Freezing mechanical crushing device suitable for preparing laser printer developing agent

Abstract

The invention discloses a freezing mechanical crushing device suitable for preparing a laser printer developer. The freezing mechanical crushing device comprises a crushing cavity, a feeding pipeline, a freezing airflow pipeline and a grading unit, wherein a feeding port and a discharging port are formed in the two ends of the crushing cavity, and the feeding pipeline and the freezing airflow pipeline are communicated with the feeding port; the grading unit comprises a grading cavity, a material conveying pipeline and a material returning pipeline, the grading cavity is provided with a material conveying opening, a material discharging opening and a material returning opening, the material conveying pipeline is communicated with the material feeding opening and the material conveying opening, and the material returning pipeline is communicated with the material returning opening and the material supplying pipeline and / or the material feeding opening. On one hand, based on mixing of materials and freezing airflow, crushing is performed by improving the brittleness of the materials, the crushing quality of the materials is effectively improved, and the sphericity of material particles is greatly improved; and on the other hand, crushing and grading are combined, materials can be continuously crushed and recovered in a grading manner, remaining materials can be circularly crushed, continuous production is achieved, energy consumption is low, production efficiency is high, and in addition, the structure is simple, operation is convenient, and input cost is low.

Description

Technical Field

[0001] The invention belongs to the field of pulverizing devices, and in particular relates to a freezing mechanical pulverizing device suitable for preparing a developer for a laser printer. Background Art

[0002] Laser printing developer is a key component in the laser printing process. Its main components are resin, magnetic powder, charge control agent, pigment, auxiliary agent, external additive, etc. The particle size is generally around 10μm and has certain heat sensitivity. Its preparation methods are divided into pulverization method and polymerization method. Among them, the pulverization method is widely used because of its simple preparation principle and low environmental pollution. The pulverization method is mainly used to prepare laser printing developer through the following steps: batching → premixing → mixing → coarse pulverization → ultrafine pulverization → classification → modification → homogenization → sieving → packaging. Ultrafine pulverization is an important step in particle forming, which plays a decisive role in the particle size distribution and microscopic shape of the particles. The consistency and microscopic shape of the particles will seriously affect the test results of the printing performance.

[0003] The existing ultrafine grinding method for developer preparation is mainly air flow grinding, which uses the energy of high-speed air flow (300-500m / s) to make particles impact, collide, and frictionally shear each other to achieve ultrafine grinding of particles. However, in the actual production process, the existing technology has the following defects:

[0004] 1. The jet mill for developer has a low particle size and requires a high gas flow rate, so it requires a large investment in equipment such as air compressors, jet mills, and induced draft fans, and consumes a lot of energy during use, resulting in high costs;

[0005] 2. The finished product after air flow crushing is often prone to over-crushing, the overall particle size is small, and there are many small particles (<3μm), which affects the effective output. After the particles are impacted and collided, the microscopic morphology often has more sharp corners and protrusions, which affects the electrical and magnetic properties of the developer. In addition, the traditional mechanical crushing generally has a low spindle speed and the material particle size does not meet the requirements of laser printer developers. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a new freezing mechanical pulverizing device suitable for preparing laser printer developer.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] A freezing mechanical pulverizing device suitable for preparing laser printer developer comprises a pulverizing cavity with a feed port and a discharge port formed at two ends, a feed pipe, a refrigerated airflow pipe, and a grading unit, wherein the feed pipe and the refrigerated airflow pipe are respectively connected to the feed port; the grading unit comprises a grading cavity, a feed pipe, and a return pipe, wherein the grading cavity has a feed port, a discharge port, and a return port, the feed pipe communicates with the discharge port and the feed port, the return pipe communicates with the return port and the feed pipe and / or the feed port, during pulverizing, the material is mixed with the refrigerated airflow and enters the pulverizing cavity from the feed port, and after pulverizing, enters the grading cavity from the discharge port through the feed pipe, wherein the finished material particles are discharged through the discharge port, and the remaining material enters the pulverizing cavity and / or the feed pipe through the return pipe for cyclic pulverization.

[0009] According to a specific implementation and preferred aspect of the present invention, the feed pipe is connected to the refrigerated air flow pipe, and the material enters the refrigerated air flow pipe from the feed pipe and enters the crushing chamber along with the flow of the refrigerated air flow. Here, the material can be fully mixed with the refrigerated air flow before entering the crushing chamber to ensure that the material is fully frozen to increase brittleness, thereby improving the crushing effect.

[0010] According to another specific implementation and preferred aspect of the present invention, the temperature of the refrigerated airflow is -15 to -20°C; and / or the flow rate of the refrigerated airflow is 3-50 m / s. Here, based on the layout of the flow rate of the refrigerated airflow, the material is pulverized slowly at a low speed (compared to the speed of traditional airflow pulverization) under refrigeration, which greatly increases the residence time of the material when passing through the pulverizing cavity, increases the number of collisions, and improves the pulverizing quality.

[0011] According to another specific implementation and preferred aspect of the present invention, the pulverizing chamber includes a chamber body having a feed port and a discharge port, and a pulverizing module arranged inside the chamber body, wherein a cooling channel connected to a cooling medium is formed on the chamber body, and during pulverization, the chamber body synchronously exchanges heat with the cooling medium. In the present application, a refrigerated airflow is introduced into the cooling channel, and the purpose of such a setting is to ensure the stability of the temperature in the pulverizing chamber, and the temperature in the pulverizing chamber is kept close to the temperature of the mixture of the material and the refrigerated airflow, so as to avoid the material from exchanging heat with the wall of the pulverizing chamber during pulverization and causing the temperature to change, thereby ensuring the stability of the pulverizing quality.

[0012] In some specific embodiments, the cooling channel spirally extends from one end of the cavity body around the center line of the cavity body to the other end, thereby achieving uniform temperature distribution of the cavity body.

[0013] Furthermore, the inlet of the cooling channel is located at one end of the cavity body close to the feed port, and the outlet is located at one end of the cavity body close to the discharge port. Here, the flow direction of the cooling medium in the cooling channel is the same as the flow direction of the mixture of the material and the refrigerated airflow in the pulverizing cavity, so that the mixture of the material and the refrigerated airflow can be in a stable low-temperature environment at any position.

[0014] Preferably, the crushing module includes a crushing roller, an inner ring body sleeved on the crushing roller, and an outer ring body fixed on the inner wall of the cavity body, the outer wall of the inner ring body is provided with a plurality of dynamic crushing blades distributed in an annular manner around its own center line, and the inner wall of the outer ring body is provided with a plurality of fixed crushing blades distributed in an annular manner around its own center line, wherein the crushing surface formed by the plurality of dynamic crushing blades and the crushing surface formed by the plurality of fixed crushing blades are spaced 1 to 2 mm apart. Here, based on the cooperation of the plurality of dynamic crushing blades and the fixed crushing blades, the material is impacted, collided, rubbed, and sheared when entering between the two, and the particle size after crushing reaches Dv90 < 11 μm.

[0015] Specifically, the distance between two adjacent fixed crushing blades is greater than the distance between two adjacent dynamic crushing blades.

[0016] Preferably, both ends of the grinding roller extend out of the cavity body, wherein both ends of the grinding roller are provided with bearing seats and cooling water circulation pipes arranged on the bearing seats and forming heat exchange with the grinding roller. Here, the grinding roller is independently arranged and cooled by circulating water, thereby improving the bearing life.

[0017] In addition, the grading cavity includes a grading cavity body and a grading wheel arranged in the grading cavity body, wherein the top of the grading cavity body forms a discharge port, the bottom forms a return port, and one side forms a feed port, and the inner cavity of the grading cavity body is gradually narrowed from top to bottom, and the return port is connected to the feed pipe.

[0018] Due to the implementation of the above technical solution, the present invention has the following advantages compared with the prior art:

[0019] The prior art developer air flow mill has a relatively low particle size and requires a high gas flow rate, so the investment in equipment such as air compressors, air flow mills, and induced draft fans is large, and the energy consumption during use is large, resulting in high costs. At the same time, the finished product after air flow milling is often prone to over-crushing, and the particle size is generally small, with a large number of undersized particles (<3 μm), which affects the effective yield. After the particles are impacted and collided, the microscopic morphology often has many sharp corners and protrusions, which affects the electrical and magnetic properties of the developer. In addition, the spindle speed of traditional mechanical milling is generally not high, and the particle size of the material does not meet the requirements of laser printer developers. The present application provides a frozen mechanical mill suitable for the preparation of laser printer developers. The structure of the device is designed as a whole, which ingeniously solves the shortcomings and defects of the prior art. After the pulverizing device is adopted, the material is mixed with the refrigerated airflow and enters the pulverizing chamber for pulverization, wherein the brittleness of the material is improved after mixing with the refrigerated airflow, and the material particles after pulverization have a good morphology and are elliptical. Compared with the traditional airflow pulverization, the sphericity of the material particles is basically increased from 60% to 85%; then the pulverized material particles continue to enter the grading chamber through the feeding pipeline under the drive of the airflow, wherein the finished material particles that meet the requirements are discharged through the discharge port, and the remaining materials re-enter the pulverizing chamber and / or the feeding pipeline through the channel return pipe to participate in the cyclic pulverization and re-grading. Therefore, compared with the prior art, the present invention is based on the mixing of the material and the refrigerated airflow, on the one hand, by improving the brittleness of the material for pulverization, the material pulverization quality is effectively improved, and the sphericity of the material particles is greatly improved; on the other hand, the pulverization is combined with the grading, the material can be continuously pulverized and graded and recovered, and the remaining materials can be circulated for pulverization, so as to realize continuous production, low energy consumption, and high production efficiency. In addition, the structure is simple, the operation is convenient, and the investment cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a front view schematic diagram of a cryomechanical pulverizing device suitable for preparing a developer for a laser printer according to the present invention;

[0021] Figure 2 for Figure 1 A half-section schematic diagram of the middle crushing chamber;

[0022] Among them: 1, grinding chamber; 10, chamber body; k0, feed port; k1, discharge port; t, cooling channel; 11, grinding module; 110, grinding roller; a0, bearing seat; a1, cooling water circulation pipeline; 111, inner ring body; p1, dynamic grinding blade; 112, outer ring body; p2, fixed grinding blade;

[0023] 2. Feeding pipeline;

[0024] 3. Refrigeration air flow duct;

[0025] 4. Classification unit; 40. Classification cavity; 400. Classification cavity body; 401. Classification wheel; k2. Feeding port; k3. Discharging port; k4. Returning port; 41. Feeding pipeline; 42. Returning pipeline. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0027] In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "center" are used interchangeably.

[0028] The directions or positional relationships indicated by “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc. are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0030] In the present invention, unless otherwise clearly defined and specified, the terms "installed", "connected", "connected", "fixed" and the like 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 directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0032] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0033] like Figure 1 and Figure 2 As shown, the present embodiment involves a freezing mechanical pulverizing device suitable for preparing a developer for a laser printer, which includes a pulverizing chamber 1 , a feeding pipeline 2 , a freezing airflow pipeline 3 , and a grading unit 4 .

[0034] Specifically, the pulverizing chamber 1 includes a chamber body 10 with a feed port k0 and a discharge port k1 formed at both ends, and a pulverizing module 11 arranged inside the chamber body 10, wherein a cooling channel t connected to a cooling medium is formed on the chamber body 10, and during pulverizing, the chamber body 10 synchronously exchanges heat with the cooling medium. In the present application, a refrigerated airflow is introduced into the cooling channel, and the purpose of such a setting is to ensure the stability of the temperature in the pulverizing chamber, and the temperature in the pulverizing chamber is kept close to the temperature of the mixture of the material and the refrigerated airflow, so as to avoid the material from exchanging heat with the wall of the pulverizing chamber during pulverizing and causing the temperature to change, thereby ensuring the stability of the pulverizing quality.

[0035] For the convenience of implementation, the cooling channel t spirally extends from one end of the cavity body 10 to the other end around the center line of the cavity body 10. Here, the temperature of the cavity body is uniformly distributed.

[0036] At the same time, the inlet of the cooling channel t is located at one end of the cavity body close to the feed port k0, and the outlet is located at one end of the cavity body 10 close to the discharge port k1. Here, the flow direction of the cooling medium in the cooling channel is the same as the flow direction of the mixture of the material and the refrigerated airflow in the pulverizing cavity, so that the mixture of the material and the refrigerated airflow can be in a stable low-temperature environment at any position.

[0037] The crushing module 11 includes a crushing roller 110, an inner ring body 111 sleeved on the crushing roller 110, and an outer ring body 112 fixed on the inner wall of the cavity body 10. The outer wall of the inner ring body 111 is provided with a plurality of dynamic crushing blades p1 distributed in an annular manner around its own center line direction, and the inner wall of the outer ring body 112 is provided with a plurality of fixed crushing blades p2 distributed in an annular manner around its own center line direction, wherein each dynamic crushing blade p1 and fixed crushing blade p2 extend along the axial direction of the crushing roller 110, and the crushing surface formed by the plurality of dynamic crushing blades p1 and the crushing surface formed by the plurality of fixed crushing blades p2 are spaced 1 to 2 mm apart, and form an annular crushing channel, during crushing, the material and the refrigerated air flow mixture are crushed through the crushing channel. Here, based on the cooperation of the plurality of dynamic crushing blades and the fixed crushing blades, the material enters between the two and is impacted, collided, rubbed, and sheared, and the particle size after crushing reaches Dv90<11μm.

[0038] Specifically, the spacing between two adjacent fixed crushing blades p2 is greater than the spacing between two adjacent dynamic crushing blades p1; the two ends of the crushing roller 110 extend out of the cavity body 10 respectively, wherein the two ends of the crushing roller 110 are respectively provided with a bearing seat a0 and a cooling water circulation pipe a1 which is arranged on the bearing seat a0 and forms a heat exchange with the crushing roller 110. As for the layout of the cooling water circulation pipe a1, it is a conventional design and will not be described here. Here, the crushing roller is independently arranged and cooled by circulating water to improve the bearing life. The linear speed of the crushing roller 110 is adjustable, which can reduce the over-crushing of particles, increase the effective output by 20%, and is more energy-saving during continuous production. The energy consumption per unit output of airflow crushing is about 4000Kw·h / t, while the energy consumption per unit output of the present invention is about 2000Kw·h / t.

[0039] In this example, the feed pipe 2 and the refrigerated air flow pipe 3 are respectively connected to the feed port k0. During pulverization, the material is mixed with the refrigerated air flow and enters the pulverizing chamber 1 from the feed port k0.

[0040] In some specific embodiments, the feed pipe 2 and the refrigerated airflow pipe 3 are connected and arranged, and the material enters the refrigerated airflow pipe 3 from the feed pipe 2, and enters the crushing chamber 1 along with the flow of the refrigerated airflow. Here, the material can be fully mixed with the refrigerated airflow before entering the crushing chamber to ensure that the material is fully frozen to increase brittleness, thereby improving the crushing effect.

[0041] For further convenience of implementation, the temperature of the refrigerated airflow is -15 to -20°C; and / or the flow rate of the refrigerated airflow is 3-50 m / s. Here, based on the layout of the flow rate of the refrigerated airflow, the material is crushed at a slow speed (compared to the speed of traditional airflow crushing) under refrigeration, which greatly increases the residence time of the material when passing through the crushing cavity, increases the number of collisions, and improves the crushing quality.

[0042] In this example, the grading unit 4 includes a grading chamber 40, a feed pipe 41, and a return pipe 42, wherein the grading chamber 40 has a feed port k2, a discharge port k3, and a return port k4, the feed pipe 41 connects the discharge port k1 and the feed port k2, the return pipe 42 connects the return port k4 with the feed pipe 2 and / or the feed port k0, and the crushed material particles, driven by the airflow, enter the grading chamber 40 from the discharge port k1 through the feed pipe 41, wherein the finished material particles are discharged through the discharge port k0, and the residual material enters the crushing chamber 1 and / or the feed pipe 2 through the return pipe 42 for cyclic crushing.

[0043] In some specific embodiments, the grading chamber 40 includes a grading chamber body 400 and a grading wheel 401 arranged in the grading chamber body 400, wherein a discharge port k3 is formed at the top of the grading chamber body 400, a return port k4 is formed at the bottom, and a feed port k2 is formed on one side, and the inner cavity of the grading chamber body 400 is gradually narrowed from top to bottom, and the return port k4 is connected to the feed pipe 2; the grading wheel 401 is a prior art, and particles of required particle size are taken out by the induced draft fan to enter the next process, and super-sized particles larger than 20 μm are retained by the grading wheel and crushed again.

[0044] In summary, after adopting the pulverizing device, the material is mixed with the refrigerated airflow and enters the pulverizing chamber for pulverization, wherein the brittleness of the material increases after being mixed with the refrigerated airflow, and the material particles have a better morphology after pulverization, presenting an elliptical shape. Compared with the traditional airflow pulverization, the sphericity of the material particles is basically increased from 60% to 85%; then the pulverized material particles continue to enter the grading chamber through the feed pipe driven by the airflow, wherein the finished material particles that meet the requirements are discharged through the discharge port, and the remaining material re-enters the pulverizing chamber and / or the feed pipe through the return pipe to participate in the cyclic pulverization and re-grading. Therefore, compared with the prior art, the present invention, on the one hand, is based on the mixing of materials and refrigerated airflow, and pulverizes the materials by increasing their brittleness, thereby effectively improving the material pulverization quality and greatly improving the sphericity of the material particles; on the other hand, the present invention combines pulverization with classification, and the materials can be continuously pulverized and graded for recovery, and the residual materials can be circulated for pulverization to achieve continuous production, low energy consumption, and high production efficiency. In addition, the structure is simple, the operation is convenient, and the investment cost is low; thirdly, the materials can be fully mixed with the refrigerated airflow before entering the pulverizing chamber to ensure that the materials are fully frozen to increase their brittleness, thereby improving the pulverizing effect; fourthly, based on the layout of the refrigerated airflow velocity, the materials can be pulverized at a slow speed (compared to the speed of traditional airflow pulverization) under freezing, which greatly increases the residence time of the materials when passing through the pulverizing chamber, increases the number of collisions, and improves the pulverizing quality; Fifthly, a refrigerated airflow is introduced into the cooling channel. The purpose of this setting is to ensure the stability of the temperature in the grinding chamber, and to keep the temperature in the grinding chamber close to the temperature of the mixture of the material and the refrigerated airflow, so as to avoid the temperature change caused by heat exchange between the material and the grinding chamber wall during grinding, thereby ensuring the stability of the grinding quality; sixthly, the flow direction of the cooling medium in the cooling channel is the same as the flow direction of the mixture of the material and the refrigerated airflow in the grinding chamber, so that the material and the refrigerated airflow mixture can be in a stable low-temperature environment when flowing to any position; seventhly, based on the cooperation of multiple dynamic grinding blades and fixed grinding blades, the material is impacted, collided, rubbed and sheared when entering between the two, and the particle size after grinding reaches Dv90<11μm; eighthly, the grinding roller is independently set and cooled by circulating water to improve the bearing life.

[0045] The above detailed description of the present invention is intended to enable persons familiar with the art to understand the contents of the present invention and implement them. It does not limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A cryomechanical pulverizing device suitable for preparing laser printer developer, characterized in that: It includes a crushing cavity with a feed port and a discharge port formed at both ends, a feed pipe, a refrigerated airflow pipe, and a grading unit, wherein the feed pipe and the refrigerated airflow pipe are respectively connected to the feed port; the grading unit includes a grading cavity, a conveying pipe, and a return pipe, wherein the grading cavity has a feed port, a discharge port, and a return port, the conveying pipe connects the discharge port and the conveying port, the return pipe connects the return port with the feed pipe and / or the feed port, during crushing, the material is mixed with the refrigerated airflow and enters the crushing cavity from the feed port, and after crushing, enters the grading cavity from the discharge port through the conveying pipe, wherein the finished material particles are discharged through the discharge port, and the remaining material enters the crushing cavity and / or the feed pipe through the return pipe for cyclic crushing.

2. The cryomechanical pulverizing device for preparing laser printer developer according to claim 1, characterized in that: The feed pipe is connected to the refrigerated air flow pipe, and the material enters the refrigerated air flow pipe from the feed pipe and enters the pulverizing cavity along with the flow of the refrigerated air flow.

3. The cryomechanical pulverizing device suitable for preparing laser printer developer according to claim 1, characterized in that: The temperature of the refrigerated air flow is -15 to -20°C; and / or the flow rate of the refrigerated air flow is 3 to 50 m / s.

4. The cryomechanical pulverizing device for preparing laser printer developer according to claim 1, characterized in that: The pulverizing chamber comprises a chamber body having the feed port and the discharge port, and a pulverizing module arranged inside the chamber body, wherein a cooling channel connected to a cooling medium is formed on the chamber body, and during pulverizing, the chamber body synchronously exchanges heat with the cooling medium.

5. The cryomechanical pulverizing device for preparing laser printer developer according to claim 4, characterized in that: The cooling channel spirally extends from one end of the cavity body around the center line of the cavity body to the other end.

6. The cryomechanical pulverizing device for preparing laser printer developer according to claim 5, characterized in that: The inlet of the cooling channel is located at one end of the cavity body close to the feed port, and the outlet is located at one end of the cavity body close to the discharge port.

7. The cryomechanical pulverizing device for preparing laser printer developer according to claim 4, characterized in that: The crushing module includes a crushing roller, an inner ring body sleeved on the crushing roller, and an outer ring body fixed on the inner wall of the cavity body. The outer wall of the inner ring body is provided with a plurality of dynamic crushing blades distributed in a circular manner around its own center line, and the inner wall of the outer ring body is provided with a plurality of fixed crushing blades distributed in a circular manner around its own center line, wherein the crushing surfaces formed by the plurality of dynamic crushing blades and the crushing surfaces formed by the plurality of fixed crushing blades are spaced 1 to 2 mm apart.

8. The cryomechanical pulverizing device for preparing laser printer developer according to claim 7, characterized in that: The distance between two adjacent fixed crushing blades is greater than the distance between two adjacent dynamic crushing blades.

9. The cryomechanical pulverizing device for preparing laser printer developer according to claim 7, characterized in that: Both ends of the pulverizing roller extend out of the cavity body respectively, wherein both ends of the pulverizing roller are provided with bearing seats and cooling water circulation pipes which are arranged on the bearing seats and form heat exchange with the pulverizing roller.

10. The cryomechanical pulverizing device for preparing laser printer developer according to claim 1, characterized in that: The grading cavity comprises a grading cavity body and a grading wheel arranged in the grading cavity body, wherein the top of the grading cavity body forms the discharge port, the bottom forms the return port, and one side forms the feed port, and the inner cavity of the grading cavity body is gradually narrowed from top to bottom, and the return port is connected to the feed pipe.

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