Papermaking retention aid treatment device and papermaking retention aid treatment method

Abstract

The invention provides a papermaking retention aid treatment device and a papermaking retention aid treatment method. The device comprises a preparation tank which is configured to receive the papermaking retention aid from the outside and enable the papermaking retention aid to be combined with water contained in the preparation tank to form a to-be-treated material containing the papermaking retention aid; the first filter is arranged at the downstream of the preparation tank to receive the material from the preparation tank so as to filter the material; a storage tank located downstream of the first filter for receiving the material filtered from the first filter; and the second filter is arranged at the downstream of the storage tank and is used for further filtering the materials passing through the storage tank. According to the invention, the filtering efficiency is improved, the selection range of dry polymer powder grades is expanded, and the manufacturing efficiency and quality of paper are improved.

Description

Technical Field

[0001] The invention relates to a papermaking treatment process, in particular to a papermaking retention agent treatment device and a papermaking retention agent treatment method. Background Art

[0002] In the papermaking process, papermaking retention aids are currently used in large quantities. Dry polymers are widely used as papermaking retention aids, and these dry polymers usually form some residual substances in the solution. In the process of preparing papermaking retention aids, due to the influence of factors such as polymer quality fluctuations and dissolution conditions, a large amount of residual substances are easily generated during the production process. If these residual substances directly enter the paper machine system, it may cause adverse consequences such as paper breaks. Therefore, filters are needed to prevent residual substances from entering the papermaking process to avoid paper product quality problems and paper breaks.

[0003] In addition, in the paper production process using retention aids, due to the extremely fast paper running speed, less residual material is needed, otherwise it will cause frequent paper breaks and affect production operations.

[0004] At present, bag filters are widely used to remove residual substances in the retention aid liquid before the retention aid solution material is sent to the papermaking system. Figure 1 The prior art papermaking retention agent treatment device shown uses a single-stage bag filter, but the conventional bag filter is easily saturated and blocked, requiring manpower to clean the bag filter. Sometimes, some batches of dry polymer have more residual substances than other batches. This results in a very short filter cleaning interval, such as 2 hours, which increases labor costs. Summary of the invention

[0005] The invention provides a novel papermaking retention agent treatment device and a papermaking retention agent treatment method, so as to achieve the cleaning of the filter at long intervals, thereby improving the operation efficiency.

[0006] The present invention provides a papermaking retention agent processing device, the papermaking retention agent processing device comprising:

[0007] A preparation tank configured to receive a papermaking retention aid from outside and combine the papermaking retention aid with water contained in the preparation tank to form a material including the papermaking retention aid to be treated;

[0008] a first filter, the first filter being disposed downstream of the preparation tank to receive the material from the preparation tank to filter the material;

[0009] a storage tank located downstream of the first filter for receiving material filtered from the first filter; and

[0010] The second filter is disposed downstream of the storage tank to further filter the material passing through the storage tank.

[0011] In one aspect, the first filter is a self-cleaning filter and / or the second filter is a single bag filter or a multi-bag filter.

[0012] In one aspect, the self-cleaning filter comprises:

[0013] shell;

[0014] A feed inlet, which is located at the upper side of the shell;

[0015] A discharge port, which is located at the lower side of the shell;

[0016] a drain port located at a lower portion of the housing; and

[0017] A filter element, the filter element comprising at least one scraper, at least one filter screen, and a support portion for supporting the filter screen to a housing,

[0018] Wherein, the support portion connects the outer side of at least one filter screen with the inner wall of the housing,

[0019] The scraper is located above the filter and is configured to rotate around an axis located at the center of the support portion or the center of the filter to scrape off residual matter on the filter that has not passed through the filter and discharge the residual matter through the drain port.

[0020] In one aspect, the at least one scraper is configured to continuously oscillate over the filter screen, or the at least one scraper is started and stopped at predetermined time intervals.

[0021] In one aspect, further comprising an inlet pressure sensor and an outlet pressure sensor,

[0022] Wherein, the inlet sensor is arranged at the feed inlet of the self-cleaning filter to sense the pressure at the feed inlet;

[0023] Wherein, the outlet sensor is arranged at the outlet of the self-cleaning filter to sense the pressure at the outlet.

[0024] In one aspect, the papermaking retention agent processing device is configured to calculate the pressure difference between the outlet sensor and the inlet sensor, and start the operation of the scraper when the pressure difference is greater than a predetermined pressure threshold; and stop the operation of the scraper when the pressure difference is less than the predetermined pressure threshold or when the scraper is operated for a predetermined time.

[0025] In one aspect, the filter element comprises two filter screens, three filter screens, four filter screens, five filter screens or six filter screens, optionally, the filter screens are arranged around the center.

[0026] On the one hand, the self-cleaning filter also includes a discharge pipeline and a collection chamber, wherein the discharge pipeline is connected to the opening of the support portion to receive residual materials scraped off by the scraper from the opening of the support portion, and the collection chamber is connected to the drain port and the discharge pipeline respectively to store the residual materials collected from the discharge pipeline in the collection chamber and discharge the residual materials when the valve of the drain port is opened.

[0027] In one aspect, the drain port is provided with a drain valve configured to open periodically or according to a predetermined setting to discharge residual matter.

[0028] In one aspect, the first filter is a multi-bag filter and / or the second filter is a single-bag filter or a multi-bag filter.

[0029] In one aspect, the multi-bag filter comprises:

[0030] shell;

[0031] a feed port located on an upper side of the housing;

[0032] a filter element including a plurality of filter bags located within the housing and supported by a support portion to an inner side wall of the housing;

[0033] a discharge port located below the side of the housing; and

[0034] A drain port located at the lower side of the housing,

[0035] The material is filtered through the multiple filter bags, the material that has passed through the multiple filter bags is sent to a storage tank, and the residual material that has not passed through the filter bags is discharged through the sewage outlet.

[0036] In one aspect, a sealing device is disposed outside the support portion, for maintaining a seal between the support portion and the filter bag and between the support portion and the inner side wall of the housing, respectively.

[0037] On the one hand, the sealing device includes a sealing ring (such as a rubber sealing ring) and a gasket (such as a PTFE gasket), wherein the sealing ring is placed around the filter bag and the support part for sealing the two, and the gasket is placed between the support part and the inner side wall of the shell for sealing the two.

[0038] In one aspect, the filter element comprises two filter bags, three filter bags, four filter bags, five filter bags or six filter bags, optionally arranged around a center.

[0039] In one aspect, the papermaking retention agent processing device further comprises a controller located in the preparation tank, and the controller is configured to control the time and flow rate of feeding the material.

[0040] In one aspect, it further includes a spare first filter and a spare second filter, wherein the spare first filter is used to be activated when the first filter is closed for cleaning, and the spare second filter is used to be activated when the second filter is closed for cleaning.

[0041] The present invention also provides a method for treating a papermaking retention aid, using the above-mentioned papermaking retention aid treatment device to filter a material including a papermaking retention aid, and the papermaking retention aid treatment method comprises the following steps:

[0042] combining the papermaking retention aid with the water in the preparation tank to form a material including the papermaking retention aid;

[0043] passing the material through a first filter to remove at least a portion of residual material, thereby forming a first liquid;

[0044] passing the first liquid through a second filter to further remove residual matter, thereby forming a second liquid,

[0045] Optionally, when the residue is a gel-like substance, the first filter is a multi-bag filter, and the second filter is a single-bag filter or a multi-bag filter,

[0046] Optionally, when the residue is particulate matter, the first filter is a self-cleaning filter and the second filter is a single bag filter or a multi-bag filter.

[0047] By using the method and apparatus of the present invention, a combination of a conventional bag filter and another filter is used in the treatment of materials including papermaking retention aids, such as retention aids, and the method can effectively remove residual materials without additional manpower, and can use cheaper but lower grade dry polymer powders. In a manufacturing process system, such as in the papermaking process, a self-cleaning or multi-bag filter device is introduced into the treatment process of conventional dry polymer powders (such as retention aids), the efficiency of filtration is improved, the range of dry polymer powder grades can be expanded, and in the case of papermaking, the manufacturing efficiency and quality of paper are also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The following is an exemplary embodiment of the present invention with reference to the accompanying drawings.

[0049] Figure 1 A schematic diagram of a papermaking retention agent treatment device in the prior art is shown.

[0050] Figure 2 A schematic diagram of a papermaking retention agent treatment device according to an embodiment of the present invention is shown.

[0051] Figure 3 A schematic diagram showing a part of a papermaking retention agent treatment device according to an embodiment of the present invention.

[0052] Figure 4 A side view of a portion of a papermaking retention agent treatment device according to an embodiment of the present invention is shown.

[0053] Figure 5 A top view of a portion of a papermaking retention agent treatment device according to an embodiment of the present invention is shown.

[0054] Figure 6A-6B A schematic diagram of a self-cleaning filter in a papermaking retention agent treatment device according to an embodiment of the present invention is shown, wherein: Fig. 6A Showing the side view of the self-cleaning filter, Figure 6B Illustration showing the filter element of a self-cleaning filter.

[0055] Figure 7 A schematic diagram of a papermaking retention agent treatment device according to another embodiment of the present invention is shown.

[0056] Figures 8A-8D A schematic diagram of a multi-bag filter in a papermaking retention agent treatment device according to another embodiment of the present invention is shown, wherein: Fig. 8A A side view showing a multi-bag filter, Figure 8B A view showing the filter element of a multi-bag filter, Figure 8C A top view showing a multi-bag filter, Figure 8C A bottom view showing a multi-bag filter.

[0057] Fig. 9 A line diagram showing the effect of a papermaking retention agent treatment device according to an embodiment of the present invention.

[0058] Description of Reference Numerals

[0059] 31-preparation tank, 311-housing, 313-discharge port, 315-drainage port, 32-self-cleaning filter, 321-housing, 323-feed port, 325-discharge port, 326-motor, 327-drainage port, 329-controller, 322-inlet pressure sensor, 328-outlet pressure sensor;

[0060] 611-motor, 613-filter, 615-shaft, 617-support part;

[0061] 800 - filter element, 801 - feed port, 802 - filter screen, 803 - support part, 805 - drain port. DETAILED DESCRIPTION

[0062] The detailed description described below is intended to describe various configurations of the subject technology, rather than being intended to represent only configurations that the subject technology can adopt. The accompanying drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details in order to provide a thorough understanding of the subject technology. However, it is apparent to those skilled in the art that the subject technology is not limited to the specific details described herein, and one or more embodiments can be used to implement. In one or more instances, the structure and components are shown in block diagram form to avoid confusing the concept of the subject technology. One or more embodiments of the present disclosure are illustrated by one or more diagrams and / or described in conjunction with one or more diagrams.

[0063] In the process of papermaking retention aid treatment, such as retention aid, self-cleaning filters are introduced to replace manpower. When the residual substances such as insoluble substances, large particles, gel, etc. clog the filter screen in the self-cleaning filter, the pressure increases or according to a specific time interval, the automatic cleaning program is started to discharge the filtered residual substances.

[0064] One embodiment of the present invention provides a papermaking retention agent processing device. Figure 2 As shown, the papermaking retention agent processing device includes a preparation tank, a first filter, a storage tank, and a second filter. First, according to an embodiment of the present invention, the preparation tank receives the papermaking retention agent or any other suitable dry material from the powder opening machine. Figure 3-Figure 5 The preparation tank 31 shown includes a shell 311, a feed port, a discharge port 313, a controller and a sewage outlet 315. A papermaking retention agent or a suitable dry material enters from the feed port, and the feed port is controlled by a control box. Then the dry material combines with the water contained in the preparation tank to form a liquid material including a papermaking retention agent to be treated, and the formed liquid material is discharged from the side lower part of the preparation tank or the discharge port below it. The control box can control the entry time of the material, set and control the pressure in the preparation tank, determine the time and flow rate of pumping the liquid material, etc., and can automatically process different delivery times according to different liquid materials. Optionally, a stirrer can also be provided to stir the liquid material in the preparation tank to make it evenly mixed.

[0065] According to one embodiment of the present invention, the first filter includes a tank-shaped shell, a filter portion, a feed port located at the upper part or upper portion of the shell side, a discharge port located at the lower part or lower portion of the shell side, and a sewage outlet located at the lower part or lower portion of the shell side. The filter portion includes one or more filter screens / filter bags and a support portion around the filter screens / filter bags. The material received by the first filter is filtered through the filter screens / filter bags. The support portion is connected to the inner wall of the storage tank to fix the position of the filter portion. The first filter can be any suitable filter, such as a single bag filter. Filtering effects that are more significant include, for example, multi-bag filters and adaptive filters.

[0066] In one embodiment, the first filter is a self-cleaning filter. Figure 3-Figure 5 As shown, the first filter 32 as a self-cleaning filter includes a can-shaped shell 321, a filter element, a feed port 323 located at the upper part or upper part of the shell side, a discharge port 325 located at the lower part or lower part of the shell side, a sewage outlet 327 located at the lower part or lower part of the shell side, and a controller 329. The shell 321 can be made of stainless steel. The material from the preparation tank enters the self-cleaning filter through the feed port 323. A motor 326 is provided at the upper part of the self-cleaning filter to drive the scraper of the filter element of the self-cleaning filter to operate, so that the liquid material is discharged through the discharge port 325 after filtering, and the residual material that has not passed through the filter screen of the self-cleaning filter is discharged through the sewage outlet 327.

[0067] like Fig. 6A and 6B As shown, the filter element includes a filter screen 613, a support portion 617 and a scraper (not shown), the scraper is located above the filter screen and in contact with the filter screen, the support portion supports the filter screen and is connected to the housing, and is sealed with the housing through a sealing element. The opening of the filter screen is substantially uniform and is made of a suitable wear-resistant and corrosion-resistant material, such as stainless steel. The filter element includes two filter screens, three filter screens, four filter screens, five filter screens or six filter screens, and the filter screens are arranged in a manner surrounding the center. The filtration area of ​​the filter element can be a suitable area determined according to the tank body, such as 0.5m 2 -1m 2 , for example 0.6m 2 -0.9m 2 , for example 0.7m 2 -0.8m 2 , for example 0.71m 2 、0.72m 2 、0.73m 2 、0.74m 2 、0.75m 2 、0.76m 2 、0.77m 2 、0.78m 2、0.79m 2 . The sealing element can be a suitable sealing material, such as a sealing ring made of fluororubber, which is respectively located between the outer side of the filter screen and the support part and between the support part and the inner wall of the shell to improve the sealing of the system. In order to avoid residue in the tank body, the inner surface of the shell is polished, for example, 80 mesh. During filtration, the liquid material containing the papermaking retention agent flows out from the preparation tank 31, enters the first filter through the feed port 323, and flows from top to bottom through the filter screen of the filter element of the first filter. The flow rate of the liquid material is, for example, 50m 3 / h-70m 3 / h, for example, 55m 3 / h-65m 3 / h, for example, 57m 3 / h、59m 3 / h、60m 3 / h、62m 3 / h. The controller is coupled to the motor and the scraper to control the motor 611 to drive the start and stop of the scraper. A feed port valve can be optionally provided at the feed port, and the opening and closing of the valve is controlled by the controller, thereby controlling the opening and closing of the feed port. The feed port valve is, for example, a manual butterfly valve, which is convenient for assembly and switching. The feed port valve can also be other valves controlled by the controller, for example, it is set to open once every few minutes and close after opening for a few seconds, so as to facilitate the entry of materials. For example, it is opened once every 5 minutes and closed 30 seconds after opening. In order to avoid sewage discharge problems and reduce sewage discharge time, a sewage outlet valve 319 is also provided at the sewage outlet, such as a pneumatic ball valve of the sewage outlet, and the controller discharges materials as needed. The pneumatic ball valve is connected by a flange, for example.

[0068] When a certain amount of residual material is collected on the surface of the filter element, a scraper moves closely against the surface of the filter element to scrape off the residual material and part of the liquid at the same time. The residual material includes gel. The scraper of the first filter can be multiple and each scraper is driven by the motor 611 to rotate around the axis 615 in the middle of each filter net, or the scraper can be only one and is driven by the motor 611 to rotate around the axis in the middle of multiple filter nets, so that the surrounding filter nets can be covered to scrape off the residual material during operation. The motor can be a three-phase motor with a power of 550W. In the present invention, the scraper is rotated at 60m 3 / h flow rate at a speed of 5-6 rpm. In the case of higher flow rate, the scraper can run at a higher speed and / or for a longer time according to the situation; in the case of lower flow rate, the scraper can run at a lower speed and / or for a shorter time according to the situation. The motor can set its running speed, cycle, etc. according to the control of the controller. The scraper can be equipped with a corrector to correct the position and force of the scraper. The shaft of the filter screen is detachably connected to the filter screen to facilitate subsequent cleaning and replacement of parts. The self-cleaning filter also includes a discharge pipeline and a collection chamber, and the discharge pipeline is connected to the opening of the support part to receive the residual material scraped by the scraper from the opening of the support part. In addition to insoluble substances, large particles, gels, etc. that have not passed through the filter screen, the residual material also includes part of the liquid scraped at the same time. The collection chamber is connected to the sewage outlet and the discharge pipeline respectively, so that the residual material collected from the discharge pipeline is stored in the collection chamber. When a certain amount of residual material is accumulated, the sewage valve connected to the sewage outlet of the collection chamber is opened to discharge the residual material for recycling and other treatments. The drain valve is opened periodically or according to a predetermined setting to discharge the residual material, and the liquid material passing through the first filter enters the storage tank.

[0069] The self-cleaning filter can be used for fully automatic continuous filtration, reducing labor costs, eliminating disposable filtration consumables, saving consumables, and facilitating process stability. The filtration pressure loss is small, and leakage can be prevented by opening the drain valve at a fixed time, thus avoiding material loss.

[0070] The scraper is driven by a motor, for example, a PTFE external scraper, which forms a suitable angle with the plane of the first filter, so that the scraper fits the surface of the filter mesh of the first filter, and the residual material stuck on the surface of the filter mesh can be scraped off better and more efficiently by shoveling, thereby more efficiently scraping, and at the same time ensuring that the flow rate of the liquid material will not change significantly, thereby ensuring the actual required transfer speed and flow rate.

[0071] The scraper can work continuously or be turned on according to the pressure difference measured by the pressure sensor or according to a predetermined time.

[0072] For example, the scraper can start the cleaning work according to the pressure difference, and the pressure difference reflects the accumulation of residual substances on the inner surface of the filter. For example, when the pressure difference is greater than a predetermined pressure threshold, the scraper is controlled by the controller to start its work, and stops working when the pressure difference is less than the predetermined pressure threshold. The pressure threshold is, for example, in the range of 0.2Mpa-1.0Mpa, for example, 0.25Mpa-0.9Mpa, for example, 0.3Mpa-0.8Mpa, for example, 0.4Mpa-0.7Mpa, for example, 0.5Mpa-0.6Mpa. It is also possible to control the scraper to start its work when the pressure difference is greater than a predetermined pressure threshold, and stop working when the pressure difference is less than another predetermined pressure threshold. In this embodiment, sensors are respectively provided at the feed port and the discharge port of the first filter, such as an inlet pressure sensor 322 and an outlet pressure sensor 328, the inlet pressure sensor senses the pressure of the feed port, and the outlet pressure sensor senses the pressure of the discharge port, thereby obtaining the pressure difference between the feed port and the discharge port. In order to avoid failure of the pressure sensor, spare pressure sensors may be provided at the feed port and the discharge port, respectively.

[0073] For example, the scraper can be operated and stopped at a specified time or a predetermined time interval, for example, it is set to run once every 3 minutes-4 hours, for example, every 5 minutes, every 10 minutes, every 15 minutes, every 20 minutes, every 25 minutes, every 30 minutes, every 35 minutes, every 40 minutes, every 45 minutes, every 50 minutes, every 55 minutes, every 1 hour, every 1.5 hours, every 2 hours, every 2.5 hours, every 3 hours, every 4 hours, etc., and the running time can be 3 minutes-4 hours, for example, it runs for 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 4 hours, etc. The first filter is provided with a timer, and according to the setting time of the timer, the scraper is controlled by the controller to start and stop running at a predetermined time interval. In one embodiment of the present invention, the scraper is driven by a motor, and rotates close to the surface of the filter screen to scrape off the residual material, and then the residual material is collected in the collection chamber along with part of the liquid scraped off at the same time. After a certain amount of residual material is accumulated, the drain valve can be opened according to a preset time or according to the amount of accumulated residual material sensed to discharge the residual material in the collection chamber. The automatic drain valve can be opened by the controller for a period of time and a duration of maintaining the open state.

[0074] For example, the scraper can be opened continuously to continuously scrape the residual material on the filter screen. Then, the residual material is collected in the collection chamber along with the part of the liquid that is scraped off at the same time. The automatic drain valve can be controlled by the controller to open according to the required time or state to discharge the residual material.

[0075] As required, the upper portion of the first filter can be opened at predetermined time intervals to remove the filter element for cleaning.

[0076] The filtration area of ​​the first filter is about 0.6m 2 -1.0m 2 , for example 0.7m 2 -0.9m2, for example 0.71m 2 、0.72m 2 、0.73m 2 、0.74m 2 、0.75m 2 、0.76m 2 、0.77m 2 、0.78m 2 、0.79m 2 、0.81m 2 、0.82m 2 、0.83m 2 、0.84m 2 、0.85m 2 、0.86m 2 、0.87m 2 、0.88m 2 、0.89m 2 The filter mesh gap is 50-100 mesh, such as 60 mesh, 70 mesh, 80 mesh, 90 mesh, etc. The filtration accuracy can be 120-180μm, such as 130μm, 140μm, 150μm, 160μm, 170μm. The fluid flow rate in the self-cleaning filter can reach 40m 3 / h or more, for example 41m 3 / h、42m 3 / h、43m 3 / h、44m 3 / h、45m 3 / h. The controller sets the duration and cycle of driving the scraper, whereby the motor drives the scraper to scrape off the residual material.

[0077] In one embodiment, the filter uses a POR series microporous filter element, the material of the filter element is 304 stainless steel, the filtration accuracy is 120-170μm, 130-160μm, for example, 140μm, 150μm, for example, four filter nets, five filter nets, six filter nets, seven filter nets, eight filter nets, etc. can be set to achieve 0.5-1.5m 2 Filtration area, for example 0.6-1.4m 2 Filtration area, for example 0.7-1.3m 2 Filtration area, for example 0.8-1.2m 2Filtration area, for example 0.9-1.1m 2 Filter area, for example 0.8m 2 , 0.88m 2 , 0.92m 2 Filtration area, etc.

[0078] In another embodiment, Figure 7 As shown, the papermaking retention agent treatment device includes a preparation tank, a first filter, a storage tank, and a second filter, wherein the first filter is a multi-bag filter. The multi-bag filter filters out insoluble residual substances through multiple filter bags, and the multi-bag filter is particularly suitable for filtering gel-like materials. The multi-bag filter of one embodiment of the present invention is as shown in FIG. Figures 8A-8D As shown, the first filter as a multi-bag filter includes a housing, a filter element 800, a feed port 801 located above or at the upper side of the housing, a discharge port located below or at the lower side of the housing, and a sewage outlet 805 located below or at the lower side of the housing. The housing can be made of stainless steel. The liquid material containing the papermaking retention agent is fed from the preparation tank into the multi-bag filter through the feed port. The fluid flow rate in the multi-bag filter can reach 40m 3 / h or more, for example 41m 3 / h、42m 3 / h、43m 3 / h、44m 3 / h、45m 3 / h. The filter element of the first filter includes a plurality of filter screens 802 and a support portion 803 arranged on almost one plane around the center on the same plane. The openings of the filter screens are substantially uniform and are made of suitable wear-resistant and corrosion-resistant materials. The filter element includes a plurality of filter bags, such as two filter bags, three filter bags, four filter bags, five filter bags or six filter bags, which are arranged around the center to form a filter layer. The filter bags are supported by a metal support mesh to protect the filter bags. The support portion 803 is connected to the inner wall of the outer shell, such as a stainless steel support portion. The support portion and the filter bag are sealed by a sealing ring, such as an EPDM rubber seal, and the support portion and the inner wall of the first filter are sealed by a PTFE gasket. The filtration area of ​​the filter layer can be 1m 2 -5 m 2 , for example 1.5m 2 -4.5m 2 , for example 2m 2 -4 m 2 , for example 2.5-3.5m 2 , for example 2.7m 2 、3.0m 2 、3.2m 2 .

[0079] In the case of a multi-bag filter with a mesh size of 40, the transfer time of a paper-grade papermaking retention aid is 670 seconds, and the transfer time of a water treatment-grade papermaking retention aid is 740 seconds, without any obvious paper machine problems, and the cleaning frequency can be once every two days. In the case of a multi-bag filter with a mesh size of 60, the transfer time of a paper-grade papermaking retention aid is 750 seconds, and the transfer time of a water treatment-grade papermaking retention aid is 900 seconds, without any obvious paper machine problems, and the cleaning frequency can be once every one and a half to two days. The multi-bag filter includes a rotating arm device located above, such as Figure 8C As shown, it is used to open the top of the multi-bag filter by rotating the arm device, remove the filter bag for cleaning and replacement. In this embodiment, sensors are respectively provided at the feed port and the discharge port of the first filter, such as an inlet pressure sensor and an outlet pressure sensor. The inlet pressure sensor senses the pressure of the feed port, and the outlet pressure sensor senses the pressure of the discharge port. The pressure is respectively sent to the controller to obtain the pressure difference between the feed port and the discharge port. In order to avoid failure of the pressure sensor, spare pressure sensors are also provided at the feed port and the discharge port. The multi-bag filter can be opened according to the pressure difference measured by the pressure sensor or according to a predetermined time. For example, the pressure difference reflects the accumulation of residual substances on the inner surface of the filter. In this embodiment, when the pressure difference between the feed port and the discharge port is greater than the predetermined pressure difference, the multi-bag filter is opened to remove the residual substances that have not passed through the filter. The predetermined pressure difference is, for example, in the range of 0.5Mpa-1.0Mpa, for example, 0.6Mpa-0.9Mpa, for example, 0.7Mpa-0.8Mpa. The multi-bag filter is particularly suitable for filtering residual substances of gel type.

[0080] For the multi-bag filter in the present invention, the mesh numbers of 40 mesh, 60 mesh, 80 mesh and 100 mesh are selected respectively, and it can be obtained that the transfer time of the papermaking retention aid of the papermaking grade is distributed as 520s, 670s, 750s, 900s, and the transfer time of the water treatment grade papermaking retention aid is 650s, 740s, 900s and 1300s respectively. In addition, for the 40-mesh multi-bag filter, it needs to be cleaned once every 3 days, but it may cause transparent spots in the paper made subsequently; while for the 100-mesh multi-bag filter, it needs to be cleaned once every 0.5-1 day, the cleaning frequency is too fast, and there may be a problem that the transfer time is too long in the subsequent paper machine process, and the previous preparation cannot keep up. Preferably, the 60-mesh and 80-mesh multi-bag filters need to be cleaned once every 1.5-2 days, and no problems will occur in the subsequent paper machine process.

[0081] The papermaking retention agent treatment device of the present invention further comprises a spare first filter and a spare second filter. The spare first filter is used to be started when the first filter is closed for cleaning, and the spare second filter is used to be started when the second filter is closed for cleaning.

[0082] The liquid passing through the first filter enters the storage tank, and a switch is provided at the top of the storage tank to help open the storage tank. The liquid stored in the storage tank enters the second filter continuously or intermittently according to demand.

[0083] The second filter may be a single bag filter, or a self-cleaning filter or a multi-bag filter as described above. In one embodiment of the present invention, the second filter is a single bag filter, which has the function of filtering out residual substances through a single filter bag, and the single bag filter is particularly suitable for filtering gel-like materials. The single bag filter of one embodiment of the present invention is can-shaped, including a shell, a filter element, a feed port located at the upper part or upper part of the shell side, a discharge port located at the lower part or lower part of the shell side, and a sewage outlet located at the lower part or lower part of the shell side. Liquid material containing papermaking retention agent is fed into the single bag filter from the outside through the feed port. The filter element is a single filter bag, which is connected to the inner wall of the shell by a support part. The liquid material passing through the filter element is fed into the paper machine system through the outlet below the single bag filter, and after a predetermined time interval, the single bag filter is opened by a rotating boom device through the opening above the single bag filter, and the filter element is taken out for cleaning to remove residual substances that have not passed through the filter element. Single bag filters are generally used in one and reserved in another. The single-bag filter is equipped with a pressure sensor and a pressure display device. When the pressure of the single-bag filter increases, it means that the single-bag filter is blocked. At this time, the single-bag filter needs to be cleaned to remove the residual substances that have not passed through the filter. Take out the filter bag in the original filter, rinse the filter bag with high-pressure water, wait for the pressure of the standby filter to increase after cleaning, and then switch to the original filter, and cycle in sequence.

[0084] The present invention also provides a method for treating a papermaking retention aid, using the above-mentioned papermaking retention aid treatment device to filter a material including a papermaking retention aid. The papermaking retention aid is combined with water in a preparation tank to generate a material including the papermaking retention aid; the material is passed through a first filter to remove at least a portion of residual substances, thereby forming a first liquid; the first liquid is passed through a second filter to further remove residual substances, thereby forming a second liquid.

[0085] The device of the present invention has a good scraping effect on residual substances, thereby realizing full-automatic continuous filtration, reducing labor costs, not producing disposable consumables, and saving consumables. The flow rate is stable and the filtration opening gap is uniform, which is conducive to continuous and stable process. At the same time, residual substances and residual liquid can be discharged to avoid material loss. Fig. 9As shown, the first filter of the present invention has a relatively stable retention rate of the surface layer, the core layer and the bottom layer, and the second filter operates smoothly. The secondary filtration can better filter the powdery residual substances.

[0086] By utilizing the solution of the present invention, the filtration area can be expanded, and at the same time, for the same filtration area, the web sticking time can be extended by four times, and the web can be cleaned once every four hours or even eight hours.

[0087] Example 1

[0088] The liquid material is transported from the preparation tank to the storage tank and then enters the paper machine system. The liquid material entering the storage tank first passes through the first filter, which is a single-bag filter device, to filter out residual substances. The liquid material passing through the first filter enters the storage tank. After being stirred in the storage tank, the liquid enters the second filter, which is a single-bag filter. The filtered material passing through the second filter is discharged from the discharge port. In this example, the first filter implemented as a single-bag filter device is located upstream of the single-bag second filter process. Compared with self-cleaning or multi-bag filter devices, the overall equipment cost investment of this solution is low and has certain effects. In this example, the first filter is cleaned once every 2 hours, and the second filter is a single-bag filter and is generally cleaned once every 8 hours.

[0089] Example 2

[0090] The liquid material is transported from the preparation tank to the storage tank and then enters the paper machine system. The liquid material entering the storage tank first passes through the first filter, which is a single-bag filter device to filter out residual substances. The liquid material passing through the first filter enters the storage tank. After being stirred in the storage tank, the liquid enters the second filter, which is a self-cleaning or multi-bag filter device. The material filtered by the second filter is discharged from the discharge port. In this example, the first filter implemented as a single-bag filter device is located upstream of the second filter process of the self-cleaning or multi-bag filter device. Compared with Example 1, the filtering effect of this scheme is better. In this example, the first filter is cleaned once every 8 hours, and the second filter self-cleaning filter device realizes manual cleaning without manual cleaning. It is cleaned according to the pressure difference and the set time. The cleaning time of the multi-bag filter is generally 12 hours.

[0091] Example 3

[0092] The liquid material is transported from the preparation tank to the storage tank. The liquid material entering the storage tank first passes through the first filter, which is a self-cleaning filter device. The residual material is filtered out and discharged to the sewage outlet through the sewage pipeline. The liquid material passing through the first filter enters the storage tank. After being stirred in the storage tank, the liquid enters the second filter, which is a single bag filter. The filtered material through the second filter is discharged from the discharge port. In this example, the first filter implemented as a self-cleaning filter device is located upstream of the single-bag second filter process, which helps to avoid clogging of the first filter, so that the effects of the first filter and the second filter are better. In this example, the self-cleaning filter device realizes manual cleaning without cleaning, and is cleaned according to the pressure difference and the set time. The second filter is a single bag filter, and the cleaning time is generally once every 8 hours. The self-cleaning filter device in this example is particularly suitable for scraping off granular insoluble matter while avoiding flow fluctuations.

[0093] Example 4,

[0094] The liquid material is transported from the preparation tank to the storage tank. The liquid material entering the storage tank first passes through the first filter, which is a multi-bag filter device. The residual material is filtered out and discharged to the sewage outlet through the sewage pipeline. The liquid material passing through the first filter enters the storage tank. After being stirred in the storage tank, the liquid enters the second filter, which is a single bag filter. The filtered material passing through the second filter is discharged from the discharge port. In this example, the first filter implemented as a multi-bag filter device is located upstream of the single-bag second filter process, which helps to avoid clogging of the first filter, so that the effects of the first filter and the second filter are better. In this example, the cleaning time of the multi-bag filter is generally once every 12 hours. The multi-bag filter device in this example is particularly suitable for scraping off gel-like insoluble matter and is easy to clean.

[0095] The word "comprising" used in this specification means "at least partially comprising". When interpreting each statement in this specification containing the word "including", there may also be features other than or beginning with this word. Related terms such as "comprising" and "including" should be interpreted in the same way.

[0096] For those skilled in the art to which the present invention belongs, many changes in structure of the present invention and widely different embodiments and applications of the present invention will be apparent without departing from the scope of the present invention as defined by the appended claims. The disclosure and description herein are purely illustrative and are not intended to be limiting in any sense. When specific integers having known equivalents in the field related to the present invention are mentioned herein, these known equivalents are deemed to be incorporated herein as if set forth separately.

[0097] As used herein, the term "and / or" means "and" or "or" or both.

[0098] In the description of this specification, reference may be made to subject matter that is not within the scope of the appended claims. Such subject matter should be easily recognized by those skilled in the art and can assist in putting the invention as defined in the appended claims into practice.

[0099] Although the present invention is generally defined above, it will be appreciated by those skilled in the art that the present invention is not limited thereto and that the present invention also includes embodiments for which the following embodiments give examples.

[0100] The foregoing description of the invention includes preferred forms thereof. Modifications may be made thereto without departing from the scope of the invention.

Claims

1. A papermaking retention agent processing device, characterized in that: The papermaking retention agent processing device comprises: A preparation tank configured to receive a papermaking retention aid from outside and combine the papermaking retention aid with water contained in the preparation tank to form a material including the papermaking retention aid to be treated; a first filter, the first filter being disposed downstream of the preparation tank to receive the material from the preparation tank to filter the material; a storage tank located downstream of the first filter for receiving material filtered from the first filter; and The second filter is disposed downstream of the storage tank to further filter the material passing through the storage tank.

2. The papermaking retention agent processing device according to claim 1, characterized in that: The first filter is a self-cleaning filter, and / or the second filter is a single bag filter or a multi-bag filter.

3. The papermaking retention agent processing device according to claim 2, characterized in that: The self-cleaning filter comprises: shell; A feed inlet, which is located at the upper side of the shell; A discharge port, which is located at the lower side of the shell; a drain port located at a lower portion of the housing; and A filter element, the filter element comprising at least one scraper, at least one filter screen, and a support portion for supporting the filter screen to a housing, Wherein, the support portion connects the outer side of at least one filter screen and the inner wall of the outer shell, and the scraper is located above the filter screen and is configured to rotate around an axis located at the center of the support portion or the axis located at the center of the filter screen to scrape off residual matter on the filter screen that has not passed through the filter screen and discharge the residual matter through the drain outlet.

4. The papermaking retention agent processing device according to claim 2, characterized in that: The at least one scraper is configured to continuously oscillate over the filter screen, or The at least one scraper starts and stops operating at predetermined time intervals.

5. The papermaking retention agent processing device according to claim 2, characterized in that: It also includes an inlet pressure sensor and an outlet pressure sensor. Wherein, the inlet sensor is arranged at the feed inlet of the self-cleaning filter to sense the pressure at the feed inlet; Wherein, the outlet sensor is arranged at the outlet of the self-cleaning filter to sense the pressure at the outlet.

6. The papermaking retention agent processing device according to claim 5, characterized in that: The papermaking retention agent processing device is configured to calculate the pressure difference between the outlet sensor and the inlet sensor, and start the operation of the scraper when the pressure difference is greater than a predetermined pressure threshold; and stop the operation of the scraper when the pressure difference is less than the predetermined pressure threshold or when the scraper is operated for a predetermined time.

7. The papermaking retention agent processing device according to claim 3, characterized in that: The filter element comprises two filter nets, three filter nets, four filter nets, five filter nets or six filter nets, and optionally, the filter nets are arranged around the center.

8. The papermaking retention agent processing device according to claim 2, characterized in that: The self-cleaning filter also includes a discharge pipeline and a collection chamber, wherein the discharge pipeline is connected to the opening of the support portion to receive residual materials scraped off by the scraper from the opening of the support portion, and the collection chamber is connected to the sewage outlet and the discharge pipeline respectively to store the residual materials collected from the discharge pipeline in the collection chamber, and discharge the residual materials when the valve of the sewage outlet is opened.

9. The papermaking retention agent processing device according to claim 2, characterized in that: The drain port is provided with a drain valve, which is configured to open periodically or according to a predetermined setting to discharge residual substances.

10. The papermaking retention agent processing device according to claim 1, characterized in that: The first filter is a multi-bag filter, and / or the second filter is a single-bag filter or a multi-bag filter.

11. The papermaking retention agent processing device according to claim 2 or 10, characterized in that: The multi-bag filter comprises: shell; a feed port located on an upper side of the housing; a filter element including a plurality of filter bags located within the housing and supported by a support portion to an inner side wall of the housing; a discharge port located below the side of the housing; and A drain port located at the lower side of the housing, The material is filtered through the multiple filter bags, the material that has passed through the multiple filter bags is sent to a storage tank, and the residual material that has not passed through the filter bags is discharged through the sewage outlet.

12. The papermaking retention agent processing device according to claim 11, characterized in that: A sealing device is arranged outside the support part, which is used to respectively maintain the seal between the support part and the filter bag and between the support part and the inner side wall of the shell.

13. The papermaking retention agent processing device according to claim 12, characterized in that: The sealing device comprises a sealing ring (such as a rubber sealing ring) and a gasket (such as a PTFE gasket), wherein the sealing ring is placed around the filter bag and the support part for sealing the two, and the gasket is placed between the support part and the inner side wall of the shell for sealing the two.

14. The papermaking retention agent processing device according to claim 11, characterized in that: The filter element comprises two filter bags, three filter bags, four filter bags, five filter bags or six filter bags, and the filter bags are optionally arranged around the center.

15. The papermaking retention agent processing device according to claim 1, characterized in that: The papermaking retention agent processing device further comprises a controller located in the preparation tank, and the controller is configured to control the time and flow rate of feeding the material.

16. The papermaking retention agent processing device according to claim 1, characterized in that: It also includes a spare first filter and a spare second filter. The spare first filter is used to be activated when the first filter is closed for cleaning, and the spare second filter is used to be activated when the second filter is closed for cleaning.

17. A method for treating a papermaking retention agent, characterized in that: The papermaking retention aid treatment device as described in any one of claims 1 to 16 is used to filter the material including the papermaking retention aid, and the papermaking retention aid treatment method comprises the following steps: combining the papermaking retention aid with the water in the preparation tank to form a material including the papermaking retention aid; passing the material through a first filter to remove at least a portion of residual material, thereby forming a first liquid; passing the first liquid through a second filter to further remove residual matter, thereby forming a second liquid, Optionally, when the residual substance is a gel-like substance, the first filter is a multi-bag filter, and the second filter is a single-bag filter or a multi-bag filter. Optionally, when the residual matter is particulate matter, the first filter is a self-cleaning filter and the second filter is a single bag filter or a multi-bag filter.

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