HK40009978B - Process and unit for harvesting and processing water hyacinths - Google Patents

Description

Method and unit for collecting and treating water hyacinth

Technical Field

The present invention belongs to the field of methods for harvesting and treating water hyacinth.

Background

Water hyacinth or water hyacinth is a type of aquatic plant in fresh water. Such plants are very aggressive. A problem arises because it grows rapidly and during its decomposition. In fact, its rapid and extensive growth has an impact on the freshwater ecosystem. The spread of water hyacinth in its environment can form a dense carpet of a single species on the underlying layer, depriving it of light of life, thereby killing indigenous species.

Furthermore, during their breakdown, water hyacinths release nutrients in their aquatic media, which may lead to environmental eutrophication or hypoxia, posing a threat to aquatic biodiversity, and possibly leading to the death of many species co-existing with water hyacinths.

In addition, the water hyacinth seeds are durable, and the dormancy time of the seeds is 20 years. These seeds can tolerate drying and germinate once immersed in an aquatic medium. Thus, even in the case of harvesting, during storage there is a risk of contamination, i.e. germination of the seeds, especially when the storage environment is moist. Therefore, there is a need to be able to avoid this risk of water hyacinth seeds germinating during storage, in order to be profitable to use in an industrial environment.

Therefore, in order to avoid the above phenomena, it is necessary to find a simple, quick solution for harvesting, handling and profitable use of water hyacinth in industry.

Disclosure of Invention

The present invention aims to overcome the drawbacks of the prior art by providing a method for harvesting and treating water hyacinths, wherein the following steps are performed:

a) cutting water hyacinth growing in the aquatic medium;

b) collecting water hyacinth on a barge at the berth;

c) transferring the collected water hyacinth to a draining device, such as a draining rack, near the dock;

d) washing the drained water hyacinth with clean water;

e) draining the washed water hyacinth on a vibrating belt to partially eliminate excess water;

f) drying water hyacinth in a dryer at 50-100 deg.C for 5-17 hr;

g) steam sterilizing at 80-100 deg.C to sterilize herba Eichhorniae and its seeds;

h) the sterilized water hyacinth and seeds are ground to facilitate the use of the water hyacinth and seeds.

Furthermore, according to a further feature of the method of the present invention:

recovering the residual water from the draining step c), which is subjected to a UV sterilization treatment inside the purification plant, in order to discharge it into the raw aquatic medium of the water hyacinth;

said clean water of step d) consists of water extracted from the raw aquatic medium of water hyacinths, said extracted water being pumped through a pumping device and filtered through a filter screen comprising an opening diameter between 6 and 10mm to clean it for the washing step;

performing said step d) by washing the drained water hyacinth at least twice with clean water in a washing device (e.g. a washing vessel);

drying the sterilized water hyacinth by a pressure hot air system after the sterilization step g) and before the grinding step h);

after the grinding step h), micronization of the obtained ground material to allow its profitable use in the field of plastics processing or insulating materials;

performing the drying step f) using a stereo hot air dryer;

after the drying step f) and before the sterilization step g), the dried water hyacinth is concentrated in a concentration device (e.g. a concentrator);

after step d) of washing the drained water hyacinth, the water hyacinth is cut into at least three or four lengths.

The invention also relates to a unit for harvesting and treating water hyacinth, allowing to carry out the method of the invention and in the following order:

a floating barge near the quay, said barge being equipped with means for cutting the water hyacinth, means for collecting and storing the cut water hyacinth and means for transferring the water hyacinth to the quay, said transfer means being intended to transfer the water hyacinth to a draining rack for draining the collected water hyacinth;

means for moving the drained water hyacinth to a washing device connected to the additional draining rack;

a drying device at the outlet of the additional draining rack;

means for concentrating the dried water hyacinth at the outlet of said drying means;

means for sterilizing the water hyacinth concentrated at the outlet of the concentrating means;

a device for grinding the water hyacinth sterilized at the outlet of the sterilization device.

Drawings

Other features and advantages of the present invention will become apparent from the following detailed description of non-limiting embodiments of the invention, when considered in conjunction with the accompanying drawings, in which:

fig. 1 schematically shows a view of a unit for harvesting and treating water hyacinths;

fig. 2 schematically shows a view of a three-dimensional hot air dryer of a unit for harvesting and treating water hyacinth.

Detailed Description

The present invention relates to a method for harvesting and treating water hyacinth.

Water hyacinth is harvested by means of a floating barge 1 equipped with cutting means, collecting and storing 110 cut water hyacinth.

Thus, an implementation of the method of the invention is achieved by successively performing the following steps:

a) cutting water hyacinth growing in an aquatic medium;

b) water hyacinth is collected on the berthed barge 1.

Once the water hyacinth has been harvested, the method of the invention allows the collected water hyacinth to be transferred to a draining device 2, i.e. a draining rack 2, near the quay.

The transfer of the harvested water hyacinth is performed using the transfer device 3. According to a particular embodiment, when the ground allows the installation of rails, the transfer means 3 may in particular consist of a rotating telescopic carriage capable of transferring the water hyacinth from the ship to the draining rack 2 on the quay.

Advantageously, the draining rack 2 is located near the quay adjacent to the aquatic medium.

According to a particular embodiment, the draining rack 2 consists of a stainless steel metal mesh elevated with respect to the ground.

The properties of stainless steel are essential to prevent premature wear of the drip stand 2 by excess water and to avoid corrosion and deterioration by rusting.

The harvested water hyacinths are drained, allowing for a first rough removal of excess water to facilitate the handling of the water hyacinths.

According to a particular embodiment of the invention, excess water, i.e. residual water from draining, is recovered. The residual water is then subjected to a UV sterilization treatment in the purification apparatus 4 and subsequently discharged into the raw aquatic medium of the water hyacinth.

After this first rough draining on the draining rack 2, the drained water hyacinth is washed with clean water. According to a particular embodiment, the clean washing water consists of water extracted from the raw aquatic medium of the water hyacinth. The extracted water is pumped through a pumping device 5 and filtered on a fine mesh with a separation diameter of 6 to 10 mm. The water is then sieved on a fine mesh with perforations between 4 and 6mm to clean it for the washing step.

Advantageously, the washing is carried out with clean water using the washing device 6, in particular in the washing vessel 6.

Advantageously, the washing operation is repeated several times.

Advantageously, the same amount of material is washed at least twice. However, depending on the composition of the aquatic medium contaminating and extracting the water hyacinths, i.e. depending on the fouling of said aquatic bio-medium of the water hyacinths, an additional washing cycle is required. These wash cycles can be up to ten consecutive wash cycles.

The washing step allows to remove and coarsely purify the impurities adhering to the drained loose substance of the water hyacinth and still present in the loose substance.

After washing, the washed water hyacinth is dried on the vibrating conveyor belt 7 in order to partially remove the excess washing water and to obtain the least hydrated possible substances.

According to a particular embodiment of the invention, the vibrating conveyor belt 7 has the form of a vibrating draining rack inclined at about 5 °, the filter mesh of which has openings with a diameter decreasing from 2mm to 0.2 mm.

Advantageously, the material (i.e. the washed water hyacinth) is drained on a series of vibrating conveyor belts 7 of stainless steel wire mesh, as shown in fig. 1.

According to a particular embodiment, the water residue is recovered after passing through the vibrating conveyor belt 7 for UV sterilization and release into the aquatic medium.

According to the invention, the water hyacinth is dried using a drying device 8, in particular on a dryer 8. The drying is carried out at a temperature of 50-110 ℃ for 5-16 hours.

According to a particular embodiment, said drying of the water hyacinth is carried out at a temperature of 50-70 ℃ for 14-16 hours.

According to another preferred embodiment, said drying of the water hyacinth is carried out at a temperature of 90-110 ℃ for 5-7 hours.

In all cases, the drying must be carried out at a temperature lower than 110 ℃ in order to avoid damaging the fibers of the water hyacinth.

According to a particular embodiment, said dryer 8 consists of a solar stereoscopic hot air dryer 8, in particular for saving the energy required for its operation, or is powered by any other power supply system.

According to this particular embodiment, and as shown in fig. 2, the three-dimensional hot air dryer 8 comprises:

an inlet 81, e.g., a conduit, at the upper portion allows for the inclusion of wet scrubbing material to be dried;

a series of meshed stainless steel conveyor belts 82 over their entire height, which vibrate and allow the material to be dried to be progressively transported from top to bottom, the meshes allowing the passage of air;

an outlet 83, e.g. a conduit, in the lower part allows the discharge of the dried material (i.e. dried water hyacinth) to the outside of the stereo hot air dryer 8.

It should be noted that the conveyor belt 82 is vibrating, and therefore, static drying of the material is avoided. In fact, static drying is slower and less efficient than vibratory dynamic drying.

In said three-dimensional hot air dryer 8, the presence of an air inlet system 84a in the lower part and an air outlet opening 84b in the upper part will allow a gradual drying of the material. The air circulation within the dryer will thus assist in drying. In this dryer 8, the circulation of hot air can allow the material to dry gradually over the entire height, i.e. through the grid. The temperature of the hot air circulating through the dryer 8 is between 50 ℃ and 110 ℃.

At the outlet 83 of the dryer 8, the dried material is recovered and the dried water hyacinth is concentrated using the concentrating device 9, in particular in the concentrator 9. The use of the concentrator 9 allows to increase the line of action and the flow of the substance.

After passing through the dryer 8, the concentrated material is sterilized with steam at a temperature of 80-100 ℃ in order to sterilize the dried water hyacinth and its seeds. Sterilization is performed using a steam sterilization device 10, particularly in a steam sterilizer 10.

The sterilization method and the temperature range used allow to avoid the germination of the water hyacinth seeds and the proliferation thereof. Sterilization allows to prevent said possible germination, i.e. when the grinding step is performed.

According to the method of the present invention, the sterilized water hyacinth and its seeds are ground in order to finally complete the treatment of the dried water hyacinth, so that it can be used advantageously at a later and industrial level.

The grinding step is performed using a grinding device 11, i.e. a grinder 11, allowing to obtain ground material with a grain size between 1 and 3 cm. Abrasive materials of this size are required for ease of use in industry, i.e., in the field of plastic processing and insulating materials.

According to a particular embodiment, in order to optimize the grinding and obtain a material that is as dry as possible with a dry matter hydration rate of less than 20% RH or "relative humidity", the sterilized material (i.e. sterilized water hyacinth) may be through-air dried by a pressure hot air system after the sterilization step g) and before the grinding step h). This through-air drying is carried out in a pressure air dryer 12.

The pressurized hot air system allows further dehydration of the sterilized water hyacinth, i.e. by contacting it with hot air at a temperature of 50-70 ℃.

According to another particular embodiment of the invention, after the grinding step h), the obtained ground material is micronized so as to allow its profitable use in the field of plastic processing or insulating materials.

Micronization in micronizer 13 allows to obtain a particle size of the ground material of less than 1 mm.

Such abrasive materials of very small particle size are readily used with advantage.

According to another embodiment of the present invention, the ground water hyacinth material may be sieved using a sieve 14 to make its particle shape easy to use. The screen 14 rejects and may be used as fuel to supply a steam boiler, thereby allowing operation of the steam sterilizer 10.

The invention also relates to a unit for harvesting and treating the water hyacinth shown in fig. 1, comprising in this order:

a floating barge 1 near a quay, said barge 1 being equipped with means for cutting water hyacinth, means for collecting and storing 110 the cut water hyacinth and means for transferring 3 said water hyacinth to the quay, said transfer means 3 being intended to transfer said water hyacinth to a draining rack 2 intended to drain the collected water hyacinth;

means for moving the drained water hyacinth to a washing device 6 connected to an additional draining rack;

a drying device 8 at the outlet of the additional draining racks;

a concentration device 9 for concentrating the dried water hyacinth at the outlet of the drying device 8;

means for sterilizing 10 the water hyacinth concentrated at the outlet of said concentrating means 9;

means for grinding 11 the water hyacinth sterilized at the outlet of said sterilizing means 10.

According to a particular embodiment, the unit for harvesting and treating water hyacinth may also comprise a dryer 12 at the outlet of the steam sterilizer 10 for further eliminating the remaining water.

According to another particular embodiment of the invention, at the outlet of the mill 11, the ground material of the dehydrated water hyacinth is micronized in a micronizer 13, and then, optionally, the micronized ground material is sieved using a sieve 14. This particular treatment thus allows to promote its profitable industrial use, the obtained micronized and/or sieved water hyacinth "powder" being stable, inert, without risk of germination, and easy to transport.

The unit for harvesting and treating water hyacinths thus allows harvesting and treating water hyacinths by converting them into ground material that is profitable for use in industry. The obtained abrasive material has such a low hydration rate, almost zero, that the risk of germination during storage has been eliminated. Thus, the abrasive material is durable and inert and can be used in industry, for example, in the field of plastic processing or insulation board manufacture.

The method for harvesting and treating water hyacinths and the harvesting unit thereof represent an easy to implement solution for eliminating contamination of aquatic media and for eliminating water hyacinths. The method and harvesting unit of the invention also allow a quick and efficient treatment of the harvested water hyacinth, so as to be able to be used profitably on an industrial level.

Claims (9)

1. A method for harvesting and treating water hyacinth, characterized in that: is to adopt a unit for harvesting and treating water hyacinth, wherein it comprises:

a floating barge (1) near a quay, the floating barge (1) being equipped with means for cutting water hyacinth, means (110) for collecting and storing the cut water hyacinth, and transfer means (3) for transferring the water hyacinth to the quay;

-a draining rack (2) intended to drain the collected water hyacinth, said conveying means (3) being intended to convey said water hyacinth to said draining rack (2);

the washing device (6) is used for washing the drained water hyacinth; the washing device (6) is also connected with a pumping device (5);

the vibrating conveyor belt (7), the vibrating conveyor belt (7) is respectively connected with the washing device (6) and the drying device (8);

a concentration device (9) for concentrating the dried water hyacinth at the outlet of the drying device (8);

a sterilization device (10) for sterilizing the water hyacinth concentrated at the outlet of the concentration device (9);

a pressure air dryer (12) for drying the sterilized water hyacinth;

a grinding device (11) for grinding the water hyacinth dried by the pressure air;

the method performs the steps of:

a) cutting water hyacinth growing in the aquatic medium;

b) collecting water hyacinth on a floating barge (1) at the berth;

c) conveying the collected water hyacinth to a draining rack (2) near the wharf;

d) washing the drained water hyacinth with clean water;

e) draining the washed water hyacinth on a vibrating conveyor belt (7) in order to partially eliminate the excess water;

f) drying water hyacinth for 5-17 hours at the temperature of 50-100 ℃ on a drying device (8);

g) steam sterilizing at 80-100 deg.C to dry fructus Cucurbitae Moschatae and its seeds for the second time;

h) grinding the secondarily dried water hyacinth and seeds to utilize the water hyacinth and seeds.

2. Method for harvesting and treating water hyacinths according to claim 1, characterized in that: the unit further comprises a purification device (4), said purification device (4) being adapted to pass the residual water collected from the draining process of step c) through a UV sterilization treatment inside the purification device (4) in order to discharge it into the raw aquatic medium of the water hyacinth.

3. Method for harvesting and treating water hyacinths according to claim 1, characterized in that: wherein the clean water of step d) consists of water extracted from the raw aquatic medium of water hyacinths, said extracted water being pumped by said pumping device (5) and filtered through a filter screen comprising an opening diameter between 6 and 10mm to clean it for the washing step.

4. Method for harvesting and treating water hyacinths according to claim 1, characterized in that: said step d) is carried out by washing the drained water hyacinth at least twice with clean water in said washing device (6).

5. Method for harvesting and treating water hyacinths according to claim 1, characterized in that: drying the sterilized water hyacinth by means of said pressure air dryer (12) after the sterilization step g) and before the grinding step h).

6. Method for harvesting and treating water hyacinths according to claim 1, characterized in that: wherein, after the grinding step h), the obtained ground material is micronized so as to allow its profitable use in the field of plastic processing or insulating materials.

7. Method for harvesting and treating water hyacinths according to claim 1, characterized in that: wherein the drying step f) is performed using a drying device (8), the drying device (8) being in particular a stereo hot air dryer.

8. Method for harvesting and treating water hyacinths according to claim 1, characterized in that: wherein after the drying step f) and before the sterilization step g), the dried water hyacinth is concentrated in a concentration device (9).

9. Method for harvesting and treating water hyacinths according to claim 1, characterized in that: wherein, after step d) of washing the drained water hyacinth, the water hyacinth is cut into at least three lengths.