 5, so that all air intering through the connection portion 7 is deflected downwards inside the tube 5. The lower end of the tube 6 is positioned closely above the lower closed end 9 of the outer tube 2, which forms the above-mentioned container 9. The . tube 6 is opened at its lower end and is proyided with serrations or semi-circular indentations 10 along its lower periphery in order to make a. regular rim. Between the inner tube 6 and the outer tube 2 there is a space 12 where the air can flow upwards at the outside- of the tube 5, Above the connection portion 7, the upper inner tube 5 at its lower end is connected 13 to the inner wall of the outer tube 2, so that all air flow¬ ing upwards outside the tube 6 is flowing inside the tube 5 to its upper end. At its upper end the inner tube 5 is provided with an outlet- opening 14, which opens closely below the upper end 15 of the outer tube 2. Between the inner tube 5 and the outer tube 2 there is provided a space 16. At abou its middle portion and closely aboye the connection 13 the outer tube 2 is provided with inlet holes 17 so that the surrounding air can enter the spac 16 and canflow up to the upper end 15 of the outer tube 2. A fan member 3 is attached to the upper end of the tube 2 and compri a housing 18 including a drive motor 19 and a fan 20. At its lower surface connected to the tube 2 the fan housing 18 comprises an inlet opening 21, through which the fan 20 sucks air, which is exhausted through outlet open- ings 22 positioned there-above in the fan housing. The drive motor 19 is preferably an electric motor and holes 23 are made in the fan housing 18 for inlet of cool air for cooling the motor, which air leaves the fan housing at its upper end, preferably through a pro tection net or similar (not shown). At its lower end the outer tube 2 is provided with a drainage openin 24 having a cover 25, which can be screwed off for cleaning the device. Moreover, there is an outlet tube 26, which is attached to the outer tube and opens in the space 12 between the outer tube 2 and the inner tube 6 at a certain level above the bottom 9 of the outer tube. Moreover, there is a rinsing tube 27 for supplying of water for generating, a whirlpool in the lower portion of the outer tube 6 in order to clean and rinse eventual par¬ ticles or fibres and discharge them through the outlet tube 26. The device according to the invention operates according to the follo ing. The damp air the wet temperature of which shall be measured is delivere to the measuring device 1 through the connection portion 7 and the air passe downwardly through the interior of the tube 6. When the air reaches the lowe end of the tube 6, the air passes through the condensed water collected in the container 9, whereupon the air is deflected upwardly on the outside of the tube 6 in the space 12 and passes upwardly to the middle of the outer tube 2 and thence into the interior of the tube 5, and finally through the outlet opening 14 to the fan member 3. Simultaneously air from the surround¬ ings is sucked through the inlet openings 17 in the outer tube and passes through the space 16 between the upper inner tube 5 and the outer tube 2 and mixed with the damp air at the inlet opening 21 to the fan means 20 in order to finally be delivered to the. surroundings through the outlet holes 22 in the inlet fan housing 18. When the air from the surroundings flows along the outside of the inner tube 5, the walls of the inner tube are cooled to below the dew point of the damp air. Water condensed on the inner surface of the tube 5 will drop downwardly along the walls to the bottom 9 of the outer tube 2 and be collected there. When the water content reaches the height of the outlet tube 26, the excess water is discharged through th s tube. When the fan 20 is started, the air is suched through the water collected at the bottom 9 of the outer tube and the air is evenly distribut¬ ed oyer the peri hery of the lower end of the inner tube 6 hy means of the indentations 10 in the lower rim 11 and passes through the space 12 and thence through the interior of the upper tube 5 where the moisture is condensed against the inner surface of the tube 5. The temperature probe is adapted with its sensitive body about in the height of the discharge tube 26 whereupon the probe 4 measures the temperature of the water collected in the container 9 and hence the wet temperature of the air. The output signal from the probe 4 can be used for controlling the temperatature of the moisture absorbing air or in any other convenient way. Eventual dust and fibre particles entering together with the medium sucked in, wil be discharged at the owerflow through the discharge tube 26 which means that a certain self-cleaning effect is obtained. However, a water flow is supplied intermittently through the rinsing tube 27. Since the tube 27 is connected essentially tangentially to the outer tube 2 there is generated a whirlpool in the lower portion of the outer tube 2 and thence the water is discharged through the outlet tube 6. This whirl¬ pool efficiently cleans eventual fibre particles, which have been gathered during the operation. The cleaning and rinsing operation can be performed automatically e.g. once a day or can be activated manually..In Fig. 2 there is shown a modificated embodiment of the invention. The lower end of the outer tube 2 is closed by an insulation plug 28. The temperature probe 4' is positioned in a V-shaped recess in the plug 28. Moreover the rinsing tube 27' and the outlet tube 26' extends vertically and does not create a whirlpool. This arrangement has the advantage that the volume of collected water in the container 9 has been decreased, which means a decreased reaction time for the temperature measurement. Moreover, the plug is removable for inspection and cleaning of the lower portion of tube 2. Hereinbefore a preferred embodiment of the invention has been describe in order to elucidate the invention but this embodiment can of course be modified in many ways within the scope of the invention. For example can the lower end of the tube 6 be connected to the lower end of the outer tube 2 and the air can pass to the space 12 through holes in the tube 6. In Fig.1 there is shown a fan having controlled and adjustable motor speed in order to adapt the capacity of the fan to the requirements. However, the fan motor can be one of constant motor speed (induction motor) and the diameter of the fan wheel can be adapted to the requirements and the capacity of each equipment. The above-mentioned modifications as well as other modifications obvious to a person sk lled in the art are intended to be within the scope of the invention, which is only limited by the appended claims.

Claims: CLAIMS 1. A device for measuring of the wet temperature of a gaseous medium, such as damp air, comprising a tube (2) having gas flow channels (7, 6, 12, 5, 16, 14, 21, 22) and a temperature probe (4), characterized by a first cooled tube (5), through which the gas is forced to flow, whereby water is 5 condensed against the surface of the tube (5) and is collected in a con¬ tainer (9), and that the temperature probe (4) continuously measures the temperature of the collected condensed water. 2. A device according to claim 1, characterized by a second tube (6) extending into the condensed collected water in the container (9), 10 whereby the damp air entering the device is adapted firstly to pass through the second tube, thence through the collected water and thence through the first tube (5) for condensation of the moisture against the cool surface of the first tube. 3. A device according to claim 1 or 2, characterized by an outer 15 tube (2) having a first, upper, inner tube (5) and a second, lower inner tube (6) whereby the incoming gaseous medium is deflected downwards inside the second tube to said container (9), thence through the collected water and upwards in a space (12) between the second tube (6) and the outer tube (2) and to the interior of t'he first tube (5), whereby the surrounding 20 air is adapted to cool the outer surface of the first tube (5) so that moisture condensates on the first tube and flows downwards to the bottom of the outer tube, which is said container (9), whereupon the air is dis¬ charged to the surroundings by means of a fan (3)-. 4. A device according to any one of the preceding claims, characteriz- 25 ed in that the container at the lower portion of the outer tube has a dis¬ charge tube (26) for overflow of excess of condensated water. 5. A device according to claim 4, characterized in that the con¬ tainer at the lower end of the outer tube has a rinsing tube (27) for supply t. of water, whereby the rinsing tube opens to the outer tube (2) essentially 30 tangentially for generating a whirlpool motion of the water in the lower end of the .tube (2), whereupon the supplied water together with loosened conta¬ minants are discharged through the discharge tube (26}. 6. A device according to any one of claims 2 to 5, characterized in that the second tube (6) at its lower end is proyided with indentations (10) 35 in order to form an irregular lower rim (11) in order evenly to distribute the air flow oyer the entire periphery of the second tube (6), yξXSZEX y. ( OMFI 7. A device according to any one of the preceding c aims,, character¬ ized in that a space (16) is arranged between the outer tube (2) and the first inner tube (5\ and that the surrounding air is sucked into said space (16) through holes (17) in the outer tube (2)_ in order to pass along the outer surface of the first tube (5}_ in order to cool said tube.

Inventors: OLBRANT GOERAN
Applicants: OLBRANT GOERAN, OLBRANT KONSULT AB, KONSULT AB OLBRANT G
Application year: 1982
Main classification: G01N25
IPC codes: G01N25