JP2005193169A - Filter press apparatus and its operating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter press apparatus in which the dryness of cake is grasped so that the cake can be dried at a suitable cycle time. <P>SOLUTION: This filter press apparatus is provided with: a cake temperature measuring means for measuring the temperature of the cake under drying treatment; a cake target temperature setting means for setting the predetermined cake target temperature corresponding to the target dryness of the cake on the basis of correlation data between preset cake dryness and cake temperature and a control means for completing the drying of the cake when the cake temperature measured by the cake temperature measuring means reaches the predetermined cake target temperature. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a filter press apparatus and an operation method thereof, and more particularly to a filter press apparatus having a function of drying cake and an operation method thereof.

  Conventionally, the number of cycles per day of a filter press device is determined by determining the cycle time in a series of processes such as filtration process, washing process and drying process (or filtration process, pressing process and drying process). The number of cycles per day was determined by dividing the time by the cycle time.

  Such a standard cycle time is usually set in accordance with the longest cycle time in order to cope with various factors affecting the drying time such as the concentration fluctuation of the supplied slurry liquid. In particular, since the dryness of the cake cannot be recognized from the outside, a sufficient drying time is set. In addition, when examining the dryness of the cake, it was necessary to investigate the dryness of the cake by once opening the filter press and sampling the cake.

  However, since the cycle time is long, the operation rate of the equipment is lowered, and there is a problem that the capacity of the apparatus cannot be fully utilized. In addition, when investigating the actual dryness of the cake, the filter press must be opened once and the dryness of the cake must be investigated by sampling, resulting in extra work and time loss. .

  For this reason, it is desired that the dryness of the cake is grasped during actual operation without opening the filter press device, and the drying process is completed within a suitable drying time.

  Accordingly, an object of the present invention is to provide a new and improved filter press apparatus and filter capable of grasping the dryness of the cake without opening the filter press apparatus and executing the cake drying process with a suitable cycle time. It is to provide a pressing apparatus method.

  In order to solve the above problems, in the first aspect of the present invention, a filter press device for filtering slurry, a filter plate provided in the filter press device, and a cake after filtering the slurry are dried. A heat source that provides the heat necessary to perform, vacuum means for lowering the evaporation temperature of water in the cake during the cake drying process, and the cake heated by the heat source during the cake drying process. In the filter press device comprising the water vapor suction means for sucking water vapor generated from the cake, the filter press device further comprises a cake temperature measuring means for measuring the temperature of the cake during the drying process of the cake, and a preset value. Based on the correlation data between the cake dryness and cake temperature, a predetermined cake target temperature corresponding to the target cake dryness is obtained. Cake target temperature setting means to be determined, and control means for terminating the drying process of the cake when the cake temperature measured by the cake temperature measuring means reaches the predetermined cake target temperature. A featured filter press apparatus is provided.

  In the above-described invention, the cake dryness is recognized as an alternative factor. Therefore, even when various factors affecting the drying time such as the concentration variation of the slurry liquid fluctuate, the optimum and shortest time is preferable. The drying process can be completed within the drying time. This reduces the number of cycles due to excessive drying time, energy loss (energy saving), omission of open frames for sampling of the filter press, and calculation of cake dryness by sampling. Reduction is realized. As a result, the operating rate of the filter press apparatus is increased, so that the capacity of the filter press apparatus can be fully utilized. The cake target dryness can be derived from, for example, the degree of vacuum in the filter press and the hot water temperature of the (hot water) heat source for the cake drying process.

  In order to solve the above problems, in a second aspect of the present invention, a filter press device for filtering slurry, a filter plate provided in the filter press device, and a cake after filtering the slurry are dried. A heat source that provides the heat necessary to perform, vacuum means for lowering the evaporation temperature of water in the cake during the cake drying process, and the cake heated by the heat source during the cake drying process. And a water vapor suction means for sucking water vapor generated from the filter, the filter press device further drains water vapor from the cake sucked by the water vapor suction means during the drying process of the cake. A capacitor, drain amount measuring means for measuring the amount of drain trapped in the capacitor over time, and the drain amount measurement. Based on the drain amount measured over time by the means, the drain change amount calculating means for calculating the amount of change in the drain amount in a predetermined time, and on the basis of the correlation data between the preset cake dryness and the drain change amount , A target drain change amount setting means for setting a predetermined target drain change amount corresponding to the target dryness of the cake, and the drain change amount calculated by the drain change amount calculation means is set to the predetermined target drain change amount. And a control means for ending the cake drying process when the cake is reached.

  In the above-described invention, since the amount of change in the amount of drain trapped in the capacitor is used as a criterion for determining the cake dryness, the cake dryness can be grasped more accurately particularly in the low dryness region. That is, it is confirmed that the amount of drain trapped in the condenser that drains the sucked water vapor decreases and finally approaches zero when the cake drying progresses and the amount of evaporation of the cake moisture decreases. Thus, if the amount of drain change directly related to the cake dryness is confirmed, the cake dryness can be more accurately determined particularly in the low dryness region.

  In order to solve the above problems, in a third aspect of the present invention, a filter press device for filtering slurry, a filter plate provided in the filter press device, and a cake after filtering the slurry are provided. A heat source that provides the heat necessary for the drying process, a vacuum means for lowering the evaporation temperature of water in the cake during the drying process of the cake, and heated by the heat source during the drying process of the cake A water vapor suction means for sucking water vapor generated from the cake; and the filter press device further comprises a cake temperature measuring means for measuring the temperature of the cake during the drying process of the cake, Based on the correlation data between the preset cake dryness and cake temperature, the predetermined cake target corresponding to the target dryness of the cake A cake target temperature setting means for setting the temperature, a condenser for draining water vapor from the cake sucked by the water vapor suction means during the drying process of the cake, and a drain amount trapped in the condenser over time. A drain amount measuring means for measuring, a drain change amount calculating means for calculating a change amount of the drain amount in a predetermined time based on the drain amount measured over time by the drain amount measuring means, and a preset cake drying Target drain change amount setting means for setting a predetermined target drain change amount corresponding to the target dryness of the cake based on the correlation data between the degree of change and the drain change amount, and the predetermined amount of dryness as an index of the cake When both the cake target temperature and the predetermined target drain change amount are set, the cake temperature measured by the cake temperature measuring means is A control means for ending the cake drying process when a predetermined cake target temperature is reached and the drain change amount calculated by the drain change amount calculation means reaches the predetermined target drain change amount; A filter press device is provided.

  In the above-described invention, the cake temperature and the drain change amount are combined and used as a criterion for determining the cake dryness. Therefore, particularly in the region where the evaporation form of the cake moisture changes (details will be described later, the intermediate dryness region) The dryness of the cake can be grasped more accurately.

  Further, if the correlation data between the cake dryness and the cake temperature, or the correlation data between the cake dryness and the amount of drain change is acquired in the preliminary operation of the filter press device, if it is configured, it depends on many factors. The data on the dryness of the cake subject to fluctuations can be obtained more accurately by testing with the pilot machine or actual equipment using the actual slurry liquid, heating medium temperature, actual equipment vacuum, etc. The degree of dryness can be determined. As a result, the drying state of the cake subject to fluctuations due to various factors can be grasped more accurately, so that the drying process is completed depending on the desired cake drying degree (for example, arbitrary drying degree such as 50%, 99%, etc.). The cake temperature to be set can be set to finish the drying process.

  The control means stores correlation data between a plurality of cake drynesses and cake temperatures or a plurality of cake drynesses and drainage change amounts according to various cake drying treatment conditions, If the controller is configured so as to select correlation data between a suitable cake dryness and cake temperature or a suitable cake dryness and drain change amount according to various cake drying processing conditions, Since the optimum correlation data is selected, it is possible to more accurately determine the dryness of the cake subject to fluctuations due to various factors.

The cake temperature value is obtained by arithmetically averaging the cake temperatures (Tc1, Tc2, Tc3... TcK) in any K chambers among the N chambers of the filter press apparatus. Value, ie
TcM = (Tc1 + Tc2 + Tc3 +... + TcK) / K
The value calculated by the following equation can be used.

Further, the cake temperature value was obtained by geometrically averaging the cake temperatures (Tc1, Tc2, Tc3... TcK) in arbitrary K chambers among the N chambers of the filter press device. Value, ie
TcM ′ = (Tc1 * Tc2 * Tc3 *... * TcK) ^{1 / K}
The value (TcM ′) calculated by the following formula can be used.

  The cake temperature may be measured at a location within 5 to 50% of the distance from the center of the cake to the edge by counting from the edge of the cake. The temperature can be suitably measured. That is, if it is 5% or less, the temperature in the vicinity of the edge of the cake is measured, which is not preferable because the accurate cake temperature cannot be measured accurately. On the other hand, if it is 50% or more, the pressure of the slurry (or filtrate) flowing in the filter plate causes the temperature sensor such as a thermocouple or resistance temperature detector to be swept away, causing deformation and being unevenly distributed in an inappropriate place. It is not preferable because it may be damaged.

  In order to solve the above problem, in a fourth aspect of the present invention, a filter press device for filtering slurry, a filter plate provided in the filter press device, and a cake after filtering the slurry are dried. A heat source that provides the heat necessary to perform, vacuum means for lowering the evaporation temperature of water in the cake during the cake drying process, and the cake heated by the heat source during the cake drying process. In the filter press device comprising the water vapor suction means for sucking water vapor generated from the cake, the cake temperature measuring means measures the temperature of the cake during the drying process of the cake, and the cake target temperature setting means is preset. A predetermined cake target temperature corresponding to the target dryness of the cake is set based on the correlation data between the cake dryness and the cake temperature. The control means provides a method for operating the filter press device, wherein the cake drying process is terminated when the cake temperature measured by the cake temperature measuring means reaches the predetermined cake target temperature. Is done.

  In the above-described invention, the cake dryness is recognized as an alternative factor. Therefore, even when various factors affecting the drying time such as the concentration variation of the slurry liquid fluctuate, the optimum and shortest time is preferable. The drying process can be completed within the drying time. This reduces the number of cycles due to excessive drying time, energy loss (energy saving), omission of open frames for sampling of the filter press, and calculation of cake dryness by sampling. Reduction is realized. As a result, the operating rate of the filter press apparatus is increased, so that the capacity of the filter press apparatus can be fully utilized. The cake target dryness can be derived from, for example, the degree of vacuum in the filter press and the hot water temperature of the (hot water) heat source for the cake drying process.

  In order to solve the above problems, in a fifth aspect of the present invention, a filter press device for filtering slurry, a filter plate provided in the filter press device, and a cake after filtering the slurry are dried. A heat source that provides the heat necessary to perform, vacuum means for lowering the evaporation temperature of water in the cake during the cake drying process, and the cake heated by the heat source during the cake drying process. And a water vapor suction means for sucking water vapor generated from the condenser, wherein the condenser drains the water vapor from the cake sucked by the water vapor suction means during the drying process of the cake, and the drain amount measuring means is The amount of drain trapped in the capacitor is measured over time, and the drain change amount calculation means Based on the measured drain amount, a change amount of the drain amount in a predetermined time is calculated, and the target drain change amount setting means is configured to perform the cake drainage based on the correlation data between the cake dryness and the drain change amount set in advance. A predetermined target drain change amount corresponding to the target dryness of the water, and the control means, when the drain change amount calculated by the drain change amount calculation means reaches the predetermined target drain change amount, There is provided a method of operating a filter press characterized by terminating the cake drying process.

  In the above-described invention, since the amount of change in the amount of drain trapped in the capacitor is used as a criterion for determining the cake dryness, the cake dryness can be grasped more accurately, particularly in the low dryness region. That is, it is confirmed that the amount of drain trapped in the condenser that drains the sucked water vapor decreases and finally approaches zero when the cake drying progresses and the amount of evaporation of the cake moisture decreases. Thus, if the amount of drain change directly related to the cake dryness is confirmed, the cake dryness can be more accurately determined particularly in the low dryness region.

  In order to solve the above problems, in a sixth aspect of the present invention, a filter press device for filtering slurry, a filter plate provided in the filter press device, and a cake after filtering the slurry are dried. A heat source that provides the heat necessary to perform, vacuum means for lowering the evaporation temperature of water in the cake during the cake drying process, and the cake heated by the heat source during the cake drying process. In the filter press device comprising the water vapor suction means for sucking water vapor generated from the cake, the cake temperature measuring means measures the temperature of the cake during the drying process of the cake, and the cake target temperature setting means is preset. A predetermined cake target temperature corresponding to the target dryness of the cake is set based on the correlation data between the cake dryness and the cake temperature. The condenser drains the water vapor from the cake sucked by the water vapor suction means during the drying process of the cake, and the drain amount measuring means measures the amount of drain trapped in the capacitor over time, and changes the drain. The amount calculating means calculates a change amount of the drain amount in a predetermined time based on the drain amount measured over time by the drain amount measuring means, and the target drain change amount setting means has a cake dryness set in advance. And a predetermined target drain change amount corresponding to the target dryness of the cake based on the correlation data between the cake and the drain change amount, and the control means uses the predetermined cake target temperature as an index of the dryness of the cake. And the predetermined target drain change amount are set, the cake temperature measured by the cake temperature measuring means reaches the predetermined cake target temperature. And an operation method of the filter press device, wherein when the drain change amount calculated by the drain change amount calculation means reaches the predetermined target drain change amount, the drying process of the cake is terminated. Provided.

  In the above-described invention, the cake temperature and the drain change amount are combined and used as a criterion for determining the cake dryness. Therefore, particularly in the region where the evaporation form of the cake moisture changes (details will be described later, the intermediate dryness region) The dryness of the cake can be grasped more accurately.

  Further, if the correlation data between the cake dryness and the cake temperature, or the correlation data between the cake dryness and the amount of drain change is acquired in the preliminary operation of the filter press device, if it is configured, it depends on many factors. The data on the dryness of the cake subject to fluctuations can be obtained more accurately by testing with the pilot machine or actual equipment using the actual slurry liquid, heating medium temperature, actual equipment vacuum, etc. The degree of dryness can be determined. As a result, the drying state of the cake subject to fluctuations due to various factors can be grasped more accurately, so that the drying process is completed depending on the desired cake drying degree (for example, arbitrary drying degree such as 50%, 99%, etc.). The cake temperature to be set can be set to finish the drying process.

  The control means stores correlation data between a plurality of cake drynesses and cake temperatures or a plurality of cake drynesses and drainage change amounts according to various cake drying treatment conditions, If the controller is configured so as to select correlation data between a suitable cake dryness and cake temperature or a suitable cake dryness and drain change amount according to various cake drying processing conditions, Since the optimum correlation data is selected, it is possible to more accurately determine the dryness of the cake subject to fluctuations due to various factors.

The cake temperature value is obtained by arithmetically averaging the cake temperatures (Tc1, Tc2, Tc3... TcK) in any K chambers among the N chambers of the filter press apparatus. Value, ie
TcM = (Tc1 + Tc2 + Tc3 +... + TcK) / K
The value (TcM) calculated by the following equation can be used.

Further, the cake temperature value was obtained by geometrically averaging the cake temperatures (Tc1, Tc2, Tc3... TcK) in arbitrary K chambers among the N chambers of the filter press device. Value, ie
TcM ′ = (Tc1 * Tc2 * Tc3 *... * TcK) ^{1 / K}
The value (TcM ′) calculated by the following formula can be used.

  The cake temperature may be measured at a location within 5 to 50% of the distance from the center of the cake to the edge by counting from the edge of the cake. The temperature can be suitably measured. That is, if it is 5% or less, the temperature in the vicinity of the edge of the cake is measured, which is not preferable because the accurate cake temperature cannot be measured accurately. On the other hand, if it is 50% or more, the pressure of the slurry (or filtrate) flowing in the filter plate causes the temperature sensor such as a thermocouple or resistance temperature detector to be swept away, causing deformation and being unevenly distributed in an inappropriate place. It is not preferable because it may be damaged.

  In the present invention, the degree of cake dryness is recognized as an alternative factor, so that even when various factors affecting the drying time, such as the concentration fluctuation of the slurry liquid, fluctuate, the drying process is performed with the optimum drying time. Can be terminated. This reduces the number of cycles due to excessive drying time, energy loss (energy saving), omission of open frames for sampling of the filter press, and calculation of cake dryness by sampling. Reduction is realized. As a result, the operating rate of the filter press apparatus is increased, so that the capacity of the filter press apparatus can be fully utilized.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
First, based on FIGS. 1-6, the structure of the filter press apparatus 1 concerning 1st Embodiment is demonstrated. FIG. 1 is a side view showing a schematic outer shape / arrangement of the filter press apparatus according to the present embodiment. FIG. 2 is an explanatory diagram for explaining the configuration of the filter press device according to the present embodiment. Unlike the prior art, the filter press device 1 according to the present embodiment is provided with a thermocouple 70 for directly measuring the cake temperature in the filter plate 3, and a calibration meter for calibrating the drain amount. 61 is attached.

  First, as shown in FIGS. 1 and 2, a filter press device 1 according to the present embodiment includes a filter having a plurality of chamber-type filter plates 3 (hereinafter simply referred to as filter plates) suspended on bars. A press device 1 is provided. The filter plate 3 is pressed together by a hydraulic unit 4 having a pump 5 and a pressure sensor 6.

  The filter press device 1 is connected to a supply system 9 via a supply line 7 and a valve 8. The supply system 9 includes a stirring tank 10, a reaction device 11 that converts the sediment provided upstream thereof into a cotton-like lump, a supply pump 12 connected to the downstream side of the stirring tank 10, and control of this pump. For this purpose, a pressure sensor 13 provided between the pump and the valve 8 is provided. The supply pump 12 can be designed as, for example, a membrane piston pump, a screw blade pump, or a centrifugal centrifugal pump. The filter press apparatus 1 is connected to a filtrate tank 17 through a filtration line 15 having a controllable valve 16. Since this filter press apparatus 1 has a cavity and is designed as a chamber filter press, it is connected to the first branch line 18 a of the pressure line 18 and the return line 19. Although details will be described later, unlike the conventional case, the filter press device according to the present embodiment is provided with a temperature sensor such as a thermocouple or a resistance temperature detector for directly measuring the cake temperature in the filter plate. It has been.

  The supply line 7 is further connected to the agitation tank 10 via a return line having a valve 14. Further, in order to avoid the solid part of the slurry in the supply line 7 from being fixed, it is preferable to configure the supply line 7 so as to be positioned at the center height of the filter press apparatus 1. Connection openings can be made at a plurality of points so that the flow can be changed on the upper side or in the middle thereof. That is, the slurry in which the solid part is likely to precipitate can be supplied from above, and the slurry in which the solid part is likely to float can be supplied from below.

  The pressure line 18 includes a plurality of branch lines as heating lines at the same time, is monitored by the temperature sensor 20, and has a relief valve 52 attached thereto. The pressure line 18 is led to a superheated steam unit 22 (specifically, an output port of the boiler 23 of the superheated steam unit 22) as a high-temperature heat source through a controllable valve 21a.

  The superheated steam unit 22 includes a temperature control device 24 that controls the output of the electric heating device 25 that heats the boiler 23 based on the temperature in the pressure line 18, and a condensation pump 26 that is controlled by the pressure control device 27 in the same manner. And a condensing device 28 connected on the return line 19 connected to the input of the condensing pump 26 via a controllable valve 29. Further, a water supply connection 31 is connected to the superheated steam unit 22 on the upstream side of the circulation pump 26 via a valve 30 controlled by a pressure control device 27.

  The pressure line 18 has two branch lines 18b, 18c, which are connected to the supply line 7 and the filtrate line 15 via controllable valves 21b, 21c, respectively.

  The vacuum plant 40 includes a vacuum pump 41 and a pressure control device 43, and a controllable valve 42 is connected to the downstream side of the vacuum pump 41. The pressure control device 43 controls the vacuum pump 41 according to the pressure in the pressure line 33. Therefore, the pressure line 33 functions as an exhaust line at the same time.

  In the present embodiment, a line for sucking water vapor generated during cake drying is provided from the filtration line 15 connected to the cake being dried and the exhaust line 33a, and the vacuum is passed through a condenser (reference numeral 60 in FIG. 3). It leads to a pump (reference numeral 41 in FIG. 3). Further, a calibration meter (reference numeral 61 in FIG. 3) for calibrating the drain amount captured by the capacitor is installed. Although details will be described later, the amount of change in drain (or the amount of drain) measured by such a calibration meter can be used as an index for recognizing the degree of cake dryness.

  The filter press device 1 is controlled by a control device 44. The control device 44 controls the opening and closing of each valve by a manual or selectable program. Each unit or plant is controlled by setting a predetermined pressure, temperature and drain amount, for example.

  Furthermore, unlike the prior art, the control device 44 according to the present embodiment receives temperature data in the cake drying process measured by a thermocouple installed on the filter plate, and the temperature data is set to a predetermined value. When the cake target temperature is reached, the cake drying process can be controlled to end. In addition, the controller 44 receives the drain amount data from the calibration meter provided in the drain pipe over time, calculates the drain change amount based on the drain amount data, and discharges it from the filter press device. It is possible to control the cake drying process to be terminated when the amount of change in the drain amount is equal to or less than a preset target drain change amount. The drain change amount data is used as effective data together with the cake temperature data.

  Next, the characteristic part of the filter press apparatus concerning this embodiment is demonstrated based on FIGS. FIG. 3 is a front view showing the configuration of the filter press apparatus according to the present embodiment. FIG. 4 is a graph showing various measurement data during the drying process of the cake according to the present embodiment. FIG. 5 is a graph showing the correlation data between the cake dryness and the cake temperature and the correlation data between the cake dryness and the drain change amount according to the first embodiment. FIG. 6 is a front view showing the configuration of the characteristic part of the filter plate according to the present embodiment.

  First, as shown in FIG. 3, the filter press device 1 according to the present embodiment is provided with a thermocouple 70 for measuring the cake temperature in the filter plate 3 in the cake drying process, unlike the conventional case. . The temperature data measured by the thermocouple is input to the control device 44 via the thermometer 71, and when the temperature data reaches a predetermined cake target temperature set in advance, the cake drying process is performed. Is controlled to end.

  That is, in the cake drying process, a phenomenon occurs in which the moisture of the cake reaches the surface of the cake through a capillary existing in the cake and evaporates. When such a phenomenon occurs, the cake temperature is kept almost constant, but when the moisture in the cake decreases, evaporation occurs in the capillary tube. In the drying stage where the evaporation phenomenon in the capillary tube occurs, the temperature corresponding to the evaporation temperature of water due to the degree of vacuum cannot be kept constant, and the cake temperature Tc increases. In the present embodiment, the cake dryness can be detected by reaching or reaching a predetermined temperature at the inflection point of the cake temperature Tc. The predetermined temperature can be derived from, for example, the degree of vacuum in the filter press and the hot water temperature of the (hot water) heat source for the cake drying process.

  Furthermore, in the filter press apparatus 1 according to the present embodiment, unlike the conventional case, the capacitor 60 for capturing the evaporated water of the cake in the cake drying process and the drain amount captured by the capacitor 60 are calibrated. The calibration meter 61 is arranged. The drain amount data is input to the control device 44 to calculate drain change amount data, and when the drain change amount reaches a preset drain change amount, the cake drying process is terminated. Be controlled. In the present embodiment, the configuration for detecting the cake dryness based on the drain change amount will be described. However, the cake dryness can also be detected by the drain amount itself.

  That is, in the above-described method for detecting the cake dryness by detecting the cake temperature, the cake dryness advances and the cake temperature starts to rise. In many cases, the cake dryness (solid content weight%) is, for example, 80 to 90%. (Hereinafter referred to as a high dryness region), it is not very effective when the target cake dryness is, for example, 80 to 90% or less. In this case, the drain change amount (the increase amount of the drain amount in a predetermined time) becomes more effective. That is, for example, in the case of 80 to 90% or less (hereinafter referred to as a low dryness region), the amount of increase in the amount of drain trapped in the capacitor is increased as drying progresses. Will decrease. In such a low dryness region, it is possible to detect that the cake has been dried by detecting the amount of drain change. Further, in the boundary region between the high dryness region and the low dryness region (hereinafter referred to as the intermediate dryness region), both the cake temperature and the drain change amount are adopted as the indicators of the cake dryness. preferable. This makes it possible to detect the cake dryness more accurately.

  As will be described in detail later, the high dryness region means a region having a higher dryness than the cake dryness indicated by the starting point (inflection point) of the cake temperature during the cake drying process. The region means a region having a dryness lower than the cake dryness indicated by the inflection point. The medium dryness region is a region near the inflection point, and is a region where the above-described cake moisture evaporation form changes. Of course, the high, medium, and low dry areas are not clearly set, and only the cake temperature is used as an index to detect the cake dryness as accurately as possible. This is a convenient standard adopted to determine whether only the drain change amount is used or whether both the cake temperature and the drain change amount are used. Further, such a standard is different depending on the cake drying treatment condition that varies depending on various factors, and can be used by design to detect the cake dryness as accurate as possible.

  Next, various measurement data during the drying process of the cake are shown in FIG. FIG. 4A is a graph showing the degree of vacuum of the filter press apparatus in the cake drying process over time. FIG. 4B is a graph showing the evaporating vapor temperature of the filter press apparatus in the cake drying process over time. FIG.4 (c) is a graph which shows the cake temperature in the filter frame of the filter press apparatus in a cake drying process with time. FIG. 4 (d) is a graph showing the dry cake DS% (Dry Solidity) of the filter press apparatus in the cake drying process over time. FIG. 4 (e) is a graph showing the amount of evaporated vapor recovered (drain amount) of the filter press device in the cake drying process over time.

  First, as shown in FIG. 4A, the cake moisture evaporates and the degree of vacuum gradually decreases as the cake drying process proceeds, but when the cake moisture decreases, the degree of vacuum gradually increases. Further, as shown in FIG. 4B, the evaporation vapor temperature of the cake moisture increases as the vacuum degree of the filter press device decreases, and the evaporation vapor temperature also decreases as the vacuum degree increases. .

  Furthermore, as shown in FIG. 4 (c), the cake temperature in the filter frame is maintained at a constant temperature for a predetermined period after the cake drying process is started, but when the cake dryness advances and reaches a predetermined stage. The cake temperature Tc rises rapidly. The cake temperature Tc is kept constant when a phenomenon occurs in which the moisture of the cake reaches the surface of the cake through the capillaries existing in the cake and evaporates. When the cake drying process proceeds and evaporation occurs in the capillary, the temperature corresponding to the evaporation temperature of water due to the degree of vacuum cannot be kept constant, and the cake temperature Tc rises.

  Further, as shown in FIG. 4D, the cake dryness increases almost linearly as the cake drying process proceeds. Further, as shown in FIG. 4 (e), the amount of recovered vapor (drain amount) rises in a gentle convex curve up to the inflection point of the cake temperature, and then the drain amount rapidly decreases. . This is because up to the inflection point of the cake temperature, the moisture content of the cake reaches the surface of the cake through the capillaries existing in the cake and evaporates, so the amount of water vapor supplied as the cake drying progresses. This is because of the gradual decrease. Also, when the inflection point of the cake temperature is passed, the evaporation of the cake moisture occurs in the capillary tube, and the cake moisture that evaporates becomes extremely reduced.

  As shown in FIG. 4C, it can be seen that the cake dryness is, for example, about 90% at the inflection point where the temperature of the cake in the filter frame rapidly increases. Thus, in this example, when the cake dryness is less than about 90% (low dryness region), the cake dryness cannot be grasped because the cake temperature is constant, but the cake dryness is, for example, about 90% or more. In the range (high dryness region), the cake dryness is data having a correlation with the cake temperature. As a result, for example, in the range where the cake dryness is about 90% or more (high dryness region), the cake dryness can be grasped by measuring the cake temperature. In addition, it is recognized that the cake temperature finally approaches the hot water temperature of the (hot water) heat source for the cake drying process. For example, the cake target is determined from the hot water temperature and the degree of vacuum in the filter press. The temperature can also be derived.

  Further, as shown in FIG. 4 (e), the amount of recovered vapor (drain amount) rises in a gentle convex curve up to the inflection point of the cake temperature, and thereafter the drain amount increases rapidly. Decrease. Thus, in this example, especially in the range of the cake dryness, the cake dryness is data having a correlation with the drain amount. In this way, it is possible to determine the degree of cake dryness based on the amount of drain, but the amount of drain varies greatly depending on, for example, the amount of cake moisture after slurry pressing (before the drying process) and the amount of cake subjected to drying. Therefore, it is preferable to use the amount of change in drain as an index of cake dryness. As a result, for example, even in a low dryness region where the cake dryness is, for example, about 90% or less, the drainage change amount can be calculated from the measured drainage amount to grasp the cake dryness.

  In this way, the amount of change in drain is calculated from the amount of drain trapped in the condenser and used as a criterion for determining the cake dryness. Therefore, it is possible to more accurately determine the dryness of the cake, especially in the low dryness region. it can. That is, when cake drying progresses and the amount of cake moisture evaporated decreases, it is confirmed that the amount of drain trapped in the condenser that drains the sucked water vapor decreases and approaches zero. Thus, if the drain change amount calculated from the drain amount is confirmed, the cake dryness can be determined more accurately.

  Next, the correlation data between the cake dryness and the cake temperature and the correlation data between the cake dryness and the drain change amount according to the present embodiment will be described with reference to FIG. FIG. 5A is a graph showing correlation data between the cake dryness and the cake temperature according to the first embodiment. FIG. 5B is a graph showing correlation data between the cake dryness and the drain change amount according to the first embodiment.

  As shown in FIG. 5A, the correlation data between the cake temperature and the cake dryness rises almost vertically up to the inflection point of the cake temperature or a predetermined dryness (for example, about 90%). After the inflection point, the cake temperature and the cake dryness become a curved curve that draws a gentle curve. In this way, in the high dryness region that has passed the inflection point of the cake temperature, correlation data between the cake dryness and the cake temperature can be obtained, so that the cake dryness can be detected by measuring the cake temperature. it can. The correlation data between the cake dryness and the cake temperature can be automatically controlled by storing it in the control device.

  FIG. 5B shows correlation data between the drain change amount and the cake dryness as correlation data of the cake dryness with respect to the reciprocal of the drain change amount in order to correspond to the time-dependent data of the cake drying process. ing. As shown in FIG. 5B, as the drain change amount decreases (that is, as the reciprocal of the drain change amount increases), the curve becomes a convex curve, particularly in the low dryness region (in the figure, more In the area close to the origin), since the rise is relatively steep, the correlation between the drain change amount and the cake dryness is higher. On the other hand, in the high dryness region (region farther from the origin in the figure), since the curve is very gentle, the correlation between the drain change amount and the cake dryness is relatively low. For this reason, it is preferable that the correlation data between the drain change amount and the cake dryness is used in the low dryness region.

  In addition, as shown in FIG. 6, it is preferable that the temperature measurement location of cake temperature exists in the range within 5 to 50% of the distance from the center part of a cake to an edge part from the edge part of a cake. . That is, if it is 5% or less, the temperature in the vicinity of the edge of the cake is measured, and therefore the cake temperature cannot be measured accurately, which is not preferable. On the other hand, if it is 50% or more, the pressure of the slurry (or filtrate) flowing in the filter plate causes the temperature sensor such as a thermocouple or resistance temperature detector to be swept away, causing deformation and being unevenly distributed in an inappropriate place. It is not preferable because it may be damaged. The diameter of the thermocouple is preferably in the range of 0.2 mm to 5 mm. If the thickness is 0.2 mm or less, the strength is not sufficient, and if it is 5 mm or more, it is difficult to insert the filter plate into the filter plate.

Further, as the cake temperature value, a temperature obtained by arithmetically averaging arbitrary K chamber cake temperatures Tc1, Tc2, Tc3,..., TcK in N chambers of the filter press apparatus, that is,
TcM = (Tc1 + Tc2 + Tc3 +... + TcK) / K, or
Temperature obtained by geometric averaging of arbitrary K chamber temperature Tc1, Tc2, Tc3,..., TcK in N chambers of the filter press apparatus, that is,
TcM ′ = (Tc1 * Tc2 * Tc3 *... * TcK) ^{1 / K} equation,
Can also be calculated.

  Unlike the prior art, the control device 44 according to the present embodiment inputs temperature data in the cake drying process measured by a thermocouple installed on the filter plate, and at the same time, the temperature data is set in a predetermined cake. When the target temperature is reached, the cake drying process can be controlled to end. For example, correlation data between cake dryness and cake temperature set in advance is stored in the control device, and the cake dryness in the drying process can be grasped by measuring the cake temperature. The correlation data between the cake dryness and the cake temperature is preferably stored as a plurality of correlation data according to various conditions such as cake type, cake composition ratio, and cake viscosity. Thus, the cake dryness can be grasped more accurately.

  Further, the controller 44 receives the time-dependent drain amount data from the calibrator provided in the drain pipe, calculates the drain change amount, and changes the drain amount discharged from the filter press device. Can be controlled to end the drying process of the cake when the value becomes equal to or less than a preset drain change amount. Such drain change data is preferably used together with the cake temperature data. For example, even when the cake temperature data reaches a predetermined cake target temperature, the drying process can be set to continue if the drain temperature is equal to or greater than a preset drain change amount. In addition, correlation data between a preset cake dryness and drain change amount is stored in the control device, and the cake dryness in the drying process is calculated by measuring the drain amount and calculating the drain change amount. I can grasp it. The correlation data between the cake dryness and the drain change amount is preferably stored as a plurality of correlation data according to various conditions such as cake type, cake composition ratio, and cake viscosity. As described above, the cake dryness can be grasped more accurately by using not only the cake temperature but also the drain change amount as an index of the cake dryness.

  Furthermore, when the preliminary operation of vacuum and heat drying is performed and the DS% after filtration is known, the DS% after compression can be obtained by calculation using the amount of filtrate at the time of compression. On the other hand, when the DS% after squeezing has already been calculated or measured, the value can be used. In either case, the DS% before starting the vacuum and heating operation is found.

  Calibrate the relationship between the amount of trapped drain and the dryness between that value and the desired DS% and a dryness of 90% or more and store it in the controller. Can do. During actual operation, the measured value of the drain amount is input to the control device every moment to calculate the amount of drain change, the dryness is calculated, and the comparison with the stored information is also used. The cake dryness inside can be determined without opening the filter press and with sufficient accuracy for practical use. According to this method, only the drain amount is calibrated and the drain change amount is calculated, and the operation is performed not only with a high dryness of, for example, 80% to 90% or more, but also with an arbitrary dryness lower than that. I can do it.

  In addition, about the said preliminary | backup operation, it is good also to drive | operate on one standard throughout the year, and can also memorize the typical preliminary | backup operation of spring, summer, autumn and winter. Alternatively, detailed preliminary operation data according to the high temperature and humidity can be used.

  In this embodiment, since the cake dryness is recognized as an alternative factor, even if various factors that affect the drying time such as the concentration fluctuation of the slurry liquid fluctuate, the optimum and shortest time is preferable. The drying process can be completed within the drying time. This reduces the number of cycles due to excessive drying time, energy loss (energy saving), omission of open frames for sampling of the filter press, and calculation of cake dryness by sampling. Reduction is realized. As a result, the operating rate of the filter press apparatus is increased, so that the capacity of the filter press apparatus can be fully utilized. Furthermore, since the amount of change in the amount of drain trapped in the capacitor (or the amount of drain itself) is also used as a criterion for determining the cake dryness, the dryness of the cake can be grasped more accurately. That is, when cake drying progresses and the amount of cake moisture evaporated decreases, it is confirmed that the amount of drain trapped in the condenser that drains the sucked water vapor decreases and approaches zero. Thus, if the drain change amount is confirmed, the cake dryness can be judged more accurately.

  The preferred embodiment according to the present invention has been described above, but the present invention is not limited to such a configuration. A person skilled in the art can assume various modifications and changes within the scope of the technical idea described in the claims, and the modifications and changes are also within the technical scope of the present invention. It is understood that it is included in

  For example, in the above embodiment, an example using a thermocouple has been described, but the present invention is not limited to such an example. Any temperature measuring device can be used as long as the cake temperature in the chamber can be measured.

  In the above-described embodiment, the drain change amount captured during the cake drying process is described as an example of the cake dryness index. However, the present invention is not limited to this example. The drain amount itself can also be used as an indicator of cake dryness. Even in this case, it is preferable to obtain correlation data between the cake dryness and the drain amount in accordance with the cake drying treatment conditions.

  Moreover, in the said embodiment, although the structure which employ | adopted cake temperature and the amount of drain changes as an example was demonstrated as an index of cake dryness, it is not limited to this example. Other data having a strong correlation with the cake dryness can also be adopted.

  In the above embodiment, an example in which the cake temperature increases as the cake drying process proceeds has been described. However, the present invention is not limited to this example. For example, it can be employed even when the cake temperature is lowered as the cake drying process proceeds.

  In the above embodiment, the slurry supply hole has been described with reference to the example shown in the upper left of the drawing, but the present invention is not limited to this example. It can be carried out at any position.

  Moreover, in the said embodiment, although the control apparatus demonstrated and demonstrated as an example the structure which complete | finishes a drying process automatically based on various correlation data, it is not limited to this example. For example, the cake drying process can be terminated manually by displaying the cake temperature or the drain change amount (or the drain amount) during the drying process on the filter press device.

  Moreover, in the said embodiment, although the structure which selects suitable correlation data from several correlation data according to various drying process conditions was mentioned as an example, it demonstrated, but it is not limited to this example. For example, even if it is one correlation data, a suitable drying process can be performed even if the cake drying conditions fluctuate by correcting the correlation data according to various drying process conditions.

  The present invention is applicable to a filter press apparatus and an operation method thereof, and particularly applicable to a filter press apparatus having cake drying means and an operation method thereof.

FIG. 1 is a side view showing a schematic outer shape / arrangement of the filter press apparatus according to the first embodiment. FIG. 2 is an explanatory diagram for explaining a configuration of the filter press apparatus according to the first embodiment. FIG. 3 is a front view showing the configuration of the filter press apparatus according to the first embodiment. FIG. 4 is a graph showing various measurement data during the drying process of the cake according to the first embodiment. FIG. 5 is a graph showing the correlation data between the cake dryness and the cake temperature and the correlation data between the cake dryness and the drain change amount according to the first embodiment. FIG. 6 is an explanatory diagram showing the configuration of the characteristic part of the filter plate according to the present embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Filter press apparatus 3 Filter plate 33a Exhaust line 41 Vacuum pump 44 Control apparatus 50 Filter cake 60 Capacitor 61 Calibration meter 70 Thermocouple 71 Thermometer

Claims (16)

A filter press apparatus for filtering the slurry, a filter plate provided in the filter press apparatus, a heat source for providing heat necessary for drying the cake after filtering the slurry, and a drying process for the cake A filter press comprising: vacuum means for lowering the evaporation temperature of water in the cake; and water vapor suction means for sucking water vapor generated from the cake heated by the heat source during the drying process of the cake In the device,
The filter press device further includes:
Cake temperature measuring means for measuring the temperature of the cake during the drying process of the cake;
Cake target temperature setting means for setting a predetermined cake target temperature corresponding to the target dryness of the cake based on correlation data between the cake dryness and the cake temperature set in advance;
Control means for terminating the drying process of the cake when the cake temperature measured by the cake temperature measuring means reaches the predetermined cake target temperature;
The filter press apparatus characterized by having. A filter press apparatus for filtering the slurry, a filter plate provided in the filter press apparatus, a heat source for providing heat necessary for drying the cake after filtering the slurry, and a drying process for the cake A filter press comprising: vacuum means for lowering the evaporation temperature of water in the cake; and water vapor suction means for sucking water vapor generated from the cake heated by the heat source during the drying process of the cake In the device,
The filter press device further includes:
A condenser for draining water vapor from the cake sucked by the water vapor suction means during the drying process of the cake;
Drain amount measuring means for measuring the amount of drain trapped in the capacitor over time;
A drain change amount calculating means for calculating a change amount of the drain amount in a predetermined time based on the drain amount measured over time by the drain amount measuring means;
A target drain change amount setting means for setting a predetermined target drain change amount corresponding to the target dryness of the cake based on correlation data between the cake dryness and the drain change amount set in advance;
Control means for terminating the drying process of the cake when the drain change amount calculated by the drain change amount calculating means reaches the predetermined target drain change amount;
The filter press apparatus characterized by having. A filter press apparatus for filtering the slurry, a filter plate provided in the filter press apparatus, a heat source for providing heat necessary for drying the cake after filtering the slurry, and a drying process for the cake A filter press comprising: vacuum means for lowering the evaporation temperature of water in the cake; and water vapor suction means for sucking water vapor generated from the cake heated by the heat source during the drying process of the cake In the device,
The filter press device further includes:
Cake temperature measuring means for measuring the temperature of the cake during the drying process of the cake;
Cake target temperature setting means for setting a predetermined cake target temperature corresponding to the target dryness of the cake based on correlation data between the cake dryness and the cake temperature set in advance;
A condenser for draining water vapor from the cake sucked by the water vapor suction means during the drying process of the cake;
Drain amount measuring means for measuring the amount of drain trapped in the capacitor over time;
A drain change amount calculating means for calculating a change amount of the drain amount in a predetermined time based on the drain amount measured over time by the drain amount measuring means;
A target drain change amount setting means for setting a predetermined target drain change amount corresponding to the target dryness of the cake based on correlation data between the cake dryness and the drain change amount set in advance;
When both the predetermined cake target temperature and the predetermined target drain change amount are set as an index of the dryness of the cake, the cake temperature measured by the cake temperature measuring means is the predetermined cake target temperature. Control means for ending the cake drying process when the drain change amount calculated by the drain change amount calculating means reaches the predetermined target drain change amount;
The filter press apparatus characterized by having.   The correlation data between the cake dryness and the cake temperature, or the correlation data between the cake dryness and the amount of drain change is acquired in a preliminary operation of the filter press device. 4. The filter press device according to any one of items 3. The control means stores correlation data between a plurality of cake dryness and cake temperature, or a plurality of cake dryness and drainage change data according to various cake drying processing conditions,
The control device selects correlation data between a suitable cake dryness and cake temperature or a correlation data between a suitable cake dryness and drain change amount according to various cake drying treatment conditions.
The filter press apparatus according to claim 4. As the cake temperature value,
A value obtained by arithmetically averaging the cake temperatures (Tc1, Tc2, Tc3... TcK) in arbitrary K chambers among the N chambers of the filter press apparatus,
TcM = (Tc1 + Tc2 + Tc3 +... + TcK) / K
The value (TcM) calculated by the formula of
The filter press apparatus according to any one of claims 1, 2, 3, 4 and 5. As the cake temperature value,
A value obtained by geometric averaging of cake temperatures (Tc1, Tc2, Tc3... TcK) in arbitrary K chambers among the N chambers of the filter press apparatus,
TcM ′ = (Tc1 * Tc2 * Tc3 *... * TcK) ^{1 / K}
The value (TcM ′) calculated by the formula of
The filter press apparatus according to any one of claims 1, 2, 3, 4 and 5. The measurement point of the cake temperature is within a range of 5 to 50% of the distance from the center of the cake to the edge, counting from the edge of the cake.
The filter press device according to any one of claims 1, 2, 3, 4, 5, 6 and 7. A filter press apparatus for filtering the slurry, a filter plate provided in the filter press apparatus, a heat source for providing heat necessary for drying the cake after filtering the slurry, and a drying process for the cake A filter press comprising: vacuum means for lowering the evaporation temperature of moisture in the cake; and water vapor suction means for sucking water vapor generated from the cake heated by the heat source during the drying process of the cake In the device,
The cake temperature measuring means measures the temperature of the cake during the drying process of the cake,
The cake target temperature setting means sets a predetermined cake target temperature corresponding to the target dryness of the cake based on the correlation data between the cake dryness and the cake temperature set in advance,
The control means ends the drying process of the cake when the cake temperature measured by the cake temperature measuring means reaches the predetermined cake target temperature.
A method for operating a filter press device. A filter press apparatus for filtering the slurry, a filter plate provided in the filter press apparatus, a heat source for providing heat necessary for drying the cake after filtering the slurry, and a drying process for the cake A filter press comprising: vacuum means for lowering the evaporation temperature of water in the cake; and water vapor suction means for sucking water vapor generated from the cake heated by the heat source during the drying process of the cake In the device,
The condenser drains the water vapor from the cake sucked by the water vapor suction means during the drying process of the cake,
The drain amount measuring means measures the amount of drain trapped in the capacitor over time,
The drain change amount calculating means calculates a change amount of the drain amount in a predetermined time based on the drain amount measured over time by the drain amount measuring means,
The target drain change amount setting means sets a predetermined target drain change amount corresponding to the target dryness of the cake based on the correlation data between the cake dryness and the drain change amount set in advance.
The control means terminates the cake drying process when the drain change amount calculated by the drain change amount calculation means reaches the predetermined target drain change amount. Method. A filter press apparatus for filtering the slurry, a filter plate provided in the filter press apparatus, a heat source for providing heat necessary for drying the cake after filtering the slurry, and a drying process for the cake A filter press comprising: vacuum means for lowering the evaporation temperature of moisture in the cake; and water vapor suction means for sucking water vapor generated from the cake heated by the heat source during the drying process of the cake In the device,
The cake temperature measuring means measures the temperature of the cake during the drying process of the cake,
The cake target temperature setting means sets a predetermined cake target temperature corresponding to the target dryness of the cake based on the correlation data between the cake dryness and the cake temperature set in advance,
The condenser drains the water vapor from the cake sucked by the water vapor suction means during the drying process of the cake,
The drain amount measuring means measures the amount of drain trapped in the capacitor over time,
The drain change amount calculating means calculates a change amount of the drain amount in a predetermined time based on the drain amount measured over time by the drain amount measuring means,
The target drain change amount setting means sets a predetermined target drain change amount corresponding to the target dryness of the cake based on the correlation data between the cake dryness and the drain change amount set in advance.
The control means, when both the predetermined cake target temperature and the predetermined target drain change amount are set as the dryness index of the cake, the cake temperature measured by the cake temperature measuring means is the predetermined temperature. The cake drying temperature is reached when the cake target temperature is reached and the drain change amount calculated by the drain change amount calculation means reaches the predetermined target drain change amount,
A method for operating a filter press device.   The correlation data between the cake dryness and the cake temperature, or the correlation data between the cake dryness and the drain change amount is acquired in a preliminary operation of the filter press device. The operation method of the filter press apparatus of any one of 11 items. The control means stores correlation data between a plurality of cake dryness and cake temperature, or a plurality of cake dryness and drainage change data according to various cake drying processing conditions,
The control device selects correlation data between a suitable cake dryness and cake temperature or a correlation data between a suitable cake dryness and drain change amount according to various cake drying treatment conditions.
The operation method of the filter press apparatus of Claim 12 characterized by the above-mentioned. As the cake temperature value,
A value obtained by arithmetically averaging the cake temperatures (Tc1, Tc2, Tc3... TcK) in arbitrary K chambers among the N chambers of the filter press apparatus,
TcM = (Tc1 + Tc2 + Tc3 +... + TcK) / K
The value (TcM) calculated by the formula of
The operation method of the filter press apparatus according to any one of claims 9, 10, 11, 12, or 13. As the cake temperature value,
A value obtained by geometric averaging of cake temperatures (Tc1, Tc2, Tc3... TcK) in arbitrary K chambers among the N chambers of the filter press apparatus,
TcM ′ = (Tc1 * Tc2 * Tc3 *... * TcK) ^{1 / K}
The value (TcM ′) calculated by the equation of
The operation method of the filter press apparatus according to any one of claims 9, 10, 11, 12, or 13. The measurement point of the cake temperature is within a range of 5 to 50% of the distance from the center of the cake to the edge, counting from the edge of the cake.
The operating method of the filter press apparatus according to any one of claims 9, 10, 11, 12, 13, 14, or 15.

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