MIXING DEVICE FOR THE APPLICATION OF A SURFACE-ACTING AGENT BY STEAM.

Description

DESCRIPTION in support of a patent application for an industrial invention entitled: MIXING DEVICE FOR APPLICATION OF A STEAM-ACTIVE SURFACE AGENT Owner: “HYGIENIO SRL”, with registered office in CITY OF CASTELLO (PG), Via Scipione Lapi 2-H. DEPOSITED ON............. DESCRIPTION TEXT The present invention relates to a device mixer for applying a surface-acting agent by steam, where the agent may be a disinfectant agent, phytopharmaceutical, disinfectant or similar and the device mixer can be used for cleaning, disinfection and surface disinfection. As is known, a very popular method for cleaning surfaces which, for various reasons, cannot be treated directly with water jets, is to use water steam obtained by heating water in a special boiler to the temperature of boiling. This method, thanks to heat and the solvent action of the steam, as well as thanks to its mechanical action, guarantees a cleaning of the treated surface, but not its disinfection. To solve this problem, there are known provisions mixers for mixing an agent with steam and dispensing vapor containing the agent. WO2005107966A1 describes such a device mixer comprising a single mixing chamber constant volume in which mixing is carried out between the steam and the agent. In the mixing chamber a calm zone in which countercurrent mixing occurs between the steam and the agent. The mixing chamber is arranged in a jacket filled with a heat transfer fluid heated by an electrical resistance. This mixing device described in WO2005107966A1 has some drawbacks due to the presence of the jacket, of the heat transfer fluid and of the resistance heating which increases complexity, costs and space requirements of the device. Furthermore, precisely because of the fact that in the chamber mixing creates a calm zone, this calm zone does not contributes to efficient mixing between steam and the agent. The purpose of this invention is to eliminate the drawbacks of the prior art, providing a device mixer for applying a surface-acting agent by steam, which is compact, space-saving, economical and easy to make. Another purpose is to provide such a device mixer that is efficient, effective and reliable. Yet another purpose is to provide such a mixing device that is versatile and easy to use. These objects are achieved in accordance with the invention with the characteristics of the attached independent claim 1. Advantageous embodiments of the invention appear from dependent claims. Further features of the invention will appear later. clear from the detailed description that follows, referring to one of his purely exemplary embodiment and therefore not limiting, illustrated in the attached drawings, in which: Fig. 1 is a sectional view of the mixing device according to the invention; Fig. 2 is a sectional view illustrating the exploded view of the body and injector of the mixing device of Fig. 1; Fig. 3 is an enlarged detail of the chamber mixing of the mixing device of Fig. 1; Fig. 4 is a perspective view of the device mixer according to the invention; Fig. 5 is a sectional view of the body and injector of the mixing device in which the steam is schematized with dots, the agent is outlined with crosses and the mixture is schematized with small triangles; Fig. 6 is an axial sectional view illustrating an exploded view a second embodiment of the mixer according to the invention. The device is described with the help of figures. mixer, according to the invention, indicated overall with reference number 100. For now with reference to Fig. 1, the mixing device (100) comprises a body (1), an injector (2), a system of steam supply (3), a system for supplying a steam agent (4) and a delivery system (5). Referring to Fig. 2, the body (1) has a shape substantially cylindrical with an axis (A), an upper wall (10), a lower wall (11) and a central wall (12). Inside the body (1) there are four chambers (C1, C2, C3, C4) communicating with each other and extending axially within the body (1). The four chambers include a first chamber (C1), a second chamber (C2) and a third chamber (C3) and a fourth chamber (C4). The four chambers (C1, C2, C3, C4) have different shape and axial symmetry with respect to the body axis (A) of the mixer. The first chamber (C1) has a cylindrical shape and has the heating chamber function as will be explained in followed. The second chamber (C2) has a tapered shape truncated cone, with decreasing diameter going from the first room (C1) to the third room (C3). The second room (C2) has an inlet section (13a) with a smaller diameter than to the diameter of the first chamber (C1). Referring to Fig. 3, the second chamber (C2) has a taper angle (α) which can be included in the range 50-70°, preferably 60°. The second chamber (C2) extends axially for a length (L2) less than the length (L1) of the first chamber (C1). The second chamber (C2) has an exit section (13b) which continues with a narrowing (16). The second chamber (C2) acts as a mixing chamber, where the mixing between the steam and the agent begins as it will be explained in detail. Returning to Fig. 2, the constriction (16) communicates with the third chamber (C3). The third chamber (C3) must serve as a chamber expansion in which the mixture of agent and vapor expands. third chamber (C3) comprises two portions (15a, 15b) of different geometry. The two portions of the third chamber (C3) they include a first portion (15a) and a second portion (15b). The first portion (15a) of the third chamber has a shape tapered with increasing diameter starting from the narrowing. In this case, the term tapered does not only mean the truncated cone shape but any shape with diameter gradually increasing. Preferably the first portion (15th) of the third chamber has a dome shape or spherical cap with the narrowing (16) arranged on one pole of the spherical cap. The second portion (15b) of the third chamber has a cylindrical or rounded shape to connect the first portion (15a) of the third chamber with the fourth chamber (C4). The second portion (15b) of the third chamber a diameter equal to the diameter maximum of the first portion (15a) of the third chamber. The fourth chamber (C4) must serve as a turbulence, in which thanks to a turbulent and whirling motion of the mixture, a perfect mix is ​​obtained between agent and steam. The fourth chamber (C4) has a tapered shape with decreasing diameter starting from the second portion (15b) of the third room. Referring to Fig. 3, the fourth chamber (C4) has a truncated cone shape with a taper angle (δ) included in the range 20 – 40°, preferably 30°. In the axial direction, the first chamber (C1) has a length (L1), the second chamber (C2) has a length (L2), the third chamber (C3) has a length (L3), the fourth chamber (C4) has a length (L4), the constriction (16) has a length (L5). The first portion (15a) of the third chamber has a length (L3a) and the second portion (15b) of the third room has a length (L3b). The length (L2) of the second chamber (C1) is smaller of the length (L1) of the first chamber (C1). The ratio between the length (L2) of the second chamber C2) and the length (L1) of the first chamber (C1) is between 0.3-0.6. The length (L3) of the third chamber (C3) is less than or equal to the length (L2) of the second chamber (C2). ratio between the length (L3) of the third chamber (C3) and the length (L2) of the second chamber (C2) is between 0.6 and 1. The length (L4) of the fourth chamber (C4) is greater of the length (L3) of the third chamber (C3). The ratio between the length (L4) of the fourth chamber (C4) and the length (L3) of the third chamber (C3) is between 2.4 and 3. The length (L5) of the constriction (16) is less than the length (L3) of the third chamber (C3). The ratio between the length (L5) of the constriction (16) and the length (L3) of the third chamber (C3) is between 0.14 -0.15. The length (L3b) of the second portion (15b) of the third chamber is greater than the length (L3a) of the first portion (15a) of the third chamber. The ratio between the length (L3b) of the second portion (15b) of the third chamber and the length (L3a) of the first portion (15a) of the third chamber is between 1.2 – 1.6. Returning to Fig. 2, in the upper wall (10) of the body there is an axial hole (17) communicating with the first chamber (C1). In the side wall (12) of the body there is a radial hole (18) communicating with the first room (C1). In the lower wall (11) of the body there is an exit hole (19) arranged axially and communicating with a section of exit of the third portion (15c) of the third chamber. The hole of exit (19) has a length (L6) shorter than the length (L4) of the fourth chamber. The injector (2) is designed to inject an agent, such as a disinfectant, phytopharmacological, pesticide agent, which can be in liquid form. The injector (2) has a cylindrical body (20) with a axial canal (21), cylindrical in shape, open at one end rear of the body (20). The body (20) of the injector has a tip (22) tapered shape with decreasing diameter. With Referring to Fig. 3, the tip of the injector has a conical shape, with a slightly smaller taper angle (β) than to the conicity angle (α) of the second chamber (C2). The angle of conicity (β) of the injector tip can be included in the range 40-60°, preferably 50°. Advantageously the ratio between the taper angle (α) of the second chamber (C2) and the taper angle (β) of the tip of the injector is between 1.1 – 1.3. The injector (2) comprises a plurality of outlet holes (23) communicating with the axial channel (21) of the injector and flowing into the tip (22) of the injector. The exit holes (23) of the injector are not radial, but have an inclined axis with respect to the axis of the injector by an angle (γ) less than 90°, preferably in the 40-60° range. The injector (2) has a collar (23) at the rear greater diameter than the body (20) of the injector. With reference to Fig. 1, the body (20) of the injector is inserted axially into the axial hole (17) of the body of the mixer, so that the body (20) of the injector is located in the first chamber (C1) and the tip (22) of the injector is located in the second chamber (C2). The collar (24) of the injector stops on the upper wall (10) of the mixer body and remains outside the mixer body. Although the figures show an injector having a collar (24) abutting the upper wall (10) of the mixer body outside the first chamber (C1), the injector (2) can have a collar in stop on the upper part (10) of the mixer body within the first chamber (C1) or the injector (2) can be made in a single body with the upper part (10) of the mixer body. With reference to Fig. 3, between the tip (22) of the injector and the wall of the second chamber (C2) generates a cavity (G) having an annular section around the tip (22) of the injector. Thanks to the different degree of conicity between the second chamber (C2) and the tip (22) of the injector, the gap (G) has a input section with amplitude (D1) greater than an amplitude (D2) of an outlet section. That is, the cavity (G) gradually decreases its amplitude from the section from entrance to exit section. Furthermore, it must be considered that the narrowing (16) has a diameter (D3) which is a minimum diameter. The second portion (15b) of the third chamber has a diameter (D4) very greater than the diameter (D3) of the constriction (16) and the axial exit hole (19) has a diameter (D5) smaller than the diameter (D4) of the second portion (15b) of the third chamber. The ratio between the diameter D4 of the second portion of the third chamber and the diameter D3 of the constriction is between 6-8. The ratio between the diameter D4 of the second portion of the third chamber and the diameter D5 of the axial exit hole is included between 3.5 - 5.5. With reference to Figs. 1 and 4, the system of steam supply (3) includes a boiler or boiler (30) contain water that is heated to generate steam (V) at a temperature of about 130 – 158 °C. A duct (31) connect the boiler (30) to the radial hole (18) of the body of the mixer, so that the steam (V) can enter the first chamber (C1) and surround the body (20) of the injector so as to heat the injector (2). In the duct (31) of the system steam supply is provided with a solenoid valve (32) and a flow regulator (33). As an example, the flow rate of the steam (V) can be set so that the system steam power (3) steam power with a pressure between 2.5 and 6 bar. The agent power system (4) comprises a tank (40) containing an agent (D). The tank (40) it is connected, by means of a duct (41), to the axial channel (21) of the injector. In the duct (41) of the fuel system agent (4) is arranged a pump (42) and a solenoid valve (43) The pump (42) is a peristaltic pump configured for self-regulate according to the pressure required for injection of the agent. For example, during operation, the pump (42) works at a pressure of 1-2 bar. The delivery system (5) comprises a lance dispensing (50) equipped with a dispensing nozzle (51) suitable for dispense the mixture of steam and agent. The dispensing nozzle (51) has a diameter of 1.2 – 2 mm. A button (52) is provided in the dispensing lance (50) user-operated for dispensing the steam mixture and agent. The dispensing lance (50) is connected to the axial hole of outlet (19) of the mixer body, by means of a pipe dispensing (53). A solenoid valve (54) is arranged in the hole axial outlet (19) or downstream of the mixer, in order to deposit the liquid that is being mixed as much as possible outside the mixer condensation when the supply is interrupted. The delivery tube (53) has been properly sized both to limit pressure drops and, above all, to allow heat exchange between steam and agent in how much the steam gives up a part of its temperature to the agent. In case in which the boiler is configured to have a flow rate of steam with a pressure of 2.5-6 bar, the delivery tube (53) It has a length of 2-3 m and an internal diameter of 5-8 mm. With particular reference to Figs. 1 and 5, it is described the operation of the mixing device (100). In an initial configuration, the solenoid valves (32, 43, 54) are all closed and the rooms (C1, C2, C3, C4) are empty. Initially the solenoid valve (32) of the system is opened of steam supply. Therefore the steam (V) (schematized in Fig. 5 with dots) enters the first chamber (C1) and surrounds the body (20) of the injector. Steam (V) is at a temperature of 130-158 °C, In this way the body (20) of the injector heats up by exchange thermal with the steam contained in the first chamber (C1). To this end purpose the body (20) of the injector is made of conductive metal heat, such as steel. A heating time of about 50-70 seconds, to heat the body (20) of the injector to a temperature of 130-158 °C equal to that of steam. Once the heating time has elapsed, the peristaltic pump (42) and open the solenoid valve (43) of the system of agent power, in this way the agent (D) (schematized in Fig. 5 with crosses) is fed into the axial channel (21) of the injector in which it heats up by exchange thermal with the body (20) of the injector. The agent (D), which has heated up in the injector body, comes out of the outlet holes (23) of the injector and starts mixing with the steam (V) in the gap (G) between the tip (22) of the injector and the second chamber (C2), forming a mixture (M) (schematized in Fig. 5 with small triangles). The fact that the agent (D) has been heated in the injector (2) avoids a shock thermal between the agent (D) and the steam (V) and limits above all the condensation formation. It must be considered that the steam (V) in the first chamber (C1) is at minimum speed and maximum pressure given that the first chamber (C1) is the chamber with the largest diameter and higher volume. When the steam (V) enters the cavity (G) the steam begins to increase in speed and decrease in pressure since the cavity (G) has a much smaller volume compared to the first chamber (C1). The mixing of the agent (D) with the steam (V) takes place in the cavity (G) where the steam mixture (M) is generated (V) and agent (D). The section of the cavity (G) gradually goes decreasing until the narrowing (16) which behaves like the neck of a mixing funnel (M). Therefore the mixture (M) in the constriction (16) has the maximum speed and minimum pressure. Once the constriction (16) has been passed, the mixture (M) expands sharply in the first portion (15a) and in the second portion (15b) of the third chamber, in which the mixture (M) has the minimum speed and maximum pressure. In fact, the diameter D4 of the second portion (15b) of the third chamber is very greater than the diameter (D3) of the constriction (16). Subsequently the mixture (M) flows into the fourth chamber (C4) in which the mixture (M) undergoes a movement turbulent and swirling indicated by the arrows (F). This vortical motion of the mixture (M) contributes to a perfect mixing of the steam (V) and the agent (D). During the flow of the mixture into the fourth chamber (C4), the the mixture pressure gradually decreases and the speed of the mixture gradually increases. Finally the mixture (M) reaches the axial outlet hole (19) with minimum pressure and maximum speed. In fact, the diameter D5 of the axial exit hole is much smaller than the diameter D4 of the second portion (15b) of the third chamber. It should be noted that there are many differences in the mixing device (100) compared to the known one described in WO2005107966A1. In fact the mixing device (100) does not require any heating jacket with heat transfer fluid heated by a resistance. In the mixing device (100) the mixing does not It happens more countercurrently in a calm room, but it happens in the second chamber (C2), in the third chamber (C3) and in the fourth room (C4) which are rooms having different sections and therefore dynamic chambers as the steam (V) and the agent (D) are subjected to new specific dynamics originating from variations continuous pressure, velocity and temperature in a flow one-way. The injector (2) is located inside the body (1) of the mixer, so that preheating is produced in the injector (2) of the agent (D) to limit its thermal stress when it goes to contact with steam (V). The dimensions of the rooms (C1, C2, C3 and C4) and the the material of the body (1) of the mixer are such as to maintain a stability of the operating temperature within the body (1) of the mixer in order to avoid internal condensation phenomena of the mixture. To further reduce the problem of condensation the body (1) of the mixer instead of steel can be made of polymer. The mixture (M) of two-phase type vapor (V) and agent (D) It is produced through a new physical process that allows a more homogeneous mixing through both a pre- heating of the agent (D) in the injector (2) which through a play of variations in pressure and velocity of fluids within the mixer body chambers. Mixing takes place in two phases: In the first mixing phase the steam (V) is conveyed into the cavity (G) where it is significantly reduced the steam passage section, significantly increases its speed and its pressure is reduced. Along this path of the steam (V) into the gap (G), the agent (D) is injected in the steam (V), through the small exit holes (23) of the injector. In this low pressure phase the first injection takes place mixing the steam with the agent. In the second mixing phase the mixture (M) of steam and agent is introduced into the first portion (15a) and in the second portion (15b) of the third chamber in which it undergoes an expansion. Exactly the opposite of what happens in the cavity (G) of the second chamber, when the mixture (M) is found in the first portion (15a) and in the second portion (15b) of the third chamber, the mixture (M) reaches a notable reduction in speed and a significant increase in pressure. These factors lead to further atomization / splitting of the particles of agent (D) which allows a perfect mixing the agent (D) with the steam (V). The two-phase mixture (M) is then directed to the fourth chamber (C4), which has a truncated cone shape with a diameter decrease towards the axial exit hole (19) located in the part mixer terminal. In this way, pressure values ​​and speed of the mixture (M) directed to the delivery tube (53) tend to be substantially equal to the pressure values ​​and velocity of the steam (V) that was fed into the body (1) of the mixer. The mixture (M) comes out of the nozzle (51) of the lance delivery (5) at a temperature of 90 °C and then arriving at approximately 25-40°C at the maximum application distance. This application temperature of the mixture causes a decrease in surface tension of the agent (D) contained in the mixture (A), allowing the agent (A) to penetrate deeply into surfaces of any shape or material, enhancing its microbicidal efficacy. This condition allows to reduce the use of excessive quantities of agent (D), especially in the case where the agent (D) is a chemical product harmful to the environment. When the mixture (M) is dispensed from the dispensing lance (50) comes into contact with a surface of a product treat, a condensation effect is created on the two-phase mixture hot in contact with the surface of the product to be treated which is at a lower temperature than the temperature of the mixture. This condensation effect produces an effective continuous and homogeneous decontaminating film that guarantees a continuous disinfection treatment, that is, without leaving undisinfected microspaces. The mixture (M) comes out of the dispensing lance (50) with a high kinetic energy that allows the mixture to reaches all surfaces to be treated and even inaccessible areas or difficult to reach places that, if not decontaminated, represent a potential microbial reservoir and limit the effectiveness of the disinfection treatment. Fig. 6 illustrates a second embodiment of the mixer, in which elements are equal or corresponding to those already present described are indicated with the same reference numbers. In this second embodiment, the part upper (10) of the mixer body is separated from the body (1) of the mixer and the nozzle (2) has a collar (24) which is fixed at the top (10) within the first chamber (C1). The first chamber (C1), the second chamber (C2) and the first portion (15a) of the third chamber are made in a body intermediate (1a). The second portion (15b) of the third chamber and the fourth chamber (C4) is made in a lower body (1b) which is fixed to the intermediate body (1a). In this embodiment, the taper angles (α, β, δ) of the second chamber (C2) of the tip (22) of the nozzle and of the fourth chamber (C4) are included in the range 50-70°, preferably 60° and are equal to each other. Furthermore the fourth room (C4) has a length shorter than the length of the fourth chamber of the first embodiment. In the present embodiment of the invention, equivalent changes and modifications may be made to the within the reach of a technician in the field, which in any case fall within the scope of the invention as expressed in the appended claims. THE AGENCY ENGINEER CLAUDIO BALDI SRL (ENG. GIANLUIGI CUTROPIA)

Claims

1. Mixing device (100) comprising: - a body (1), - a steam supply system (3) connected to the body for supplying steam (V) into the body, - an injector (2) mounted in the body (1), - an agent supply system (4) connected to the injector (2) for supplying an agent (D) into the injector, and - a delivery system (5) connected to the body (1) for supplying a mixture (M) of steam (V) and agent (D), characterised in that within said body (1) of the mixing device there are a first chamber (C1), a second chamber (C2), a third chamber (C3) and a fourth chamber (C4) communicating with each other and arranged axially; wherein said steam supply system (3) is configured to supply steam (V) into the first chamber (C1) and said injector has a body (20) arranged in the first chamber (C1) to be heated by the steam;wherein said injector (2) is configured to inject the agent (D) into the second chamber (C2) where it mixes with the steam (V) to obtain said mixture (M) which flows into the third chamber (C3) and into the fourth chamber (C4) to exit from an outlet hole (19) towards said delivery system (5); wherein the second chamber (C2) is tapered with decreasing dimensions going towards the third chamber (C3), the third chamber (C3) has increasing dimensions going towards the fourth chamber (C4) so ​​as to act as an expansion chamber, and the fourth chamber (C4) is tapered with decreasing dimensions going towards the outlet hole (19) to act as a turbulence chamber in which the mixture performs a vortical motion.; 2. Mixing device (100) according to claim 1, wherein said injector (2) has a conical tip (22) arranged in said second chamber (C2) so as to generate an interspace (G) having an annular section, between the tip of the injector and the second chamber and a plurality of outlet holes (23) communicating with an axial channel (21) of the injector and flowing into the tip (22) of the injector.

3. Mixing device (100) according to claim 2, wherein the second chamber (C2) has a conicity angle (α) and the injector (2) has a conicity angle (β) smaller than the conicity angle (α) of the second chamber (C2) so that said gap (G) between the tip of the injector and the second chamber has the gap (G) has an inlet section with width (D1) greater than an width (D2) of an outlet section.

4. Mixing device (100) according to claim 3, wherein the second chamber (C2) has a conicity angle (a) in the range 50-70° and the tip (22) Ing. CLAUDIO BALDI Srl - Viale Cavallotti 13 - Jesi (An) of the injector has a conicity angle (P) in the range 40-60°.

5. Mixing device (100) according to any of the preceding claims, wherein between the second chamber (C2) and the third chamber (C3) there is a constriction (16).

6. Mixing device (100) according to claim 5, wherein the third chamber (C3) has a first portion (15a) having a dome or spherical cap shape with the constriction (16) arranged on one pole of the spherical cap.

7. Mixing device (100) according to claim 6, wherein the third chamber (C3) has a second portion (15b) having a cylindrical or rounded shape.

8. Mixing device (100) according to any of the preceding claims, wherein the fourth chamber (C4) has a truncated cone shape with a taper angle (δ) in the range 20 - 40°, preferably 30°.

9. Mixing device (100) according to any of the preceding claims, wherein the second chamber (C2) has a length (L2) less than the length (L1) of the first chamber; the third chamber (C3) has a length less than or equal to the length (L2) of the second chamber, and the fourth chamber (C4) has a length (L4) greater than the length of the third chamber (C3).