Patent Application
20210227870
The present invention belongs to the field of mechanics and consists of a horizontal axis pressure washer, which particularly allows the removal of mucilage from fermented coffee. Said washer allows obtaining a mucilage-free coffee bean thanks to the novel system of three specialized fingers located in rows on a horizontal rotor and a horizontal circular basket containing said rotor.
Coffee cherries are the raw fruit of the coffee plant, which is made up of two coffee beans covered in a thin parchment, as a hull surrounded by pulp. The transformation process of the coffee cherry into the final product for commercialization is known as “the coffee benefit” and basically comprises the following steps: 1) selective or non-selective coffee harvesting, 2) classification of cherry coffee, 3) depulping, 4) demucilaging or washing and 5) drying.
The demucilagination stage is the process to eliminate the mucilage that covers the endocarp or parchment of the bean that is exposed after carrying out the depulping process. Said demucilagination can be carried out by various techniques, among which are the chemical demucilagination process, where products such as sodium, potassium or calcium hydroxide are applied to the depulped coffee stacks to trigger an alkaline hydrolysis. However, coffee subjected to this chemical process is characterized by being less acidic.
Alternatively, the demucilagination can be done by mechanical means, where the use of demucilagination machines is required, such as that described in document US20120328751, which performs said process mechanically. However, these types of processes, which do not include the microbial fermentation stage, can result in physicochemical and sensory modifications in the coffee.
On the other hand, in the state of the prior art, machines that carry out the depulping, fermentation and washing processes within a machine that mechanically transports the coffee between compartments for each of said processes are also known. For example, the machine described in document WO2013114341 allows the fruits to be washed after their fermentation. Said washing is carried out in a washer that consists of a rotor, which has stirrers and spacers, the latter separate the stirrers that are rotationally connected to a square cross-section steel shaft, in addition said shaft is connected in its upper part to a motor. As a particular characteristic, within the stirrers described above there are ones with a longer vane called a cleanser, which has the same cross section as the stirrers, allowing the interior surface of the basket that contains the entire system to be kept clean.
Among the machines described in the state of the prior art for the integral treatment of coffee (depulping, demucilagination, drying) document U.S. Pat. No. 2,261,560A is found. In said document, in order to depulp the bean, the use of water injected under pressure along a tube that conveys the beans is described. Additionally, the post-depulping washing stage is carried out in a rotating metal basket.
Finally, it is pertinent to highlight that demucilagination can be carried out through fermentation processes that are based on solubilization of the mucilage due to the decomposition of pectins, a process that occurs during the fermentation of the ripe fruit.
However, the traditional processes of demucilagination by fermentation of the depulped bean imply high costs at an ecological level, because the post-fermentation washing stage requires the use of large quantities of water to wash the beans and eliminate the residual mucilage from the fermentation. For example, in the vast majority of mills this washing is carried out by manually stirring the beans with paddles in a washing tank. In this process, extensive use of water is necessary, approximately 25 to 30 m3 of water per metric ton of processed coffee.
Alternatively, mechanical washers are known, which can have a horizontal or vertical axis, which are characterized by comprising a cylinder within which a central axis rotates provided with blades to ensure the stirring and advancement of the coffee mass (see Coffee Technology Volume 2. R. J Clarke and R. Macrae. Elseivier Science Publishers LTD. 1987. ISBN 13-978-94-010-8028-6 Page 19).
In this sense, the fermented coffee washing machine, MEGAWASHER, is widely known in the market. This machine has a vertical axis in which the fermented coffee enters the lower area of the equipment and is driven by an endless conveyor, then a rotor with fingers drives the coffee, printing the necessary rotation speed to create the centrifugal force that separates the mucilage attached to the beans that comes out of the grooves of the basket.
Within the state of the prior art there is also the washing machine described in patent U.S. Pat. No. 1,796,856, where the beans are immersed in water and transported in a direction with a steep upward inclination, in such a way that said beans rise slowly while the water travels in the opposite direction, until it is discharged at a lower level together with the residue carried in said wash water.
From all the foregoing, it is clear that the need for machines that allow the washing of fermented coffee in order to eliminate mucilage and that reduce the amount of water and power required in the process persists in the state of the prior art.
The present invention relates to a washing machine useful for removing mucilage attached to coffee beans after they have been subjected to the fermentation process.
Said washer has as its main characteristic the efficient use of washing water, due to the unique configuration of a circular basket and a rotor comprising specialized fingers located along it.
In this way, the coffee enters the hopper and is transported along the circular basket thanks to the movement of the rotor. During this transport, the fermented coffee beans are stirred by metal stirrer fingers fixed to the rotor. Additionally, the fermented coffee beans are subjected to jets of water under pressure ejected by finger injectors. At the same time, cleaning fingers, which are moving parts attached to the rotor, perform a cleaning of the circular basket by efficiently removing mucilage and impurities.
In this way, the joint action of the three types of fingers mounted on the horizontal rotor ensure the complete elimination of the mucilage adhered to the coffee beans, which were previously fermented, with a low consumption of water and power.
According to
Inside the circular basket (2) the fermented coffee comes into direct contact with the metal fingers (3A), (3B) and (3C), which are welded to the central body of the rotor (3). Each finger has a particular role in the process of removing mucilage from fermented coffee:
Stirring finger (3A): these are metal fingers welded to the rotor (3) that serve to stir and rub the fermented coffee beans, in such a way that the mucilage adhering to them is released after the fermentation process.
Injector finger (3B): they are perforated metal fingers, welded to the rotor (3) that allow the passage of water into the chamber formed by the rotor tube (3) and the circular basket (2). Thanks to its design, it is possible to inject and atomize the water coming from the electric pump (14), coming into contact with the fermented coffee beans. This action achieves an efficient use of water.
Cleaning finger (3C): corresponds to a set of three pieces, two metallic and one plastic. The first metal piece acts as a base and is welded to the rotor. The second metal part is mounted on the first metal part and carries the plastic part. The second metal part and the plastic part move as a consequence of the centrifugal force generated by the rotation of the rotor (3), so that the plastic part rubs with the internal part of the circular basket (2). Said rubbing manages to keep the circular basket (2) clean, allowing the evacuation of mucilage and impurities efficiently.
The fingers (3A), (3B) and (3C) are mounted on the rotor (3), and are distributed in rows around it, where each row has the three types of fingers.
The fingers (3A), (3B) and (3C) that are mounted on the rotor (3), rotate with it, work simultaneously as a team, so that: (3A) agitates and rubs the beans, (3B) injects and atomizes the water at high pressure, and (3C) cleans the internal part of the circular basket (2), thus achieving a very low water consumption and a very good washing of the fermented coffee beans.
Now, the mucilage and contaminants removed from the fermented coffee beans by the action of the rotor (3), the stirring fingers (3A) and the pressurized water injected by the fingers (3B), are ejected from the system by the action of the cleaning fingers (3C) through the circular basket (2). This is possible thanks to the structure of the circular basket (2) that is made of square, round, or perforated sheet rods. In this way, the mucilage and contaminants are stored in the mucilage tank (11), which is a metal or plastic container, which receives the mucilage and water eliminated during the process.
Once the mucilage is effectively removed from the fermented coffee beans, it moves to the outlet frame (5) which is screwed to one end of the circular basket (2), to the outlet mouth (9) and to the flange (6). With the help of the rotor outlet auger (3) and water from the electric pump (14), the washed coffee is expelled from the horizontal axis pressure washer through the outlet mouth (9) which is inclined. Alternatively, the washed coffee can be expelled without water from the electric pump (14), as long as the outlet frame (5) and the outlet mouth (9) are disposed downward.
Now, for the correct operation of the horizontal axis pressure washer of the invention, an efficient clean water distribution system is required. Said system is composed of the electric pump (14) which corresponds to a high pressure and low flow self-priming electric motor pump, a distributor (19) and additional elements as described below.
The electric pump (14) is fed by the suction hose (16) that corresponds to a plastic or rubber duct that comprises at its end a foot valve (15), where said foot valve (15) corresponds to a metallic or plastic device that prevents the electric pump (14) from discharging and at the same time filters the water used in the process.
As shown in
The first outlet of the distributor (19) comprises a reducer socket (20), which is a metal or plastic accessory that is connected to the distributor (19) allowing the passage of water to the rotor (3) through the seal holder (10), the latter in turn is a mechanical device used to regulate and allow the passage from the water to the rotor (3) through a mechanical seal. Once the clean water has entered the rotor (3) it is injected under pressure into the circular basket (2) by means of the injector fingers (3B). The second outlet of the distributor (19) leads the clean water to the inlet hopper (8), and the third outlet leads the clean water to the outlet frame (5), said two outlets are regulated by valves (21). Finally, the fourth outlet leads the clean water to a tee (17) that corresponds to a metal or plastic accessory that allows interconnecting the suction of the electric pump (14) with the distributor (19), to achieve a bypass, necessary to balance the operation of the electric pump (14).
Additionally, for the correct operation of the horizontal axis pressure washer of the invention, a mechanical system is required that allows control of the movement of the rotor (3). Said system is composed of a motor (23) located on a base (24), which secures and supports it, a pulley that is a metallic piece that is mounted on the shaft of the electric motor (23) and transfers the movement through the belts (26) to the flywheel (27), this in turn is mounted on the rotor (3) that has two shaft ends welded at its ends and is mounted on the rolls of the bearings (7), which are secured with screws to the flanges (6), which in turn correspond to two metal pieces that are secured with screws to the inlet (4) and outlet (5) frames.
Finally, the systems described above are supported by a chassis that is a metallic structure, which is secured by screws: the circular basket (2), the electric motor (23), the electric pump (14), the guards (28), (29), (30) and (31) and the trolley (32); The latter supports the entire horizontal axis pressure washer and facilitates its movement.
Other structures necessary for the protection of the horizontal axis pressure washer and the user are: the mucilage tank lid (11), the lid complement (13), the motor guard (28), the rear guards (30), right side (28) and left side (31) guards. Finally, the horizontal axis pressure washer is secured with screws to a metal trolley (32) to facilitate the movement of the machine.
In order to highlight the operation and advantages of the horizontal axis pressure washer disclosed in the present invention, below is a comparison of the average consumption of water and power as a function of the amount of fermented coffee processed using a manual washing, the known MEGAWASHER and the horizontal axis pressure washer disclosed in the present invention.
From the above, it is possible to affirm that the horizontal axis pressure washer for fermented coffee disclosed in the present invention allows to radically reduce the use of water and the power required for the removal of mucilage.
For example, according to the previous table and carrying out the conversions of the case, the manual washing process consumes 1 L of water for every 0.04 Kg of washed coffee, the MEGAWASHER is capable of washing 2.9 Kg of coffee for every liter of water, ECOM ILL is capable of washing 5.5 kg of coffee per liter of water, and surprisingly, the horizontal axis pressure washer of the invention processes 8.5 kg of coffee per liter of water.
Finally, it is also clear from the above table that the horizontal axis pressure washer for fermented coffee of the invention reduces the mechanical damage of washed coffee compared to the systems known in the prior art.
The efficiency achieved by the horizontal axis pressure washer disclosed in the present invention corresponds, in fact, to a considerable improvement compared to what is known in the state of the prior art, given the efficient use of water, thus becoming a practical and efficient alternative to reduce the costs and ecological impact of processing fermented coffee.
| Number | Date | Country | Kind |
|---|---|---|---|
| NC2018/0005205 | May 2018 | CO | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2019/054047 | 5/15/2019 | WO | 00 |
