Low-temperature drying method for pretreated materials

Abstract

The invention provides a low-temperature drying method for pretreated materials, which adopts a low-temperature multi-temperature-section baking process, and adopts a baking room atmosphere temperature of 30-45 DEG C to perform baking operation in the drying process. In the drying process, water molecules in the drying room atmosphere are efficiently captured through a water catcher, the atmosphere humidity in the drying room is reduced, the large humidity difference is formed between the surface of the baked material and the drying room atmosphere, and water enriched on the surface of the material is promoted to move towards the drying room atmosphere. In the drying process, the lowest atmosphere temperature in a drying room is only 30% of that of a conventional baking process, the highest process temperature is only 50% of a conventional baking set temperature, the total heating cost in the whole baking process is reduced by 50.69%, the total time is reduced by 33.3%, and the baking quality is improved by 11%.

Description

Technical Field

[0001] This invention relates to the field of drying technology, and more particularly to a low-temperature drying method for pretreated materials. Background Technology

[0002] Drying is a fundamental processing step, widely used in biopharmaceuticals, food processing, and machinery manufacturing. Drying workshops are high-energy-consuming departments in various enterprises. Due to a lack of emphasis on baking technology and a scarcity of theoretical research and experimental methods, the industry has not yet developed efficient and energy-saving baking equipment, and most practitioners are small workshops.

[0003] However, drying is a rapidly developing market. We have approximately 125,000 existing drying rooms across various industries, with 4,000-5,000 new drying rooms of various types added annually. These generally rely on coal and wood as energy sources, resulting in low efficiency, high energy consumption, significant pollution, high labor costs, and poor drying quality. Given the national policy of vigorously promoting energy conservation and environmental protection, the research and promotion of energy-saving and environmentally friendly drying technologies are essential. Summary of the Invention

[0004] In view of this, the present invention proposes a low-temperature drying method for pretreated materials.

[0005] The technical solution of this invention is implemented as follows: This invention provides a low-temperature energy-saving drying method for materials, which includes the following steps: S1. The circulating fan blows dry, hot air at 28℃-31℃ from the baking machine into the drying chamber at a speed of 1-2 m / s, heating the material and causing water molecules on the surface to evaporate. These water molecules then move into the drying chamber atmosphere, increasing humidity. After 70 minutes, the temperature of the drying chamber atmosphere stabilizes at 30℃, and the humidity reaches 85%. The circulating fan then forces the high-humidity atmosphere from the drying chamber into the baking machine, entering the water trap at a speed of 2-3 m / s. Water molecules in the atmosphere are efficiently captured by the water trap, reducing the humidity of the circulating air. The water molecules gather into droplets and fall into the water collection tray, exiting the baking machine through the drain. After exiting the water trap, the circulating air passes through the heater. The heater uses a temperature probe to detect the atmosphere temperature. If the temperature is lower than the set temperature, the heater starts heating the flowing atmosphere; otherwise, the heater does not operate. After exiting the heater, the circulating air re-enters the drying chamber under the action of the circulating fan. The relatively dry hot air quickly absorbs water molecules around the material. This process continues for 3 hours, reducing the humidity in the drying chamber to 40%, thus ending the first stage of baking. S2, After the first stage is completed, the free water on the surface of the material is removed, and the baking operation enters the second stage. The baking goal is to dry and remove the bound water in the material. The heater of the baking machine is started to continuously heat the circulating air until the atmosphere in the drying chamber is maintained at 35-38℃. The atmosphere in the drying chamber removes moisture through circulation, reducing the humidity in the drying chamber. After 3 hours, the humidity in the drying chamber is reduced to 20%, and the second stage of baking ends. S3, the baking operation enters the third stage. The heater raises the temperature of the baking chamber to 42-45℃. The baking and dehydration lasts for 2 hours to remove the chemically bound water inside the material. When the humidity of the baking chamber decreases to 10% ±2℃ and remains unchanged for 15 minutes, the baking operation ends.

[0006] Based on the above technical solutions, preferably, before proceeding to step S1, the material to be baked is placed in the drying room and left to stand for 1 hour before proceeding to step S1.

[0007] Based on the above technical solutions, preferably, in step S1, the water catcher is the core component, which captures and removes water molecules in the circulating air without taking away the heat in the circulating air, thus avoiding energy waste.

[0008] Based on the above technical solutions, preferably, in step S1, the speed of the high-humidity circulating air flowing through the water trap should not be too high, and should be controlled at 2-3 m / s. Too high or too low a speed will reduce efficiency. The speed of the circulating air blowing on the surface of the material should not be too high, as it will cause powder to fly and block the air duct for biopharmaceutical materials, and may cause the lost foam mold shell to crack.

[0009] Based on the above technical solution, preferably, in steps S2 and S3, the process temperature setting needs to be set according to the specific material characteristics and experimental data. The low-temperature drying method for pretreated materials of the present invention has the following advantages over the prior art: (1) The three-temperature-segment low-temperature baking process requires less energy than traditional baking methods, resulting in lower energy costs. Overall energy costs are reduced by 30%-51%.

[0010] (2) Low-temperature baking significantly improves the quality of material baking. Taking a drying room that processes 1 ton of wet Polygonum cuspidatum material per day as an example, the material extraction yield increases by 6-10%, increasing the company's revenue by about 50,000 yuan per day.

[0011] (3) The baking process is fully automated, which improves the accuracy of process execution, reduces labor costs, and increases the efficiency of the drying room by 33%. Detailed Implementation

[0012] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0013] The present invention provides a low-temperature drying method for pretreated materials, comprising the following steps: First, the preparation stage. Load the material into a tray or rack, then into the drying room, close the drying room door, and let the material stand for 70 minutes. This allows the material to fully contact and exchange heat with the drying room atmosphere, and the free water molecules on the surface of the material will evaporate naturally, causing the humidity in the drying room to gradually increase and then gradually reach equilibrium.

[0014] Then, the first stage of baking and dehydration begins. S1. The circulating fan blows dry, hot air (28℃-31℃) from the baking machine into the drying chamber at a speed of 1-2 m / s, heating the material and causing water molecules on the surface to evaporate. These water molecules then move into the drying chamber atmosphere, increasing humidity. After 70 minutes, the temperature of the drying chamber atmosphere stabilizes at 30℃, and the humidity reaches 85%. The circulating fan then forces the high-humidity atmosphere from the drying chamber into the baking machine, entering the water trap at a speed of 2-3 m / s. Water molecules in the atmosphere are efficiently captured by the water trap, reducing the humidity of the circulating air. The water molecules gather into droplets and fall into the water collection tray, exiting the baking machine through the drain. After exiting the water trap, the circulating air passes through the heater. The heater uses a temperature probe to detect the atmosphere temperature. If the temperature is lower than the set temperature, the heater activates to heat the flowing atmosphere; otherwise, the heater does not operate. After exiting the heater, the circulating air re-enters the drying chamber under the action of the circulating fan. The relatively dry hot air quickly absorbs water molecules around the material. This process continues for 3 hours, reducing the humidity in the drying chamber to 40%, thus ending the first stage of baking.

[0015] During this stage, the drying chamber maintains an absolutely closed loop, with water molecules constantly being expelled from the chamber. However, apart from a small amount of heat loss due to heat dissipation from the insulated walls, there is no heat wasted.

[0016] In traditional baking processes, the oven temperature is raised to 60-110°C, and once the humidity reaches the set value, exhaust fans are manually activated to force the hot and humid atmosphere out of the oven. This creates a negative pressure inside the oven, drawing in outside air to maintain pressure balance. However, because the humidity of the outside air is maintained at 40-70% and the temperature at 10-18°C, the temperature inside the oven drops rapidly after the air enters. Therefore, traditional baking processes suffer from significant heat energy waste during the dehumidification process, prolonging the baking time.

[0017] S2. After the first stage is completed, the free water on the surface of the material is removed, and the baking operation enters the second stage. The baking objective is to dry and remove the bound water in the material. The heater of the baking machine is started to continuously heat the circulating air until the atmosphere in the drying chamber is maintained at 35-38℃. The atmosphere in the drying chamber removes moisture through circulation, reducing the humidity in the drying chamber. After 3 hours, the humidity in the drying chamber is reduced to 20%, and the second stage of baking ends.

[0018] S3, the baking operation enters the third stage. The heater raises the temperature of the baking chamber to 42-45℃. The baking and dehydration lasts for 2 hours to remove the chemically bound water inside the material. When the humidity of the baking chamber decreases to 10% ±2℃ and remains unchanged for 15 minutes, the baking operation ends.

[0019] After the first two stages of processing, the moisture content of the material does not exceed 25%. At this stage, water molecules move slowly, making moisture removal difficult. Therefore, it is necessary to increase the temperature of the drying chamber and use intermittent dehydration operations for the water trap to improve efficiency.

[0020] The present invention provides a low-temperature drying method for pretreated materials, which changes the high-temperature constant temperature baking of 60℃-110℃ to a multi-stage variable temperature baking of 30℃-45℃, resulting in rapid heating and low energy consumption.

[0021] The present invention provides a low-temperature drying method for pretreated materials. The water trap efficiently and continuously captures and removes water molecules from the circulating air, which is more efficient than the dehumidification method of the exhaust fan, has no heat loss, and can improve the dehydration efficiency of the materials.

[0022] The present invention provides a low-temperature drying method for pretreated materials. It has conducted in-depth theoretical research on the baking process, and has made targeted baking process arrangements based on the existence forms of water molecules that need to be removed from the materials. The process is solidified in the form of computer programs, which improves the accuracy of baking operations, ensures baking quality, and avoids energy and time waste.

[0023] This invention discloses a low-temperature drying method for pretreated materials. Low-temperature baking avoids damage to the materials caused by high temperatures and improves the yield. Especially in the baking of biopharmaceutical and food materials, low-temperature baking can increase the material extraction yield by 6%-10%, bringing considerable economic benefits to users.

[0024] The present invention provides a low-temperature drying method for pretreated materials. For different materials to be baked, a targeted baking process is developed through experiments and executed precisely by computer. The baking machine and the equipment in the drying room are specially customized according to the process requirements.

[0025] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for low-temperature drying of pretreated materials, characterized in that: It includes the following steps, S1. The circulating fan blows dry, hot air at 28℃-31℃ from the baking machine into the drying chamber at a speed of 1-2 m / s, heating the material and causing water molecules on the surface to evaporate. These water molecules then move into the drying chamber atmosphere, increasing humidity. After 70 minutes, the temperature of the drying chamber atmosphere stabilizes at 30℃, and the humidity reaches 85%. The circulating fan then forces the high-humidity atmosphere from the drying chamber into the baking machine, entering the water trap at a speed of 2-3 m / s. Water molecules in the atmosphere are efficiently captured by the water trap, reducing the humidity of the circulating air. The water molecules gather into droplets and fall into the water collection tray, exiting the baking machine through the drain. After exiting the water trap, the circulating air passes through the heater. The heater uses a temperature probe to detect the atmosphere temperature. If the temperature is lower than the set temperature, the heater starts heating the flowing atmosphere; otherwise, the heater does not operate. After exiting the heater, the circulating air re-enters the drying chamber under the action of the circulating fan. The relatively dry hot air quickly absorbs water molecules around the material. This process continues for 3 hours, reducing the humidity in the drying chamber to 40%, thus ending the first stage of baking. S2, After the first stage is completed, the free water on the surface of the material is removed, and the baking operation enters the second stage. The baking goal is to dry and remove the bound water in the material. The heater of the baking machine is started to continuously heat the circulating air until the atmosphere in the drying chamber is maintained at 35-38℃. The atmosphere in the drying chamber removes moisture through circulation, reducing the humidity in the drying chamber. After 3 hours, the humidity in the drying chamber is reduced to 20%, and the second stage of baking ends. S3, the baking operation enters the third stage. The heater raises the temperature of the drying chamber to 42-45℃. The baking and dehydration lasts for 2 hours to remove the chemically bound water inside the material. When the humidity of the drying chamber decreases to 10%±2℃ and remains unchanged for 15 minutes, the baking operation ends.