WO2020155840A1

WO2020155840A1 - Hollow helical blade heated thin-film evaporator and evaporation method

Info

Publication number: WO2020155840A1
Application number: PCT/CN2019/122681
Authority: WO
Inventors: 邹传军
Original assignee: 武汉美味源生物工程有限公司
Priority date: 2019-02-01
Filing date: 2019-12-03
Publication date: 2020-08-06

Abstract

Disclosed are a hollow helical blade heated thin-film evaporator and an evaporation method. The thin-film evaporator comprises a heating and evaporation tank. A feeding pipe is provided on an upper wall portion of the heating and evaporation tank. A discharging pipe is provided on a lower wall portion of the heating and evaporation tank. A hollow helical blade heating device is provided inside the heating and evaporation tank. The hollow helical blade heating device comprises a hollow rotation shaft provided at two ends of the heating and evaporation tank by means of bearing seats. A gearmotor is provided at a driving end of the hollow rotation shaft. A closure plate is provided in the middle of the hollow rotation shaft. A hollow and continuous helical blade is provided on an outer wall of the hollow rotation shaft. Openings at two ends of the helical blade are provided at two ends of the closure plate, and communicate with the hollow rotation shaft. A method for performing ultra-low temperature evaporation and high viscosity evaporation on a liquid by using the hollow helical blade heated thin-film evaporator achieves ultra-low temperature evaporation and high viscosity evaporation. The invention has high heat transfer efficiency, and achieves material uniformity.

Description

Hollow spiral blade heating thin film evaporator and evaporation method

Technical field

The invention relates to an evaporator, in particular to a hollow spiral blade heating thin film evaporator and an evaporation method, in particular to an ultra-low temperature evaporation and high viscosity evaporation method.

Background technique

In the concentration process of many materials, such as heat-sensitive proteins, low-temperature evaporation is required to maintain the activity of the materials, and other materials, such as honey, need to be concentrated to a very high concentration for easy storage. Existing evaporators, in order to achieve ultra-low temperature evaporation and high-viscosity evaporation of liquids, often use thin-film evaporation technology, that is, the material is formed on the surface of the heating body to form a thin film, which can increase the evaporation speed and reduce the evaporation temperature. That is, the thinner the material, the easier it is to evaporate.

In order to realize thin-film evaporation, the most typical method at present is a scraper evaporator, that is, the material is evenly distributed on the inner wall of a vertical steel pipe through a rotating scraper. The outer wall of the steel pipe has an interlayer. It uses steam, hot water, heat transfer oil and other heat sources for heating. The material uses the weight of the liquid itself to move from top to bottom, and the water or other solvents contained in the material quickly evaporate. If the material has high viscosity or crystals, the rotating scraper can also push the material down and discharge at the bottom. The disadvantage of this equipment is that it requires high processing accuracy and requires a close fit between the scraper and the inner wall of the steel plate to ensure the uniform distribution of the liquid. At the same time, the surface area of the structure is limited, and large-scale equipment cannot be produced. The largest equipment area is only 20 square meters, and the power consumption of the rotating scraper is high.

Summary of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art, and provide a hollow spiral blade heating thin film evaporator and evaporation method, specifically, ultra-low temperature evaporation and high viscosity evaporation method. The present invention utilizes a horizontally placed screw conveying auger. The blades of the screw auger have a double-jacket structure with steam, hot water, and heat transfer oil in the middle. A part of the screw is immersed in the material. Through the rotation of the screw blade, the material is uniform Coated on the surface of the blade, in a high-vacuum environment, ultra-low temperature evaporation and evaporation of high-viscosity materials can be realized. High-viscosity materials can be conveyed to the discharge port by screw propulsion and finally discharged. The hollow spiral blade plays the role of heating, diluting, forming, advancing and stirring the material in the process.

In order to achieve the above-mentioned object, the present invention designs a hollow spiral blade heating film evaporator, which includes a heating evaporation tank, the upper tank wall of the heating evaporation tank is provided with a feed pipe, and the lower tank wall of the heating evaporation tank is provided There is a discharge pipe, the heating evaporator is provided with a hollow spiral blade heating device, the wall of the heating evaporator is connected with a steam outlet pipe, and the steam outlet pipe is sequentially connected with a condenser and condensed water through a steam pipe The upper wall of the condensed water tank is provided with a vacuum tube; the hollow spiral blade heating device includes a hollow rotating shaft tube arranged at both ends of the heating evaporation tank through a bearing seat, and the transmission end of the hollow rotating shaft tube is provided with a reduction motor, An intercepting plate is arranged in the middle of the hollow rotating shaft tube, a hollow spiral blade is arranged on the outer wall of the hollow rotating shaft tube, and two ends of the spiral blade are opened at both ends of the intercepting plate and communicated with the hollow rotating shaft tube.

The above-mentioned hollow spiral blade heating device includes a hollow rotating shaft tube, and the hollow rotating shaft tube transfers an external heat source into the spiral blade and transports it out of the equipment. An important feature of the hollow shaft tube is that the middle of the shaft is equipped with a blocking plate, which divides the hollow shaft into two parts: "hot water" and "cold water". Rotary joints are installed at both ends of the hollow shaft to ensure that the heat source can enter and exit the vacuum tank when the shaft is rotating. The two ends of the hollow shaft are connected with bearing seats and seals and are driven by a geared motor;

The spiral blade is welded to the hollow shaft tube, and the outside is sealed with steel plate welding. The spiral blade becomes a continuous cavity. The two ends of the cavity are connected to the two ends of the hollow shaft, and the opening, hot water or other heat source is from the hollow shaft. Enter one end of the spiral blade, and then exit from the other end of the spiral blade through the hollow shaft. The hollow spiral blade heating device is used for the heater of the evaporator. It uses the film forming, stirring and propelling effects played during the rotation of the spiral blade to play the role of ultra-low temperature thin film evaporation and high viscosity evaporation. The spiral surface and the inner wall of the evaporation tank are protected against Sticky coating to prevent scaling.

Further, a discharge pump is provided on the discharge pipe.

Furthermore, a heating jacket is provided outside the heating evaporation tank to maintain the temperature of the material.

Still further, a vacuum pump is provided on the vacuum tube.

Still further, the bottom plate of the condensed water tank is provided with a water outlet pipe.

Still further, the inner wall of the heating evaporation tank and the surface of the spiral blade are coated with polytetrafluoroethylene. The parts in contact with the materials are treated with anti-sticking treatment, preferably with Teflon (polytetrafluoroethylene) for surface treatment to avoid scaling of the materials.

The present invention also provides a method for liquid ultra-low temperature evaporation and high viscosity evaporation by using the above hollow spiral blade heating thin film evaporator, which is characterized in that it comprises the following steps:

1) Turn on the vacuum pump to control the pressure of the system at 1500～2500pa. At the same time, the hollow shaft and the jacket of the heating evaporation tank are filled with hot water or heat transfer oil. The temperature of the hot water or heat transfer oil is 40℃-90℃; the hot water is piped from the hollow shaft The water inlet enters, flows into the spiral blade, and returns from the spiral blade to the outlet end of the hollow shaft tube;

2) Open the feed valve and start the deceleration motor, the material enters the heating evaporation tank;

3) During the rotation of the hollow spiral blade heating device, the material is evenly spread on the surface of the spiral, heated and evaporated. When the spiral is transferred into the material, the friction between the surface and the material causes the spiral surface to be cleaned and diluted to avoid accumulation and accumulation. Fouling; while the hollow spiral blade heating device heats and evaporates the material, it also stirs the material to avoid excessive local concentration of the material, avoid material accumulation and scaling, and at the same time, push the material forward;

4) The hollow spiral blade heating device pushes the materials forward, and is discharged through the discharge pipe and the discharge pump for collection; to obtain concentrated materials;

5) The steam produced by evaporation enters the condenser through the steam pipe, the condensed water flows into the condensate water tank, and the non-condensed gas is discharged by the vacuum pump.

The beneficial effects of the present invention:

1) The invention realizes ultra-low temperature evaporation: by adjusting the vacuum pump, the boiling point of water can be adjusted in a large range. For example, a combination of a first-stage water ring vacuum pump and a two-stage roots vacuum pump can achieve a vacuum degree of 2000 PA, so the evaporation temperature is only At 17.5℃, if the vacuum is 1000pa, the water can be evaporated at 7℃.

2) The present invention realizes high-viscosity evaporation: due to the film-forming, stirring and propelling effects of the spiral blade, the material can also evaporate and discharge when the viscosity is high.

3) The present invention has a large output: the surface of the spiral can play the role of evaporation. In a certain space, by adjusting the diameter and pitch of the spiral, a large evaporation area can be achieved, with a diameter of 1 meter, a pitch of 15 cm, and a length of 1.5 meters. The heating area can reach 15 square meters. By increasing the diameter and number of spirals, it is easy to achieve an evaporation area of more than 100 square meters, which is unmatched by other thin film evaporators.

4) The equipment of the present invention is simple and reliable: the screw is used as a conveying tool, and the rotation speed is slow, generally only a few seconds, and the processing difficulty of the system is low, simple and reliable.

5) The invention has high heat transfer efficiency: the material is uniformly filmed on the surface of the spiral blade, and the material is continuously mixed, stirred and propelled. At the same time, the surface in contact with the material is treated with anti-sticking treatment, which does not scale, and ensures that all contact with the material The surface can uniformly transfer heat energy, and the heat transfer efficiency is high.

6) The material of the present invention has good uniformity: due to the movement of the spiral, friction with the material in the lower part of the tank plays a continuous self-cleaning effect on the surface of the spiral. Products that are bonded to each other and accumulated on the leaf surface can be removed and re-enter the production process. The spiral is continuously stirred and advanced to form a stable concentration difference in the longitudinal direction of the evaporation tank.

Description of the drawings

Figure 1 is a schematic diagram of the structure of a hollow spiral blade heating film evaporator;

Figure 2 is a schematic view of the structure of the hollow spiral blade heating device;

In the figure, heating evaporation tank 1, feed pipe 1.1, discharge pipe 1.2, steam outlet pipe 1.3, heating jacket 1.4, hollow spiral blade heating device 2, hollow shaft tube 2.1, intercepting plate 2.11, spiral blade 2.2, opening 2.21 , Steam pipe 3, condenser 4, condensate tank 5, water outlet pipe 5.1, vacuum pipe 6, vacuum pump 6.1, geared motor 7, discharge pump 8.

detailed description

In the following, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments to facilitate the understanding of those skilled in the art.

The hollow spiral blade heating thin film evaporator shown in Figures 1 to 2 includes a heating evaporation tank 1, a feed pipe 1.1 is arranged on the upper tank wall of the heating evaporation tank 1, and a discharge pipe is arranged on the lower tank wall of the heating evaporation tank 1. Pipe 1.2, a discharge pump 8 is arranged on the discharge pipe 1.2, and a heating jacket 1.4 is arranged outside the heating evaporation tank 1;

The heating evaporator 1 is provided with a hollow spiral blade heating device 2, and the wall of the heating evaporator 1 is connected with a steam outlet pipe 1.3. The steam outlet pipe 1.3 is connected to a condenser 4 and a condensate water tank 5 through the steam pipe 3 in turn to condense The bottom plate of the water tank 5 is provided with a water outlet pipe 5.1;

The upper wall of the condensate tank 5 is provided with a vacuum tube 6; the vacuum tube 6 is provided with a vacuum pump 6.1; the hollow spiral blade heating device 2 includes a hollow rotating shaft tube 2.1 installed at both ends of the heating evaporation tank 1 through a bearing seat, and the hollow rotating shaft tube 2.1 is provided with a transmission end There is a geared motor 7, the hollow shaft tube 2.1 is provided with a blocking plate 2.11 in the middle of the hollow shaft tube 2.1 is provided with a hollow and continuous spiral blade 2.2 on the outer wall of the hollow shaft tube 2.1, and the two ends of the spiral blade 2.2 are opened at both ends of the blocking plate 2.11 and connected with the hollow shaft Pipe 2.1 is connected. The inner wall of the heating evaporation tank 1 and the surface of the spiral blade 2.2 are coated with polytetrafluoroethylene.

The method of using the above hollow spiral blade heating film evaporator to perform liquid ultra-low temperature evaporation and high viscosity evaporation includes the following steps:

1) Turn on the vacuum pump to control the pressure of the system at 1500～2500pa. At the same time, the hollow shaft and the jacket of the heating evaporator 1 are filled with hot water or heat transfer oil. The temperature of the hot water or heat transfer oil is 40℃-90℃; the hot water is from the hollow shaft The water inlet of pipe 2.1 enters, flows into the spiral blade 2.2, and returns from the spiral blade 2.2 to the outlet end of the hollow shaft pipe 2.1;

2) Open the feed valve and start the deceleration motor, the material enters the heating evaporation tank 1;

3) When the hollow spiral blade heating device 2 rotates, the material is evenly spread on the surface of the spiral, heated and evaporated. When the spiral is transferred into the material, the friction between the surface and the material causes the spiral surface to be cleaned and diluted to avoid accumulation and Scaling; the hollow spiral blade heating device 2 spirals heating and evaporating the material, and at the same time it also stirs the material to avoid excessive local concentration of the material, avoid material accumulation and scaling, and at the same time push the material forward;

4) The hollow spiral blade heating device 2 pushes the material forward, and discharges it through the discharge pipe 1.2 and the discharge pump 8 for collection; to obtain concentrated materials;

5) The steam generated by evaporation enters the condenser 4 through the steam pipe, the condensed water flows into the condensate tank 5, and the non-condensed gas is discharged by the vacuum pump 6.1.

Other parts that are not described in detail are all prior art. Although the above embodiments give a detailed description of the present invention, they are only a part of the embodiments of the present invention, rather than all of them. People can also obtain other embodiments based on this embodiment without creativity, such as increasing the vacuum. To obtain a lower evaporation temperature and achieve a lower evaporation temperature, or increase the heating temperature to achieve a higher concentration evaporation, two sets of interlaced spirals are designed to obtain a larger evaporation area in a certain space. These embodiments All belong to the protection scope of the present invention.

Claims

A hollow spiral blade heating thin film evaporator, characterized in that it comprises a heating evaporation tank (1), the upper tank wall of the heating evaporation tank (1) is provided with a feed pipe (1.1), the heating evaporation tank (1) 1) A discharge pipe (1.2) is provided on the lower tank wall, a hollow spiral blade heating device (2) is provided in the heating evaporation tank (1), and steam is connected to the heating evaporation tank (1). The outlet pipe (1.3), the steam outlet pipe (1.3) is connected to the condenser (4) and the condensate tank (5) through the steam pipe (3) in turn, and the upper wall of the condensate tank (5) is provided with a pump Vacuum pipeline (6); the hollow spiral blade heating device (2) includes a hollow rotating shaft tube (2.1) arranged at both ends of the heating evaporation tank (1) through a bearing seat, and the transmission end of the hollow rotating shaft tube (2.1) is provided with a speed reducer The motor (7), the hollow shaft tube (2.1) is provided with a blocking plate (2.11) in the middle, and the hollow shaft tube (2.1) is provided with a hollow and continuous spiral blade (2.2) on the outer wall, the spiral blade (2.2) ) Two-end openings (2.21) are arranged at both ends of the intercepting plate (2.11) and communicate with the hollow shaft tube (2.1).
The hollow spiral blade heating film evaporator according to claim 1, characterized in that: a discharge pump (8) is provided on the discharge pipe (1.2).
The hollow spiral blade heating thin-film evaporator according to claim 1, wherein a heating jacket (1.4) is provided outside the heating evaporation tank (1).
The hollow spiral blade heating thin film evaporator according to claim 1, characterized in that: the vacuum tube (6) is provided with a vacuum pump (6.1).
The hollow spiral blade heating film evaporator according to claim 1, characterized in that: a water outlet pipe (5.1) is provided at the bottom of the condensate water tank (5).
The hollow spiral blade heating film evaporator according to claim 1, characterized in that: the inner wall of the heating evaporation tank (1) and the surface of the spiral blade (2.2) are coated with polytetrafluoroethylene.
A method for using the hollow spiral blade heating thin film evaporator of claim 1 to perform liquid ultra-low temperature evaporation and high viscosity evaporation, characterized in that it comprises the following steps:

1) The pressure of the vacuum pump control system is 1500～2500pa. At the same time, the hollow shaft and the jacket of the heating evaporation tank (1) are filled with hot water or heat transfer oil. The temperature of the hot water or heat transfer oil is 40℃-90℃; hot water or The heat transfer oil enters the water inlet of the hollow shaft tube (2.1), flows into the spiral blade (2.2), and returns from the spiral blade (2.2) to the outlet end of the hollow shaft tube (2.1);

2) Open the feed valve and start the decelerating motor, the material enters the heating evaporation tank (1);

3) Hollow spiral blade heating device (2) During the rotation process, the material is evenly spread on the surface of the spiral blade, heated and evaporated. When the spiral blade is transferred into the material, the friction between the surface and the material causes the spiral surface to be cleaned and diluted , To avoid material accumulation and fouling; the hollow spiral blade heating device (2) while heating and evaporating the material, the screw also stirs the material to avoid excessive local concentration of the material, avoid material accumulation and scaling, and at the same time, Advance the material;

4) The hollow spiral blade heating device (2) pushes the materials forward, and discharges them through the discharge pipe (1.2) and the discharge pump (8) for collection; to obtain concentrated materials;

5) The steam generated by evaporation enters the condenser (4) through the steam pipe, the condensed water flows into the condensate water tank (5), and the non-condensed gas is discharged by the vacuum pump (6.1).