Vacuum dehumidifying and drying device for heavy calcium carbonate powder

Abstract

The utility model relates to calcium carbonate powder drying technical field, and disclose a kind of heavy calcium carbonate powder vacuum dehumidification drying device, including drying cabinet, the one end of drying cabinet is connected with hot blast inlet pipe, and the upper end surface one end of drying cabinet is connected with suction pipe, vacuum exhaust fan is installed on the suction pipe, and the air outlet end of vacuum exhaust fan is connected with external discharge pipe, further including heat recovery subassembly, between hot blast inlet pipe and external discharge pipe is connected, the heat recovery subassembly is used to recycle the heat in external discharge pipe and is sent back to hot blast inlet pipe;The heat carried by the wet hot air in external discharge pipe is transferred to normal temperature gas in air inlet pipe by spiral heat exchange pipe, and the gas after heat exchange reenters hot blast inlet pipe by reflux pipe, becomes the heat source of drying cabinet, avoids the heat waste caused by direct emission wet hot air, reduces the energy consumption input of hot blast fan, secondly, the condensation speed of water vapor in wet hot air can also be accelerated.

Description

Technical Field

[0001] This utility model relates to the field of calcium carbonate powder drying technology, and in particular to a vacuum dehumidification and drying device for heavy calcium carbonate powder. Background Technology

[0002] In the field of calcium carbonate powder production, the drying process is a key link to ensure product quality. Traditional drying equipment usually uses hot air convection to evaporate the moisture in the material and then exhausts the hot and humid air through vacuum extraction.

[0003] A search revealed a Chinese patent application (application number 202321952218.8) that discloses a drying device for nano-calcium carbonate powder. This device uses a storage pipe to connect the output of a hot air device to the input of an inlet pipe, supplying hot air into the drying chamber. A stirring mechanism then stirs the nano-calcium carbonate within the chamber, improving the drying efficiency. After evaporating the moisture inside the nano-calcium carbonate, a vacuum fan is activated to remove the water vapor through the storage pipe, preventing water vapor from remaining inside the drying chamber and dripping into the nano-calcium carbonate, thus affecting the drying quality and improving efficiency. However, in actual use, the vacuum fan removes a large amount of hot air when expelling water vapor, causing temperature fluctuations within the drying chamber and increasing energy consumption. Therefore, this paper proposes a vacuum dehumidification drying device for heavy calcium carbonate powder. Utility Model Content

[0004] This invention proposes a vacuum dehumidification and drying device for heavy calcium carbonate powder to solve the problem that existing vacuum fans take away a large amount of hot air when expelling water vapor, causing temperature fluctuations in the drying chamber and increasing energy consumption.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a vacuum dehumidification and drying device for heavy calcium carbonate powder, comprising a drying chamber, one end of which is connected to a hot air inlet pipe, and one end of the upper surface of the drying chamber is connected to an exhaust pipe, a vacuum exhaust fan is installed on the exhaust pipe, and the outlet end of the vacuum exhaust fan is connected to an external exhaust pipe, further comprising:

[0006] A heat recovery assembly is connected between the hot air inlet pipe and the exhaust pipe. The heat recovery assembly is used to recover the heat in the exhaust pipe and send it back to the hot air inlet pipe.

[0007] A viewing window is mounted on the drying oven, and the inner layer of the viewing window is permeable to dry hot air.

[0008] Preferably, the heat recovery assembly includes:

[0009] Spiral heat exchange tubes are installed inside the external exhaust pipes;

[0010] The air inlet pipe is connected at one end to the air inlet end of the spiral heat exchanger tube, and at the other end extends to the outside of the exhaust pipe.

[0011] The reflux pipe connects the outlet end of the spiral heat exchanger tube and the hot air inlet pipe.

[0012] Preferably, the exhaust pipe is inclined downwards from one end of the vacuum blower to the other end.

[0013] Preferably, the viewing window includes a first glass and a second glass, with a vacuum cavity between the first glass and the second glass.

[0014] Preferably, a gas supply branch pipe is connected between the hot air inlet pipe and the vacuum chamber, and a flow control component is installed on the gas supply branch pipe.

[0015] Preferably, a feeding hopper is installed at the top of the drying chamber, and a discharge pipe is connected to the bottom of the drying chamber.

[0016] The technical effects and advantages provided by this utility model in the above technical solution are as follows:

[0017] (1) By setting up a heat recovery component, when in use, the heat carried by the humid air in the exhaust pipe is transferred to the room temperature gas in the intake pipe through the spiral heat exchange tube. The gas after heat exchange is re-entered into the hot air intake pipe through the return pipe and becomes the heat source of the drying box. This avoids the waste of heat caused by directly discharging humid air and reduces the energy consumption of the hot air blower. In addition, it can also accelerate the condensation rate of water vapor in the humid air and shorten the residence time of condensate in the pipe.

[0018] (2) The viewing window uses double-layer vacuum glass with hot air circulation to avoid fogging caused by temperature difference between inside and outside, ensuring clear observation for staff. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0021] Figure 2 This is a schematic diagram of the structure of the external discharge pipe and heat recovery assembly of this utility model;

[0022] Figure 3 This is a schematic diagram of the structure of the heat recovery component of this utility model;

[0023] Figure 4 This is a schematic diagram of the structure of the viewing window of this utility model;

[0024] In the diagram: 1. Drying oven; 2. Hot air inlet pipe; 3. Exhaust pipe; 4. Vacuum exhaust fan; 5. Exhaust pipe; 6. Viewing window; 61. First glass; 62. Second glass; 63. Vacuum chamber; 7. Gas supply branch pipe; 8. Heat recovery assembly; 81. Inlet pipe; 82. Spiral heat exchanger tube; 83. Return pipe; 9. Feed hopper. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] This utility model provides, for example Figures 1-4 The vacuum dehumidification and drying device for heavy calcium carbonate powder shown includes a drying chamber 1. The drying chamber 1 is made of high-temperature resistant stainless steel with a smooth inner wall and an insulation layer (filled with aluminum silicate fiber) to reduce heat loss. A feeding hopper 9 is installed at the top of the drying chamber 1, and a discharge pipe is connected to the bottom of the drying chamber 1. Valves are installed on both the feeding hopper 9 and the discharge pipe to open and close them. A support frame is also provided at the bottom of the drying chamber 1 for mounting and supporting it. A hot air inlet pipe 2 is connected to one end of the drying chamber 1, which is connected to a hot air delivery pipe for a hot air blower. An exhaust pipe 3 is connected to one end of the upper surface of the drying chamber 1. The exhaust pipe 3 is used to extract moisture and is located away from the feeding hopper 9 to avoid material suction. A valve is installed on the exhaust pipe 3. Vacuum exhaust fan 4, with its outlet end connected to exhaust pipe 5. Exhaust pipe 5 is inclined downwards from one end of vacuum exhaust fan 4 to the other, specifically from the outlet end of vacuum exhaust fan 4 to the end, at a downward angle of 5°-10°. A condensate collection port is provided at the lowest point, which is connected to a water storage tank through a pipe. Temperature and humidity sensors (top and both sides) are also installed on the inner wall of drying chamber 1. It also includes a viewing window 6 and a heat recovery component 8. The viewing window 6 is embedded in drying chamber 1, and the inner layer of the viewing window 6 can pass dry hot air to prevent condensation and fogging. The heat recovery component 8 is connected between hot air inlet pipe 2 and exhaust pipe 5. The heat recovery component 8 is used to recover the heat in exhaust pipe 5 and send it back to hot air inlet pipe 2 to reduce heat loss, reduce energy consumption, and stabilize the temperature inside drying chamber 1.

[0027] See Figure 4As shown, the viewing window 6 includes a first glass 61 and a second glass 62, with a vacuum chamber 63 between the first glass 61 and the second glass 62. A gas supply branch pipe 7 is connected between the hot air inlet pipe 2 and the vacuum chamber 63. A flow control component, preferably a valve, is installed on the gas supply branch pipe 7. During use, some hot air can be introduced into the vacuum chamber 63. The hot air flows in the vacuum chamber 63, raising the temperature inside the chamber and effectively preventing condensation and fogging caused by the temperature difference between the inside and outside. This ensures that the viewing window 6 remains clear and transparent, providing a good field of vision for the staff. An exhaust pipe can be installed on the other side of the vacuum chamber 63 to discharge cooled steam for steam replacement. A scale line can also be set on the viewing window 6 to observe the feeding amount.

[0028] In actual use, the valve of the feeding hopper 9 is opened, and the heavy calcium carbonate powder is poured into the drying chamber 1. The feeding amount is observed through the viewing window 6. After reaching the scale line, the valve is closed. Then, the hot air blower and vacuum exhaust fan 4 are started. Dry hot air enters the drying chamber 1, comes into contact with the powder, and evaporates the moisture. At the same time, the vacuum state can lower the boiling point of water and accelerate dehumidification. The hot and humid air enters the exhaust pipe 5 through the exhaust pipe 3. When the temperature and humidity sensor detects that the humidity in the drying chamber 1 is lower than the set threshold, the discharge valve can be opened to complete the unloading.

[0029] A stirring mechanism can be installed in the drying oven 1 to improve the uniformity of drying by turning the powder. The stirring mechanism adopts the existing conventional stirring structure, which is the existing technology. The specific structure will not be described in detail here.

[0030] See Figure 2 and Figure 3 As shown, the heat recovery assembly 8 includes an air inlet pipe 81, a spiral heat exchanger pipe 82, and a return pipe 83. The spiral heat exchanger pipe 82 is disposed inside the exhaust pipe 5. One end of the air inlet pipe 81 is connected to the air inlet end of the spiral heat exchanger pipe 82, and the other end of the air inlet pipe 81 extends to the outside of the exhaust pipe 5. The air inlet pipe 81 is connected between the air outlet end of the spiral heat exchanger pipe 82 and the hot air inlet pipe 2.

[0031] As described above, when extracting humid and hot air using the extraction pipe 3, room temperature gas can be introduced through the inlet pipe 81. After entering the spiral heat exchange pipe 82, the room temperature gas will fully contact the humid and hot air in the exhaust pipe 5 along a spiral path. The two will undergo efficient heat exchange through the pipe wall. The heat exchanged air in the exhaust pipe 5 will be returned to the hot air inlet pipe 2 through the return pipe 83. The heat structure can reduce energy consumption and heat loss on the one hand, and accelerate the cooling of humid and hot air and improve the condensation rate on the other hand.

[0032] Additionally, it should be noted that, in order to reduce the impact of dry hot air on calcium carbonate powder, an inert gas (dry nitrogen) can be used as a substitute.

[0033] In addition, by controlling the gas flow rate and pressure, a micro-positive pressure or low vacuum mode (such as maintaining the vacuum level at 500-1000Pa) is adopted to balance the heat transfer requirements and vacuum efficiency.

[0034] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A vacuum dehumidification and drying device for heavy calcium carbonate powder, comprising a drying chamber (1), one end of which is connected to a hot air inlet pipe (2), and one end of the upper surface of the drying chamber (1) is connected to an exhaust pipe (3), a vacuum fan (4) is installed on the exhaust pipe (3), and the outlet end of the vacuum fan (4) is connected to an external exhaust pipe (5), characterized in that, Also includes: A heat recovery assembly (8) is connected between the hot air inlet pipe (2) and the exhaust pipe (5). The heat recovery assembly (8) is used to recover the heat in the exhaust pipe (5) and send it back to the hot air inlet pipe (2). A viewing window (6) is mounted on the drying box (1), and the inner layer of the viewing window (6) is permeable to dry hot air.

2. The vacuum dehumidification and drying device for heavy calcium carbonate powder according to claim 1, characterized in that: The heat recovery assembly (8) includes: Spiral heat exchange tube (82) is installed inside the external exhaust pipe (5); The air inlet pipe (81) is connected at one end to the air inlet end of the spiral heat exchange tube (82) and at the other end to the outside of the exhaust pipe (5); The return pipe (83) is connected between the outlet end of the spiral heat exchanger (82) and the hot air inlet pipe (2).

3. The vacuum dehumidification and drying device for heavy calcium carbonate powder according to claim 1, characterized in that: The exhaust pipe (5) is inclined downward from one end of the vacuum blower (4) to the other end.

4. The vacuum dehumidification and drying device for heavy calcium carbonate powder according to claim 1, characterized in that: The viewing window (6) includes a first glass (61) and a second glass (62), with a vacuum cavity (63) between the first glass (61) and the second glass (62).

5. The vacuum dehumidification and drying device for heavy calcium carbonate powder according to claim 4, characterized in that: A gas supply branch pipe (7) is connected between the hot air inlet pipe (2) and the vacuum chamber (63), and a flow control component is installed on the gas supply branch pipe (7).

6. The vacuum dehumidification and drying device for heavy calcium carbonate powder according to claim 1, characterized in that: The top of the drying box (1) is equipped with a feeding hopper (9), and the bottom of the drying box (1) is connected to a discharge pipe.

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