WO2025172746A1

WO2025172746A1 - Multi-stage liquid medium pulverization apparatus and method thereof

Info

Publication number: WO2025172746A1
Application number: PCT/IB2024/060909
Authority: WO
Inventors: Shreepad Hegde
Original assignee: Individual
Current assignee: Individual
Priority date: 2024-02-16
Filing date: 2024-11-05
Publication date: 2025-08-21
Anticipated expiration: 2026-08-16

Abstract

The present invention relates to a pulverization apparatus (100) for reducing the particle size of solid materials in a liquid medium, comprises a pump housing (101) with an integrated liquid-solid slurry inlet (102) and pulverized material outlet (111), a central rotating shaft (110) within the pump housing (101), a series of perforated discs (107) mounted on the central shaft (110), each disc having a plurality of apertures, one or more shearing cutters (112) and shearing cutter blades (113) associated with each perforated disc (107), positioned to shear solid particles as they pass through the apertures, and a power unit (200) mechanically linked to the central shaft (110) to impart rotational movement The series of perforated discs (107) are configured in a multi-stage arrangement to enable multi-stage pulverization of solid particles within the liquid in a single pass.

Description

FIELD OF THE INVENTION

Embodiments of the present invention generally relate to the industrial processing equipment. Particularly, the present disclosure relates to providing a apparatus and method for the pulverization of solid particles suspended in a liquid medium.

BACKGROUND OF THE INVENTION

The subject matter discussed in the background section should not be assumed to be prior art merely as a result of it being mentioned in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also correspond to implementations of the claimed technology.

Mechanical milling, a prevalent pulverization process, is utilized to reduce the particle size of powdered materials to a uniform and required size. This process is crucial for improving various material properties, including dissolvability, surface area, reactivity, aerosolization, and absorption. In many applications, finer particles are more desirable. The terms pulverization and milling are often used interchangeably in the context of size reduction.

Powders or solids in various industries are typically produced through chemical reactions, resulting in crystallization. These solids, mixed with liquids, form a slurry. Post-crystallization, these solids are separated from the liquid through filtration and subsequently dried. The dried solid products are then pulverized to a desired size, which can range from few millimeter to nano scale.

The current state of technology for powder pulverization includes a variety of machines, such as pulverizers, hammer mills, multi mills, conical mills, ball mills, grinders, and pin mills. These machines, while effective, are not without drawbacks. One significant issue is the generation of heat due to the energy released during pulverization. This heat can degrade product quality, change characteristics, and even pose fire hazards. Specifically, heat-sensitive powders cannot be effectively processed in most of these machines. Air jet mills are an exception, used specifically for heat-sensitive powders in industries like pharmaceuticals and chemicals, where maintaining a low solid temperature during milling is essential.

Another type of equipment, known as delumpers, is used to reduce agglomerated powders back into smaller particles before further milling or grinding to the required size.

Despite the variety of available equipment, the pulverization process as currently practiced has several disadvantages:

Dust Generation: The process generates a significant amount of dust, leading to environmental pollution, operator exposure, product loss, and potential dust explosions.

Heat Generation: The mechanical pulverization process releases heat energy, potentially degrading products and changing their characteristics.

Manual Operation: Most existing machines require manual operations such as charging, discharging, and collection, leading to exposure to chemicals, manual errors, and accidents.

Noise Pollution: The process involves mechanical vibration, contributing to noise pollution.

Difficulty with Hard Chemicals: Hardened chemicals, especially when dried, are difficult to pulverize effectively. Some require multiple iterations of pulverization to achieve the desired particle size.

Sensitivity to Impact and Oxygen: Many solids are sensitive to impact or react with oxygen, necessitating special handling or inert atmospheres for pulverization.

Static Electricity Risks: Non-conductive powdered materials can generate static electricity during pulverization, posing significant safety risks.

High Energy Consumption: The process generally requires high impact energy, leading to high energy consumption. Cleaning Challenges: Cleaning of the equipment is often manual and uses large quantities of cleaning liquids, which are potential environmental pollutants.

Therefore, there is a need for the present invention to address aforesaid challenges by introducing an apparatus and method for the pulverization of solid particles suspended in a liquid medium which is a more efficient, safe, and environmentally friendly pulverization process.

OBJECT OF THE INVENTION

An object of the invention is to provide a apparatus and method for pulverizing solid particles in a liquid medium, significantly minimizing or eliminating dust generation during the pulverization process.

Another object of the invention is to achieve low heat generation in the pulverization process, ensuring the suitability for heat-sensitive materials and preventing alteration of product characteristics.

Yet another object of the present invention is to enhance the safety of the pulverization process by reducing manual handling and exposure to chemicals, thereby decreasing the risk of manual errors and accidents.

Another object of the invention is to efficiently pulverize hard or impact -sensitive materials, potentially in a single pass, thereby increasing the overall process efficiency.

Yet another object of the present invention is to enable safe and efficient pulverization of materials that react with oxygen, by providing a apparatus capable of operating in an inert atmosphere when necessary.

A further object of this invention is to reduce the overall energy consumption of the pulverization process through an efficient design that maximizes energy transfer.

Another object of the invention is to facilitate easier and more environmentally friendly cleaning processes, reducing the use of cleaning liquids and the generation of effluents.

SUMMARY OF THE INVENTION According to an aspect of the present invention, there is provided a liquid medium pulverization apparatus for reducing the particle size of solid materials in a liquid medium, comprises a pump housing with an integrated liquid-solid slurry inlet and pulverized material outlet; a central rotating shaft within the pump housing; a series of perforated discs mounted on the central shaft, each disc having a plurality of apertures; one or more shearing cutters associated with each perforated disc, positioned to shear solid particles as they pass through the apertures; and a power unit mechanically linked to the central shaft to impart rotational movement. Wherei n the series of perforated discs are configured in a multi-stage arrangement to enable multi-stage pulverization of solid particles within the liquid in a single pass.

In accordance with an embodiment of the present invention, the apertures of the perforated discs vary in size, allowing for gradual reduction of particle size as the slurry progresses through the discs.

In accordance with an embodiment of the present invention, the design of perforated disc is selected from conical, cylindrical, and flat.

In accordance with an embodiment of the present invention, each shearing cutter consists of one or more shear blades to shear the solid particles and pushes them through the apertures.

In accordance with an embodiment of the present invention, the gap between the shear blades and corresponding perforated disc is adjustable to control the particle size, shearing force, and capacity of the slurry flow.

In accordance with an embodiment of the present invention, the apparatus is fully sealed to prevent slurry leakage and minimize environmental exposure.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular to the description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, the invention may admit to other equally effective embodiments. These and other features, benefits and advantages of the present invention will become apparent by reference to the following text figure, with like reference numbers referring to like structures across the views, wherein:

Fig. 1 illustrates a liquid-medium pulverization apparatus, in accordance with an embodiment of the present invention;

Fig. 2 illustrates an exemplary configuration of multi-stage liquid medium pulverization apparatus, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

The present invention is described hereinafter by various embodiments with reference to the accompanying drawing, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description.

While the present invention is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments of drawing or drawings described and are not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated in certain figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claims. As used throughout this description, the word "may" is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense, (i.e., meaning must). Further, the words "a" or "an" mean "at least one” and the word “plurality” means “one or more” unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention.

This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only and are not intended to limit the scope of the claims. In addition, a number of materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary and are not intended to limit the scope of the invention.

The present invention relates to a liquid medium pulverization apparatus, which is specifically designed to enhance the efficiency and safety of pulverizing solid particles in a liquid medium. This advanced apparatus addresses several limitations of traditional dry pulverization methods, providing significant improvements in terms of environmental safety, operational efficiency, and processing quality.

Figure 1 illustrates a liquid medium pulverization apparatus (1 ), in accordance with an exemplary embodiment of the present invention. The liquid medium pulverization apparatus composed of three main sub-assemblies: the liquid medium pulverization apparatus pump (100), the power unit (200), and the support frame (300), each playing a crucial role in its operation. The liquid medium pulverization apparatus pump (100) serves as the primary operational unit. The pump incorporates a housing (101 ), where the pulverization of materials takes place. The slurry inlet (102) and outlet (1 1 1 ) are located on the pump housing, facilitating the efficient management of the slurry's ingress and egress under high-pressure conditions, thereby ensuring smooth processing and flow. As shown in figure 2, the inlet (102) is positioned to receive the incoming slurry, which comprises a mixture of solid particles and liquid. This positioning prevents turbulence while slurry entered to the pulverizing components that could impede the system's efficiency and ensures smooth entry of the slurry into the pump housing. Similarly, the outlet (1 1 1 ) is located on a different plane of pump housing (as shown in fig 2), to prevent clogging or pressure build-up in the pump housing, a consideration is given to the finer particle size of the slurry postpulverization. The outlet’s design and location are optimized to maintain a steady flow rate, ensuring that the processed slurry exits the system smoothly and continuously. Both the inlet (102) and outlet (1 1 1 ) construction and other parts of liquid medium pulverization apparatus include the use of high-strength, corrosion-resistant materials capable of maintaining integrity under high pressure conditions. The fittings and connectors are selected for their durability and ability to form airtight seals, thus preventing leakage. The dimensions and shape of the inlet and outlet are decided based on the specific characteristics of the slurry, such as viscosity and particle size, to minimize resistance and pressure drops during the flow.

Moreover, the power unit supplies the necessary mechanical power to the liquid medium pulverization apparatus pump (100) for its operation. The power unit includes a motor (200) operationally coupled with the pump via timer and pully arrangement, aiding in the milling process. Lastly, the support frame (300) maintains the stability and security of the liquid medium pulverization apparatus pump and power unit assembly during operation. The support frame (300) is typically constructed from materials such as heavy-duty steel or reinforced alloys. These materials are chosen for their strength and durability, as well as their ability to withstand the vibrational forces generated by the milling process.

As shown in figure 2, a diagram depicts the components in the pulverization apparatus (100), in accordance with an embodiment of the present invention. The apparatus may comprise, but not limited to, a pump housing (101 ), a slurry inlet (102), a slurry outlet (1 1 1 ) a central rotating shaft (1 10), a series of perforated discs (107), one or more shearing cutters (1 12) and mechanical seals (103).

In accordance with an embodiment of the present invention, the pump housing (101 ) crafted from high-grade stainless steel, selected for its strength, durability, and corrosion resistance. The housing is constructed to effectively manage the high- pressure flow of the slurry mixture. Incorporated into the pump housing (101 ) are the slurry inlet (102) and outlet (1 1 1 ), designed to handle high-pressure conditions, typically within the range of 3-10 bar. They are often reinforced with wear-resistant materials, enhancing their longevity and ensuring consistent performance under rigorous industrial conditions. The pump housing (101 ) is composed of a plurality of pump sleeves (106) along its length, and end plates (105) are located at both ends of the pump housing (101 ).

The apparatus's functionality hinges on a central rotating shaft (1 10), constructed from hardened steel or alloy material. The shaft (1 10) runs through the end plates (105) in the centre of the pump housing (101 ) and rotated by the power unit (200), and further supporting and rotating the pulverizing components like perforated discs (107) and shearing cutters (1 12). The electric motor of power unit (200), selected for its power output and efficiency, is mechanically linked to the one end of the shaft (1 10). The motor is capable of operating at variable speeds, which may range from 3000 to 10000 rpm, to cater to different pulverization requirements. The connection between the motor and the shaft (1 10) may be facilitated by a timing pulley (109) and belt arrangement, ensuring reliable and consistent power transfer.

Mounted on the central shaft (1 10) are the series of perforated discs (107). Each perforated disc is positioned within the respective pump sleeve (106) and arranges in series to aid stage wise pulverizing process. The perforated discs, made from tempered steel or a durable alloy, are designed to withstand the pressurised fluid pressure during the pulverization process. Each disc has plurality of apertures, which vary in size and shape, aiding in achieving the desired particle size reduction at each pulverization stage. Depending on specific milling requirements, the discs (107) may be conical, or cylindrical, or flat. The shearing cutters (1 12), associated with each perforated disc (107), feature one or more blades (1 13) made from high-strength materials, the cutters are not limited to a single-blade design; they can have multiple blades, depending on the requirements of the pulverization process. The blades (1 13) efficiently shear the solid particles as they pass through the disc apertures. The blades aid in pushing the sheared particles through the apertures to ensure that once the particles are reduced in size, they are moved to next stage or outlet, without clogging and maintaining a smooth operation. The adjustable gap between the cutter blades and the discs allows for precise control over particle size, shearing force, and slurry flow capacity. To prevent slurry leakage, mechanical seals (103) are employed at both ends of the pump housing (101 ). These seals are made from materials compatible with the slurry composition, ensuring effectiveness and longevity. For added safety, especially when handling flammable or sensitive materials, earthing lugs (not shown in figures) are integrated into the design to prevent static electricity accumulation and discharge due to high velocity of the liquid.

The multi-stage arrangement of the series of perforated discs (1 12), within the plurality of pump sleeves (106), enables multi-stage pulverizing in a single pass, thereby reducing energy consumption compared to traditional dry pulverizing systems. Additionally, the fully sealed design of the apparatus ensures that there is no leakage, reducing environmental exposure.

Designed with ease of maintenance in mind, the apparatus allows for easy access and replacement of components as needed.

In accordance with an embodiment of the present invention, a jacket (not shown in figures) may optionally be fitted around the liquid medium pulverization apparatus housing to regulate temperature during the milling process. Depending on the requirements for temperature control, this jacket can be either air-cooled, liquid- cooled, or heated. Further, the apparatus is designed for continuous operation, allowing for seamless integration into various industrial processes. This includes the potential for connecting to subsequent operations like filtration.

The present invention offers several significant advantages over traditional pulverization methods. These benefits enhance the efficiency, safety, environmental concerns, and operational effectiveness of the milling process:

• No Dust Generation and Environmental Impact: The apparatus operates in a closed airtight condition and the solid products are in liquid medium, hence there is no possibility of dust generation.

• Enhanced Safety for Operators: By eliminating dust generation and containing the pulverization process within a closed system, the invention greatly reduces the risk of operator exposure to fine particulates and potentially harmful materials. The enclosed operation also minimizes the risk of accidental spillage. • High-Efficiency Pulverization: The multi-stage pulverization process within a single pass, facilitated by the arrangement of perforated discs and shearing cutters, ensures efficient particle size reduction.

• Adaptability to Various Materials: The apparatus is capable of handling a range of materials, including those that are heat-sensitive, hard, or impact-sensitive. This flexibility makes the system suitable for diverse industrial applications.

• Low Heat Generation: The cooling liquid circulation in the jackets ensure the heat generated is taken away during pulverization process. This is particularly beneficial for processing heat-sensitive materials, as it prevents alteration of their properties or degradation.

• Ease of Maintenance and Cleaning: The present invention has in-place cleaning system for easy maintenance, with components that can be readily accessed and cleaned.

• Safety from Static Electricity: The earthing lugs mitigates the risk of static electricity build-up, enhancing operational safety, especially when handli ng flammable or explosive materials.

Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but is to be providing broadest scope of consistent with the principles and the novel and inventive features disclosed or suggested herein. Accordingly, the invention is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present invention and the appended claims.

Claims

I claim:

1. A liquid medium pulverization apparatus (100) for reducing the particle size of solid materials in a liquid medium, comprising: a pump housing (101 ) with an integrated liquid-solid slurry inlet (102) and pulverized material outlet (1 1 1 ); a central rotating shaft (1 10) within the pump housing (101 ); a series of perforated discs (107) mounted on the central shaft (1 10), each disc having a plurality of apertures; one or more shearing cutters (1 12) associated with each perforated disc (107), positioned to shear solid particles as they pass through the apertures; and a power unit (200) mechanically linked to the central shaft (1 10) to impart rotational movement, wherein the series of perforated discs (107) are configured in a multi-stage arrangement to enable multi-stage pulverization of solid particles within the liquid in a single pass.

2. The apparatus (100) as claimed in claim 1 , wherein the apertures of the perforated discs (107) vary in size, allowing for gradual reduction of particle size as the slurry progresses through the discs.

3. The apparatus (100) as claimed in claim 2, wherein the design of perforated disc (107) is selected from conical, cylindrical, and flat.

4. The apparatus (100) as claimed in claim 1 , wherein each shearing cutter (1 12) consists of one or more shear blades (1 13) to shear the solid particles and pushes them through the apertures.

5. The apparatus (100) as claimed in claim 1 , wherein the gap between the shear blades (1 13) and corresponding perforated disc (107) is adjustable to control the particle size, shearing force, and capacity of the slurry flow.

6. The apparatus (100) as claimed in claim 1 , wherein the apparatus is fully sealed to prevent slurry leakage and minimize environmental exposure.