Soy sauce low-loss high-efficiency membrane filtration treatment device and application thereof

Abstract

The invention discloses a soy sauce low-loss high-efficiency membrane filtration treatment device and application thereof. The device comprises a circulating tank, a feeding pump and a prefilter which are sequentially communicated, the prefilter and the circulating pump are communicated with an inlet of a membrane device, a clear liquid side inlet of the membrane device is communicated with a constant pressure tank, an outlet and a clear liquid side outlet of the membrane device are communicated with the constant pressure tank and a clear liquid tank, and a flushing tank is communicated with the inlet of the membrane device through a dissolved air pump and a flushing pump. An outlet of the membrane device is communicated with the circulating pump, the circulating tank and the flushing tank. The application of the device comprises the following steps: running the membrane module with a material, stopping the material passing of the membrane module, replenishing water and applying pressure to the constant-pressure tank, flushing the membrane module at a high speed, flushing the membrane module with gas and liquid, exhausting and flushing the membrane module, recovering the running of the membrane module with the material and the like. According to the invention, a plurality of membrane assemblies run in parallel, and long-period continuous operation of membrane equipment and ultra-low loss of soy sauce permeate liquid are realized by balancing pressure on two sides of a membrane surface and a high-speed membrane surface air-water flushing technology, so that the soy sauce membrane treatment filtering efficiency and the product yield are improved.

Description

Technical Field

[0001] The invention relates to a soy sauce low-loss and high-efficiency membrane filtration processing device and application thereof, belonging to the technical field of condiment production. Background Art

[0002] Soy sauce is a condiment widely used worldwide, and the clarification and filtration process in its production process is crucial. In the traditional soy sauce production process, heating and diatomaceous earth filtration are often used for clarification, but these methods have problems such as high energy consumption, flavor loss, and solid waste pollution. With the development of membrane separation technology, its application in soy sauce clarification and filtration has gradually increased, because it can achieve solid-liquid separation while retaining the original flavor and nutritional components of soy sauce. However, existing membrane filtration technology still faces some challenges in soy sauce applications, such as membrane pollution recovery, difficulty in maintaining high-throughput processing efficiency, frequent chemical cleaning, and high loss of membrane liquid products. These problems limit the further application and promotion of membrane filtration technology in the soy sauce industry.

[0003] The patent document with publication number CN 101766290 A describes a method for producing pure raw soy sauce using membrane filtration technology, which removes unnecessary proteins through a 0.1-0.45 μm hollow fiber micro-membrane column, prolongs the shelf life, and retains the original flavor of the soy sauce. However, this technology is only a simple experimental device, with a low cross-flow filtration speed, short high-throughput retention time, severe membrane pollution, and short chemical cleaning cycle. The patent document with publication number CN 111296817A relates to a soy sauce inorganic ceramic membrane impurity removal and clarification process. The patent uses ultra-microfiltration membrane separation technology to directly filter raw soy sauce to remove bacteria and macromolecular substances. The technology mentions that "every 5 to 10 minutes of operation, the membrane components in the ultrafiltration membrane system are instantly backwashed one by one, and the backwashing time for each membrane component is about 3 to 5 seconds: when the membrane group is instantaneously backwashed, other membrane components can operate normally." Although the document does not mention the materials used for backwashing, it can be inferred that the backwashing liquid may be soy sauce that permeates the membrane. Therefore, this patented technology has the problem of frequent backwashing causing increased loss of soy sauce permeating the membrane and frequent discharge of unfiltered soy sauce in the membrane cavity, reducing the effective time of continuous operation of the membrane device, and the backwashing may cause the pollutants that have been flushed to adhere to the membrane surface again when the operating pressure rises subsequently, accelerating membrane pollution and reducing the backwashing effect, resulting in a shortened continuous operation cycle of the membrane equipment and an increase in the number of shutdowns for chemical cleaning. Summary of the invention

[0004] The technical problem to be solved by the present invention is: how to achieve long-term continuous operation of membrane equipment and ultra-low loss of soy sauce permeate, and improve the soy sauce membrane treatment filtration efficiency and product yield.

[0005] In order to solve the above problems, the present invention provides a low-loss and high-efficiency membrane filtration processing device for soy sauce, which comprises a circulation tank, a feed pump, and a prefilter which are connected in sequence, wherein the outlets of the prefilter and the circulation pump are connected with the inlet of a membrane device, the clear liquid side inlet of the membrane device is connected with the liquid outlet of a constant pressure tank, the clear liquid side outlet of the membrane device is connected with the constant pressure tank and the clear liquid tank, the flushing tank is connected with the inlet of the membrane device through an air dissolving pump and a flushing pump, the outlets of the air dissolving pump and the flushing pump are also connected with the flushing tank to form a loop, and the outlet of the membrane device is connected with the inlet of the circulation pump, the circulation tank, and the flushing tank.

[0006] Preferably, the circulation tank is provided with a level gauge for monitoring high and low liquid levels. Feeding is stopped at high liquid level, and new material is added at low liquid level. Equipment is protected at ultra-low liquid level, and new material is provided by the previous process.

[0007] Preferably, the liquid outlet of the constant pressure tank is located at the bottom of the constant pressure tank, and the top of the constant pressure tank is provided with an air inlet, an air outlet, and a liquid replenishment port. The air outlet is connected to a vent valve, and the air inlet is connected to the compressed air through the air inlet valve and the pressure reducing valve in turn, and the liquid replenishment port is connected to the clear liquid side outlet of the membrane device.

[0008] Preferably, the feed pump is a fixed frequency pump, the circulation pump and the flushing pump are variable frequency centrifugal pumps, and the air dissolving pump is a gas-liquid mixing pump that can generate tiny bubbles of 20 to 150 microns.

[0009] Preferably, the flushing tank is divided into a reflux zone, a defoaming zone and a bubble-free zone by a partition; a connecting port is provided at the bottom of the reflux zone and the defoaming zone, and the defoaming zone and the bubble-free zone are replenished by gravity through the liquid level difference; the defoaming zone and the bubble-free zone are both provided with liquid level gauges for monitoring the liquid level in the area, which are interlocked with the dissolved air pump and the flushing pump for control; the top of the reflux zone is connected to the clear liquid side outlet of the membrane device, and the bottom of the reflux zone is provided with a sludge hopper for collecting pollutants shed by flushing the membrane; the inlets of the dissolved air pump and the flushing pump are both connected to the bottom of the bubble-free zone.

[0010] Preferably, the membrane device includes more than one membrane assembly, the bottom of the membrane assembly is provided with an inlet, the top is provided with an outlet, and the two sides of the upper part are respectively provided with a clear liquid side inlet and a clear liquid side outlet; the inlet of each membrane assembly is connected with the outlet of the pre-filter and the circulation pump through a circulation inlet valve, the inlet of each membrane assembly is connected with the outlet of the dissolved air pump and the flushing pump through a flushing inlet valve, the outlet of each membrane assembly is connected with the flushing tank through a flushing outlet valve, the outlet of each membrane assembly is connected with the circulation tank and the inlet of the circulation pump through a circulation outlet valve, the clear liquid side inlet of each membrane assembly is connected with the constant pressure tank through a clear liquid constant pressure inlet valve, the clear liquid side outlet of each membrane assembly is connected to a clear liquid outlet valve, and the clear liquid outlet valve is connected with the liquid replenishment port of the constant pressure tank and the clear liquid tank through a three-way valve; the outlet of the dissolved air pump and the flushing pump is connected with the flushing tank through a drain valve, and the outlet of the dissolved air pump is also provided with a check valve.

[0011] More preferably, a membrane assembly of the membrane device is provided with a plurality of membrane tubes; and a pressure sensor for monitoring the operating pressure value is provided in the membrane assembly.

[0012] The present invention also provides an application of the soy sauce low-loss and high-efficiency membrane filtration treatment device, comprising the following steps:

[0013] Step 1: The membrane module is running with material;

[0014] Step 2: The membrane module stops feeding;

[0015] Step 3: Add water and apply pressure to the constant pressure tank;

[0016] Step 4: High-speed flushing of membrane components;

[0017] Step 5: Gas-liquid flushing of membrane components;

[0018] Step 6: Exhaust and flush the membrane assembly;

[0019] Step 7: The membrane assembly resumes running with material;

[0020] Step 8: Switch to other membrane components for flushing.

[0021] Preferably, the application of the soy sauce low-loss and high-efficiency membrane filtration treatment device comprises the following steps:

[0022] Step 1: When the soy sauce liquid level in the circulation tank reaches the specified level, open the circulation inlet valve and the circulation outlet valve in sequence, start the feed pump, and after the liquid refluxes from the top of the circulation tank, start the circulation pump. After the circulation pump runs to the specified frequency, open the clear liquid outlet valve and the three-way valve to discharge the soy sauce permeate produced by the membrane device into the clear liquid tank;

[0023] Step 2: After the membrane module runs for the set time, some of the membrane modules are gradually flushed online. The execution steps for online flushing of one of the membrane modules are as follows: close the circulation liquid outlet valve and the clear liquid outlet valve of the membrane module, open the flushing liquid outlet valve, and after the flushing tank reaches the specified liquid level, close the circulation liquid inlet valve and the sewage valve, open the flushing liquid inlet valve, and stop the membrane module from feeding; at the same time, automatically control the operating frequency of the circulation pump to keep the operating pressure of other membrane modules the same as that before the membrane module stops feeding;

[0024] Step 3: Open the vent valve, switch the three-way valve to allow the soy sauce permeate to flow into the constant pressure tank, and when the specified liquid level is reached, switch the three-way valve to allow the soy sauce permeate to flow to the clear liquid tank, close the vent valve, open the air inlet valve, and reduce the pressure to the specified pressure to ensure that the pressure in the constant pressure tank is consistent with the membrane cavity pressure of the membrane assembly;

[0025] Step 4: Start the flushing pump, wait for the flushing pump to run to the specified frequency, open the clear liquid constant pressure inlet valve of the membrane assembly, the pressure difference between the inside and outside of the membrane surface of the membrane assembly is zero, the pollutants on the membrane surface are removed under the high-speed membrane surface flow rate, the membrane surface pollution rate is alleviated, and the flushing time is 3 to 10 minutes;

[0026] Step 5: After the high-speed flushing time of the membrane assembly is completed, first close the clear liquid constant pressure inlet valve, then open the dissolved air pump, until the pressure in the membrane assembly reaches the specified value, then adjust the pressure reducing valve to the pressure in the constant pressure tank consistent with the pressure in the membrane assembly, open the clear liquid constant pressure inlet valve, under the common operation of the flushing pump and the dissolved air pump, the membrane surface of the membrane assembly produces a high-speed gas-liquid mixed liquid, further flushing the pollutants on the membrane surface, under the constant pressure balance of the constant pressure tank, the pollutants on the membrane surface are not squeezed by external force, and the high-speed flowing water containing microbubbles cuts the pollutants attached to the membrane surface, the membrane surface is easy to clean, and the loss of soy sauce permeate during the membrane cleaning process is reduced; the membrane surface gas-liquid flushing of this process is 5 to 10 minutes;

[0027] Step 6: Turn off the air dissolving pump, and adjust the pressure reducing valve synchronously to make the pressure in the constant pressure tank the same as the pressure of the membrane assembly. The soy sauce liquid without microbubbles is delivered by the flushing pump to flush the membrane surface for 1 to 5 minutes. The purpose of this process is to discharge the bubbles remaining in the membrane assembly due to gas-liquid flushing, so as to avoid bubbles being brought into the continuous material circulation system in the subsequent steps, causing unstable system operation and reducing the risk of cavitation of the circulation pump impeller.

[0028] Step 7: Open the circulating liquid outlet valve, close the flushing liquid outlet valve and the clear liquid constant pressure inlet valve simultaneously, close the flushing liquid inlet valve and the flushing pump, and open the circulating liquid inlet valve; synchronously adjust the operating frequency of the circulating pump to be consistent with that before cleaning; open the clear liquid outlet valve after 1 to 2 minutes, and the membrane module resumes running with material;

[0029] Step 8: Switch to other membrane components for flushing. The flushing steps are the same as steps 1 to 7. After other membrane components reach the operating cleaning conditions, the above steps can be repeated.

[0030] More preferably, the circulation pump runs to a specified frequency specifically when the operating pressure of the membrane device reaches a specified value; in the eighth step, the other membrane components meet the operating cleaning conditions specifically when the set operating time is reached.

[0031] Compared with the prior art, the present invention aims to address the drawbacks of short continuous operation time and large soy sauce permeate loss during backwashing in the existing soy sauce membrane treatment process. By innovating the parallel operation design of multiple membrane components and the gas-liquid flushing technology for balancing the membrane surface pressure, the continuous operation time of the equipment is significantly improved, the soy sauce permeability loss during flushing is reduced, membrane pollution is effectively alleviated, a high membrane flux operation state is maintained, the chemical cleaning cycle is extended, and the downtime and maintenance time is shortened, thereby greatly improving the production utilization efficiency and permeate product yield of the equipment, realizing a resource-saving and environmentally friendly production process, and demonstrating its technological advancement and application value in the field of soy sauce membrane treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the low-loss and high-efficiency membrane filtration treatment device for soy sauce provided in Example 1. DETAILED DESCRIPTION

[0033] In order to make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0034] The equipment used in the present invention are all commercially available products, and the specific selection is as follows:

[0035] Circulation tank, model: HSSUS-316-10, China Haicheng Engineering Technology Co., Ltd.;

[0036] Feed pump, model: NISO-100-65-200G / 11, Nanfang Pump Industry Co., Ltd.

[0037] Pre-filter, model: DN65-5 bags, Henan Ketwei Environmental Protection Equipment Co., Ltd.;

[0038] Circulation pump, model: NISO-65-40-200 / 22, Nanfang Pump Industry Co., Ltd.;

[0039] Membrane device, model: HSGSCI-60, China Haicheng Engineering Technology Co., Ltd.;

[0040] Dissolved air pump, model: 50EDQS75S, Shanghai Yidun Electromechanical Equipment Co., Ltd.;

[0041] Flushing pump, model: NISO-100-65-200G / 15, Nanfang Pump Industry Co., Ltd.;

[0042] Flushing tank, model: HSSUSTAN-316-5, China Haicheng Engineering Technology Co., Ltd.;

[0043] Constant pressure tank, model: A28W-16P, Zhejiang Fuyu Valve Manufacturing Co., Ltd.;

[0044] Cleaning liquid tank, model: HSSUSTAN-316-8, China Haicheng Engineering Technology Co., Ltd.;

[0045] Automatic control valve, model: Q681F-16RL series, Zhejiang Linuo Fluid Control Technology Co., Ltd.

[0046] Example 1

[0047] like Figure 1 As shown, a low-loss and high-efficiency membrane filtration treatment device for soy sauce provided in this embodiment includes a circulation tank E-1, a feed pump E-2, and a pre-filter E-3 which are connected in sequence. The outlets of the pre-filter E-3 and the circulation pump E-4 are connected to the inlet of the membrane device E-5, the clear liquid side inlet of the membrane device E-5 is connected to the liquid outlet of the constant pressure tank E-9, the clear liquid side outlet of the membrane device E-5 is connected to the constant pressure tank E-9 and the clear liquid tank E-10, the flushing tank E-8 is connected to the inlet of the membrane device E-5 through the dissolved air pump E-6 and the flushing pump E-7, the outlets of the dissolved air pump E-6 and the flushing pump E-7 are also connected to the flushing tank E-8 to form a loop, and the outlet of the membrane device E-5 is connected to the inlet of the circulation pump E-4, the circulation tank E-1, and the flushing tank E-8.

[0048] The circulation tank E-1 is provided with a liquid level gauge for monitoring the high liquid level and the low liquid level respectively.

[0049] The liquid outlet of the constant pressure tank E-9 is located at the bottom of the constant pressure tank E-9. The top of the constant pressure tank E-9 is provided with an air inlet, an air outlet and a liquid replenishing port. The air outlet is connected to a vent valve V-19, and the air inlet is connected to the compressed air through the air inlet valve V-20 and the pressure reducing valve V-22 in turn. The liquid replenishing port is connected to the clear liquid side outlet of the membrane device E-5.

[0050] The feed pump E-2 is a fixed frequency pump, the circulation pump E-4 and the flushing pump E-7 are variable frequency centrifugal pumps, and the air dissolving pump E-6 is a gas-liquid mixing pump that can generate tiny bubbles of 20 to 150 microns.

[0051] The flushing tank E-8 is divided into a reflux zone, a defoaming zone and a bubble-free zone by partitions; a connecting port is provided at the bottom of the reflux zone and the defoaming zone, and the defoaming zone and the bubble-free zone are replenished by gravity through the liquid level difference; the defoaming zone and the bubble-free zone are both provided with liquid level gauges for monitoring the liquid level in the area, and are interlocked with the dissolved air pump E-6 and the flushing pump E-7; the top of the reflux zone is connected to the outlet of the membrane device E-5, and the bottom of the reflux zone is provided with a sludge hopper for collecting pollutants shed by the flushing membrane; the inlets of the dissolved air pump E-6 and the flushing pump E-7 are both connected to the bottom of the bubble-free zone.

[0052] The membrane device E-5 includes three membrane modules, namely, 1# membrane module, 2# membrane module, and 3# membrane module; each membrane module is provided with multiple membrane tubes; a pressure sensor for monitoring the operating pressure value is provided in the membrane module. The bottom of the membrane module is provided with an inlet, the top is provided with an outlet, and the two sides of the upper part are provided with a clear liquid side inlet and a clear liquid side outlet respectively. The inlets of the 1# membrane assembly, the 2# membrane assembly, and the 3# membrane assembly are connected to the outlets of the prefilter E-3 and the circulating pump E-4 through the circulating liquid inlet valve 1 V-1, the circulating liquid inlet valve 2 V-2, and the circulating liquid inlet valve 3 V-3, respectively. The inlets of the 1# membrane assembly, the 2# membrane assembly, and the 3# membrane assembly are connected to the outlets of the dissolved air pump E-6 and the flushing pump E-7 through the flushing liquid inlet valve 1 V-7, the flushing liquid inlet valve 2 V-8, and the flushing liquid inlet valve 3 V-9, respectively. The outlets of the 1# membrane assembly, the 2# membrane assembly, and the 3# membrane assembly are connected to the flushing tank E-8 through the flushing liquid outlet valve 1 V-13, the flushing liquid outlet valve 2 V-14, and the flushing liquid outlet valve 3 V-15, respectively. The outlets of the 1# membrane assembly, the 2# membrane assembly, and the 3# membrane assembly are connected to the circulating tank E-4 through the circulating liquid outlet valve 1 V-4, the circulating liquid outlet valve 2 V-5, and the circulating liquid outlet valve 3 V-6, respectively. -1, the inlet of the circulation pump E-4 is connected, the clear liquid side inlet of the 1# membrane assembly, the 2# membrane assembly, and the 3# membrane assembly are connected with the constant pressure tank E-9 through the clear liquid constant pressure inlet valve 1 V-16, the clear liquid constant pressure inlet valve 2 V-17, and the clear liquid constant pressure inlet valve 3 V-18 respectively, the clear liquid side outlets of the 1# membrane assembly, the 2# membrane assembly, and the 3# membrane assembly are connected with the clear liquid outlet valve 1 V-10, the clear liquid outlet valve 2 V-11, and the clear liquid outlet valve 3 V-12 respectively, the clear liquid outlet valve 1 V-10, the clear liquid outlet valve 2 V-11, and the clear liquid outlet valve 3 V-12 are respectively connected with the liquid replenishing port of the constant pressure tank E-9 and the clear liquid tank E-10 through the three-way valve V-21; the outlets of the dissolved air pump E-6 and the flushing pump E-7 are connected with the flushing tank E-8 through the drain valve V-23, and the outlet of the dissolved air pump E-6 is also provided with a check valve V-24.

[0053] Example 2

[0054] The application of the soy sauce low-loss and high-efficiency membrane filtration treatment device of Example 1 comprises the following specific steps:

[0055] Step 1: The membrane module is operated with material. When the soy sauce liquid level in the circulation tank E-1 reaches 85%, the circulation inlet valve 1 V-1, the circulation inlet valve 2 V-2, the circulation inlet valve 3 V-3 and the circulation outlet valve 1 V-4, the circulation outlet valve 2 V-5, and the circulation outlet valve 3 V-6 are opened in sequence, and the feed pump E-2 is turned on. After the liquid refluxes from the top of the circulation tank E-1, the circulation pump E-4 is turned on. After the circulation pump E-4 runs to the specified frequency of 45Hz and the operating pressure of the membrane module reaches 0.25MPa, the clear liquid outlet valve 1 V-10, the clear liquid outlet valve 2 V-11, the clear liquid outlet valve 3 V-12 and the three-way valve V-21 are opened to discharge the soy sauce permeate produced by the membrane operation into the clear liquid tank.

[0056] Step 2: Stop feeding the membrane assembly. After the membrane assembly has been running for 30 minutes, flush the 1# membrane assembly online. First, close the circulating liquid outlet valve V-4 and the clear liquid outlet valve V-10, open the flushing liquid outlet valve V-13, and when the two liquid level gauges of the flushing tank E-8 are both higher than 70%, close the circulating liquid inlet valve V-1, the sewage valve V-23 and open the flushing liquid inlet valve V-7, and stop the 1# membrane assembly from feeding liquid from the outlet pipe of the circulating pump E-4. At the same time, automatically adjust the operating frequency of the circulating pump E-4 to 39Hz, so that the operating pressure of other membrane assemblies remains unchanged at 0.25MPa.

[0057] Step 3: Replenish water and apply pressure to the constant pressure tank E-9. First, open the vent valve V-19, switch the three-way valve V-21 to allow the soy sauce permeate to flow into the constant pressure tank E-9. When the liquid level reaches 80%, switch the three-way valve V-21 to allow the soy sauce permeate to flow to the clear liquid tank E-10, close the vent valve V-19, then open the air inlet valve V-20, and adjust the pressure reducing valve V-22 until the pressure value of the constant pressure tank E-9 is 0.25Mpa.

[0058] The fourth step is high-speed flushing of the membrane assembly. Turn on the flushing pump E-7 and adjust the operating frequency of the flushing pump E-7 to 40Hz. At this time, the pressure value in the 1# membrane assembly is 0.25MPa; open the clear liquid constant pressure inlet valve V-16, the pressure difference between the inside and outside of the membrane surface in the 1# membrane assembly is zero, and the membrane surface pollutants (such as easily removable mud cakes, etc.) are removed under the high-speed membrane surface flow rate, which reduces the membrane surface pollution rate. The flushing time is 5min.

[0059] Step 5: Gas-liquid flushing of membrane components. After the high-speed flushing time of the 1# membrane component is completed, first close the clear liquid constant pressure inlet valve V-16, then open the air dissolving pump E-6 until the pressure in the 1# membrane component reaches 0.3MPa, and simultaneously adjust the pressure reducing valve V-22 to the pressure in the constant pressure tank E-9 to be consistent with the pressure in the 1# membrane component, both of which are 0.3MPa. Open the clear liquid constant pressure inlet valve V-16, and under the joint operation of the flushing pump E-7 and the air dissolving pump E-6, the membrane surface of the 1# membrane component produces a high-speed gas-liquid mixed liquid to further flush the membrane surface pollutants. At the same time, under the constant pressure balance of the constant pressure tank E-9, the membrane surface pollutants are not squeezed by external force, and the high-speed flowing water containing microbubbles cuts the pollutants attached to the membrane surface, making the membrane surface easy to clean, while greatly reducing the loss of soy sauce permeate during the membrane cleaning process. This process of gas-liquid flushing of the membrane surface takes about 5 minutes.

[0060] Step 6: Exhaust and flush the membrane assembly. Turn off the air dissolving pump E-6, and adjust the pressure reducing valve V-22 synchronously so that the pressure in the constant pressure tank E-9 and the pressure of the 1# membrane assembly are both 0.25MPa. The flushing pump E-7 delivers bubble-free soy sauce to flush the membrane surface, and the flushing time is 1.5 minutes.

[0061] Step 7: The membrane assembly resumes running with material. Open valve V-4, close valves V-13, V-16, and valve V-7 simultaneously, turn off the flushing pump (E-7), and open valve V-1; at the same time, automatically adjust the operating frequency of the circulation pump to 45Hz to keep the operating pressure of the membrane assembly at 0.25MPa; 1 minute later, open the clear liquid outlet valve V-10, and the 1# membrane assembly resumes running with material.

[0062] Step 8: Switch to other membrane components for flushing. When the 2# membrane component has been running for 1 hour, the operations from the first to the seventh steps of the above-mentioned cleaning of the 1# membrane component are the same (only the corresponding valve number of the same type is changed), and the above flushing steps are repeated. This cycle is repeated to clean different membrane components, so as to achieve continuous low permeate loss and high-efficiency membrane filtration operation of the membrane equipment.

[0063] Comparative Example 1

[0064] The running parameters of Comparative Example 1 are the same as those of Example 2. In Comparative Example 1, continuous running is adopted, and no membrane module is flushed during the running process.

[0065] The operating results of Example 2 and Comparative Example 1 are shown in Table 1.

[0066] Table 1 Comparison of continuous flux changes in soy sauce filtration treatment in Example 2 and Comparative Example 1

[0067]

Claims

1. A soy sauce low-loss and high-efficiency membrane filtration treatment device, characterized in that: The invention comprises a circulation tank (E-1), a feed pump (E-2), and a prefilter (E-3) which are connected in sequence. The outlets of the prefilter (E-3) and the circulation pump (E-4) are connected with the inlet of the membrane device (E-5). The inlet of the clear liquid side of the membrane device (E-5) is connected with the liquid outlet of the constant pressure tank (E-9). The outlet of the clear liquid side of the membrane device (E-5) is connected with the constant pressure tank (E-9) and the clear liquid tank (E-10). The flushing tank (E-8) is connected with the inlet of the membrane device (E-5) through the dissolved air pump (E-6) and the flushing pump (E-7). The outlets of the dissolved air pump (E-6) and the flushing pump (E-7) are also connected with the flushing tank (E-8) to form a loop. The outlet of the membrane device (E-5) is connected with the inlet of the circulation pump (E-4), the circulation tank (E-1), and the flushing tank (E-8).

2. The soy sauce low-loss high-efficiency membrane filtration treatment device according to claim 1, characterized in that, The circulation tank (E-1) is provided with a liquid level meter for monitoring the high liquid level and the low liquid level respectively.

3. The soy sauce low-loss high-efficiency membrane filtration treatment device according to claim 1, characterized in that, The liquid outlet of the constant pressure tank (E-9) is located at the bottom of the constant pressure tank (E-9), and the top of the constant pressure tank (E-9) is provided with an air inlet, an air outlet, and a liquid replenishing port. The air outlet is connected to a vent valve (V-19), and the air inlet is connected to compressed air through an air inlet valve (V-20) and a pressure reducing valve (V-22) in sequence. The liquid replenishing port is connected to the clear liquid side outlet of the membrane device (E-5).

4. The soy sauce low-loss high-efficiency membrane filtration treatment device according to claim 1, characterized in that: The feed pump (E-2) is a fixed frequency pump, the circulation pump (E-4) and the flushing pump (E-7) are variable frequency centrifugal pumps, and the air dissolving pump (E-6) is a gas-liquid mixing pump that can generate tiny bubbles of 20 to 150 microns.

5. The soy sauce low-loss high-efficiency membrane filtration treatment device according to claim 1, characterized in that: The flushing tank (E-8) is divided into a reflux zone, a defoaming zone and a bubble-free zone by a partition; a connecting port is provided at the bottom of the reflux zone and the defoaming zone, and the defoaming zone and the bubble-free zone are replenished by gravity through the liquid level difference; the defoaming zone and the bubble-free zone are both provided with a liquid level meter for monitoring the liquid level in the area, and are interlocked with the dissolved air pump (E-6) and the flushing pump (E-7) for control; the top of the reflux zone is connected to the outlet of the membrane device (E-5), and the bottom of the reflux zone is provided with a sludge hopper for collecting pollutants shed by the flushing membrane; the inlets of the dissolved air pump (E-6) and the flushing pump (E-7) are both connected to the bottom of the bubble-free zone.

6. The soy sauce low-loss high-efficiency membrane filtration treatment device according to any one of claims 1 to 5, characterized in that: The membrane device (E-5) includes more than one membrane assembly, the bottom of the membrane assembly is provided with an inlet, the top is provided with an outlet, and the upper two sides are provided with a clear liquid side inlet and a clear liquid side outlet respectively; the inlet of each membrane assembly is connected to the outlet of the pre-filter (E-3) and the circulation pump (E-4) through a circulation inlet valve, the inlet of each membrane assembly is connected to the outlet of the dissolved air pump (E-6) and the flushing pump (E-7) through a flushing inlet valve, the outlet of each membrane assembly is connected to the flushing tank (E-8) through a flushing outlet valve, and the outlet of each membrane assembly is connected to the flushing tank (E-8) through a circulation outlet valve. The inlets of the circulation tank (E-1) and the circulation pump (E-4) are connected, the inlet of the clear liquid side of each membrane assembly is connected to the constant pressure tank (E-9) through a clear liquid constant pressure inlet valve, and the outlet of the clear liquid side of each membrane assembly is connected to a clear liquid outlet valve, and the clear liquid outlet valve is respectively connected to the liquid replenishing port of the constant pressure tank (E-9) and the clear liquid tank (E-10) through a three-way valve (V-21); the outlets of the air dissolving pump (E-6) and the flushing pump (E-7) are connected to the flushing tank (E-8) through a drain valve (V-23), and the outlet of the air dissolving pump (E-6) is also provided with a check valve (V-24).

7. The soy sauce low-loss high-efficiency membrane filtration treatment device according to claim 6, characterized in that: The membrane assembly of the membrane device (E-5) is provided with a plurality of membrane tubes; the membrane assembly is provided with a pressure sensor for monitoring the operating pressure value.

8. An application of the soy sauce low-loss high-efficiency membrane filtration treatment device according to claim 6 or 7, characterized in that: The following steps are involved: Step 1: The membrane module is running with material; Step 2: The membrane module stops feeding; Step 3: Add water and apply pressure to the constant pressure tank; Step 4: High-speed flushing of membrane components; Step 5: Gas-liquid flushing of membrane components; Step 6: Exhaust and flush the membrane assembly; Step 7: The membrane module resumes running with material; Step 8: Switch to other membrane components for flushing.

9. Application of the soy sauce low-loss high-efficiency membrane filtration treatment device as claimed in claim 8, characterized in that, The following steps are involved: The first step: when the soy sauce liquid level in the circulation tank reaches the specified liquid level, the circulation inlet valve and the circulation outlet valve are opened in sequence, and the feed pump (E-2) is turned on. After the liquid refluxes from the top of the circulation tank (E-1), the circulation pump (E-4) is turned on. After the circulation pump (E-4) runs to the specified frequency, the clear liquid outlet valve and the three-way valve are opened to discharge the soy sauce permeate generated by the membrane operation into the clear liquid tank (E-10); Step 2: After the membrane assembly has run for the set time, some of the membrane assemblies are gradually flushed online. The steps for online flushing of one of the membrane assemblies are as follows: close the circulation outlet valve and the clear liquid outlet valve of the membrane assembly, open the flushing outlet valve, and after the flushing tank (E-8) reaches the specified liquid level, close the circulation inlet valve and the sewage valve (V-23), open the flushing inlet valve, and stop the membrane assembly from feeding; at the same time, automatically control the operating frequency of the circulation pump (E-4) to keep the operating pressure of other membrane assemblies the same as before the membrane assembly stops feeding; The third step: open the vent valve (V-19), switch the three-way valve (V-21) to allow the soy sauce permeate to flow into the constant pressure tank (E-9), and when the specified liquid level is reached, switch the three-way valve (V-21) to allow the soy sauce permeate to flow to the clear liquid tank (E-10), close the vent valve (V-19), open the air inlet valve (V-20), and adjust the pressure reducing valve (V-22) to the specified pressure to ensure that the pressure in the constant pressure tank (E-9) is consistent with the membrane cavity pressure of the membrane assembly; Step 4: Start the flushing pump (E-7). When the flushing pump (E-7) runs to the specified frequency, open the clear liquid constant pressure inlet valve of the membrane assembly. The pressure difference between the inside and outside of the membrane surface in the membrane assembly is zero. The pollutants on the membrane surface are removed under the high-speed membrane surface flow rate, which reduces the pollution rate of the membrane surface. The flushing time is 3 to 10 minutes. Step 5: After the high-speed flushing time of the membrane assembly is completed, first close the clear liquid constant pressure inlet valve, then open the air dissolving pump (E-6), until the pressure in the membrane assembly reaches a specified value, then adjust the pressure reducing valve (V-22) to the constant pressure tank (E-9) so that the pressure is consistent with the pressure in the membrane assembly, open the clear liquid constant pressure inlet valve, and under the common operation of the flushing pump (E-7) and the air dissolving pump (E-6), the membrane surface of the membrane assembly produces a high-speed gas-liquid mixed liquid, which further flushes the pollutants on the membrane surface. Under the constant pressure balance of the constant pressure tank (E-9), the pollutants on the membrane surface are squeezed without external force, and the high-speed flowing micro-bubble water flow cuts the pollutants attached to the membrane surface, and the membrane surface is easy to clean, while reducing the loss of soy sauce permeation liquid in the membrane cleaning process; this process membrane surface gas-liquid flushing 5 to 10 minutes; Step 6: turn off the aerosol pump (E-6), synchronously adjust the pressure reducing valve (V-22) to make the pressure in the constant pressure tank (E-9) the same as the pressure of the membrane assembly, and use the flushing pump (E-7) to deliver the soy sauce liquid without bubbles to flush the membrane surface for 1 to 5 minutes; Step 7: Open the circulating liquid outlet valve, and simultaneously close the flushing liquid outlet valve and the clear liquid constant pressure liquid inlet valve, close the flushing liquid inlet valve and the flushing pump (E-7), and open the circulating liquid inlet valve; synchronously adjust the operating frequency of the circulating pump to be consistent with that before cleaning; After 1-2 minutes, the clear liquid outlet valve is opened, and the membrane module resumes running with material; Step 8: Switch to other membrane components for flushing. The flushing steps are the same as steps 1 to 7. After other membrane components reach the operating cleaning conditions, the above steps can be repeated.

10. Application of the soy sauce low-loss and high-efficiency membrane filtration processing device as claimed in claim 9, wherein in the first step, the circulation pump (E-4) runs to the specified frequency, specifically: the operating pressure of the membrane equipment reaches a specified value; in the eighth step, the other membrane components reach the operating cleaning conditions, specifically: reach the set operating time.

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