Spray drying system and spray drying method

Abstract

The invention relates to the technical field of drying equipment, and provides a spray drying system and a spray drying method.The system comprises a spray drying module used for drying feed liquid to obtain a target product and high-temperature waste gas; the heat pump module comprises a compressor and a heat exchanger which are connected in sequence; the compressor is used for introducing high-temperature waste gas, compressing the high-temperature waste gas to increase enthalpy and converting the high-temperature waste gas into high-temperature high-pressure gas; the heat exchanger is used for heat exchange between high-temperature and high-pressure gas and inlet gas of the spray drying module, and waste gas with heat released is obtained. According to the spray drying system and the spray drying method, the compressor compresses high-temperature waste gas to increase enthalpy, and the high-temperature waste gas is converted into high-temperature and high-pressure gas; the heat exchanger is used for heat exchange between high-temperature and high-pressure gas and inlet gas of the spray drying module, waste gas with heat released is obtained, the temperature of the inlet gas is increased, low-grade heat energy in the high-temperature waste gas is recycled, and the heat energy is used as a drying heat source after being pressurized and enthalpy-increased, so that the energy consumption of the drying system is reduced, and the carbon emission is also reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of drying equipment, and in particular to a spray drying system and a spray drying method. Background Art

[0002] Spray drying is a process that disperses the material to be dried into very fine mist-like particles through mechanical action. After contact with hot air, most of the moisture is removed and the solid matter in the material is dried into powder.

[0003] In the chemical, pharmaceutical, textile, paper, food, agricultural product processing and other industries, it is often necessary to remove moisture from materials in order to facilitate storage, transportation and further processing to meet production requirements. Spray drying can directly dry solutions and emulsions into powder or granular products, eliminating the evaporation, crushing and other processes.

[0004] However, in the prior art, Figure 1 As shown, most spray drying systems discharge high-temperature exhaust gas directly into the atmosphere, resulting in high system energy consumption and low thermal efficiency. Summary of the invention

[0005] The present invention provides a spray drying system and a spray drying method, which are used to solve the defects of high energy consumption and low thermal efficiency of the spray drying system in the prior art, and realize the use of low-grade thermal energy in high-temperature exhaust gas as a drying heat source after pressurization and enthalpy increase, and recover condensed water at the same time.

[0006] The present invention provides a spray drying system, comprising: Spray drying module, used to dry the liquid to obtain the target product and high-temperature waste gas; The heat pump module includes a compressor and a heat exchanger connected in sequence; the compressor is used to allow the high-temperature exhaust gas to pass in, and compress the high-temperature exhaust gas to increase enthalpy and convert it into high-temperature and high-pressure gas; the heat exchanger is used to exchange heat between the high-temperature and high-pressure gas and the intake air of the spray drying module to obtain the exhaust gas after releasing heat.

[0007] According to a spray drying system provided by the present invention, the heat pump module also includes a condensed water tank, and the exhaust gas after releasing heat is discharged into the atmosphere after passing through the condensed water tank, and the condensed water tank is used to store condensed water generated by the exhaust gas after releasing heat.

[0008] According to a spray drying system provided by the present invention, the spray drying module comprises: Liquid tank, used to store the dilute liquid material to be dried; A driving device connected to the liquid tank, the driving device being used to transport the material; A centrifugal atomizer is arranged downstream of the driving device, and is used to convert the dilute liquid material into atomized liquid droplet material; An air supply module, used for providing intake air; and the intake air of the air supply module exchanges heat with the high-temperature and high-pressure gas in the heat exchanger; A drying chamber, disposed downstream of the centrifugal atomizer, the drying chamber providing a place for hot air to contact the atomized liquid droplet material; A cyclone separator is used to achieve gas-solid separation. The target product is precipitated in the cyclone separator, and the high-temperature exhaust gas is output from the top of the cyclone separator.

[0009] According to a spray drying system provided by the present invention, the spray drying module further comprises a bag filter, wherein the bag filter is arranged downstream of the cyclone separator, and the bag filter is used to filter dust particles in the gas.

[0010] According to a spray drying system provided by the present invention, the spray drying module further comprises an exhaust fan disposed downstream of the bag filter, and the exhaust fan is used to input the high-temperature exhaust gas into the compressor.

[0011] According to a spray drying system provided by the present invention, the air supply module comprises: The primary filter is used for preliminary filtration of the air entering the system; The air inlet fan is arranged downstream of the primary filter; and the air at the outlet of the air inlet fan enters the heat exchanger.

[0012] According to a spray drying system provided by the present invention, the air supply module further includes: An electric heater, arranged on the air intake pipeline and located downstream of the heat exchanger; A secondary filter is arranged downstream of the electric heater, and an outlet of the secondary filter is connected to the drying chamber.

[0013] According to a spray drying system provided by the present invention, the driving device is a peristaltic pump.

[0014] The present invention also provides a spray drying method, using the spray drying system as described above, comprising: The liquid feed is dried by a spray drying module to obtain the target product and high-temperature waste gas; The high-temperature exhaust gas enters the compressor, which compresses the high-temperature exhaust gas to increase its enthalpy and converts it into the high-temperature and high-pressure gas; The high-temperature and high-pressure gas exchanges heat with the intake air of the spray drying module to increase the temperature of the intake air and obtain exhaust gas after releasing heat.

[0015] A spray drying method provided by the present invention also includes: the waste gas after releasing heat is discharged into the atmosphere after passing through a condensation water tank, and the condensation water tank is used to store condensation water.

[0016] The spray drying system and spray drying method provided by the present invention dry the liquid feed through a spray drying module to obtain a target product and high-temperature exhaust gas; the heat pump module includes a compressor and a heat exchanger connected in sequence, the high-temperature exhaust gas is passed into the compressor, and the compressor compresses the high-temperature exhaust gas to increase enthalpy and converts it into high-temperature and high-pressure gas; the heat exchanger exchanges heat between the high-temperature and high-pressure gas and the intake air of the spray drying module to obtain exhaust gas after heat release, and the temperature of the intake air is increased, and the low-grade thermal energy in the high-temperature exhaust gas is recovered and this part of the thermal energy is pressurized and increased in enthalpy and used as a drying heat source, thereby reducing the waste of waste heat resources and reducing the energy consumption and carbon emissions of the drying system.

[0017] In addition, since the exhaust gas after releasing heat will condense to form condensed water, the condensed water is stored in the condensed water tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a spray drying system in the prior art.

[0020] Figure 2 The invention provides a spray drying system.

[0021] Reference numerals: 1. Spray drying module; 2. Heat pump module; 21. Compressor; 22. Heat exchanger; 23. Condensate tank; 11. Liquid tank; 12. Driving device; 13. Centrifugal atomizer; 14. Air supply module; 141. Primary filter; 142. Air inlet fan; 143. Electric heater; 144. Secondary filter; 15. Drying chamber; 16. Cyclone separator; 17. Bag filter; 18. Exhaust fan. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0024] Combine the following Figure 2 The spray drying system of the present invention is described, comprising a spray drying module 1 and a heat pump module 2 .

[0025] Among them, the spray drying module 1 is used to dry the liquid, and high-temperature exhaust gas will be generated while obtaining the target product. In order to reduce carbon emissions, a heat pump module 2 is set. The heat pump module 2 includes a compressor 21 and a heat exchanger 22 connected in sequence; the compressor 21 is used to allow the high-temperature exhaust gas to enter, and compress the high-temperature exhaust gas to increase enthalpy, and convert it into high-temperature and high-pressure gas; the heat exchanger 22 provides heat exchange between the high-temperature and high-pressure gas and the intake air of the spray drying module 1, which not only obtains the exhaust gas after the heat is released, reducing carbon emissions, but also increases the intake temperature of the spray drying module 1, improves energy utilization, and reduces the waste of thermal resources and carbon emissions.

[0026] In a feasible embodiment of the present invention, since the exhaust gas after releasing heat will produce condensed water, the heat pump module 2 also includes a condensed water tank 23, which is arranged downstream of the heat exchanger 22. The exhaust gas after releasing heat is discharged into the atmosphere after passing through the condensed water tank 23, and the condensed water tank 23 is used to store the condensed water generated by the exhaust gas after releasing heat.

[0027] In a feasible embodiment of the present invention, the spray drying module 1 includes a liquid tank 11, a driving device 12, a centrifugal atomizer 13, an air supply module 14, a drying chamber 15 and a cyclone separator 16. The liquid tank 11 is used to store the thin liquid material to be dried; the driving device 12 is connected to the liquid tank 11, and the driving device 12 is used to transport the thin liquid material; the centrifugal atomizer 13 is arranged downstream of the driving device 12, and the centrifugal atomizer 13 is used to convert the thin liquid material into an atomized droplet state; the air supply module 14 is used to provide intake air, usually high-temperature hot air, so as to dry the liquid in the thin liquid material. And the intake air of the air supply module 14 exchanges heat with the high-temperature and high-pressure gas in the heat exchanger; the drying chamber 15 is arranged downstream of the centrifugal atomizer 13, and the drying chamber 15 provides a place for the hot air to contact the atomized droplet material; the cyclone separator 16 realizes gas-solid separation, the target product is precipitated in the cyclone separator 16, and the top of the cyclone separator 16 outputs high-temperature exhaust gas.

[0028] Among them, during the rotation of the cyclone separator 16, solid particles or liquid droplets with large inertial centrifugal force are thrown to the outer wall surface, and fall along the cylinder wall to the liquid storage area at the bottom of the equipment under the action of gravity, while the clean gas is discharged from the discharge port at the top.

[0029] In a feasible embodiment of the present invention, the spray drying module 1 further comprises a bag filter 17, which is arranged downstream of the cyclone separator 16. The bag filter 17 is used to filter dust particles in the gas to ensure the cleanliness of the outflowing high-temperature gas.

[0030] In a feasible embodiment of the present invention, the spray drying module 1 also includes an exhaust fan 18, which is arranged downstream of the bag filter 17. The exhaust fan 18 is used to input the high-temperature exhaust gas into the compressor 21. The exhaust fan drives the fan blades to rotate through the motor to promote the discharge of the outlet gas of the bag filter 17.

[0031] In a feasible embodiment of the present invention, the air supply module 14 includes a primary filter 141 and an air intake fan 142. The primary filter 141 usually has a large pleated filtering area, which ensures the fresh air volume while effectively filtering large particles, dust, mosquitoes, hair, etc. in the air entering the room from the outside. It is located at the beginning of the air supply module 14 and is the first barrier for air to enter the system. The air intake fan 142 is arranged downstream of the primary filter 141. The air intake fan 142 inhales the air purified by the primary filter 141 and transports it to the heat exchanger 22, that is, the air at the outlet of the air intake fan 142 enters the heat exchanger 22. In the heat exchanger 22, the temperature of the air can be increased within a certain range, thereby reducing the energy consumption of the air supply module 14.

[0032] In a feasible embodiment of the present invention, the air supply module 14 also includes an electric heater 143 and a secondary filter 144. The electric heater 143 is arranged on the air intake pipeline and is located downstream of the heat exchanger 22. The electric heater 143 can further heat the air to ensure that the air reaches the required temperature range. The secondary filter 144 is arranged downstream of the electric heater 143, and can intercept, adsorb and filter particulate matter in the air using filter materials under high temperature conditions, provide a higher level of air purification, and remove tiny particles in the air. The outlet of the secondary filter 144 is connected to the drying chamber 15, and the air after secondary filtration and deep purification enters the drying chamber 15.

[0033] It should be noted that, in actual application, if the heat provided by the heat pump module 2 has caused the air intake input by the fan to reach the required drying temperature, the electric heater 143 can be powered off.

[0034] That is, the air supply module 14 is a comprehensive system including multi-stage filtering, temperature regulation and air purification functions, and its purpose is to provide the drying chamber 15 with clean air that meets the temperature requirements.

[0035] In a feasible embodiment of the present invention, the driving device 12 is a peristaltic pump, which can squeeze and release the hose through a roller to achieve precise control of the fluid, so that the peristaltic pump can maintain a stable flow rate and pressure when conveying gas or liquid. The peristaltic pump can handle high-viscosity, corrosive or particulate-containing fluids.

[0036] In summary, the present invention provides a spray drying system, in which a peristaltic pump pumps the material in the liquid tank 11 into the centrifugal atomizer 13, and the centrifugal atomizer 13 converts the dilute liquid material into atomized droplets, which are sprayed into the drying chamber 15 by the nozzle. At the same time, the air intake fan 142 inputs air from the atmosphere into the primary filter 141 for filtering large particles, and then enters the heat exchanger 22 to absorb heat. The air after absorbing heat enters the electric heater 143 for heating until the temperature required for drying is met, and then passes through the secondary filter 144 for secondary filtration of particles, and finally enters the drying chamber 15 to contact with the material for drying.

[0037] After the drying process, the high-temperature exhaust gas first enters the cyclone separator 16 for solid-liquid-gas separation, and then enters the bag filter 17 to further filter out the tiny particles. Finally, the exhaust fan 18 inputs the clean high-temperature exhaust gas into the compressor 21 for compression and enthalpy increase.

[0038] The compressor 21 compresses the input high-temperature exhaust gas to increase enthalpy and converts it into high-temperature and high-pressure gas, which is input into the plate heat exchanger 22 for heat exchange with the intake air input by the air intake fan 142. The exhaust gas after releasing heat is directly discharged into the atmosphere after passing through the condensate tank 23, and the generated condensate is stored in it.

[0039] By using a heat pump module consisting of a compressor, a heat exchanger, and a condensed water tank, the original spray drying system is transformed into a waste heat recovery system to reduce the waste of waste heat resources and lower the energy consumption and carbon emissions of the drying system.

[0040] A second aspect of the present invention provides a spray drying method, using the above-mentioned spray drying system, comprising: S1. Drying the liquid feed through the spray drying module 1 to obtain the target product and high-temperature waste gas.

[0041] During the drying process, the liquid is atomized to form tiny droplets, which come into contact with hot air to quickly evaporate the water and obtain the dry target product. At the same time, high-temperature waste gas is generated during the drying process, which carries a large amount of heat energy.

[0042] S2. The high-temperature exhaust gas enters the compressor 21, which compresses the high-temperature exhaust gas to increase its enthalpy and converts it into high-temperature and high-pressure gas.

[0043] Compression enthalpy increase can increase the temperature and pressure of the exhaust gas, creating conditions for subsequent heat energy recovery and utilization.

[0044] S3. The high-temperature and high-pressure gas exchanges heat with the intake air of the spray drying module 1 to increase the temperature of the intake air and obtain exhaust gas after releasing heat.

[0045] During the heat exchange process, the high-temperature and high-pressure gas releases heat to increase the temperature of the intake air, thereby improving the energy efficiency of the spray drying module 1, reducing the temperature of the exhaust gas after heat exchange, and reducing carbon emissions.

[0046] A spray drying method according to the present invention further comprises: S4. The waste gas after releasing heat is discharged into the atmosphere after passing through a condensation water tank. The condensation water tank 23 is used to store condensation water.

[0047] The condensed water tank 23 is used to collect and store the water condensed from the exhaust gas. In practical applications, the condensed water may still have a certain thermal energy value and can be used to preheat the feed liquid, heat other fluids, etc.

[0048] Therefore, the spray drying method provided by the present invention can recover low-grade thermal energy in high-temperature tail gas, and use the thermal energy as a drying heat source after pressurizing and increasing enthalpy, thereby reducing electric heating energy consumption, improving energy utilization, and recovering condensed water.

[0049] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0050] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "mode", "specific mode", or "some modes" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or mode are included in at least one embodiment or mode of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or mode. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or modes in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or modes described in this specification and the features of the different embodiments or modes, without contradiction.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A spray drying system, characterized in that: include: The spray drying module (1) is used to dry the liquid feed to obtain the target product and high-temperature waste gas; The heat pump module (2) comprises a compressor (21) and a heat exchanger (22) connected in sequence; the compressor (21) is used to allow the high-temperature exhaust gas to enter, and compress the high-temperature exhaust gas to increase enthalpy, thereby converting it into high-temperature and high-pressure gas; the heat exchanger (22) is used to exchange heat between the high-temperature and high-pressure gas and the intake air of the spray drying module (1), thereby obtaining exhaust gas after heat release.

2. The spray drying system according to claim 1, characterized in that: The heat pump module (2) further comprises a condensed water tank (23), and the waste gas after releasing heat passes through the condensed water tank (23) and is discharged into the atmosphere. The condensed water tank (23) is used to store condensed water generated by the waste gas after releasing heat.

3. The spray drying system according to claim 1, characterized in that: The spray drying module (1) comprises: A liquid material tank (11) for storing the dilute liquid material to be dried; A driving device (12) connected to the liquid tank (11), the driving device (12) being used to transport the material; A centrifugal atomizer (13) is arranged downstream of the driving device (12), and the centrifugal atomizer (13) is used to convert the dilute liquid material into atomized liquid droplet material; An air supply module (14) is used to provide intake air; and the intake air of the air supply module (14) exchanges heat with the high-temperature and high-pressure gas in the heat exchanger; A drying chamber (15) is arranged downstream of the centrifugal atomizer (13), and the drying chamber (15) provides a place for hot air to contact the atomized liquid droplet material; The cyclone separator (16) realizes gas-solid separation, the target product is precipitated in the cyclone separator (16), and the high-temperature exhaust gas is output at the top of the cyclone separator (16).

4. The spray drying system according to claim 3, characterized in that: The spray drying module (1) further comprises a bag filter (17), wherein the bag filter (17) is arranged downstream of the cyclone separator (16), and the bag filter (17) is used to filter dust particles in the gas.

5. The spray drying system according to claim 4, characterized in that: The spray drying module (1) further comprises an exhaust fan (18) disposed downstream of the bag filter (17), the exhaust fan (18) being used to input the high-temperature exhaust gas into the compressor (21).

6. The spray drying system according to claim 3, characterized in that: The air supply module (14) comprises: A primary filter (141) for preliminary filtering of air entering the system; The air inlet fan (142) is arranged downstream of the primary filter (141); and the air at the outlet of the air inlet fan (142) enters the heat exchanger (22).

7. The spray drying system according to claim 6, characterized in that: The air supply module (14) further comprises: An electric heater (143) disposed on the air intake pipeline and located downstream of the heat exchanger (22); A secondary filter (144) is arranged downstream of the electric heater (143), and an outlet of the secondary filter (144) is connected to the drying chamber (15).

8. The spray drying system according to claim 3, characterized in that: The driving device (12) is a peristaltic pump.

9. A spray drying method, characterized in that: A spray drying system according to any one of claims 1 to 8, comprising: Drying the liquid feed by a spray drying module (1) to obtain a target product and high-temperature waste gas; The high-temperature exhaust gas enters the compressor (21), which compresses the high-temperature exhaust gas to increase its enthalpy and converts it into the high-temperature and high-pressure gas; The high-temperature and high-pressure gas exchanges heat with the intake air of the spray drying module (1) to increase the temperature of the intake air and obtain exhaust gas after releasing heat.

10. The spray drying method according to claim 9, characterized in that Also includes: The waste gas after releasing heat is discharged into the atmosphere after passing through a condensation water tank, and the condensation water tank (23) is used to store condensation water.

Images