FR3025791A1 - OZONATION APPARATUS, PARTIAL OZONATION SYSTEM, AND PARTIAL OZONATION METHOD - Google Patents

Abstract

The invention relates to an ozonation apparatus (2), comprising a water supply line to be treated, an ozonated air supply, characterized in that it comprises a treatment line (7) consisting of branches forming laces, a process water / ozonated air mixing device connected to the water supply line (5) and to the ozonated air supply (9) for injecting a mixture of water to be treated / ozonated air into the treatment pipe (7) for forming in the treatment pipe (7) a cocurrent of water to be treated and ozonized air, the laces of the treatment pipe (7) being formed in an inclined vertical plane relative to the horizontal, a degassing device (11, 12) being furthermore arranged at elbows (8) of the treatment pipe (7), a residual ozonated air removal device (15) being in further connected at the outlet of the treatment pipe (7) for separating the ozonated treated water and the residual ozonized air for supplying the ozonation apparatus (2) at the outlet (6) with ozone-treated and ozone-free water. The invention also relates to a partial ozonation system and method using said apparatus.

Description

The invention relates to the field of water treatment, and relates more particularly to an ozonation apparatus, a partial ozonation system and a method for the purification of water. partial ozonation, especially for pool water. The process for ozonating swimming-pool water is known, which method consists in bringing the water to be treated into contact with an ozone-containing gas. There are usually two ways of contacting the water to be treated in an ozonation reactor, either statically in a tank, or dynamically in a flow of water to be treated. In the static case, the ozonation reactor may consist of a plurality of tanks, the ozonated gas injection being performed at the inlet of each tank. The vessel (s) may include a degassing system. In the dynamic case, ozonated gas is injected into a flow of water to be treated. In existing systems, the contact time between process water and ozonated gas is not controlled with certainty. In addition, still in existing systems, the flow of treated water is returned directly into the pool, inducing risks of ozone in the water of the pool, which is prohibited by the legislation . There is therefore a need for an ozonation apparatus that promotes control of contact time between treated water / ozonated air and a partial ozonation system involving pre-ozonation, for a more secure water treatment.

The present invention aims to solve the problems mentioned above, by proposing to carry out a partial pre-ozonation with recycling on a buffer tank. The pre-ozonation circuit consists of successive pipes which make it possible to precisely control the water contact time to be treated / ozonated air. The ozonized air is injected upstream of these pipes. The invention therefore firstly relates to an ozonation apparatus, comprising a water supply line to be treated, a supply of ozonated air, characterized in that it comprises a treatment line consisting of branches forming laces, a device for mixing water to be treated / ozonated air connected to the water supply line to be treated and to the ozonated air supply for injecting a mixture of water to be treated / ozonized air into the treatment pipe, to form into the treatment pipe a co-current of water to be treated and ozonized air, the laces of the treatment pipe being preferably formed in a vertical plane, inclined relative to the horizontal, a degassing device being furthermore disposed at elbows of the treatment pipe, a residual ozonated air removal device being further connected at the outlet of the treatment pipe for separating the treated water treated with ozone and the air oz residual ion to provide at the output of the ozonation apparatus ozone-treated water, désozonées. The treatment line in laces in a vertical plane allows a management of the water flows to be treated / ozonized air on a constant surface and a length, thus an optimal control of the time of contact between water to be treated and ozonized air. The lace treatment pipe has several branches, connected by elbows, which can be 3025791 3 U when the different branches are vertical. The branches can also be horizontal, connected by U bends when they are parallel. In what follows, the term "high elbow" denotes a bend 5 of the treatment pipe located above the horizontal median plane of the treatment pipe. In addition, the fact that the treatment duct forms laces allows a reduced overall size of the apparatus, while facilitating degassing at the high bends of the treatment duct, when the treatment duct is in a vertical plane. It should be noted that the branches of the treatment pipe could be horizontal, without departing from the scope of the present invention.

The fact that the treatment pipe forms laces finally makes it possible to have branches in which the flow of the mixture of water to be treated / ozonized air is ascending, and branches in which the flow of the mixture of water to be treated / ozonized air is downward. , which makes it possible to control the contact time as a function of the number of branches of the treatment pipe. The fact that the residual ozonated air removal device is vertical makes it possible to ensure a final degassing therein by falling water in the residual ozonated air elimination device which is at negative relative pressure, thereby creating a pressure differential with the upstream portion of the process line. The height of the waterfall in the residual ozonized air removal device is provided by a final butt which feeds the buffer tank which is at atmospheric pressure. Without departing from the scope of the present invention, it is understood that the process line may initially have a horizontal portion, especially for the mixing device. According to a particular embodiment, the branches of the treatment pipe are vertical.

The overall size of the treatment apparatus is thus reduced, and the flow of ozonized air in the treatment line to the high elbow where a degassing device is located is optimized. According to a particular embodiment, the branches of the treatment pipe are of the same diameter. The calculation of the contact time is thus precisely known, since the water flow rate is fixed. The number of branches depends on the flow rate, the diameter and the desired contact time. A degassing device is then disposed at each of the upper bends of the process line. According to a particular embodiment, the treatment line comprises one or more pairs of branches, the branches of a pair having the same length, the length of the branches of a pair increasing in the direction of the entry of the pipe. treatment to the output of the treatment line. According to a particular embodiment, the mixing device is constituted by a bypass line on the water supply line, ozonated air being injected via an ejector into the water to be treated. flowing in the bypass line, the water to be treated and ozonated being reinjected at the outlet of the bypass line 30 in the water supply line to be treated. According to a particular embodiment, the mixing device is a tubular membrane diffuser at the inlet of the treatment pipe, downstream from the connection with the water supply pipe. The tubular diffuser may for example be an ABS (acrylonitrile butadiene styrene) diffuser with an EPDM membrane (ethylene-propylene-diene monomer). This injection will ensure a transfer of the air / ozone mixture under microbulling in the treatment line. According to a particular embodiment, each degassing device disposed at bends of the treatment pipe is constituted by a stitch connected to an ozone destruction device by activated carbon. Advantageously, when the branches of the treatment pipe are vertical, the connections are connected gradually to the high elbows to the residual ozonated air removal device, the tapping of a high elbow being connected to the quilting of the adjacent high elbow. The stitching may for example be a stitching of DN 25 or DN 32 type, optionally followed by an isolation valve. According to a particular embodiment, the residual ozonized air elimination device is constituted by an ascending column at the top of which is disposed a device for venting and tapping towards an ozone destruction device. activated carbon, and a downcomer downstream of the riser in which the ozone treated process streams are vented. According to a particular embodiment, the ozonation apparatus further comprises, at the outlet of the residual ozonated air elimination device, a drop column comprising in the upper part a trap connected to the active carbon ozone destruction device. . According to one particular embodiment, the ozonation apparatus further comprises, at the outlet of the residual ozonized air elimination device, or the case 3025791 6 at the outlet of the drop column, a bypass circuit comprising a device destruction of residual ozone by UV in ozone treated waters. The invention also relates to a partial ozonation system, characterized in that it comprises: a water supply to be treated; an outlet of treated water; one or more ozonation apparatus as defined above; a buffer tank comprising three compartments, a first ozone-treated water recovery compartment, a second water-treatment receiving compartment and a third level-management compartment, the first compartment having an overflow towards the second compartment; compartment, the second compartment having an overflow to the third compartment, the water supply line to be treated discharging into the second compartment, the second compartment constituting the water supply to be treated or ozonation devices, the outlet of the ozonation device (s) flowing into the first compartment; and a filtration system, to which water from the first and third compartments is directed, the outlet of the filtration system corresponding to the treated water outlet of the partial ozonation system. The system thus allows, via the overflow compartment buffer tank, a partial preozonation of the water to be treated injected from the second compartment to the ozonation apparatus. The filtration system may include two filtration tanks. The first filtration tank comprises an inlet of ozone-treated water connected to an outlet of the first compartment, and an outlet. The second filtration tank comprises an intake of a water fraction of the third compartment and an outlet. Flows from the outlets of the first filter tank and the second filter tank are mixed before treatment with chlorine. The filtration tanks may, for example, be of the type conventionally encountered in the treatment of pool water. Thus, only a portion of the water to be treated arriving in the second compartment are sent to the ozonation apparatus, the other part overflowing into the third compartment.

The portion of the water to be treated directed to the ozonation apparatus undergoes ozonation and is directed through the first compartment of the buffer tank to the filtration system. This part of the water to be treated therefore undergoes a preozonation step before filtration. The other part of the water to be treated, going over to the third compartment, is directed to the filtration system. It follows therefore a partial preozonation of the water to be treated. The invention also relates to a partial ozonation process of pool water, characterized in that it consists in continuously taking a quantity of pool water, treating said quantity of pool water by the partial ozonation system as defined above, said quantity of pool water being injected into the water supply to be treated of said partial ozonation system, and to reinject the water obtained at the outlet of said system of partial ozonation in the pool.

The amount of pool water may advantageously be constituted by the overflow waters of the pool. The system and method according to the present invention thus allow a partial pre-ozonation of the pool water to be treated by an ozonation apparatus looping on the buffer tank. This buffer tank is designed to allow successive dilutions of water to be treated with treated water. The present invention thus allows a reduced consumption of ozone. In addition, because the ozonation treatment line comprises a succession of constant diameter branches and ozonized air degassing means, the system and method according to the present invention ensure a contact time optimally controlled between the waters to be treated and the ozonated air, and therefore an optimized ozonation. To better illustrate the object of the present invention, will be described hereinafter a particular embodiment with reference to the accompanying drawing.

In this drawing: - Figure 1 is a schematic view of a partial preozonation system according to one embodiment of the invention.

In Figure 1, it can be seen that there is shown a partial ozonation system 1 according to the present invention, applied to a S overflow system of a pool P pool.

The partial ozonation system 1 comprises an ozonation apparatus, generally designated by the reference numeral 2, a buffer tank 3 and a filtration zone 4.

The ozonation apparatus 2 comprises a water inlet inlet 5 to be treated and an outlet 6 for ozonated water to be treated. Between the inlet 5 and the outlet 6 of the ozonation apparatus 2 is disposed a treatment pipe 7, having a lace-like shape, with in the embodiment shown six vertical branches extending in the same plane vertical, interconnected by U-bends 8. Although in the embodiment shown, the treatment line 7 has six branches, one skilled in the art will understand that the ozonation apparatus 2 may have more or less than six branches, without departing from the invention. The number of branches depends on the flow of water to be treated, the diameter of the branches, and the desired contact time between the water and the ozonized air. In addition, the branches could be inclined without being vertical, without departing from the spirit of the present invention. The water to be treated is injected at the inlet 7a of the treatment pipe 7, and ozonated air is injected into the water to be treated downstream of the inlet 7a of the treatment pipe 7, by a tubular membrane diffuser 9 , in order to create in the treatment line 7 a cocurrent of water to be treated and ozonated air.

The ozonized air is created by an ozone generator 10, which may be a conventionally-encountered generator, for example an ozone generator manufactured by Kaufmann. Ozone is produced from the ambient air and is injected as an air / ozone mixture (also referred to herein as ozone air). Advantageously, the ozone concentration is 20 g for 1 Nm3 / h of mixture. The air is first dried and then treated in order to dissociate the oxygen molecules to recombine them into ozone molecules. The production line is made by negative pressure produced by three air compressors. At each upper bend 8 of the treatment pipe 5, there are tappings 11, followed by an isolation valve 12, each of said tappings 11 being connected to an ozone trap 13 via a pipe 14. The trap In the illustrated embodiment, ozone 13 is an activated carbon ozone trap, but any other ozone trap is within the scope of the present invention. The advantage of the connections 11 at the top bends 8 of the treatment pipe 7 is to allow degassing at each of the upper bends 8, to evacuate any pockets of ozonated air injected at 9. The connections 15 11 are advantageously connected step by step to the degassing column 15 described below. In the upward branches of the process line 7, the ozonized air has, in the embodiment shown, a speed of 0.60 m / s, whereas in the downward branches of the process line 7, the ozonized air has, in the embodiment shown, a speed of 0.20 m / s, the waters to be treated having meanwhile a constant speed of about 0.40 m / s. This speed control makes it possible to guarantee constant entrainment of the residual ozonized air in order to limit the formation of gaseous heads at the upper part of the branches. The water contact time to be treated / ozonized air is thus controlled. At the outlet 7b of the treatment line there is a degassing column 15, vertical, the outlet of the treatment line 7 arriving at the bottom of the degassing column 15. The degassing column 15 constitutes the elimination device of FIG. residual ozonized air. The degassing column 15 allows the separation of the injected air and the ozonated water to be treated, by venting through a quill equipped with a double-acting valve, the products from degassing being directed by a pipe 14 to the ozone trap 13 by a tapping 16. The degassing column 15 has a first upward vertical portion of greater diameter than the upstream branches of the treatment pipe 7, rising from its connection to the treatment pipe 7, and a second downward vertical portion, shorter than the first upstanding vertical portion, the tapping 16 being located on the junction between the two vertical portions of the degassing column 15. The main degassing of the air / ozone mixture is in the degassing column 15, after respect of the contact time by: venting, the dynamic pressure of the falling water favoring the release of the microbubbles at the column head ; Natural climbs of air, favored by the low speed of the water; the rain water drop from the first portion of the degassing column 15 to the second portion of the degassing column 15; A slight depression created by an aspiration at the outlet of the activated carbon trap 13. At the outlet of the degassing column 15 is provided a drop column 17, comprising an ascending branch and a descending branch, and comprising in the upper part 30 a bleeder 18 connected to the ozone trap 13 by a pipe 14. The outlet of the drop column 17 is connected to a bypass device 19, comprising a conventional pipe 20, and bypass thereon, a bypass pipe 21 having a residual ozone destructor 22, by low pressure UV. The outlet of the bypass device 19 5 corresponds to the outlet 6 of the ozonation unit 2. It should be noted that the mixture of water to be treated / ozone air could also be done before the inlet 7a of the treatment pipe, by a bypass on the supply line of the treatment pipe 7, by means of an ozone ejector, a pump then making it possible to reinject the ozonated water to be treated in the treatment pipe 7, without depart from the scope of the present invention. By way of example, the first pair of branches 15 of the treatment pipe 7, named 11, will be horizontal or vertical for a length of 7 linear meters. The second pair of branches of the treatment pipe 7, called T2, will be U-shaped for a length of 8 linear meters.

The third pair of branches of the treatment pipe 7, called T3, will be U-shaped for a length of 9 linear meters. The ascending branch of the degassing column 15, named 14, will be vertical and upward for a height of 10 linear meters. The descending branch of the degassing column 15, named 14 bis, will be vertical and downward for a height of 4.5 linear meters. The descending branch of the fall column 17, named T5, will be vertical downward for a height of 4.5 linear meters.

The ascending branch of the fall column 17, called T5 bis, will be U-shaped for a height of 7 linear meters. Table 1 below groups together the 5 characteristics of the different elements of the ozonation apparatus 2 for different water flows to be treated.

3 0 2 5 7 9 1 14 Ozonated water flow 100 m3 / h 60 m3 / h 40 m3 / h Ozone dosage 0.8 to 1.5 mg / L 0.8 to 1.5 mg / L 0.8 at 1.5 mg / L Ozone flow 80 to 150 g / h 48 to 90 g / h 32 to 60 g / h Ozone air flow 4 to 7.5 Nm3 / h 2.4 to 4.5 Nm3 / h 1.6 to 3 Nm3 / h Ozone injection Microbulling, pressure 1.5 to 2 bar Speed and 0 0.4 m / s 0.4 m / s 0.4 m / s passage +/- 10 % +/- 10% +/- 10 "Yo of water on T1, T2 and T3 0 315 0 250 0 200 Speed and 0 of 0,1 m / s 0,1 m / s 0,1 m / s passage +/- 10% +/- 10% +/- 10 "Yo of water on T4 0 630 0 500 0 400 Speed and 0 of 0.66 m / s 0.66 m / s 0.66 m / s passage +/- 10% +/- 10% +/- 10 "Yo water on T5 0 250 0 200 0 160 Drop height T4 1.50 ml 1.50 ml 1.50 ml Manometric height 12 to 15 meters 12 to 15 mce 12 to 15 mce total (HMT) available water column (mce) Pressure service 2.5 bar 2.5 bar 2.5 bar Table 1: characteristics of the ozonation device for different flow rates 5 Buffer 3 has three compartments and a first compartment 23 in which the water treated by the ozonation apparatus 2 (ozone-treated and ozone-free) discharges, the first compartment 23 23 pouring into a second compartment 24 into which the water to be treated flows, for example from a swimming pool, and from which are taken the water to be treated sent to the ozonation apparatus 2, as will be described in more detail below. The waters to be treated represent a part of the waters of the swimming pool. The second compartment 24 is in turn discharged into a third compartment 25, said third compartment 25 being intended for water level / disconnect water management, basin level management and suction to the zone. filtration 4, also described in more detail below. The structure of the buffer tank 3 allows the first compartment comprising the water treated by the ozonation unit 2 flowing into the second compartment in which the water to be treated flows from a source of water to be treated type The pool, from which the water to be treated sent to the ozonation apparatus 2 is taken, sends to the ozonation unit 2, once the system is in operation, water to be treated mixed with water treated with water. the ozonation apparatus 2, which reduces the amount of water treated by preozonation in the second compartment 24 of the buffer tank 3.

The filtration zone 4 comprises two filtration tanks. The number of filtration tanks can be adapted according to flow rates. The first filtration tank 27 comprises a water inlet connected to an outlet of the third compartment 25, and an outlet. The second filtration tank 26 comprises an inlet of a water fraction of the first compartment 23 and an outlet. The flows from the outlets of the first filtration tank 27 and the second filtration tank 26 are mixed before treatment with chlorine.

The filtration tanks 26, 27 may for example be of the type conventionally encountered in the treatment of swimming pool water. The partial pre-ozonation system according to the present invention also comprises, not shown in FIG. 1, a float flowmeter for controlling the air / ozone flow injected into the treatment pipe 7, an ozone measurement probe equipping the treatment line 7 after injection, a measurement of absence of ozone equipping the ozonation apparatus 2 output after UV treatment 21, which probe is activated regularly by a micro-injection of ozone so maintain its calibration over time, a pallet flow controller equipping the ozonation apparatus 2; if there is no flow, the production of ozone is cut off. The information from the sensors is sent to a programmable digital controller. The flow of pool water in the partial ozonation system 1 according to the present invention will now be described. Overflow water from a pool basin is fed into the second compartment 24 of the buffer tank 3 where they are mixed with water previously treated by the ozonation apparatus 2, from the first compartment 23. fraction of said mixture is brought by pouring into the third compartment 25. The fraction of water of overflow thus diluted out of the third compartment 25 by the outlet of the third compartment 25 at the bottom and is brought to the first filtration tank 27 of the zone The second fraction of said wastewater / pre-treated water mixture exits from the second compartment 24 through the outlet of the second compartment 24 at the bottom and constitutes the water to be treated which is fed to the ozonation apparatus 2. water to be treated pass either by a primary loop where ozonated air is previously injected or are injected directly to the inlet 7a of the pipe treatment 7 with ozonated air. The water to be treated is contacted with the ozonated gas at the inlet 7a of the treatment pipe 7 and the two flows flow cocurrently. Ozonated air can be evacuated at each upper bend 8. All the remaining ozonized air is degassed at the top of the degassing column 15. The stream of treated water free of ozonated air passes either through the 5 destructor d. residual ozone 22, either through the bypass circuit 20, leaves the ozonation apparatus 2 and is fed into the first compartment 23 of the buffer tank 3. The residual ozone destroyer 22 shown in FIG. UV, but it can also be an activated carbon trap. The degassing must be sufficient to extract the ozonated air, but since the pollution of the pool water is related to the number of bathers, it is possible for ozone to remain in the water at the outlet of the degassing column 15. The fraction pours overflow into the second compartment 24 where it mixes with the pool overflow waters. The second fraction exits the outlet of the first compartment 23 at the bottom and is fed to the second filtration tank 26 of the filtration zone 4. The flows leaving the first and second filtration tanks 26, 27 are combined and treated with chlorine. before reinjection into the pool. 25

Claims (3)

CLAIMS1 - Ozonation apparatus (2), comprising a water supply line to be treated, a supply of ozonated air, characterized in that it comprises a treatment line (7) consisting of branches forming laces, a process water / ozonated air mixing device connected to the water supply line (5) and to the ozonated air supply (9) for injecting a mixture of process waters and ozonized air into the process line. treatment (7), to form in the treatment pipe (7) a cocurrent of water to be treated and ozonized air, the laces of the treatment pipe (7) being preferably formed in a vertical plane, inclined relative to the horizontal, a degassing device (11, 12) being further disposed at elbows (8) of the treatment line (7), a residual ozonized air removing device (15) being further connected at the outlet of the treatment line (7) for separating the treated water and at the outlet (6) of the ozonation apparatus (2), treated with ozone and residual ozonized air, the ozonated water treated with ozone. 2 ozonation apparatus (1) according to claim 1, characterized in that the branches 25 of the treatment pipe (7) are vertical. 3 - ozonation apparatus (2) according to one of claims 1 or 2, characterized in that the branches of the treatment pipe (7) are of the same diameter. 4 - ozonation apparatus (2) according to one of claims 1 or 2, characterized in that the treatment pipe (7) comprises one or more pairs of branches, the branches of a pair having the same 3025791 19 length, the length of the branches of a pair increasing in the direction of the inlet (7a) of the treatment pipe (7) to the outlet (7b) of the treatment pipe (7). - ozonation apparatus (2) according to one of claims 1 to 4, characterized in that the mixing device is constituted by a bypass line on the water supply line, ozonated air being injected via an ejector into the water to be treated flowing in the bypass line, the ozonated treated water being reinjected at the outlet of the bypass line into the water supply line to be treated . 6 - ozonation apparatus (2) according to one of claims 1 to 4, characterized in that the mixing device is a tubular membrane diffuser inlet of the treatment pipe (7), downstream of the connection with the water supply line treat. 7 - ozonation apparatus (2) according to one of claims 1 to 6, characterized in that each degassing device (11, 12) arranged at bends (8) of the treatment pipe (7) is constituted by a quilting (11) connected to an activated carbon destruction device (13). 8 - ozonation apparatus (2) according to one of claims 1 to 7, characterized in that the device for removing residual ozonized air (15) is constituted by an ascending column at the top of which is disposed a venting device and a stitching (16) to an activated carbon ozone destruction device (13), and a downcomer downstream of the ascending column in which the treated water flows. ozone released to the atmosphere. Ozonation apparatus (2) according to claim 8, characterized in that it further comprises at the outlet of the residual ozonized air elimination device (15) a drop column (17) comprising upper portion a trap (18) connected to the activated carbon destruction device (13). - ozonation apparatus (2) according to one of claims 1 to 9, characterized in that it further comprises at the outlet of the residual ozonated air elimination device 10 (15), or where appropriate in outlet of the drop column (17), a bypass circuit (19) comprising a device for destroying residual ozone (22) by UV in ozone-treated waters. Partial ozonation system (1), characterized in that it comprises: a water supply to be treated; an outlet of treated water; one or more ozonation devices (2) according to any one of claims 1 to 10; a buffer tank (3) comprising three compartments (23, 24, 25), a first compartment (23) for the recovery of water treated with ozone, a second compartment (24) for receiving water to be treated and a third compartment (25) level management, the first compartment (23) having an overflow to the second compartment (24), the second compartment (24) having an overflow to the third compartment (25), the water supply pipe to be treated in the second compartment (24), the second compartment (24) constituting the water supply to be treated of the ozonation device (s) (2), the outlet of the ozonation device (s) (2) discharging into the first compartment (23); and a filtration system (4) to which water from the first (23) and third (24) compartments is directed, the outlet of the filtration system corresponding to the treated water outlet of the ozonation system. partial. 12 - Process for partial ozonation of pool water, characterized in that it consists in continuously taking a quantity of pool water, treating said quantity of pool water by the partial ozonation system 10 (1) according to claim 11, said quantity of pool water being injected into the water supply to be treated of said partial ozonation system (1) and reinject the water obtained at the outlet of said partial ozonation system (1) in the swimming pool. 15