RU2222421C1 - Aeroabrasive mixer of apparatus for abrasive-jet treatment of surface - Google Patents

Abstract

FIELD: abrasive-jet treatment, possibly for cleaning surfaces and for imparting to them predetermined roughness degree before applying protective coatings. SUBSTANCE: mixer includes vessel for abrasive, metering device having rod of gate valve and seat with axial duct communicated with ejection type mixer. The last may be freely rotated relative to outlet branch pipe of vessel for abrasive; seat may be moved in axial direction for controlling its position relative to that of said rod having through duct along its whole length for blowing metering device. Rod of gate valve is mounted with possibility of separate rotation and axial reciprocation motion. Unit for loosening abrasive is in the form of ribs on outer portion of rod outside zone of its engagement with seat. EFFECT: improved design, enhanced operational characteristics and stability of mixer, simplified process of controlling parameters of treatment independently upon condition of abrasive media. 5 cl, 5 dwg

Description

 The invention relates to means for abrasive-jet surface treatment of products and structures and can be used in industry, construction, in everyday life for processing and cleaning surfaces from various types of contaminants, in particular, before applying protective coatings.

 From the technology of jet-abrasive surface treatment, the use of two modes is known: processing using a cold abrasive-air jet and thermal abrasive treatment. In the first case, an abrasive flow is formed by means of a high-speed jet of compressed air coming directly from a compressor or other source, and the kinetic energy of the abrasive particles is the main factor in this treatment (see, for example, SU 0221534, Pichko, 08/01/1968; SU 1703425 A1 Marchuk et al. 01/07/1992). In the second case, the device contains means for generating a high-temperature gas jet and mixing with the flow of abrasive medium. Two energy factors act on the surface to be treated - thermal energy and kinetic energy of the abrasive, while thermal energy can be in the form of a hot gas stream (see, for example, SU 0344977, VPTILP, 07.14.1972; WO 01/81044 A1, Danilov, etc. ., November 1, 2001) or jets of flame (see, for example, US 5607342, Evdokimenko et al., March 4, 1997).

 The common components of devices for abrasive-jet surface treatment, regardless of the temperature nature of the impact, are nozzle tools connected by a hose through an abrasive and carrier gas mixer, respectively, to the abrasive tank, and a receiver connected to a source of compressed gas. Overpressure is also created in the abrasive tank, for which it is also connected to a source of compressed gas for the purpose of stimulating the consumption of abrasive material (see, for example, US 5460025, Champaigne, 10.24.1995).

 A number of inventions are known regarding the means for preparing an aeroabrasive mixture before feeding it into a nozzle tool. For dosing, an aeration unit with a porous diaphragm for fluidizing the abrasive is described in the tank bottom (see, for example, US 5433653, Friess, 06/18/1995). In another invention (JP 6035111 B4, Sato Key et al., 05/11/1994), the abrasive blasting apparatus comprises means for automatically controlling the pressure inside the tank in communication with the means for filling the tank with an abrasive. When pressure drops under the weight of the abrasive, the poppet is automatically opened and the tank is replenished with an abrasive. The solution regarding the automation of the remote control of the flow rate of the abrasive is described in the invention EP 0694367, Al Kegler, 01/31/96: in the outlet of the tank there is an adjustment needle on the lever, the position of which is remotely controlled by a double-acting jack with a gearbox. For the uninterrupted supply of abrasive to the mixer, it is proposed to use several tanks, and their switching for alternating work is carried out by manually switching the valves (see, for example, RU 2173630 C1, Brezgin et al., September 20, 2001).

 However, all of the above principles of dispensing and transporting abrasive material to the mixer can only be successfully used for specially dried and prepared abrasive media that do not have a tendency to caking and arching. Otherwise, the formation of blood clots and the abrasive supply to the gas stream are possible, which will make the processing process uncontrollable, and therefore the quality of processing, for example, surface roughness, is not reproducible. Significantly, such a violation of the technology will affect in the thermoabrasive mode due to the aforementioned uncontrolled supply of abrasive to the treatment zone.

 The closest analogue in terms of features to the patented is an aero-abrasive mixer of an abrasive blasting device according to US Pat. No. 5,605,497, Pickard, 02/25/1997, containing an abrasive vessel, an outlet pipe of which is connected through a dispenser containing a spool rod and a saddle with an axial discharge channel with ejection type mixer. The mixer is connected by a flexible hose with a nozzle of the feed channel of the aeroabrasive mixture of the nozzle tool. A pipe for connecting to a source of compressed air is in communication with the cavity of the vessel for abrasive. Means for loading the abrasive are placed in the upper part of the vessel. The end of the slide valve stem is sealed to the top cover of the abrasive vessel. Axial movement of the rod changes the bore and allows you to adjust the flow rate of the abrasive.

 However, this device does not provide for the availability of means for starting, uninterrupted operation and stability of the working stream, for example, at high humidity of the abrasive material due to the formation of plugs in the dispenser and mixer, which does not allow this device to be considered universal and suitable for using abrasive media of different condition.

 The objective of the patented invention is the creation of an aeroabrasive mixer of a device for abrasive-jet surface treatment that does not have the aforementioned drawbacks and allows processing with both a cold abrasive-air jet and a hot gas-abrasive jet.

 The technical result of the patented invention consists in increasing the stability of the device, the possibility of simple and convenient control of parameters, regardless of the condition of the abrasive media. An additional technical result is to improve performance by reducing kinks and obfuscating a flexible hose for supplying aeroabrasive mixture.

 The technical result is ensured by the fact that the aero-abrasive mixer of the device for abrasive-jet surface treatment contains a vessel for abrasive, the outlet pipe of which through a dispenser, including a spool rod and a saddle with an axial channel, is connected to an ejector-type mixer having an outlet pipe for connecting a flexible hose for supplying an aero-abrasive mixtures to the nozzle tool and a pipe for connecting to a source of compressed air in communication with the abrasive vessel, and means for loading the abrasive. It is equipped with a means of free rotation of the mixer relative to the outlet of the abrasive vessel when changing the position of the hose and moving the seat in the axial direction to regulate its position relative to the position of the spool rod, means for loosening the abrasive and drives separate rotation and axial reciprocating movement of the spool rod associated with the free end of the latter, hermetically withdrawn to the upper part of the abrasive vessel, while the dispenser is attached to the mixer and with communicating with them through the channel in the side wall of the mixer, means for loosening the abrasive is in the form of ribbing on the outside of the spool shaft is the zone of interaction with the seat, and in said rod throughout its length is formed a through channel, communicating with a compressed air source for blowing dispenser.

 The mixer may be characterized in that the means of free rotation of the mixer relative to the outlet of the abrasive vessel and axial movement of the saddle are made in the form of a flare nut, the internal thread of which is responsive to the external thread of the abrasive vessel outlet pipe, and the flange is freely placed in the annular groove between a recess on the dispenser housing and the back of the saddle sleeve, while the dispenser housing and the saddle sleeve are interconnected by means of a threaded connection.

 The mixer can also be characterized in that it is equipped with a rotational mechanism of the union nut, made in the form of a pneumatic drive with gear rack-pinion gear, while the gear is connected to the union nut.

 The mixer can be characterized by the fact that at least one of the drives of separate rotation and axial reciprocating movement of the spool rod is made pneumatic.

 The mixer can be characterized, in addition, by the fact that it is equipped with a partition installed in the cavity of the mixer on a part of its length in the diametrical plane perpendicular to the axis of the channel in the side wall of the mixer.

The invention is disclosed in detail in the drawings,
where figure 1 shows the design of the device;
figure 2 - design of the dispenser;
figure 3 presents the drive control dispenser;
figure 4 is the same as in figure 3, view aa;
figure 5 - actuator control spool rod.

 In FIG. 1 shows the design of the device. A conical part 12 with an outlet pipe 14 is attached to the body 10 of the abrasive vessel in its lower part. The vessel has a filling hole in the upper part with a cover (not shown). The conical part is connected to the housing 10 by means of a flange connection 16. A dispenser 18 is connected to the outlet pipe, comprising a spool rod 20 and a seat 22 with an axial discharge channel 24. The dispenser 18 is attached to the ejection type mixer 26 and communicates with it through an opening 27 in the side wall.

 The mixer 26 has a fitting 28 for connecting to a source of compressed air and an outlet outlet pipe 30 for attaching a flexible hose for supplying aeroabrasive mixture to a nozzle tool (not shown). The mixer 26 is equipped with a flow divider, for this, a baffle 32 is installed on the side wall of the body of the mixer 26 in a diametrical plane perpendicular to the axis of the discharge channel and the rod 20. The baffle 32 also prevents the passage of the mixer 26 from clogging with the abrasive when it is inoperative. The separation of the stream of compressed air entering through the nozzle 28 during operation, provides the subsequent increased turbulization of the air-abrasive mixture during the interaction of the upper and lower parts of the stream behind the partition 32.

 The spool rod 20 is hollow, a hollow cone 34, which acts as a spool, is attached to its lower part, with a through hole 36 at the top of the cone and ribs 37 mounted on its non-working part and intended for loosening the abrasive when driving the saddle. To center the rod 20 in the conical part 12, a sleeve 38 is installed.

 The spool rod 20 is mounted with the possibility of separate rotation and axial reciprocating movement. One of the embodiments of the mechanism is shown in figure 1. The free end 40 of the rod 20 is hermetically withdrawn to the upper part of the abrasive vessel body 10, is threaded and connected to the actuator 42. A fitting 44 is installed on the free end 40 for connecting a flexible hose to the compressed air receiver while blowing the dispenser. To move the cone 34 up and down, there is a nut 46 with handles 48, having a thread consistent with the thread on the rod. The nut 46 is mounted rotatably relative to the sleeve 50 sealed in the housing 10 and has fastening and sealing elements 52. A driven gear 54 is attached to the rod 20, which is meshed with a pinion gear 56 connected to an air motor 58 mounted by means of a mount 60 on the housing 10.

 In FIG. 2, means are shown enlarged to ensure free rotation of the mixer 26 relative to the outlet pipe 14 of the vessel 10 for abrasive and axial movement of the saddle 22. These means are made in the form of a flare nut 62 with flanging 63, the internal thread 64 of which corresponds to the external thread of the outlet pipe 14 of the abrasive vessel. The flange 63 is freely positioned in the annular groove 65 between the recess 66 on the housing 67 and the rear part 68 of the sleeve 69 of the saddle, interconnected by means of a threaded connection 70 and the support sleeve 72. The sleeve 69 of the saddle is expediently made wear-resistant, for example in the form of a rubberized metal sleeve.

 This embodiment allows you to adjust the effective section of the dispenser by raising / lowering the sleeve 69 by rotating the nut 62. At the same time, this solution allows the mixer to easily rotate in the horizontal plane following the movements of the sandblasting hose without being frayed and tangled.

 The rotation of the nut 62 for adjusting the vertical position of the metering seat can be easily mechanized by using an additional pneumatic gear drive, similar to that described for the drive 42. The embodiment is shown in FIG. 3. The pneumatic cylinder 76 is mounted on the bottom of the abrasive vessel body 10 via an arm 77, and its rod 78 is kinematically connected by gearing to the gear 79 on the nut 62. The translational movement of the pneumatic cylinder rod causes the nut 62 to move up and down along the thread 64 and thereby control the effective section dispenser.

 In FIG. 5 shows another embodiment of the actuator 42, allowing manipulation of the axial movement of the rod 20 while ensuring its rotation. For this purpose, there are two pneumatic engines 82, 84. The engine 82 is mounted on the housing 10, has a drive gear 85 connected to the driven wheel 86, mounted on the stem 20. The rod 20 is mounted in the housing 10 of the abrasive vessel with the possibility of axial movement and rotation by means of a sleeve 50 having seal assemblies 87 with glands. The vertical movement unit 88 is driven by an air motor 84 having a gear 90 that is engaged with a gear rack 91 formed at the end 40 of the rod 20.

 The node 88 is mounted with the possibility of sliding it in the horizontal plane, for which the node 88 is placed on the slide 92, which are moved along the base 93 attached to the wall 95. When gears 90 and the rack 91 are engaged, the gear transmission is fixed with a screw 96.

 Providing reciprocating movement of the rod 20 can be implemented using other known mechanisms of pneumatic and electroautomatics used in dusty environments.

 The device operates as follows.

 Before starting work, the vessel through the filling hole is filled with abrasive. Powders of abrasive materials, metallurgical waste products - slag, coarse sand and similar media can be used as an abrasive. Before starting work, the dispenser 18 is locked, that is, the slide valve 20 and the seat 22 are brought into contact. Then, overpressure is created in the vessel, that is, the corresponding valve is opened that connects the vessel with the receiver and compressed air is supplied to the mixer 26 through the fitting 28.

 Rotating the union nut 62 controls the bore of the dispenser 18. Due to this, the required amount of abrasive is supplied through the axial discharge channel 24 to the mixer 26 and then mixed with the flow of compressed air, forming an aeroabrasive mixture. Next, the aero-abrasive mixture through the pipe 30 through a hose is fed to the nozzle tool, where it is accelerated and prepared for direct sandblasting. Depending on the design used, the nut 62 is rotated either manually (Fig. 1), or by means of a gear 79 connected to the rack on the rod 78 of the mechanism with the pneumatic cylinder 76 (Fig. 3).

 In the process, the flow mode of the air-abrasive mixture can be conveniently controlled by changing the position of the hollow cone 34 of the spool rod relative to the seat 22 by rotating the nut 46 (Fig. 1) manually or by the “gear 90 - gear rack 91” drive associated with the drive 42 (Fig. 5) .

 If interruptions in the formation of the aeroabrasive mixture are observed, this may indicate a violation of the flow regime in channel 27, for example, due to a violation of the condition of the abrasive and / or its increased humidity. In this case, the spool rod is rotated from mechanical drives 42 with pneumatic motors 58, 82 (see FIGS. 1, 5). For the drive shown in FIG. 5, the screw 96 is loosened first and the gear train is disconnected. The ribs 37 carry out the loosening of the abrasive in the saddle zone. If the abrasive forms a plug in the channel 24, through the nozzle 44 serves compressed air from the receiver directly into the cavity of the hollow rod. In this case, air blowing through the opening 36 at the top of the cone eliminates the plug in the hole 27. In practice, in case of violation of the formation mode of the air-abrasive mixture, it is advisable to combine both loosening by rotation of the rod 20 and air blowing.

 Industrial applicability.

 The device can be manufactured using traditional engineering technologies and materials, as well as the principles of constructing tools operating under high pressure. Serially produced models of a patented aeroabrasive mixer with a loading capacity of an abrasive vessel of 140-300 kg provide, when using metallurgical slag as an abrasive, a processing time of 30-60 minutes, easy commissioning and ease of use when adjusting the parameters of mixing the abrasive with air.

POSITIONS ON THE DRAWINGS
10 - vessel body for abrasive
12 - conical part
14 - exhaust pipe
16 - flange connection
18 - dispenser
20 - spool rod
22 - saddle
24 - axial discharge channel
26 - ejection type mixer
27 - hole in the side wall
28 - fitting for connecting to a source of compressed air
30 - exhaust outlet for connecting a flexible hose
32 - partition
34 - hollow cone
36 - through hole at the top of the cone
37 - ribs
38 - sleeve
40 - free end
42 - drive
44 - fitting for connecting a flexible hose to the receiver
46 - nut
48 - handle
50 - sleeve
52 - items
54 - driven gear
56 - pinion gear
58 - air motor
60 - mount
62 - flare nut
63 - flanging
64 - internal thread
65 - ring groove
66 - recess
67 - case
68 - back
69 - seat sleeve
70 - threaded connection
72 - support sleeve
76 - pneumatic cylinder
77 - bracket
78 - stock
79 - gear
82, 84 - pneumatic engines
85 - drive gear
86 - driven wheel
87 - seal assembly with glands
88 - node vertical movement
90 - gear
91 - rack
92 - slide
93 - base
95 - wall
96 - screw.

Claims (5)

1. Aeroabrasive mixer device for abrasive-jet surface treatment, containing a vessel for abrasive, the outlet pipe of which through a dispenser, including a spool rod and a seat with an axial channel, is connected to an ejection type mixer having an outlet pipe for attaching a flexible hose for supplying the aeroabrasive mixture to the nozzle tool and pipe for connecting to a source of compressed air in communication with the vessel for abrasive, and means for loading the abrasive, characterized in that it is equipped with a means of freedom rotation of the mixer relative to the outlet pipe of the abrasive vessel when changing the position of the hose and moving the seat in the axial direction to adjust its position relative to the position of the spool rod, means for loosening the abrasive and drives separate rotation and axial reciprocating movement of the spool rod associated with the free end of the latter sealed to the top of the abrasive vessel, the dispenser attached to the mixer and communicated with it through the channel in the side wall of the mixer, means for abrasive loosening is in the form of ribbing on the outside of the spool shaft is the zone of interaction with the seat, and in said rod throughout its length is formed a through channel, communicating with a compressed air source for blowing dispenser. 2. The mixer according to claim 1, characterized in that the means of free rotation of the mixer relative to the outlet pipe of the vessel for abrasive and axial movement of the saddle is made in the form of a union nut with a flange, the internal thread of which is responsive to the external thread of the outlet pipe of the abrasive vessel, and the flange placed freely in the annular groove between the recess on the dispenser housing and the rear of the saddle sleeve, while the dispenser housing and the saddle sleeve are interconnected by means of a threaded connection. 3. The mixer according to claim 2, characterized in that it is equipped with a rotational mechanism of the union nut, made in the form of a pneumatic drive with gear rack-pinion gear, while the gear is connected with a union nut 4. The mixer according to any one of claims 1 to 3, characterized in that at least one of the drives of separate rotation and axial reciprocating movement of the spool rod is made pneumatic. 5. The mixer according to any one of claims 1 to 3, characterized in that it is equipped with a partition installed in the cavity of the mixer on a part of its length in the diametrical plane perpendicular to the axis of the channel in the side wall of the mixer.

Images