Negative pressure combined sealing device

Abstract

The utility model relates to the technical field of material conveying equipment, in particular to a negative pressure combined type sealing device which is used for sealing a rotating shaft of the equipment and comprises a barrel, one end of the barrel is fixedly connected with the outer wall of the equipment, the barrel is sleeved on the shaft and is in clearance fit with the rotating shaft, and a gas channel is formed by a gap between the barrel and the rotating shaft. One end of the gas channel is communicated with the equipment inner cavity, the other end of the gas channel is a sealed end, an annular high-pressure cavity is formed in the barrel, an air inlet communicated with an external air compressor is formed in the outer side face of the annular high-pressure cavity, a plurality of accelerating holes communicated with the gas channel are formed in the inner side face of the annular high-pressure cavity, and a gas supplementing opening is formed in the barrel. The air supply port is located between the sealing end of the air channel and the annular high-pressure cavity, one end of the air supply port is communicated with an external air compressor, and the other end is communicated with the air channel. The technical problem that a rotating shaft of powder conveying equipment in the prior art is prone to being untight in sealing is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of material conveying equipment, in particular to a negative pressure combined sealing device. Background Art

[0002] In many industries such as petroleum, chemical, pharmaceutical, grain, food, electricity, building materials, metallurgy and mining, conveying equipment is an important process equipment in system engineering. In the process of conveying powder and granular materials, traditional conveying equipment often causes material leakage due to poor sealing, especially at the position of the rotating shaft, which affects production efficiency and causes environmental pollution. Existing sealing technologies, such as packing seals or skeleton oil seals, have the problem of low reliability. Therefore, it is of great practical value to develop a new type of sealing device to solve the above problems. Utility Model Content

[0003] In order to solve the technical problem that the rotating shaft of the powder conveying equipment in the prior art is prone to poor sealing, the present application proposes a negative pressure combined sealing device to solve the above technical problem.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] The utility model provides a negative pressure combined sealing device, which is used for sealing at the rotating shaft of the equipment, comprising: a cylinder, one end of which is fixedly connected to the outer wall of the equipment, the cylinder is sleeved on the shaft and matched with the rotating shaft gap, and the gap between the cylinder and the rotating shaft forms a gas channel; a gas channel, one end of which is connected to the inner cavity of the equipment, and the other end is a sealing end; an annular high-pressure cavity, which is formed on the cylinder, the outer side surface of the annular high-pressure cavity is formed with an air inlet connected to an external air compressor, and the inner side surface of the annular high-pressure cavity is formed with a plurality of acceleration holes connected to the gas channel; a gas replenishment port The air supply port is formed on the cylinder and is located between the sealing end of the gas channel and the annular high-pressure chamber. One end of the air supply port is connected to an external air compressor, and the other end is connected to the gas channel. The sealing gas enters the annular high-pressure chamber from the air inlet, and the sealing gas entering the annular high-pressure chamber is accelerated at the acceleration hole and enters the gas channel. At the moment of entering the gas channel, the sealing gas generates negative pressure due to the Venturi effect to absorb the sealing gas supplemented from the air supply port. The merged sealing gas flows unidirectionally in the gas channel toward the inner cavity of the equipment to seal the inner cavity of the equipment.

[0006] Furthermore, the passage of the acceleration hole is inclined so that the gas passing through the acceleration hole flows toward the inner cavity of the device.

[0007] Furthermore, starting from the connection point between the gas channel and the acceleration hole, the part of the gas channel toward the inner cavity of the equipment forms an outward expansion section with a gradually increasing cross-sectional area, and the part of the gas channel toward the gas replenishment port forms an inward contraction section with a gradually decreasing cross-sectional area.

[0008] Furthermore, a sealing stuffing box is arranged on the sealing end of the gas channel, and the sealing stuffing box comprises: a box body, one end of which is sealingly connected to an end of the cylinder away from the inner cavity of the equipment; a sealing material, which is clamped between the rotating shaft and the inner wall of the box body; and a pressure cover, which is fixed to an end of the box body away from the cylinder body to press the sealing material in the axial direction.

[0009] Furthermore, the box body is made of stainless steel.

[0010] Furthermore, the sealing material is PTFE or skeleton oil seal.

[0011] Furthermore, the material of the cylinder is stainless steel.

[0012] Based on the above technical solution, the technical effects that can be achieved by the utility model are:

[0013] The utility model discloses a negative pressure combined sealing device, wherein the sealing gas enters the annular high-pressure chamber from the air inlet, the sealing gas entering the annular high-pressure chamber is accelerated at the acceleration hole and enters the gas channel, and the sealing gas generates negative pressure due to the Venturi effect at the moment of entering the gas channel to absorb the sealing gas supplemented from the air supply port, and the combined sealing gas flows unidirectionally toward the inner cavity of the equipment in the gas channel to seal the inner cavity of the equipment, thereby solving the technical problem that the rotating shaft of the powder conveying equipment in the prior art is prone to poor sealing, and when the sealing air enters the annular high-pressure chamber from the air inlet, it is ejected into the inner cavity of the equipment at high speed through the internal physical structure, and the high-speed airflow is ejected at the inlet Due to the "Venturi effect", a high negative pressure area (vacuum) is generated, so the sealing gas at the air supply port is sucked into the inner cavity of the equipment by the high-pressure airflow. The powder in the inner cavity of the equipment flows inward due to the external pressure and cannot flow to the outside. This one-way airflow method is used to convey pressure, and the speed is achieved by adjusting the switch and flow of the air compressor. Other sealing structures are used to enhance the sealing effect. The sealing effect at this time is more reliable than the simple packing (or skeleton oil seal) seal on the market, and it is very easy to control. It is relatively simple in structure, advanced in principle, and low in manufacturing and maintenance costs. It ensures stable operation of the equipment, effectively prevents system paralysis caused by equipment failure and shutdown, and reduces customers' economic losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the negative pressure combined sealing device of the present utility model.

[0015] Among them: a-rotating shaft; 1-cylinder; 2-gas channel, 21-outward expansion section, 22-inward contraction section; 3-annular high-pressure chamber, 31-air inlet, 32-acceleration hole; 4-air supply port; 5-box; 6-sealing material; 7-pressure cover. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the utility model and its application or use. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0017] like Figure 1As shown, the utility model provides a negative pressure combined sealing device, which is used for sealing at the rotating shaft a of the equipment, including a cylinder 1. The design specification of the cylinder 1 is designed according to the shaft diameter of the rotating shaft a. One end of the cylinder 1 is fixedly connected to the outer wall of the equipment. The cylinder 1 is sleeved on the shaft and is matched with the rotating shaft a. The gap between the cylinder 1 and the rotating shaft a forms a gas channel 2. One end of the gas channel 2 is connected to the inner cavity of the equipment, and the other end is a sealing end. An annular high-pressure chamber 3 is formed on the cylinder 1. The outer side surface of the annular high-pressure chamber 3 is formed with an air inlet 31 connected to an external air compressor. The inner side of the annular high-pressure chamber 3 is formed with a plurality of acceleration holes 32 connected with the gas channel 2. A gas replenishment port 4 is formed on the cylinder 1. The gas replenishment port 4 is located between the sealing end of the gas channel 2 and the annular high-pressure chamber 3. One end of the gas replenishment port 4 is connected with the external air compressor, and the other end is connected with the gas channel 2. The sealed gas enters the annular high-pressure chamber 3 from the air inlet 31. The sealed gas entering the annular high-pressure chamber 3 is accelerated at the acceleration hole 32 and enters the gas channel 2. At the moment of entering the gas channel 2, the sealed gas generates a negative pressure due to the Venturi effect to absorb the gas from the gas replenishment port 31. The sealing gas supplemented at the port 4 flows unidirectionally toward the inner cavity of the equipment in the gas channel 2 after the confluence to seal the inner cavity of the equipment, thereby solving the technical problem that the rotating shaft a of the powder conveying equipment in the prior art is prone to poor sealing. When the sealing air enters the annular high-pressure chamber 3 from the air inlet 31, it is ejected at high speed into the inner cavity of the equipment through the internal physical structure. This high-speed airflow generates a high negative pressure area (vacuum) at the inlet due to the "Venturi effect", so the sealing gas at the air replenishment port 4 is sucked into the inner cavity of the equipment by the high-pressure airflow. The powder in the inner cavity of the equipment flows inward due to the external pressure and cannot flow to the outside. The pressure is conveyed by this unidirectional flow of airflow, and the speed is achieved by adjusting the switch and flow of the air compressor. Other sealing structures are used to enhance the sealing effect. The sealing effect at this time is more reliable than the simple packing (or skeleton oil seal) seal on the market, and it is very easy to control. It is relatively simple in structure, advanced in principle, and low in manufacturing and maintenance costs. It ensures stable operation of the equipment, effectively prevents system paralysis caused by equipment failure and shutdown, and reduces customers' economic losses.

[0018] In a preferred embodiment of the present invention, the passage of the acceleration hole 32 is inclined so that the gas passing through the acceleration hole 32 flows toward the inner cavity of the device, thereby ensuring that the sealing gas flows in the correct direction.

[0019] In a preferred embodiment of the utility model, starting from the connection point between the gas channel 2 and the acceleration hole 32, the part of the gas channel 2 toward the inner cavity of the equipment is formed with an outward expansion section 21 with a gradually increasing cross-sectional area, and the part of the gas channel 2 toward the gas replenishing port 4 is formed with an inward contraction section 22 with a gradually decreasing cross-sectional area, thereby ensuring the correct flow direction of the sealing gas.

[0020] In a preferred embodiment of the utility model, a sealing stuffing box is arranged on the sealing end of the gas channel 2, and the sealing stuffing box includes a box body 5, a sealing material 6 and a pressure cover 7. One end of the box body 5 is sealed and connected to the end of the cylinder 1 away from the inner cavity of the equipment, and the sealing material 6 is clamped between the rotating shaft a and the inner wall of the box body 5. The pressure cover 7 is fixed to the end of the box body 5 away from the cylinder 1 to press the sealing material 6 in the axial direction.

[0021] Furthermore, in the negative pressure combined sealing device of the present invention, its structure can be designed to be split or integral according to the structural characteristics of the equipment, that is, the box body 5 and the cylinder body 1 can be designed to be split or integral.

[0022] In a preferred embodiment of the present invention, the material of the box body 5 is stainless steel.

[0023] In a preferred embodiment of the present invention, the sealing material 6 is PTFE or a skeleton oil seal, and the material can be selected according to the working environment.

[0024] In a preferred embodiment of the present invention, the material of the cylinder 1 is stainless steel, and the material can be selected according to the application.

[0025] It should be understood that the specific embodiments described above are only used to explain the present invention, and are not used to limit the present invention. Obvious changes or modifications derived from the spirit of the present invention are still within the scope of protection of the present invention.

Claims

1. A negative pressure combined sealing device, used for sealing at the rotating shaft (a) of an equipment, characterized in that: include: A cylinder (1), one end of the cylinder (1) being fixedly connected to the outer wall of the device, the cylinder (1) being sleeved on the shaft and having a clearance fit with the rotating shaft (a), and the clearance between the cylinder (1) and the rotating shaft (a) forming a gas channel (2); A gas channel (2), one end of the gas channel (2) is connected to the inner cavity of the device, and the other end is a sealed end; an annular high-pressure chamber (3), the annular high-pressure chamber (3) being formed on the cylinder (1), the outer side surface of the annular high-pressure chamber (3) being formed with an air inlet (31) communicating with an external air compressor, and the inner side surface of the annular high-pressure chamber (3) being formed with a plurality of acceleration holes (32) communicating with the gas channel (2); an air supply port (4), the air supply port (4) being formed on the cylinder (1) and being located between the sealed end of the gas passage (2) and the annular high-pressure chamber (3), one end of the air supply port (4) being connected to an external air compressor, and the other end of the air supply port (4) being connected to the gas passage (2); The sealing gas enters the annular high-pressure chamber (3) from the gas inlet (31). The sealing gas entering the annular high-pressure chamber (3) is accelerated at the acceleration hole (32) and enters the gas channel (2). At the moment of entering the gas channel (2), the sealing gas generates negative pressure due to the Venturi effect to absorb the sealing gas supplemented from the gas replenishment port (4). The merged sealing gas flows unidirectionally in the gas channel (2) toward the inner cavity of the device to seal the inner cavity of the device.

2. The negative pressure combined sealing device according to claim 1, characterized in that: The passage of the acceleration hole (32) is inclined so that the gas passing through the acceleration hole (32) flows toward the inner cavity of the device.

3. The negative pressure combined sealing device according to claim 1, characterized in that: Starting from the connection point between the gas channel (2) and the acceleration hole (32), the portion of the gas channel (2) facing the inner cavity of the device is formed with an outward expansion section (21) with a gradually increasing cross-sectional area, and the portion of the gas channel (2) facing the gas replenishment port (4) is formed with an inward contraction section (22) with a gradually decreasing cross-sectional area.

4. The negative pressure combined sealing device according to claim 1, characterized in that: A sealing stuffing box is arranged on the sealing end of the gas passage (2), and the sealing stuffing box comprises: A box body (5), one end of the box body (5) being sealedly connected to an end of the cylinder body (1) away from the inner cavity of the device; A sealing material (6), wherein the sealing material (6) is clamped between the rotating shaft (a) and the inner wall of the box body (5); A pressure cover (7) is fixed to an end of the box body (5) away from the cylinder body (1) to press the sealing material (6) in the axial direction.

5. The negative pressure combined sealing device according to claim 4, characterized in that: The material of the box body (5) is stainless steel.

6. The negative pressure combined sealing device according to claim 4, characterized in that: The sealing material (6) is PTFE or a skeleton oil seal.

7. The negative pressure combined sealing device according to claim 1, characterized in that: The material of the cylinder (1) is stainless steel.

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