JP2013120173A - Fouling detecting sensor and fouling detecting device - Google Patents

Abstract

An object of the present invention is to prevent a time lag from being detected when detecting an adhering matter adhering to the outer surface of a detecting unit due to a change in temperature in the detecting unit caused by energization of a heating element.
A detection portion K in which a heat-conductive filler 13 is filled in a metal tube 10 in which a heating element 11 and a temperature measuring element 12 are inserted is immersed in the water for investigating adhering matter to generate heat. A sensor 1 for detecting a deposit on the outer surface K1 of the detection unit K according to a change in temperature in the detection unit K caused by energization of the body 11, wherein the outer surface of the metal tube 10 is Covering with the scale G, the outer surface K1 of the detection part K was formed by the surface of the scale G. When the deposit is a scale, the scale adheres to the entire outer surface K1 of the detection unit K quickly.
[Selection] Figure 1

Description

  The present invention relates to a sensor for detecting an adhering matter and an adhering matter detecting device for detecting the generation state of scale and slime in an industrial water system such as a cooling water system or a paper pulp process.

  For example, in industrial water systems and pulp and paper processes, impurities dissolved in water adhere to the inner surfaces of the flow paths of equipment and piping due to crystal precipitation etc. due to fluctuations in the quality of the water used in equipment and piping. However, scales are generated by laminating and solidifying (fixing) them. In addition, slime is generated on the inner surface of the flow path of equipment and piping due to the action of microorganisms and the like present in the water used.

  As an apparatus capable of continuously detecting such a scale or slime generation state, for example, there is an adhering substance detection apparatus described in Patent Document 1. This adhering matter detection device uses water (hereinafter referred to as investigation water) in which a detection unit in which a metal tube in which a heating element and a temperature measuring element are inserted is filled with a heat conductive filler is investigated. ) The sensor (probe) is placed in the sensor, and the heating element is energized while the sensor's detector is immersed in the survey water. It detects that scale or slime has adhered to the outer surface of the detection unit.

JP 2010-101840 A

  However, in such an adhering matter detection device, since the outer surface of the sensor detection unit is made of a smooth outer surface of a metal tube, the adhering matter such as scale and slime hardly adheres to the outer surface of the detection unit. It takes a form in which this part spreads throughout while adhering partially to the outer surface of the part. For this reason, at the initial stage of attachment of the attached matter, the temperature measuring device cannot sufficiently catch the temperature rise due to the attached matter, and there is a problem that a time lag occurs between the start of attachment of the attached matter and the detection of the attached matter. It was.

  In view of the above points, the present invention does not cause a time lag in the detection of adhering matter when detecting adhering matter adhering to the outer surface of the detecting unit due to a change in temperature in the detecting unit caused by energization of the heating element. It is an object of the present invention to provide a sensor for detecting a kimono and a deposit detection apparatus including the sensor.

  According to the first aspect of the present invention, the detection unit filled with the heat-conducting filler in the metal tube in which the heating element and the temperature measuring element are inserted is immersed in the survey water of the deposit, A sensor for detecting a deposit on the outer surface of the detection unit based on a change in temperature in the detection unit caused by energization of the heating element, the outer surface of the metal tube being a predetermined rough surface It is characterized by being formed so as to have a predetermined degree of roughness on the outer surface of the detection unit.

  In this invention, after the detection part of a sensor is immersed in the investigation water which investigates generation | occurrence | production of a deposit | attachment, it supplies with electricity to a heat generating body, this is heated, and this calorie | heat amount is discharge | released to the outer surface side of a detection part substantially uniformly. Then, by measuring the temperature T0 in the detection unit with a temperature measuring body, the temperature increase due to heat conduction of the water temperature + water heat transfer boundary film + the metal pipe or the like is measured. Next, after a predetermined time has elapsed from the measurement of the temperature T0, the temperature Tp in the detection unit is measured by a temperature measuring element, so that the temperature of the survey water and the temperature rise due to the heat transfer boundary film are constant. If a temperature difference (Tp−T0) occurs between T0 and Tp, the adhering matter has adhered to the outer surface of the detection unit.

  By the way, when the outer surface of the detection part of the sensor is a smooth outer surface of the metal tube, the adhering substance is difficult to adhere, so that it partially spreads on the outer surface of the detection part and spreads throughout. Take. Also, since the thermal conductivity of the deposit is generally smaller than that of the metal tube that forms the detector, heat is generated at the beginning of the deposit (when the deposit is partially formed on the outer surface of the detector). Most of the heat from the body is released from the side of the metal tube where there is no deposit, and the temperature measuring body cannot sufficiently detect the temperature rise due to the deposit.

  In this invention, since the predetermined roughness is given to the outer surface of the detection unit, the viscous boundary film around the outer surface of the detection unit is thicker than when the outer surface of the detection unit is the outer surface of a smooth metal tube, The adhering matter is likely to stay and adhere to the outer surface of the detection unit. For this reason, in this invention, it becomes easy for a deposit | attachment to adhere to the outer surface whole surface of a detection part.

  In the invention according to claim 2 of the present invention, the detection part filled with the heat-conducting filler in the metal tube in which the heating element and the temperature measuring element are inserted is immersed in the survey water of the deposit, A sensor for detecting a deposit on the outer surface of the detection unit based on a change in temperature in the detection unit caused by energization of the heating element, the outer surface of the metal tube being covered with a scale And the outer surface of the said detection part is formed with the surface of the said scale, It is characterized by the above-mentioned.

  In this invention, since the outer surface of the detection part is formed by the surface of the scale (the surface whose roughness is increased by the adhesion of scale particles), it is detected compared with the case where this is the outer surface of a smooth metal tube. The viscous boundary film around the outer surface of the part becomes thick, and the adhering matter tends to stay and adhere to the outer surface of the detection part. For this reason, the deposits easily adhere to the entire outer surface of the detection unit. Further, in the present invention, the surface of the scale having the same crystal as the attached scale crystal is used as the outer surface of the detection unit. Therefore, the attached scale crystal is on an energy stable scale compared to the outer surface of the metal tube. That is, it tends to occur on the outer surface of the detection unit.

  According to a third aspect of the present invention, in the case of the second aspect, the scale components are calcium carbonate, basic zinc carbonate, calcium sulfate, calcium sulfite, barium sulfate, aluminum sulfate, calcium phosphate, phosphorus One of zinc oxide, calcium silicate, magnesium silicate, calcium oxalate, magnesium hydroxide, and zinc hydroxide, or a mixture of at least two of them To do.

  According to a fourth aspect of the present invention, there is provided a sensor in which a detection unit in which a heat conductive material is filled in a metal tube in which a heating element and a temperature measuring element are inserted is immersed in the survey water of the deposit. And an energization amount control means for controlling the energization amount of the sensor to the heating element, and a change in temperature in the detection unit caused by energization of the sensor to the heating element, and the adhering matter to the outer surface of the detection unit A deposit detection device comprising: a deposit detection means for detecting the adhesion of the sensor, wherein the outer surface of the metal tube of the sensor is covered with a scale, and the outer surface of the detection unit is formed by the surface of the scale It is characterized by being.

  According to a fifth aspect of the present invention, in the case of the fourth aspect of the present invention, the energization amount control means sets the current value to a predetermined magnitude in the first time zone, but the second value following the current value. In the time zone, the amount of current supplied to the heating element of the sensor is controlled so that the current value is set to zero or close to zero continuously.

  In this invention, when the energization current value to the heating element is zero or a value close to zero (second time zone), the temperature of the survey water can be measured by the temperature measuring element. Even if the temperature of the survey water fluctuates, the adhering matter detection means detects the temperature from the temperature measuring body when the current value to the heating element is a predetermined magnitude (first time zone). It can be easily adjusted in consideration of the temperature fluctuation.

  According to the first aspect of the present invention, since the predetermined roughness is given to the outer surface of the detection unit, the deposits such as scale and slime are likely to adhere to the entire outer surface of the detection unit. Thus, it is possible to detect the attachment of the adhering substance without time lag compared to the case of adhering the adhering substance in the actual machine.

  According to the second, third, and fourth aspects of the present invention, since the outer surface of the detection unit is formed of the surface of the scale having a certain roughness, the entire outer surface of the detection unit is referred to as scale or slime. Therefore, it is possible to detect the adhesion of the adhered material without a time lag from the adhesion of the actual material. Further, in this invention, since the surface of the scale is the outer surface of the detection unit, the scale components in the survey water are also more likely to adhere to the outer surface of the detection unit than in the actual device, and the scale adheres to the actual device. Before doing so, scale adhesion detection can be performed.

  According to the fifth aspect of the present invention, since the temperature of the survey water can be measured with the temperature measuring body, the configuration of the adhering matter detection device is simplified and the adhering matter can be easily detected.

It is sectional drawing of the sensor which concerns on one embodiment of this invention. It is explanatory drawing in the case of forming a scale coating | coated part in the detection part of a sensor. When scale generation water generates a scale on a test piece, it is a figure which shows a scale generation speed with a graph. It is the figure which detects generation | occurrence | production of the scale by survey water using a sensor. It is a figure which shows the change of the electric current of the heating current supplied to a sensor, and the change of the temperature in the detection part corresponding to a heating current. It is a figure explaining the temperature around the cross section of a detection part, (a) shows the state before adhesion of a scale, (b) shows the state after adhesion of a scale. It is a figure which shows the temperature rise in the detection part by generation | occurrence | production of a scale with a graph, a is a case where a detection part has a scale coating | coated part, b is a case where a detection part does not have a scale coating | coated part. It is the figure which has detected generation | occurrence | production of the scale by the cooling water in a cooling tower using a sensor.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an adhering matter detection sensor according to an embodiment of the present invention.

  As shown in FIG. 1, the sensor 1 includes a metal tube 10 whose one end is closed, a heating element 11 and a temperature measuring body 12 inserted into the metal tube 10, and a heating element 11 and a temperature measuring body 12. It is formed so that the filler 13 filled in the metal tube 10 so as to surround and the inner and outer surface sides of the opening end portion 10a of the metal tube 10 are inserted, and the opening end portion 10a is closed and the metal tube 10 The resin part 14 formed sufficiently larger in diameter than the metal tube 10 so as to be a support part and the entire outer surface of the protruding part 10b of the metal pipe 10 outside the resin part 14 are made of a scale (hereinafter referred to as a scale component). And a scale covering portion 15 covered with a covering scale G).

  The portion protruding from the resin portion 14, that is, the protruding portion 10 b of the metal tube 10, the heating element 11, the temperature measuring body 12 and the filler 13 in the protruding portion 10 b, and the scale covering portion 15 are attached. The detection part K is formed.

  This sensor 1 immerses the detection unit K in survey water W0 (see FIG. 4) for investigating the occurrence of deposits (mainly scales, so the deposits will be described as scales below). However, the temperature change in the detection unit K caused by energization of the heating element 11 is measured via the temperature measuring body 12, and the temperature rise due to the heat transfer boundary film of water caused by the flow velocity of the survey water W0 (described later) ) Is constant, it is detected that the scale has adhered to the outer surface of the detection portion K (hereinafter referred to as detection surface K1) due to the change in temperature.

  One end of the metal tube 10 is closed in a hemispherical shape, and the outer surface is made smooth by a corrosion-resistant metal such as brass or stainless steel. As for the size of the metal tube 10, for example, the diameter D is 3 mm, the wall thickness is 0.1 mm, and the protruding portion 10 b length L excluding the opening end portion 10 a is 18 mm.

  The heating element 11 generates heat by energization and gives a predetermined heat flux to the entire detection unit K. The heating element 11 is formed by forming a platinum thin film on an insulating substrate, and has a size of 1.7φ × 4.0 mm and a metal film resistance of 120Ω. The heating element 11 is positioned at the center position of the metal tube 10 so that the center line overlaps the center axis of the metal tube 10, and generates a substantially uniform heat flow rate toward the detection surface K1 side. Three lead wires 11a, 11b, and 11c are attached to the heating element 11 via the metal tube 10, and a predetermined heating current is supplied to the heating element 11 via the lead wires 11a, 11b, and 11c and the metal tube 10. I is supplied.

  The temperature measuring element 12 measures the internal temperature of the detection unit K (preferably the inner surface temperature of the metal tube 10), and a thermocouple is used for this. The temperature measuring body 12 is positioned so as to contact the inner surface of the metal tube 10. Two lead wires 12a and 12b are attached to the temperature measuring body 12, and a temperature signal S can be taken out to the outside.

  The filler 13 is used to make the temperature in the metal tube 10 substantially uniform, and includes magnesium oxide (having good thermal conductivity and electrical insulation and an average particle size of 100 μm). Magnesia) powder is used. An epoxy resin having heat insulation and electrical insulation is used for the resin portion 14.

  The scale covering portion 15 is formed of a covering scale G made of the same scale component as the scale component of the scale to be detected (hereinafter referred to as the adhesion scale F, see FIG. 6). In this embodiment, the same calcium carbonate as the scale component of the adhesion scale F is used as the scale component of the coating scale G.

  The scale components of the coating scale G include calcium carbonate, basic zinc carbonate, calcium sulfate, calcium sulfite, barium sulfate, aluminum sulfate, calcium phosphate, zinc phosphate, calcium silicate, magnesium silicate, calcium oxalate, magnesium hydroxide , And zinc hydroxide, or a mixture of at least two of these may be considered.

  In this case, it is preferable that the scale component of the covering scale G be as close as possible to the scale component of the adhesion scale F generated by the survey water W0 in the actual machine. This is because the adhesion of the scale becomes easy and the adhesion of the scale can be detected earlier. As an example of bringing the scale component of the covering scale G closer to the scale component of the adhesion scale F, it is conceivable that these scale components are the same type. Examples of the same type of scale component include carbonates such as calcium carbonate and basic zinc carbonate, sulfates such as calcium sulfate, calcium sulfite, barium sulfate and aluminum sulfate, and phosphates such as calcium phosphate and zinc phosphate. Silicates such as calcium silicate and magnesium silicate, oxalates such as calcium oxalate, and hydroxides such as magnesium hydroxide and zinc hydroxide.

  In addition, the scale component of the adhesion scale F is carbonate scale component, sulfate scale component, phosphate scale component, silicate scale component, oxalate scale component, hydroxylation In the case where the scale component of at least any two of the physical scale component and the phosphate scale component is mixed, for example, the scale component of the coating scale G is replaced with the scale component of the adhesion scale F. Of these, a scale component including two or three main scale components (this may also be said to be the same type of scale component) may be considered.

  Next, a method of forming the scale covering portion 15 with the covering scale G on the outer surface of the protruding portion 10b of the metal tube 10 will be described. FIG. 2 shows a test facility A for forming the scale covering portion 15 on the outer surface of the protruding portion 10 b of the metal tube 10.

  As shown in FIG. 2, the test facility A is filled with a scale-generating water W1 that generates a scale, and is filled with a cylindrical container 100 having a capacity of 1 L (liter) having a closed lower end and the scale-generating water W1. The stirrer 110 that stirs the scale-generated water W1 magnetically using the stirrer 111 and the thermostat 120 that keeps the scale-generated water W1 in the container 100 at a constant temperature (for example, 30 ° C.). A pump 131, a pipe 132, and a container 133 filled with a calcium chloride aqueous solution, a calcium hardness replenisher 130 for supplying a hardness component (calcium) into the container 100, a pump 141, a pipe 142, and a sodium hydrogen carbonate aqueous solution. And a container 143 filled with a liquid in which a maleic acid polymer is added. M alkalinity (carbonic acid etc.) is contained in the container. And M alkalinity such supply machine 140 to supply, and a overflow pipe 150. by overflowing the scale formation water W1 in the container 100.

Scale generation water W1 is distilled water, calcium hardness (CaCO ₃ conversion) is 500 mg / L, M alkalinity (CaCO ₃ conversion) is 500 mg / L, and maleic acid polymer is only 5 mg / L (solid content concentration). It is dissolved and the scale component produces a calcium carbonate scale. The maleic acid polymer is a reaction inhibitor that prevents solid calcium carbonate from being generated and precipitated in water before scale generation.

  The stirrer 110 agitates the scale generation water W1 in the container 100 via the stirrer 111, and functions to keep the calcium hardness, M alkalinity, and maleic acid polymer concentrations in the scale generation water W1 constant. Have. In addition, this stirrer 110 is a heat transfer boundary film of water when the scale 1 is detected by the sensor 1 while the flow rate of the scale generation water W1 around the metal tube 10 immersed in the scale generation water W1 is kept constant. It also has the function of keeping the temperature rise (described later) due to.

  The calcium hardness replenisher 130 and the M alkalinity replenisher 140 are for replenishing the calcium hardness and M alkalinity in the scale-generated water W1, which are insufficient due to the generation of scale, and each supply flow rate is very small. The residence time in the container 100 is, for example, about 200 min, and the container 100 overflows from the overflow pipe 150 by the supply amount.

FIG. 3 shows a test piece made of stainless steel (SUS304) immersed in the scale generation water W1 in the container 100, taken out at regular intervals, weighed, and the scale deposition rate (mcm) by the scale generation water W1. In detail, mg / cm ² / month) is measured. From this figure, it can be understood that the adhesion rate of the scale increases almost linearly, and the scale generation water W1 sufficiently generates the scale.

  The scale covering portion 15 immerses the protruding portion 10b of the metal tube 10 in, for example, 48 hours in the scale generated water W1 of the test equipment A, and the scale generated water is placed on the entire outer surface of the protruding portion 10b of the metal tube 10. It is formed by depositing and fixing the dissolved component in W1 so that the scale component is coated with a coating scale G made of calcium carbonate with a substantially equal thickness.

  Next, a specific example of detecting the scale using the sensor 1 will be described. FIG. 4 shows a state in which the generation of scale due to the scale-generated water W <b> 1 of the test facility A is detected by the deposit detection device B provided with the sensor 1. In addition, since the scale generation water W1 can be said to be the survey water W0 for investigating the occurrence of the scale, the scale generation water W1 is hereinafter referred to as the survey water W0.

The attached matter detection device B includes a sensor 1, a detection controller 2, and a power source 3.
The detection controller 2 is a computer having a central processing unit (CPU), a memory such as a RAM and a ROM, and an input / output interface. The detection controller 2 operates according to a program. An amount control means 20 and an adhering matter detection means 21 are provided.

  The energization amount control means 20 controls the power source 3 so that the heating current I given from the power source 3 to the sensor 1 becomes a pulsed current as shown in FIG. In other words, the energization amount control means 20 sets the current value applied to the heating element 11 of the sensor 1 to a predetermined magnitude I0 in the first time zone t1, but the second time following the first time zone t1. In the band t2, the power supply 3 is controlled so as to continuously repeat zeroing. The energization amount control means 20 also has a function of notifying the adhering matter detection means 21 of the end timings of the first time zone t1 and the second time zone t2.

  Here, as shown in FIG. 5, when a constant current of magnitude I0 is applied to the heating element 11 of the sensor 1 during the first time zone t1, the heating element 11 generates heat by a predetermined amount of heat. A substantially uniform heat flow rate is generated from the detection part K of the sensor 1 toward the detection surface K1. Therefore, for example, as shown in FIG. 6A, around the detection portion K of the sensor 1 where the scale is not attached to the detection surface K1, the temperature rise ΔT1 due to the metal tube wall and the covering scale G A temperature rise ΔT2 and a temperature rise ΔT3 due to the heat transfer boundary film of water caused by the flow of the survey water W0 and the like occur, and the temperature measuring body 12 of the sensor 1 adds the survey water W0 to the sum of these temperature rises (ΔT1 + ΔT2 + ΔT3). The temperature T0 obtained by adding the water temperature TW0 is measured.

Subsequently, as shown in FIG. 5, when the current to the heating element 11 of the sensor 1 is set to zero only during the second time zone t2, the heating element 11 does not emit heat, so that the inside of the metal tube 10 of the sensor 1 The temperature gradually decreases and approaches the same temperature as the water temperature TW0 of the survey water W0, and the temperature measuring body 12 finally measures the water temperature TW0 of the survey water W0.
That is, T0 = ΔT1 + ΔT2 + ΔT3 + TW0,
T0−TW0 = ΔT1 + ΔT2 + ΔT3 (Equation (1)), and T0−TW0 can be calculated by the above equation (1).

  In addition, the temperature change in the detection part K when the heat generating body 11 is generating heat and when not generating heat is shown in FIG. Since the movement of heat takes time, a certain time is required until the temperature measured by the temperature measuring body 12 reaches the temperature to be obtained.

On the other hand, when the scale adheres to the detection surface K1, the temperature rise by the heat transfer boundary film of the survey water W0 becomes constant (ΔT3) by the action of the stirrer 110, and therefore, as shown in FIG. As described above, the temperature measuring element 12 measures the temperature Tp obtained by adding the temperature increase ΔT4 due to the adhesion scale and the temperature TWp of the survey water W0 to the above-described temperature increase (ΔT1 + ΔT2 + ΔT3) due to the heat generation of the heating element 11. Following this, when the current to the heating element 11 becomes zero and does not generate heat, the temperature measuring element 12 measures the temperature TWp of the survey water W0.
That is, Tp = ΔT1 + ΔT2 + ΔT3 + ΔT4 + TWp,
Tp-TWp = [Delta] T1 + [Delta] T2 + [Delta] T3 + [Delta] T4 (2) Equation (2), and Tp-TWp can be calculated from equation (2).

Therefore, the temperature rise ΔT4 due to scale adhesion is expressed by the following equation (2) − (1):
ΔT4 = Tp−TWp− (T0−TW0)
= Tp-T0- (TWp-TW0) (3) In this case, if the temperature of the survey water W0 is constant, the temperature rise ΔT4 is
ΔT4 = Tp−T0 (4).

  The adhering matter detection means 21 calculates and detects whether or not a scale has adhered to the detection surface K1 of the sensor 1 based on the temperature signal S from the sensor 1. The adhering matter detection means 21 stores the temperature T0 in the detection unit K and the temperature TW0 of the investigation water W0 in a state where the adhering scale F is not present on the detection surface K1 of the sensor 1, and this temperature T0, TW0 and the following (3) from the temperature Tn (n = 1, 2, 3,...) In the detection unit K measured at regular intervals and the temperature TWn (n = 1, 2, 3,...) Of the survey water W0. ) To calculate the temperature rise ΔT4 due to the scale.

  In this attached matter detection apparatus B, the energization amount control means 20 makes the first time zone t1 60 seconds, the second time zone t2 60 seconds, and the current magnitude I0 in the first time zone t1 to 40 mA. The power source 3 is controlled so that the adhering matter detection means 21 calculates the temperature increase ΔT4 due to the adhering scale F at regular intervals based on the equation (3) or (4). The temperature increase ΔT4 due to the adhesion scale F is indicated by a graph a in FIG. In this case, in order to clarify the action of the scale covering portion 15 of the sensor 1, the temperature rise in the similar detection portion (metal tube) by the conventional sensor not having the scale covering portion 15 on the outer surface of the metal tube 10 is illustrated. This is indicated by a graph b in FIG.

  In the conventional sensor in which the outer surface of the protruding portion 10b of the metal tube 10 is the detection surface, as is clear from the graph b in FIG. 7, a large temperature rise occurs in the detection portion (metal tube) even if time passes. Not. This is because the detection surface of the sensor is a smooth outer surface of the metal tube, so that the scale is difficult to adhere to the detection surface, and is partially attached to the detection surface while spreading over the entire surface. Moreover, since the thermal conductivity of the deposit is generally smaller than that of the metal tube that forms the detection surface, the heat from the heating element at the beginning of deposition of the scale (a state in which the scale is partially formed on the detection surface). Is released from the metal surface side without scale. For this reason, at the beginning of the adhesion of the scale, the temperature riser cannot sufficiently capture the temperature rise in the detection unit due to the scale.

  On the other hand, in the sensor 1 in which the outer surface of the scale covering portion 15 is the detection surface K1, the temperature in the detection portion K starts to rise immediately after the start of temperature measurement, as is apparent from the graph a in FIG. Has a temperature rise of about 0.2 ° C. in the detection section K. From this, it can be recognized that the scale has started to adhere to the entire surface of the detection surface K1 of the sensor 1 immediately after the start of temperature measurement.

  That is, in this sensor 1, the deposit detection surface K1 is formed from the surface of the coated scale G whose surface roughness is increased by the adhesion of the scale particles, so that this is a case where this is a smooth outer surface of the metal tube. As a result, the viscous boundary film around the detection surface K1 becomes thick, the scale particles easily stay and adhere to the detection surface K1, and the scale easily adheres to the entire detection surface K1. The same can be said for slime produced by microorganisms or the like in the survey water W0. Therefore, the sensor 1 is in a state in which deposits such as scales and slimes are likely to be adhered to the entire detection surface K1, and adhesion of the deposits in the actual machine can be detected without time lag.

  Further, in this sensor 1, since the outer surface of the coating scale G having the same crystal as the crystal of the adhesion scale F is used as the detection surface K1, the crystal of the adhesion scale F is more stable in terms of energy than the outer surface of the metal tube. It tends to occur on the coating scale C, that is, on the detection surface K1. For this reason, in this sensor 1, the scale component in the survey water W0 is also more likely to adhere to the detection surface K1 than in the case of the actual machine, and the adhesion of the scale is detected before the scale is attached in the actual machine. Can do.

  In this case, in this sensor 1, the scale component of the covering scale G is the same type as the scale component of the adhesion scale F in the actual machine. Therefore, the scale easily adheres to the detection surface K1, and the adhesion of the scale is detected earlier. It can be carried out.

  Furthermore, in the adhering matter detection apparatus B provided with the sensor 1, the current value is set to a predetermined magnitude I0 in the first time zone t1, but the current value is set to zero in the second time zone t2 following this. Since the energization amount control means 20 for controlling the energization amount to the heating element 11 of the sensor 1 is provided so as to repeat continuously, the energization current value to the heating element 11 is zero (second time). In the case of the belt), the temperature of the survey water W0 can be measured by the temperature measuring body 12 of the sensor 1, and the apparatus can be simplified and the detection of the adhering matter can be facilitated.

  Here, the scale coating portion 15 is not provided in the detection portion B of the sensor 1, and the entire outer surface of the protruding portion 10b of the metal tube 10 immersed in the survey water W0 is formed to have a predetermined roughness. Even when the entire outer surface of the protruding portion 10b is used as the detection surface K1 for the adhered matter, the viscous boundary film around the detection surface K1 is thicker than when the outer surface of the detection portion K is an outer surface of a smooth metal tube. Thus, the adhering matter is likely to stay and adhere to the detection surface K1. For this reason, even in this case, the deposit (scale or slime) easily adheres to the entire surface of the detection surface K1, and it is possible to detect the deposit on the actual machine and the deposit detection without time lag. In this case, the outer surface roughness of the metal tube 10 is similar to, for example, the outer surface roughness of the coating scale G, or the surface roughness of the casting, which is considered to have a large roughness on the inner surface of the pipe or the like. What is necessary is just to make it similar.

  In the sensor 1, the scale component of the coating scale G is the same type of scale component as that of the adhesion scale F, but the scale component of the coating scale G is not the same type as the scale component of the adhesion scale F. Even when the scale component is used, the sensor 1 can detect the occurrence of the scale before the scale is attached in the actual machine. Even if the scale components are different, the scale forming the detection surface K1 and the scale adhering to the scale are different from those in the water compared to the case where the metal surface and the scale adhering to the metal surface are completely different as in the case of the actual machine. This is because the scale is the same as the scale formed by precipitation of the melt.

  Further, when the energization amount control means 20 of the attached matter detection apparatus B is energized to the heating element 11 of the sensor 1, the energization amount control means 20 does not have a time zone during which no current flows (second time zone t2). The temperature of the survey water W0 may be measured by temperature measuring means different from the temperature measuring body 12, and the temperature signal may be transmitted to the detection controller 2.

  Further, the current control value in the second time zone t2 by the energization amount control means 20 may not be zero but may be a small value close to zero.

  Next, a case where the generation of scale due to the cooling water W2 in the cooling tower 200 is detected using another attached matter detection device C will be described with reference to FIG.

  Here, the cooling tower 200 sprays the cooling water W2 from the water spray nozzle 201a provided in the upper header 201, and cools the sprinkled cooling water W2 in contact with the outside air Q in the filler 202. The cooled cooling water W2 is temporarily stored in the lower tank portion 203. The cooling water W2 in the tank unit 203 is sent to the heat exchanger 230 via the pump 210 and the pipe 220, and after the fluid in the heat exchanger 230 is cooled and warmed, the cooling tower 200 is cooled by the pipe 220. Is returned to the header 201 and circulated.

  The adhering matter detection device C includes a sensor 1, a determination controller 2, a power source 3, a measurement cell 4, a pump 5, an inlet pipe 6 and an outlet pipe 7.

  The measurement cell 4 has the sensor 1 installed therein and is connected to the tank unit 203 of the cooling tower 200 via the inlet pipe 6 and the outlet pipe 7. The cooling water W2 in the tank unit 203 of the cooling tower 200, that is, the investigation water W0 is sent into the measurement cell 4 through the inlet pipe 6 and the pump 5, and the detection unit K of the sensor 1 is After contact, it is returned to the cooling tower 200 via the outlet pipe 7.

  Here, in the measurement cell 4, the detection unit K of the sensor 1 and the survey water W0 are located in the position of the detection unit K and the survey water so that the temperature rise ΔT3 due to the heat transfer boundary film of the survey water W0 is always constant. It is assumed that the flow rate of W0 is adjusted. When the pulsed current is supplied as the heating current I from the power source 3 to the sensor 1, the water temperature of the survey water W0 is constant from the end of the first time zone t1 to the end of the second time zone t2. Suppose that Furthermore, in this investigation water W0, it is assumed that no slime is generated as a deposit.

  For example, if the survey water W0 is considered to have a sulfate-based scale component, the scale coating portion 15 of the sensor 1 uses a coating scale G in which the scale component is, for example, calcium sulfate. Is formed. Further, when the survey water W0 is considered to have, for example, a carbonate-based and phosphate-based scale component, the scale component is, for example, using a coating scale G made of calcium carbonate and calcium phosphate, A scale covering portion 15 of the sensor 1 is formed.

The deposit detection means 21 of the determination controller 2 calculates the temperature rise ΔT4 due to the deposit scale F using the equation (3). If this temperature rise ΔT4 is 0.1 ° C. or more, for example, the sensor 1 It is determined that the scale is attached to the detection unit K (the attached scale F is generated).
Note that the temperature difference value (0.1 ° C.), which is a criterion for determining scale adhesion, should be determined in consideration of temperature measurement errors and the like.

  The sensor 1 of the deposit detection apparatus B can also detect the occurrence of scale before the scale adheres to the cooling tower 200. In addition, after detecting the adhesion scale F, in order to detect the adhesion of the scale by the adhesion detection means 21, the temperatures Tn and TWn at the time when it is determined that the adhesion scale F has occurred are set as T0 and TW0. The adhesion of a new scale to the detection unit K of the sensor 1 may be detected.

DESCRIPTION OF SYMBOLS 1 Sensor 10 Metal pipe 11 Heating element 12 Temperature sensing element 13 Filler 20 Energizing amount control means 21 Adhered matter detection means B, C Adhered matter detection apparatus G Covering scale K Detection part K1 Detection surface (outer surface of a detection part)
W0 survey water

Claims (5)

In the detection unit, which is generated by energizing the heating element by immersing a detection unit filled with a heat-conducting filler in a metal tube in which the heating element and the temperature measuring element are inserted. A sensor for detecting an adhering substance that detects adhering substances adhering to the outer surface of the detection unit according to a change in temperature of
A sensor for detecting attached matter, wherein an outer surface of the metal tube is formed to have a predetermined roughness, and the outer surface of the detection unit is given a predetermined roughness. In the detection unit, which is generated by energizing the heating element by immersing a detection unit filled with a heat-conducting filler in a metal tube in which the heating element and the temperature measuring element are inserted. A sensor for detecting an adhering substance that detects adhering substances adhering to the outer surface of the detection unit according to a change in temperature of
A sensor for detecting an adhering substance, wherein an outer surface of the metal tube is covered with a scale, and an outer surface of the detection unit is formed by a surface of the scale.   The scale components include calcium carbonate, basic zinc carbonate, calcium sulfate, calcium sulfite, barium sulfate, aluminum sulfate, calcium phosphate, zinc phosphate, calcium silicate, magnesium silicate, calcium oxalate, magnesium hydroxide, and water. The sensor for deposit detection according to claim 2, wherein any one of zinc oxides or a mixture of at least two of them is mixed. A sensor in which a heat-conducting filler is filled in a metal tube in which a heating element and a temperature sensing element are inserted, a sensor immersed in the investigation water for deposits, and energization of the sensor to the heating element An energizing amount control means for controlling the amount, and an adhering matter detecting means for detecting adhering matter adhering to the outer surface of the detecting portion by a change in temperature in the detecting portion caused by energizing the heating element of the sensor. An attached matter detection apparatus comprising:
An attached matter detection apparatus, wherein an outer surface of the metal tube of the sensor is covered with a scale, and an outer surface of the detection unit is formed by a surface of the scale.   The energization amount control means continuously sets the current value to a predetermined magnitude in the first time zone, but sets the current value to zero or a value close to zero in the second time zone following this. The attached matter detection apparatus according to claim 4, wherein an energization amount of the sensor to the heating element is controlled.

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