Microbial multi-stage fermentor

Abstract

The application relates to the field of fermentation tanks, in particular to a microbial multi-stage fermentation tank. The fermentation tank comprises a tank body provided with a feeding port and a discharging port, an upper temperature control interlayer and a lower temperature control interlayer are arranged in the side wall of the tank body in an axial direction, and the two are respectively embedded in the tank wall of the tank body; at least two temperature sensors connected with a controller are arranged in the tank body in the axial direction, the temperature sensors respectively monitor the material temperature of an upper section area and a lower section area in real time and feed back to the controller; a liftable separation component is arranged in the tank body. Through the synergistic effect of the dynamic separation component and the partition temperature control system, the upper and lower cavities are physically isolated in the single tank body, the main fermentation high-temperature stage and the after-ripening low-temperature stage can be independently carried out in different axial areas at the same time, the fundamental defect that the traditional single tank cannot simultaneously meet the multi-stage differentiated temperature requirement is solved, and the process cycle is significantly shortened.

Description

Technical Field

[0001] This application relates to the field of fermenters, and in particular to a multi-stage microbial fermenter. Background Technology

[0002] In the beer brewing industry, microbial fermentation is the core process that shapes the flavor, aroma, and alcohol content of the product. Traditional processes typically use separate fermentation vessels for the primary fermentation and post-fermentation (also known as diacetyl reduction) stages. To simplify the process, save space, and reduce equipment investment, modern industry has gradually developed single-tank multi-stage fermentation technology. This technology aims to continuously complete the complex microbial metabolic processes—such as yeast proliferation, vigorous fermentation, settling, and diacetyl decomposition and reduction—which originally occurred in different stages or different tanks, within a single large, sealed container (usually a conical-bottom tank) using temperature control and other methods. These integrated single-tank systems theoretically have the potential to reduce equipment complexity, minimize racking losses, and shorten the overall fermentation cycle.

[0003] However, existing single-tank multi-stage fermentation technology still reveals a series of key shortcomings in industrial applications. The fundamental reason lies in its inability to accurately simulate and adapt to the differentiated physiological needs of brewer's yeast at different fermentation stages. Firstly, yeast requires relatively high temperatures (e.g., 12-18°C) during the vigorous primary fermentation phase to promote rapid metabolism and alcohol production, while the post-fermentation stage requires lower temperatures (usually below 10°C or even close to 0°C) to facilitate yeast sedimentation, slow down the metabolic rate, and effectively reduce diacetyl. In a single fermentation tank, overall temperature regulation via external jackets or internal coils often suffers from response lag and temperature gradient issues within the tank. Slow temperature changes in the central region of the tank, and difficulty in forming and precisely maintaining different temperature layers in the upper, middle, and lower regions, make it difficult to quickly and uniformly reach and maintain a lower post-fermentation temperature after primary fermentation. The direct consequence of this is incomplete or excessively time-consuming diacetyl reduction, affecting the purity and freshness of the beer flavor and potentially limiting the improvement of overall production efficiency. Utility Model Content

[0004] The purpose of this application is to overcome at least one deficiency in the prior art and to provide a multi-stage fermenter for microorganisms, which achieves precise multi-stage control of the fermentation process through a partitioned temperature control structure and a dynamic isolation mechanism.

[0005] To achieve the above objectives, this application discloses a multi-stage microbial fermenter, which includes a tank body with an inlet and an outlet. The tank body wall adopts a composite layered structure, consisting of an inner liner layer, a heat-conducting layer, a heat-insulating layer, and an outer protective layer, arranged sequentially from the inside out. The heat-conducting layer and the heat-insulating layer are spaced apart to form mounting positions for installing the upper and lower temperature-controlling jackets. The inner liner layer, the heat-conducting layer, and the heat-insulating layer are all arranged in upper and lower segments, with the junction of the two segments separated by a pre-set annular heat-insulating gap of not less than 30 mm in width.

[0006] The tank body has two independent upper and lower temperature control jackets arranged axially on its side wall. The two jackets are respectively embedded in the tank wall, specifically between the heat conduction layer and the heat insulation layer. Both the upper and lower temperature control jackets are made of spiral coils. Their input ends are connected to the external refrigerant circulation unit and the heat conduction unit respectively via solenoid valve groups. According to the controller command, the spiral coils can selectively introduce heat exchange medium at a set temperature and transfer the temperature to the material inside the tank through the heat conduction layer.

[0007] At least two temperature sensors connected to the controller are installed inside the tank along the axial direction to monitor the material temperature in the upper and lower sections in real time and feed it back to the controller.

[0008] The tank is equipped with a liftable partition assembly, which includes a vertically mounted servo electric push rod and a composite partition mechanism connected to the end of the push rod. The partition mechanism consists of a central support tray and an annular inflatable sealing ring disposed on the outer edge of the central support tray. The diameter of the central support tray is controlled to be 0.6-0.9 times the inner diameter of the tank. The annular inflatable sealing ring is connected to an air pump installed outside the tank and controlled by a controller. In the non-working state, the partition mechanism is housed at the top of the tank, and the annular inflatable sealing ring is in an uninflated and contracted state. When the controller issues a partitioning command, the electric push rod drives the partition mechanism to descend to the height corresponding to the annular heat insulation gap, and the annular inflatable sealing ring inflates and expands to form an interference fit with the inner wall of the tank, dividing the tank into a sealed upper cavity and a lower cavity.

[0009] The controller, based on preset fermentation process parameters and temperature sensor feedback data, performs the following operations in a coordinated manner: when the main fermentation stage is detected to be over, it immediately triggers the baffle mechanism to descend and inflate, forming a physical isolation; simultaneously, it controls the upper temperature-controlled jacket to introduce a medium to maintain the temperature, while simultaneously injecting a low-temperature heat exchange medium into the lower temperature-controlled jacket to achieve rapid cooling. This structure allows the tank to achieve parallel processing of continuous post-fermentation in the upper cavity and low-temperature clarification in the lower cavity while maintaining the integrity of the single tank, eliminating the problems of temperature conduction lag and excessive regional temperature differences in traditional single-tank fermentation processes.

[0010] Compared with the prior art, this application has at least one of the following beneficial technical effects:

[0011] 1. This application, through the synergistic effect of dynamic partition components and zoned temperature control system, forms physically isolated upper and lower cavities within a single tank, enabling the primary fermentation high-temperature stage and the post-ripening low-temperature stage to proceed independently in different axial regions at the same time. This solves the fundamental defect of traditional single tanks being unable to simultaneously meet the differentiated temperature requirements of multiple stages, and significantly shortens the process cycle.

[0012] 2. This application utilizes the segmented heat conduction / insulation design of the composite tank wall, combined with an independent temperature control jacket that is strictly matched with the axial partition, to eliminate the lag in temperature gradient conduction inside the tank, ensuring the real-time and uniformity of temperature control response at each fermentation stage, and structurally guaranteeing the process stability of flavor substance metabolism.

[0013] The beneficial effects listed above are not exhaustive of all advantages. Other potential beneficial effects and detailed technical implementation methods will be further disclosed in the embodiments or other descriptive sections of this application. Attached Figure Description

[0014] A better understanding of various aspects of this disclosure will be achieved by reading the following detailed description in conjunction with the accompanying drawings. The positions, dimensions, and extents of the structures shown in the drawings, etc., do not always represent actual positions, dimensions, and extents. In the drawings:

[0015] Figure 1 This is a schematic diagram of the structure of one embodiment disclosed in this application.

[0016] Figure 2 This is a schematic diagram of the internal structure of one embodiment disclosed in this application, in which the liftable partition component is located in the initial position.

[0017] Figure 3 This is a schematic diagram of the internal structure of one embodiment disclosed in this application, in which the liftable partition component is located in the working position and in the unfolded state.

[0018] Figure 4 This is a schematic cross-sectional view of a portion of the tank wall according to an embodiment of this application. Detailed Implementation

[0019] The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure more complete and to fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

[0020] It should be understood that the same reference numerals denote the same elements in all the accompanying drawings. For clarity, the dimensions of certain features may be modified in the drawings.

[0021] It should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit this disclosure. All terms used in this specification (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. For the sake of brevity and / or clarity, techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail; however, where appropriate, such techniques, methods, and apparatus should be considered part of this specification.

[0022] Unless otherwise specified, the singular forms “a,” “the,” and “the” used in this specification include the plural forms. The terms “comprising,” “including,” and “containing” used in this specification indicate the presence of the claimed feature but do not exclude the presence of one or more other features. The term “and / or” used in this specification includes any and all combinations of one or more of the relevant listed items.

[0023] See attached document Figure 1-4 This embodiment uses a 20 m³ multi-stage microbial fermentation tank as an example scenario. The entire device is arranged in a fermentation workshop with a cleanliness level of C. The tank 1 is vertically installed on a load-bearing platform, and the verticality error between its central axis and the horizontal plane is controlled within 1 mm. The tank 1 is composed of a food-grade stainless steel inner liner 101, a high thermal conductivity aluminum alloy thermal conductive layer 102, a high-density aluminum silicate fiber thermal insulation layer 103, and a 304 stainless steel outer protective layer 104, stacked from the inside out. The total wall thickness is controlled at about 100 mm, balancing strength and thermal insulation. The inner liner, thermal conductive layer, and thermal insulation layer are all arranged in two sections. The dividing point between the two sections in the height direction of the tank is located at 55% of the total height of the tank. A 40 mm wide rubber structural component is preset at the dividing point to form an annular thermal insulation gap. This thermal insulation gap not only blocks the thermal bridge between the upper and lower sections, but also provides a sealed docking position for the liftable partition mechanism.

[0024] An upper temperature-controlled jacket 2 and a lower temperature-controlled jacket 3 are embedded axially inside the side wall of tank 1. Both are located between the heat-conducting layer 102 and the insulation layer 103, and they do not interfere with each other. The upper and lower temperature-controlled jackets 2 and 3 are composed of φ20 mm × 1.5 mm 316L stainless steel spiral coils with a coil pitch of 25 mm and total lengths of approximately 55 m and 45 m, respectively. The inlet and outlet of the coils pass through the outer protective layer 104 via compression fittings and are connected to the external refrigerant circulation unit and heat-circulating unit via stainless steel corrugated hoses. Servo proportional solenoid valve assemblies are installed on the pipelines to achieve temperature control.

[0025] Thermal grease is filled between the outer wall of the spiral coil and the thermally conductive layer 102 to reduce contact thermal resistance; the inner wall of the coil is electropolished to Ra≤0.4 μm to reduce scaling.

[0026] In this embodiment, the internal temperature monitoring system of tank 1 consists of two Pt100 platinum resistance temperature sensors. One sensor is fixed to the inner wall at a distance of 1.2 m from the bottom of the tank, and the other is fixed to the lower section of the inner wall at a distance of 0.3 m from the bottom of the tank. The sensor probe is 150 mm long and has a PTFE sleeve at the end to prevent corrosion. The sensor signal is sent to the controller 4 via a loop. The sampling period is 500 ms. The controller 4 outputs adjustment commands to the solenoid valve group and the circulation pump in real time.

[0027] The liftable partition assembly 5 is installed at the top center inside the tank 1. Its servo electric push rod 501 has a stroke of 1.5 m, a rated thrust of 2 kN, and a repeatability of ±0.5 mm. The flange at the end of the push rod is connected to the composite partition mechanism 502, which includes a central support tray 503. The central support tray 503 is made of 316L stainless steel and laser-cut. Its diameter is 0.75 times the inner diameter of the tank. The tray surface is double-sided mirror polished and has heat insulation material sandwiched inside.

[0028] In addition, the outer edge of the central support tray 503 is vulcanized and bonded with a EPDM rubber annular inflatable sealing ring 504 with a Shore hardness of 60 HA. The sealing ring has an Ω-shaped cross-section, and its outer diameter expands after inflation, forming a line contact pressure of ≥0.3 MPa with the inner liner layer 101. The air pump 505 is an oil-free rotary vane type, installed on the top platform of the tank 1, and connected to the annular inflatable sealing ring 504 through a φ8 mm × 1 mm PU hose. The hose is introduced into the servo electric push rod 501 through a rotary joint to avoid entanglement during lifting and lowering. The partition mechanism is stored on the top of the tank 1 when not in operation.

[0029] The controller 4 is a PLC. When the slope of the temperature curve during the main fermentation stage is lower than 0.02 ℃ / min for three consecutive sampling values, the controller 4 determines that the main fermentation has ended and then executes the following linkage actions: the electric push rod 501 descends to the position of the annular heat insulation gap at a speed of 5 mm / s; the air pump 505 inflates the sealing ring to 0.35 MPa; the upper temperature control jacket 2 switches to a medium circulation of 28 ℃ to maintain post-ripening, and the lower temperature control jacket 3 switches to a medium circulation of 5 ℃ to achieve rapid clarification.

[0030] Based on the aforementioned structure and operation process of the 20 m³ demonstration tank, this paper further clarifies the specific implementation path of zoned temperature control and its resulting technological advantages. When the PLC confirms the completion of primary fermentation based on the temperature slope criterion, the controller immediately activates the "zoned temperature control" linkage script: physically dividing tank 1 into an upper and lower cavity; simultaneously, the upper temperature control jacket 2 ensures the mild environment required for yeast post-fermentation; the lower temperature control jacket 3 operates in the opposite direction, lowering this area to 5 ℃, forming the low-temperature field required for rapid yeast settling. The annular insulation gap and the composite partition mechanism 502 jointly block the thermal bridge between the upper and lower cavities, avoiding the "colder at the top and colder at the bottom" or "hot spot in the center" phenomenon caused by central lag during traditional single-tank overall cooling. Thus, the upper cavity continuously completes diacetyl reduction and flavor maturation, while the lower cavity simultaneously achieves yeast flocculation and beer clarification. The entire post-fermentation-clarification parallel cycle is shortened, and the final diacetyl value decreases; no tank turning is required, and the freshness of the finished product is significantly improved.

[0031] While exemplary embodiments of this disclosure have been described, those skilled in the art will understand that various changes and modifications can be made to the exemplary embodiments of this disclosure without departing from the spirit and scope thereof. Therefore, all changes and modifications are included within the scope of protection of this disclosure as defined by the claims. This disclosure is defined by the appended claims, and equivalents of those claims are also included.

Claims

1. A multi-stage microbial fermenter, characterized in that: The fermenter includes a tank body with an inlet and an outlet. The tank sidewall is provided with an independent upper temperature control layer and a lower temperature control layer along the axial direction, and the two are respectively embedded in the tank wall. At least two temperature sensors connected to the controller are installed inside the tank along the axial direction to monitor the material temperature in the upper and lower sections in real time and feed it back to the controller. The tank is equipped with a liftable partition assembly, which includes a vertically mounted servo electric push rod and a composite partition mechanism connected to the end of the push rod. The partition mechanism consists of a central support tray and an annular inflatable sealing ring disposed on the outer edge of the central support tray. The annular inflatable sealing ring is connected to an air pump installed outside the tank and controlled by a controller. In the non-working state, the partition mechanism is housed in the top of the tank, and the annular inflatable sealing ring is in an uninflated and retracted state.

2. The multi-stage microbial fermenter as described in claim 1, characterized in that: Both the upper and lower temperature-controlled interlayers are composed of spiral coils, and their input ends are connected to the external refrigerant circulation unit and the heat transfer medium circulation unit respectively via solenoid valve groups.

3. The multi-stage microbial fermenter as described in claim 1, characterized in that: The tank wall adopts a composite layered structure, consisting of an inner liner layer, a heat-conducting layer, a heat-insulating layer, and an outer protective layer from the inside out. The heat-conducting layer and the heat-insulating layer are spaced apart to form installation positions for the upper and lower temperature-controlling jackets. The inner liner layer, heat-conducting layer, and heat-insulating layer are all arranged in upper and lower segments, with a pre-set annular heat-insulating gap at the junction of the two segments through the heat-insulating material.

4. The multi-stage microbial fermenter as described in claim 1, characterized in that: The width of the annular thermal insulation gap shall not be less than 30mm.

5. The multi-stage microbial fermenter as described in claim 1, characterized in that: The diameter of the center support tray should be controlled to be 0.6-0.9 times the inner diameter of the tank.

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