ITUB20154865A1 - MOBILE SYSTEM FOR REMOVAL AND TREATMENT OF RESIDUE FROM TANKS OF PURIFICATION AND SIMILAR SYSTEMS - Google Patents

Description

MOBILE PLANT FOR THE REMOVAL AND TREATMENT OF RESIDUES FROM TANKS OF PURIFICATION PLANTS AND SIMILAR

The present invention relates to the cleaning of tanks containing solid, muddy and / or liquid residues with the presence of sand and / or other materials that can be recovered, and in particular a mobile plant suitable for carrying out on-site removal and treatment and / or the recovery of the removed residues. Such a plant is useful in cleaning the tanks of civil and / or industrial waste water purifiers, such as sand traps, oxidation-nitrification and denitrification tanks and tanks for regulating the flow of waste water sent for purification, but also for cleaning of the rain collection tanks of industrial plants, of various types of sedimentation basins and other similar types of tanks.

It is known that the cleaning of the aforesaid tanks is currently carried out by removing the residues from the tanks, loading the residues on means of transport and transferring them to authorized treatment centers, or directly to a controlled landfill in the case of residues that do not require any treatment. Removal can be accomplished by Γ using wheel loaders and excavators when the residues are solid enough, or by suction or pumping for muddy or liquid residues or added with water to make them liquid enough to be vacuumed or pumped if you cannot proceed, for various reasons, to removal by wheel loader and excavator.

In any case, the current state of the art presents serious environmental drawbacks since in the transport of large quantities of residues, which in effect are special waste, there is always the risk of various types of accidents with dispersion or spillage of residues. along the route and in the surrounding areas, with soil pollution and the need for subsequent reclamation. Furthermore, the various types of transported residues almost always contain a substantial organic fraction that is a source of unpleasant odors, with consequent dispersion of odors along the transport path.

In addition, there are also drawbacks of an economic nature, since together with the recoverable materials, non-recoverable materials (waste) and water are also transported, in particular if the residues have been fluidized for their removal. By way of example, in most cases the non-recoverable part represents over Γ80% of all the residue, reaching up to 95% and more for liquid and / or liquid waste for the reasons explained above. Therefore, transport costs significantly affect the entire cleaning operation of the tanks, especially with the increase in the distance between the location of the tanks to be cleaned and the authorized treatment and recovery center.

To this higher cost for transport must be added the higher cost of treatment and recovery at duly authorized centers, in which obviously a rate proportional to the quantity of residues treated is applied. The cost of this treatment is also significant as these centers are built indoors in large industrial warehouses and have a permanent staff organization which further affects costs.

Finally, it should be noted that even if the residues are sent directly to a controlled landfill, at a lower unit cost, this implies an additional cost since the residues often contain recoverable materials which are thus lost.

The aim of the present invention is therefore to provide a mobile system for cleaning the tanks which exceeds the limits of the known art. Said object is achieved by means of a mobile plant comprising at least one group for removing residues from the tank and a group for separating the residues removed directly connected to said removal group, as well as possibly a chemical-physical treatment group connected directly to said separation group. if the tank is not part of a purification plant.

The main advantage of the mobile plant according to the present invention is therefore that of operating on site the separation and eventual treatment of residues in order to avoid the transport of large quantities of residues, with a considerable reduction in pollution risks and great cost savings. cleaning.

A second significant advantage of this mobile system lies in its ability to perform the functions listed above using machines and devices that are quick and easy to install, which are of the traditional type and therefore have a low cost and are easily repairable or replaceable in case of failure.

Further advantages and characteristics of the mobile plant according to the present invention will be evident to those skilled in the art from the following detailed and non-limiting description of some of its embodiments with reference to the attached drawings in which:

Fig. 1 is a schematic view of a first embodiment of a system for cleaning a tank accessible with a wheel shovel and containing solid residues or in the state of paired sludge, the tank forming part of a purification plant;

Fig. 2 is a schematic view of a second embodiment of a plant for cleaning a tank accessible with a wheel shovel and containing solid residues or in the state of paiable sludge, said plant also comprising a chemical-physical treatment unit with recirculation of purified water;

Fig, 3 is a schematic view of a third embodiment of a plant for cleaning a tank not accessible with a wheel shovel and containing residues that can be vacuumed or made vacuum, the tank being part of a purification plant;

Fig.4 is a schematic view of a fourth embodiment of a system for cleaning a tank not accessible with a wheel shovel and containing residues that can be sucked up or made suckable, said system also including a chemical-physical treatment unit with recirculation of the purified water;

Fig.5 is a schematic view of a variant of the removal assembly of the third or fourth embodiment of the system in the case of a tank containing residues that can be pumped or made pumpable; And

Fig, 6 is a schematic view of a variant of the separation unit applicable to any of the previous embodiments.

With reference to the aforementioned figures, it can be seen that a mobile plant according to the present invention comprises at least one RIM group for the removal of residues from a tank V and a SEP group for the separation of the removed residues, connected to said RIM removal group as described in detail later.

The first embodiment of the plant illustrated in Fig. liquid fraction is completed by natural evaporation. In this case, the RIM removal group consists of a PG wheel loader, lowered with a crane or introduced in another way inside the tank V, which conveys the solid or in any case paired residues in a limited area of the tank where the residues are taken by an ES excavator. The latter acts as a connection with the SEP separation group by loading the residues into a TC loading hopper equipped with an NE extractor belt with adjustable speed, which regulates the flow rate of the residues feeding to the rest of the SEP group which provides for separation and recovery of any recyclable materials.

More specifically, the NE extractor belt feeds the residues to a mixing tank VM through a small feed hopper into which the residues to be treated and dilution water pumped by an ID purification plant are made to flow in an adequate ratio. tank V starts. Depending on the pulping needs of solid residues or in any case that can be coupled, the feeding hopper of the VM tank can be of various types:

- a TU hopper equipped with a series of high pressure dissolving nozzles fed with dilution water from the ID purification plant;

- a TFZ hopper equipped with toothed roller clod breakers suitable for crushing residues into clods;

- a CAT hopper equipped with a friction cell capable of removing any contaminants adhering to the sandy particles from the recoverable sand by vigorous stirring with special agitators.

From the feed hopper, the mixture of water and residues, in a water / residue ratio of approximately 10: 1, flows into the mixing tank VM which can possibly be equipped with a stirrer to facilitate mixing. In this way, a water / residue mixture is obtained, suitable for being treated by means of a cyclone C, to which said mixture is fed by means of a pump PC placed on the outlet duct of the mixing tank VM.

Cyclone C, due to the effect of the centrifugal force which acts differently on the particles depending on the size and density, separates the sand from the mud made up of water, silts and organic particles. The slurry is sent back to the ID purification plant, where it undergoes the entire purification cycle, flowing into the urban / industrial wastewater arriving from the sewers.

The sand that comes out of the lower nozzle of cyclone C, with still a water content of around 20 ÷ 30%, reaches a VS vibratory dryer in which it is dried up to a humidity of 7 ÷ 10%. The drainage water from the VS vibratory dryer falls into the VM mixing tank below, while the sand is conveyed to an NSS conveyor belt which discharges it into a CS sand collection box,

Generally, this sand may still contain organic particles of such dimensions that it is not possible to separate them with cyclone C, therefore, as it is not yet reusable as a raw material, it is transported to an authorized treatment and recovery plant for final cleaning. However, it should be noted that this transport concerns a material that not only constitutes a minor fraction of the residues removed from the tank V but is also a reusable material, which has a reduced humidity and a limited content of organic particles, for which the problems of an environmental and economic costs of such transportation are minimized.

The second embodiment of the plant illustrated in Fig. 2 applies to the cleaning of a tank V of an industrial plant or the like which is not equipped with its own purification plant, or in any case with a purification plant of adequate capacity to treat the flow rate of the slurry. coming from the separation process. Therefore, the plant, in addition to including the RIM and SEP groups (identical to those of Fig. 1), also includes a third TCF group for the chemical-physical treatment of the slurry, also easily transportable and quickly installed, connected to the separation group SEP.

More specifically, the slurry coming from cyclone C is received in the chemical-physical treatment group TCF by an RCF chemical-physical reactor in which RG tanks feed suitable reagents that allow the purification of the slurry. The RCF reactor is of the type used in waste recycling plants from street sweeping such as the one described in EP 1775267, and the slurry treated with the reagents is pumped from the RCF reactor to an FL flocculator which allows coagulation and flocculation, if necessary. with the addition of further reagents fed from the RG tanks, organic particles, silts and colloids, so as to make them separable with sedimentation in a subsequent SD sedimenter where the flocculated particles are separated from the water.

The flocculated particles that settle on the bottom of the settler are sent for mechanical dehydration, possibly after adding a polyelectrolyte PE, by means of a CG centrifuge or equivalent device such as a plate or belt filter press, and the resulting sludge is discharged into a collection tank of CF sludge to be sent for disposal in a controlled landfill. The water that comes out of the weir edge of the SD sedimenter and the water from the CG centrifuge flow into an AC storage tank, and from here are recirculated into the feed hopper of the VM mixing tank.

Since part of the water is eliminated together with the sludge and the recovered materials, a pipeline is preferably provided that feeds the AR make-up water, coming from the water mains or from an industrial well, to the AC accumulation tank when, as the water level below a predetermined threshold, an LC level regulator commands the opening and closing of an EV solenoid valve.

The third form of the plant illustrated in Fig. 3 is similar to the first form of construction, as it does not include the chemical-physical treatment group TCF, but is applied to the cleaning of a tank V not accessible with the wheel loader for for any reason, for example due to the presence of a fixed cover or because devices for sand removal or aerators AE are installed on the bottom of the tank V for the aeration of the oxidation-nitrification tanks of the purification plants.

In this case, if the slurry is not aspirable, it is added with water coming from the ID purification system to make it aspirable with an AS aspirator which sucks the sludge and conveys it into a CR tipper body, which acts as a connection between the RIM removal group. 'and the separation group SEP' which form regret. In fact, the sludge is discharged from the tipper body CR into an accumulation tank CA, upstream of a grate GR which serves to retain any non-pumpable coarse materials. In the CA storage tank, the sludge is mixed with an adequate amount of water from the ID purification system so as to make it pumpable by means of a P pump capable of pumping sandy-silty water up to the feed hopper of the VM mixing tank.

Also the CA storage tank, like the AC storage tank in Fig.2, is equipped with an LC level regulator that controls the opening and closing of a solenoid valve to maintain an adequate level of water in the CA storage tank. The rest of the separation group SEP 'is practically the same as the separation group SEP of the first two embodiments, with the only difference that the TFZ feeding hopper is not provided since the residues arrive at the mixing tank VM through the pump P (the CAT hopper with friction cell is instead provided even if it is not shown in Fig. 3).

The fourth embodiment illustrated in Fig, 4 is similar to the second embodiment, as it includes the chemical-physical treatment group TCF, but is applied to the cleaning of a tank V, not accessible with the wheel loader, of an industrial plant. or similar which is not equipped with its own purification plant, or in any case with a purification plant of adequate capacity to treat the flow rate of the slurry coming from the separation process. Therefore the system includes the RIM 'and SEP' groups, identical to those of Fig.3, and also the TCF group identical to that of Fig.2.

A possible variant of the third and fourth embodiment is constituted by the removal group RIM "illustrated in Fig. 5, which replaces the group RIM 'in the case in which the sludge in the tank V is pumpable or made pumpable, so as to be pumped directly to the CA storage tank by means of a PD dredging pump for muddy-sandy waters which is hung on an ES excavator and driven by the hydraulic motor of the excavator itself. In this case it is the PD dredging pump that acts as a connection between the RIM "removal group and the SEP 'separation group, similarly to the function performed by the ES excavator in the first two embodiments and by the CR tipper body in the third and fourth form. realization.

Finally, a variant of the SEP / SEP 'separation group is illustrated in Fig. 6, this variant therefore being applicable to any of the previous embodiments. In this case, the sand that comes out of the lower nozzle of cyclone C does not directly reach the vibratory dryer VS but is loaded into a spiral separator SP which is able to very effectively separate the organic particles from the sand, obtaining three outflows:

- a flow of sand that follows the same path described above, that is, it reaches the vibratory dryer VS (where the drainage water falls into the mixing tank VM) and is then conveyed to the NSS conveyor belt which discharges it into the CS collection bin, from which it can be sent directly for reuse without sending it to a treatment center if it has been sufficiently cleaned in the SP separator;

- a flow of organic particles, containing about 80% of water, which follow a similar path reaching a second vibratory dryer VO which reduces the water content to about 60% (the drainage water falls back into the mixing tank VM) , and are then conveyed to a second conveyor belt NSO which discharges them into a corresponding collection box for the organic particles CO, and from there they are then sent to a controlled landfill or a composting plant;

- a third flow, containing a mixture of organic particles and fine sand, which returns to the mixing tank VM for recirculation towards cyclone C and separator SP by means of the PC pump, in order to repeat the process of separating the sand from the particles organic.

For summarizing purposes, the following is a list of the elements mentioned above that make up the various embodiments of the plant according to the present invention, it being clear that each form made will include only a part of the elements listed:

Ref. Description

AE aerators

AC storage tank for purified water

AR make-up water

AS aspirator

C cyclone

CA tank for the accumulation of residues to be treated

CAT hopper with friction cell

CF mud collection box

CG centrifuge

CO tank for collecting organic particles

CR tipper body

CS sand collection box

ES excavator

EV solenoid valve

FL flocculator

GR grill

1D existing purification plant

LC level regulator

NE extractor belt

NSS sand conveyor belt

NSO conveyor belt of organic particles

P pump for sandy-silty waters

PC cyclone pump

PD dredging pump

PE polyelectrolyte

PG wheel loader

RCF chemical-physical reactor

RG reagent reservoirs

SD settler

SP spiral separator

TC loading hopper

TFZ hopper with clod breaker

TU hopper with nozzles

V tub

VO vibro dryer for organic particles

VM mixing tank

VS sand vibro dryer

It is clear that the above-described and illustrated embodiments of the mobile plant according to the invention are only examples susceptible to numerous variations. In particular, the individual elements belonging to the RIM / RIM 7RIM ", SEP / SEP 'and TCF groups can be replaced with other technically equivalent elements or vary according to the quantity and nature of the residues to be removed and treated.

Claims (10)

CLAIMS 1. Mobile plant for the removal and treatment of residues from tanks (V) of purification plants and the like, characterized by the fact of comprising at least one removal unit (RIM; REM '; RIM ") able to perform the removal of said residues from said tanks (V) and a separation group (SEP; SEP ') suitable for carrying out the separation of the removed residues, said removal group (RIM; RIM'; RIM ") being directly connected to said separation group (SEP ; SEP '). 2. Mobile plant according to claim 1, characterized in that it further comprises a chemical-physical treatment group (TCF) suitable for carrying out the chemical-physical treatment of a slurry coming from the separation group (SEP; SEP '), said group chemical-physical treatment (TCF) being connected directly to said separation group (SEP; SEP '). 3. Mobile plant according to claim 1 or 2, characterized in that the removal assembly (RIM) comprises a wheel loader (PG) and an excavator (ES). 4. Mobile system according to claim 1 or 2, characterized by the fact that the removal unit (REM ') includes an aspirator (AS) and a tipping body (CR). 5. Mobile plant according to claim 1 or 2, characterized in that the removal unit (RIM ") comprises a dredging pump (PD) and an excavator (ES). 6. Mobile plant according to claim 3, characterized in that the separation unit (SEP) comprises: a) a loading hopper (TC) arranged to receive the residues from the removal group (RIM), b) a mixing tank (VM) equipped with a feeding hopper, c) an extractor belt with adjustable speed (NE) arranged to receive the residues from said loading hopper (TC) and feed them to said mixing tank (VM) through said feeding hopper, d) a pump (PC) placed on an outlet pipe of the mixing tank (VM) and suitable for pumping a water / residue mixture, e) a cyclone (C) arranged to receive said water / residue mixture fed by said pump (PC), f) a vibro dryer (VS) arranged to receive sand coming out of said cyclone (C), said vibro dryer (VS) being positioned to make the drainage water produced therein fall back into the mixing tank (VM), g) a conveyor belt (NSS) arranged to receive the sand exiting the vibratory dryer (VS), and h) a sand collection box (CS) arranged to receive the sand discharged from said conveyor belt (NSS). 7. Mobile plant according to claim 4 or 5, characterized by the fact that the separation group (SEP ') includes: a) an accumulation tank (CA) arranged to receive the residues from the removal group (RIM '), said accumulation tank (CA) being equipped with a grid (GR) suitable for retaining non-pumpable materials and located downstream of the position receiving residues, and being equipped with a level regulator (LC) able to control a solenoid valve that regulates the flow of water into the storage tank (CA), b) a mixing tank (VM) equipped with a feeding hopper, c) a first pump (P) capable of pumping sandy-silty waters from the storage tank (CA), in a position downstream of said grid (GR), to said mixing tank (VM) through said feed hopper , d) a second pump (PC) placed on an outlet duct of said mixing tank (VM) and suitable for pumping a water / residue mixture, e) a cyclone (C) arranged to receive said water / residue mixture fed by said second pump (PC), f) a vibro dryer (VS) arranged to receive sand coming out of said cyclone (C), said vibro dryer (VS) being positioned to make the drainage water produced therein fall back into the mixing tank (VM), g) a conveyor belt (NSS) arranged to receive the sand exiting the vibratory dryer (VS), and h) a sand collection box (CS) arranged to receive the sand discharged from said conveyor belt (NSS), 8. Mobile plant according to claim 6 or 7, characterized in that the feeding hopper of the mixing tank (VM) can be equipped with high pressure dissolving nozzles (TU) and / or clod breakers with toothed rollers (TFZ) and / or an attrition cell (CAT). Mobile plant according to one of claims 2 to 8, characterized in that the chemical-physical treatment group (TCF) comprises: a) a chemical-physical reactor (RCF) arranged to receive the slurry coming from the separation group (SEP; SEP '), b) a flocculator (FL) arranged to receive the slurry treated in said chemical-physical reactor (RCF), c) tanks (RG) arranged to feed the chemical-physical reactor (RCF) and said flocculator (FL) with reagents designed to purify the slurry, d) a settler (SD) arranged to receive the slurry treated in the flocculator (FL), e) a centrifuge (CG) arranged to receive flocculated particles deposited on the bottom of said settler (SD), f) a sludge collection box (CF) arranged to receive sludge exiting said centrifuge (CG), and g) an accumulation tank (AC) arranged to receive water coming from the settler (SD) and from the centrifuge (CG). 10. Mobile system according to claim 9, characterized in that the storage tank (AC) is equipped with a level regulator (LC) adapted to control a solenoid valve (EV) which controls the inflow of make-up water (AR). The mobile plant according to one of claims 6 to 10, characterized in that the separation unit (SEP; SEP ') also includes: a) a spiral separator (SP) arranged to receive sand leaving the cyclone (C) and able to generate three flows at the outlet: a flow of organic particles, a flow containing a mixture of organic particles and fine sand that returns to the tank mixing tank (VM) and a flow of sand that reaches the vibratory dryer (VS) and is then conveyed to the conveyor belt (NSS) which discharges it into the sand collection box (CS), b) a second vibratory dryer (VO) arranged for to receive said flow of organic particles and to make the drainage water produced therein fall back into the mixing tank (VM), c) a second conveyor belt (NSO) arranged to receive the organic particles leaving said second vibratory dryer (VO), and d) a container for collecting the organic particles (CO) arranged to receive the organic particles discharged from said second conveyor belt (NSO).