Patent Application
20220331812
The present invention is directed to a device that grinds and reduces solids to a small particle size while simultaneously controlling the size distribution of the exit particles thereby narrowing the target particle size produced. More specifically, the invention is directed to a device that can be integrated into a grinding system or it can be containerized, transported and operated in a modular/separate fashion as a mobile and stand-alone unit or can be integrated into a grinding facility.
Previous grinding systems have utilized the following grinding approach: fixed impact elements that rotate as opposed to free floating impact elements (e.g. grinding balls inside rotating drum). Rotating elements such as; hammers, knife, pins, etc. have been designed specifically to break down materials based on the impact forces.
The present invention provides a finer grind and is more energy efficient with higher throughputs for similar operating conditions than previous systems. The streamlined design can more precisely control the grinding process and the distribution/classification of particles.
According to an aspect of the invention, the grinding device includes a plurality of stacked rows of knives having a predetermined separation between each knife.
According to yet another aspect of the invention, the device includes a stator and rotor arrangement, the rotor has a plurality of stacked rows of knives having a predetermined separation between each row.
According to still another aspect of the invention, the device includes a pair of stator and rotor arrangement.
In accordance to an aspect of the invention, an inlet port is located at a bottom portion of a grinder casing.
According to one aspect of the invention, the device is provided with a pair of inlet ports located at a bottom portion of a grinder casing.
According to another aspect of the invention, an outlet port is located at a top portion of a grinder casing.
According to one aspect of the invention, the device is provided with a pair of outlet ports located at a top portion of a grinder casing.
According to another aspect of the invention, an outlet port adapter is provided for selectively changing the position of said outlet port in relation to a center of the rotor.
According to still another aspect of the invention, one or more discharge ports are provided at a bottom portion of a grinder casing.
According to yet another aspect of the invention, the rotors of a pair of stator and rotor arrangement are rotated in opposite directions.
According to one aspect of the invention, a grinder casing is provided with heat dissipating elements.
According to an aspect of the invention, the device includes at least one temperature sensor inside a grinder casing, the at least one temperature sensor can be positioned between a discharge port and an inlet port.
According to another aspect of the invention, a discharge lid element is provided on the discharge port to completely or partially block the passage of particles through a discharge port.
According to still another aspect of the invention, an air circulating device is provided outside a grinder casing to circulate air around the stator to reduce the temperature of the grinder.
According to yet another aspect of the invention, the stator includes two impacting screens provided with a separation in order to allow passage of the particles between the impacting screens.
According to an aspect of the invention, an attachment tube is inserted into a rotor cylindrical cavity.
According to another aspect of the invention, the amount and/or length of the knives provided on the rows of knives is different on each row.
According to still another aspect of the invention, the discharge port is positioned behind the inlet port in relation to the flow of the particles inside the grinder.
According to yet another aspect of the invention, the device is coupled with fans and an adjustable outlet port (with discreet or continuous adjustment) to remove the particles exiting the grinding chamber through draft forces which are varied and controlled by placement positions of an outlet flange or placed on the outside. Larger and heavier particles in a rotational motion will have more outward inertia, therefore the placement of the vacuum outlet further from the center of the spinning blades will remove particles of larger diameter. For ultrafine particles, the outlet is placed in the middle of the rotating rotor and there is an attachment that extends the vacuum port into the center hole of the rotor with finer screening capabilities.
Further features and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying figure showing illustrative embodiments of the invention, in which:
Throughout the figures, the same reference numbers and characters, unless otherwise stated, are used to denote like elements, components, portions or features of the illustrated embodiments. The subject invention will be described in detail in conjunction with the accompanying figures, in view of the illustrative embodiments.
According to a preferred embodiment of the invention, the grinder device includes two sets of counter-rotating impact elements that pulverize the material via collisions, which represent impact forces twice as powerful as previous systems through the doubling of the tip velocity.
A continuous self-discharge of harder and heavier particles (most are contaminants) assures higher energy efficiency and a cleaner product that subjects the unit to less wear and tear. The particles reside in the system until they are ground or discharged through the discharge port. The particles reside a short period of time in the grinding chamber and are discharged at a faster rate than previous systems (seconds instead of minutes/hours or even failure to discharge). Many previous systems do not have discharge capabilities and the particles can remain in the chamber. Also, this approach makes it possible to produce a cleaner product as these particles are generally impurities such as soil, sand, metal shavings, biomass particles and/or mineral components from the biochar that is being separated thus concentrating the carbon and organic fractions in the fine particles. The device of the present invention can be provided in a container for integrating into an existing system or to operate as a standalone unit.
The ratio of draft force to centrifugal force (or the apparent outward force), which is modulated by the adjustable speed of the blades and the vacuum created by pneumatic blowers as well as the position of the outlet port precisely, define and classify a narrow particle size with a narrow size distribution.
Grinding systems typically produce a dust on the surroundings (particles that leak from the system). System with positive pressure have the problem that the particles can leak out anytime leaking particles out throughout the entire system. However, the device of the invention does not generate dust at all due to the design feature of a vacuum being present throughout the system regardless of any problems or malfunctions before the dust collector (if dust collector break, e.g. filter break then it could leak out). An important advantage of the present invention is that it can be kept containerized outside and isolated.
The present invention provides a self-cleaning grinder device that does not require external cleaning or a shutdown procedure since it features a continuous on-demand cleaning procedure. This self-cleaning ability represents: a purer material with less contaminants, a reduction on energy consumption (since the presence of heavy particles that can wear down the system and are very difficult to grind are reduced or eliminated), faster grinding speeds at a comparable power consumption rate, less heat produced by the blades, less hazardous temperatures that might produce an ignition or explosion, more energy efficiency and less power consumption overall.
As shown in
Each flange cap (4a, 4b) is attached to the outside casing by a plurality of securing points 5 located around the border of the flange cap. The position of the outlet ports is adjusted by detaching each flange cap (4a, 4b) at the securing points 5, independently rotating the flange caps (4a, 4b) until each outlet port (3a, 3b) reside at a desired position in relation to center of the grinder unit (2a, 2b) and reattaching the flange cap (4a, 4b) back to the outer casing at the securing points 5. The outlet ports (3a, 3b) can also be automatically rotated by rotating clamps that perform the same manual function without the intervention of the operator and/or without the need to stop operation of the system.
As can be appreciated on
Normally, small particles that are heavier than carbon usually reside in an equipment as they are being continuously ground thereby wearing down the equipment. For example, sand and silica components or metal shavings and glass powders reside in the equipment until ground (or some are unable to be ground down) and this causes wear on hammers and higher energy consumption as particles remain for long periods of time or even days. However, the grinder device of the present invention provides a port that allows for continuous cleaning and reducing wear and tear of the equipment.
In operation, particles enter the grinder device 1 from an inlet port (12a, 12b) and travel around the grinder's inner space (11a, 11b) almost an entire rotation before being able to be discharged through a discharge port (13a, 13b). Heavier particles such as sand, silica, rocks, metal shavings and other heavier elements are discharged via self-discharge tubes (7a, 7b) connected to said discharge ports (13a, 13b) and augured out of the system via auger 7c thereby preventing wear and tear. By removing these particles from inside the grinder device 1, the temperature of the grinder device decreases quite significantly reducing flammable hazards and the electrical consumption of the motor (up to 50% energy reduction is achieved when the device is completely cleaned). This is especially true, when the material being ground contains a large percentage of foreign material. Moreover, the grinder device 1 includes a plurality of heat dissipating fins 6 provided on the outside casing as shown in
The stator of the grinder device 1 can have different configurations for different materials. For example, as shown in
A typical configuration of a system using the grinder device of present invention will be explained in conjunction with
In addition, the material can be collected only with the dust collector 50 without using the cyclone 30 to reduce equipment usage. However, for finer material, the cyclone 30 is recommended as it separates larger particles.
According to a preferred embodiment of the invention, the system is completely or partially housed in a shipping container with an end of an infeed auger 60 being coupled to a bin 62 containing the material to be ground and suction is used to elevate the material through the infeed auger 60 into the grinder device 1. This is preferably done pneumatically by coupling a vacuum blower to an infeed port 63 of the infeed auger 60 which creates the necessary suction to transfer the material to be ground into the inlet ports (12a, 12b) of the grinder device 1. A drum 61 is coupled to another end of the infeed auger 60 and collects and removes rocks and very large and dense particles as well as foreign material since those are not drawn in by the suction forces, representing the first layer of protection and impurity separation for the grinder and cleaning system of the present invention. Suction forces allow the proper material to continue through the process while filtering out the unwanted material. Of course, it will be appreciated that the pressure used to carry out this step is selected and controlled based on the amount and type of material.
According to an embodiment of the invention, the system can be configured so that the outlet ports 3a and 3b are both connected to the same cyclone 30 and the dust collector 50 or can be individually connected in parallel to separate cyclone and dust collection lines (30/50) allowing for different particle size collection. The finished ground product obtained via the cyclone 30 and dust collector 50 is augured out and dropped into supersacks ready for shipping as shown in
One important aspect of the invention is that the seals of the motors and the reducers do not need to be as tight and precise as the ones used in prior systems. On positive pressure systems, the dust will go or slip between the bearing and shaft of the motors or from the gear reducers to the motor destroying the bearings and the motors. In order to avoid this problem, those systems use special motors and sophisticated seals. However, the vacuum arrangement created in the system of the present invention allows the use of regular inexpensive motors. According to an embodiment of the invention, all motors used in the system are outside the container except for the grinder device for safety and prevention of fires or explosions. It is also envisioned to enclose the grinder and include openings on the grinder enclosure for outside air access (a ventilation screen on the outside wall with screens on the side of the container). This is done to maintain the grinder separate inside the container, like a division or a room with its own ventilation to the outside.
Another advantage of the present invention is that for some materials the cyclone 30 is unnecessary as the particle grinding is very precise. While it has been explained as a common component of the system, the grinder device 1 and the dust collector 50 can be used without a cyclone 30 as the unit can classify the particles very well for some applications and materials. The system can also provide air circulating externally around the stator in order to cool down the grinder and speed up the process while improving safety.
The grinder temperature is a key aspect during the grinding process which is controlled and automated according to the present invention. For example, when the temperature reaches 90° C. the infeed auger is stopped since higher temperatures can start smoldering the particles and have a smokeless fire or in other materials/situations fires and explosions. Also, if the electrical current consumed by the grinder device 1 is too high then a problem is identified. Accordingly, the infeed auger is stopped until the electrical current load drops. If it does not drop, then the self cleaning port might be clogged and the vacuum created is not adequate (filtration socks plugged), or for example, moisture of the material is too high making the particles too dense so that the particles will not exit the grinding chamber with typical running parameters. In addition, the infeed auger speed (i.e., feeding rate) is controlled by the amperage of the motor, so as to keep maximum grinding capacity, energy efficiency, wear, and a safe operation of the system. If the amperage requirement of the grinder is low then the infeed is increased and viceversa.
According to an embodiment of the invention, the level, intensity and amount of vacuum is monitored in various places throughout the system. The most important location being at the inlet of the baghouse where the vacuum is kept preferrably at a vacuum pressure of six inches of water (which can be changed with different configurations, for the different particle size and for the different material characteristics). Then one dust collector system might be off or running very slow (while is being cleaned or serviced) and the other dust collector system compensates with high speed and vacuum to keep the pressure of six inches of water constant all the time. Pressures values are dependent on system configuration and equipment used, so the exemplary values are for explanation purposes. Another important aspect of the invention is that no airlocks are used. The system of the invention provide augers that create the air locks with the material inside in order to save money, energy and avoid associated problems.
System automation is an important aspect of the invention. The system can monitor the particle amount and flow throughout the process so as to turn off or halt the system when the filtration socks for example are damaged or broken. The amperage of each motor is also monitored to identify any problem. For example, during normal operation augers use four amps so if only two amps are being consumed then it is possible that the material is not being transferred (likely problems of bridging in the inlet) or if six amps are being consumed then there might be moisture or contaminants causing higher energy needs (larger particles). Also, when there is a large rock or chunk in the infeed auger the system automatically stops the auger. Then the auger is reversed and forwarded a few times to allow the particle to go through and if it is small enough it will go through and be collected in a drum contaminant container. Otherwise, the system is stopped to prevent any damage and to further evaluate or correct the problem. The same approach is used with the temperature sensors and the amperage on the motors.
While the present invention has been described in what are presently considered to be its most practical and preferred embodiments or implementations, it is to be understood that the invention is not to be limited to the particular embodiments disclosed hereinabove. On the contrary, the present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the claims appended hereinbelow, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as are permitted under the law.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US20/45072 | 8/5/2020 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 62882731 | Aug 2019 | US |
