Mechanical sealing device of boiler feed pump

Abstract

The invention discloses a mechanical sealing device of a boiler feed pump, and aims to solve the problem of performance change caused by long-term high-temperature environment of a mechanical sealing spring in the prior art. The device comprises a ring seal set arranged in a gap between a feed pump end shell and a shaft body, a spring set is arranged on the side edge of the ring seal set, and the end, away from the ring seal set, of the spring set protrudes out of the end shell and makes contact with an end plate arranged on the shaft body in a sleeving mode. The key point is that an air bin is arranged at a gap formed by the spring group and the shaft body, and the air bin is communicated with the outside through a ventilation pipe; and the side edge of the end plate is sleeved with an exhaust fan synchronously rotating with the shaft body. When the water feeding pump works, the exhaust fan rotates, hot air in the space where the spring set is located is pumped out, and meanwhile the air bin sucks cold air from the outside to form continuous airflow circulation, so that the spring set is effectively cooled, the risk that the performance of the spring is reduced due to high temperature is reduced, and the stability and the service life of the mechanical seal are guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical seal, in particular to a mechanical seal device with heat dissipation function for a boiler feed water pump. BACKGROUND

[0002] At present, the boiler feed water pump is an important part of the boiler system, which mainly functions to transport water from the water source to the boiler to maintain the normal water level and pressure of the boiler and prevent dry burning and other accidents. The feed water pump is driven by the motor shaft and impeller rotation to ensure effective delivery of the medium and prevent leakage, and a sealing device is usually arranged between the feed water pump shell and the rotating shaft.

[0003] The mechanical seal device is widely used in the feed water pump due to its good sealing performance, long service life, wide application condition range and other advantages. The typical mechanical seal is composed of a static ring, a dynamic ring, a spring, a push ring and other components, and the dynamic ring and the static ring are tightly attached by the spring force to form a reliable sealing barrier. However, in the boiler system, the medium transported by the feed water pump is usually high-temperature water or steam, which makes the entire mechanical seal device long-term in a high-temperature environment. High temperature has many adverse effects on the core elastic element, the spring: first, high temperature may cause changes in the metallographic structure of the spring material, causing a decrease in mechanical properties such as strength and hardness; second, high temperature will reduce the elastic modulus of the material and may cause creep or relaxation, causing the spring to permanently deform and unable to provide enough pre-tightening force to maintain the attachment of the sealing end face; in addition, the high-temperature environment will also accelerate the fatigue process of the spring, and even under the joint action of corrosive medium, stress corrosion cracking will be caused, eventually leading to sealing failure.

[0004] Therefore, how to provide a mechanical seal device for a boiler feed water pump that can effectively cool the spring in the mechanical seal device to avoid performance degradation due to long-term exposure to high-temperature environments has become a technical problem that needs to be solved in the field. SUMMARY

[0005] The present application aims to provide a mechanical seal device for a boiler feed water pump, which aims to solve the problem of the mechanical seal being in a high-temperature environment for a long time, causing the spring to change in performance.

[0006] To achieve the above object, the present application provides the following technical scheme: a mechanical sealing device of a boiler feed water pump, comprising a ring seal group, the ring seal group being arranged in a gap between an end shell of the feed water pump and a shaft body; a spring group, the spring group being arranged at a side of the ring seal group, an end of the spring group away from the ring seal group protruding from the end shell of the feed water pump; an end plate, the end plate being sleeved on the shaft body and being in contact with the protruding end of the spring group; an exhaust fan, the exhaust fan being sleeved on the shaft body and being arranged at a side of the end plate; an air warehouse, the air warehouse being arranged at a gap between the spring group and the shaft body; and a ventilation pipe, the ventilation pipe being arranged in communication with a side of the air warehouse; wherein an end of the ventilation pipe is in communication with a space formed by a semiconductor refrigerating sheet and a set housing.

[0007] Specifically, the present application comprises the following schemes:

[0008] The ring seal group is arranged in a gap between the end shell of the feed water pump and the shaft body.

[0009] The spring group is arranged at a side of the ring seal group, and an end of the spring group away from the ring seal group protrudes from the end shell of the feed water pump.

[0010] The end plate is sleeved on the shaft body and is in contact with the protruding end of the spring group.

[0011] The exhaust fan is sleeved on the shaft body and is arranged at a side of the end plate.

[0012] The air warehouse is arranged at a gap between the spring group and the shaft body.

[0013] The ventilation pipe is arranged in communication with a side of the air warehouse.

[0014] An end of the ventilation pipe is in communication with a space formed by a semiconductor refrigerating sheet and a set housing.

[0015] Preferably, the ring seal group comprises a static ring, a dynamic ring and a sealing sleeve; the static ring and the dynamic ring are in contact; a second sealing ring is arranged on an outer side of the dynamic ring; and the sealing sleeve is sleeved on the outer sides of the static ring and the dynamic ring.

[0016] Preferably, a positioning hole and a third sealing ring are arranged on a side of the static ring away from the dynamic ring; a positioning pin inserted into the positioning hole is inserted into the end shell of the feed water pump; the third sealing ring is in contact with a side wall of the end shell of the feed water pump; a first sealing ring is arranged on an outer side wall of the sealing sleeve, and the first sealing ring is filled in a gap between the sealing sleeve and the end shell of the feed water pump.

[0017] Preferably, the spring group comprises a spring, a first push plate and a second push plate; the first push plate and the second push plate are arranged at two ends of the spring respectively; the first push plate is in contact with the dynamic ring, and the second push plate is in contact with the end plate; a protruding column is arranged on a side wall of each of the first push plate and the second push plate away from the other, and the protruding column is inserted into a groove of the dynamic ring or the end plate.

[0018] Preferably, the spring comprises a plurality of arc-shaped segments connected end to end, and a connecting pipe (55) is arranged at the joint of two adjacent segments (54).

[0019] Preferably, the end plate (6) comprises two joint plates (61) connected by bolts and arranged symmetrically, a plurality of convex plates are fixedly arranged on the inner side walls of the two joint plates (61), and the end portions of the convex plates are attached to the shaft body; a pressing plate (62) is further arranged on the inner side of each joint plate (61), the pressing plate (62) is in contact with the second push plate (52) and can move axially to adjust the compression amount of the spring set (5).

[0020] Preferably, the exhaust fan (3) comprises two clamping arc plates (31) connected by bolts and a plurality of fan blades (32); the two clamping arc plates (31) are arranged in a clamping manner on the shaft body; and the plurality of fan blades (32) are arranged on the outer sides of the two clamping arc plates (31).

[0021] Preferably, the air warehouse (7) comprises two half-ring warehouses (76) connected in communication; a plurality of air holes (72) are arranged on the side wall of the air warehouse (7) near the exhaust fan (3).

[0022] Preferably, the air warehouse (7) further comprises two fastening plates (75); a screw rod (73) is arranged on the side wall of the half-ring warehouse (76); and the fastening plate (75) is arranged at the joint of the two half-ring warehouses (76) and is sleeved on the screw rod (73).

[0023] Preferably, a buckle groove (42) is arranged on the outer frame of the semiconductor refrigeration sheet (4); a sleeving shell (41) is sleeved on the outer frame, a buckle column (43) is arranged on the side wall of the sleeving shell (41) in contact with the outer frame, the buckle column (43) is installed in the buckle groove (42); and a ventilation pipe (71) is installed in communication at one end of the sleeving shell (41), and a ventilation gap is left between the other end of the sleeving shell (41) and the semiconductor refrigeration sheet (4).

[0024] Compared with the prior art, the application has the beneficial effects that: by setting the exhaust fan on the shaft body, the exhaust fan rotates synchronously with the shaft body when the water supply pump is working, so that the hot air in the space where the spring group is located can be actively extracted, and forced air cooling is realized. At the same time, by setting the air warehouse and the ventilation pipe connected thereto, external cold air is introduced into the space, and a continuous gas circulation passage is formed. This active and continuous cooling method can significantly reduce the working temperature of the spring group, effectively slow down the problems of material performance degradation, permanent deformation and fatigue fracture of the spring caused by long-term high-temperature environment, so as to ensure that the spring group can continuously provide stable sealing force, greatly improve the reliability and service life of the mechanical sealing device. In addition, by setting the semiconductor refrigerating sheet at the air inlet end to pre-cool the inhaled air, the cooling effect is further enhanced, and more reliable guarantee is provided for the stable work of the spring.

[0025] Other features and advantages of the present application will become apparent from the following detailed description of illustrative embodiments thereof, which proceeds with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings incorporated in and forming a part of the specification illustrate embodiments of the present application and, together with the description, serve to explain the principles of the application.

[0027] Figure 1 is a schematic diagram of the overall structure of the embodiment of the present application;

[0028] Figure 2 is a schematic diagram of the local structure of the embodiment of the present application;

[0029] Figure 3 is a schematic diagram of the structure of the ring seal group, the exhaust fan and the semiconductor refrigerating sheet part of the embodiment of the present application;

[0030] Figure 4 is a schematic diagram of the structure of the ring seal group, the spring group and the end plate part of the embodiment of the present application;

[0031] Figure 5 is a schematic diagram of the structure of the ring seal group of the embodiment of the present application;

[0032] Figure 6 is a schematic diagram of the structure of the spring group and the end plate of the embodiment of the present application;

[0033] Figure 7 is a schematic diagram of the structure of the spring group of the embodiment of the present application;

[0034] Figure 8 is a schematic diagram of the structure of the spring of the embodiment of the present application;

[0035] Figure 9 is a schematic diagram of the structure of the end plate of the embodiment of the present application;

[0036] Figure 10 is a structural schematic diagram of an exhaust fan of an embodiment of the present application;

[0037] Figure 11 is a structural schematic diagram of a semiconductor refrigeration sheet, a wind warehouse of an embodiment of the present application;

[0038] Figure 12 is a structural schematic diagram of a semiconductor refrigeration sheet of an embodiment of the present application;

[0039] Figure 13 is a structural schematic diagram of a sleeve shell of an embodiment of the present application;

[0040] Figure 14 is a structural schematic diagram of a wind warehouse of an embodiment of the present application.

[0041] BRIEF DESCRIPTION OF DRAWINGS 1, multi-stage centrifugal pump; 11, end cover; 12, motor; 2, ring seal group; 21, static ring; 22, dynamic ring; 23, sealing sleeve; 24, first sealing ring; 25, second sealing ring; 26, third sealing ring; 27, positioning hole; 3, exhaust fan; 31, clamping arc plate; 32, fan blade; 4, semiconductor refrigeration sheet; 41, sleeve shell; 42, buckle groove; 43, buckle column; 5, spring group; 51, first push plate; 52, second push plate; 53, spring; 54, splicing section; 55, connecting pipe; 6, end plate; 61, splicing plate; 62, pressing plate; 63, threaded column; 64, limiting column; 7, wind warehouse; 71, ventilation pipe; 72, air hole; 73, screw rod; 75, fastening plate; 76, half ring warehouse. DETAILED DESCRIPTION

[0042] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions, and numerical values set forth in these embodiments are illustrative only and do not limit the scope of the present application unless otherwise specifically stated.

[0043] The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the scope of the application its application or uses.

[0044] Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail herein. However, the techniques, methods, and devices should be considered part of the specification.

[0045] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0046] It should be noted that like reference numerals and letters refer to like items throughout the several views, whereupon once an item is defined in one view, it need not be discussed further in subsequent views.

[0047] Embodiment 1

[0048] Referring to Figures 1 to 4 The present application provides a mechanical seal device for a boiler feed pump. The core idea of the device is to add an active air-cooling heat dissipation system to the traditional mechanical seal to solve the problem of performance degradation of the spring set in high temperature environment. The device mainly includes a ring seal set 2, a spring set 5 and an end plate 6 for realizing the sealing function, and an exhaust fan 3, an air warehouse 7 and a semiconductor refrigeration sheet 4 for realizing the heat dissipation function.

[0049] In assembly, the ring seal set 2 is installed in the gap between the end shell 11 of the feed pump (for example, a multi-stage centrifugal pump 1) and the shaft body, for forming the main seal between the dynamic and static parts. The spring set 5 is arranged at the side of the ring seal set 2, with one end acting on the ring seal set 2 and the other end protruding outside the end shell 11. The end plate 6 is sleeved on the shaft body and in contact with the protruding end of the spring set 5, providing a fixed support point for the spring set 5. The shaft body of the feed pump is usually driven by a motor 12.

[0050] The key innovation of the present application lies in the design of the heat dissipation system. The exhaust fan 3 is fixedly sleeved on the shaft body and located outside the end plate 6. When the motor 12 drives the shaft body to rotate, the exhaust fan 3 also rotates synchronously. The air warehouse 7 is arranged in the annular space between the spring set 5 and the shaft body and is in communication with the outside atmosphere through a ventilation pipe 71. In this way, when the exhaust fan 3 rotates, it will produce negative pressure and draw out the hot air in the space where the spring set 5 is located, and the heat will be taken away at the same time. At the same time, the cold air outside will be sucked into the space where the spring set 5 is located through the ventilation pipe 71 and the air warehouse 7 under the action of pressure difference, cooling the spring set 5. This process of suction and exhaust forms a continuous air flow circulation, thereby realizing active and continuous heat dissipation of the spring set 5.

[0051] To further improve the heat dissipation effect, as shown in Figure 3 and Figure 11 , a cooling unit composed of a semiconductor refrigeration sheet 4 and a sleeving shell 41 is arranged at the air inlet end of the ventilation pipe 71. The external air will be pre-cooled by flowing through the cold end of the semiconductor refrigeration sheet 4 before entering the ventilation pipe 71. The low-temperature gas after cooling enters the air warehouse 7 to cool the spring set 5, and the heat dissipation effect is better. The heat generated by the semiconductor refrigeration sheet 4 when working can be dissipated to the surrounding environment through its hot end, and the rotation of the exhaust fan 3 can also stir the surrounding air to assist the heat dissipation of the hot end.

[0052] The specific structure of each component will be described in detail below.

[0053] Please refer to Figure 5 In order to realize reliable sealing, the ring seal group 2 includes a static ring 21, a dynamic ring 22 and a seal sleeve 23. The static ring 21 is fixed circumferentially with the end shell 11 by a positioning pin to prevent rotation, and realizes radial static sealing with the end shell 11 through a third sealing ring 26. The dynamic ring 22 rotates with the shaft body, and its end face closely abuts the end face of the static ring 21 to form a main sealing pair. The dynamic ring 22 and the seal sleeve 23 realize sealing through a second sealing ring 25. The seal sleeve 23 is integrally sleeved outside the static ring 21 and the dynamic ring 22, and realizes static sealing with the end shell 11 through a first sealing ring 24 to form multiple sealing guarantees.

[0054] Please refer to Figure 7 and Figure 8 In order to apply and transmit sealing force, the spring group 5 includes a spring 53, a first push plate 51 and a second push plate 52. The spring 53 is located between the first push plate 51 and the second push plate 52. The first push plate 51 contacts the dynamic ring 22 to transmit the elastic force of the spring 53 to the dynamic ring 22 so that it is tightly pressed on the static ring 21. The second push plate 52 contacts the end plate 6. In order to enable the spring group 5 to rotate synchronously with the shaft body, a convex column is arranged on the end face of the first push plate 51 and the second push plate 52 to cooperate with the recesses on the dynamic ring 22 and the end plate 6 respectively to realize torque transmission. In order to facilitate installation and replacement, the spring 53 can be designed as a split structure, which is composed of a plurality of arc-shaped splicing segments 54 connected end to end, and the joints of adjacent splicing segments 54 are connected and fixed by sleeving a connecting pipe 55.

[0055] Please refer to Figure 9 In order to facilitate installation and adjustment on the shaft body, the end plate 6 can be formed by two symmetrical splicing plates 61 connected by bolts. A convex plate is arranged on the inner side wall of each splicing plate 61 for abutting and positioning with the shaft body. In addition, in order to be able to adjust the compression amount of the spring 53, i.e. adjust the sealing specific pressure, an axially movable abutting plate 62 is further arranged on the inner side of each splicing plate 61. The abutting plate 62 contacts the second push plate 52, and its position can be adjusted by rotating a threaded column 63, and a limiting column 64 is used to guide and limit the movement of the abutting plate 62. By adjusting the position of the abutting plate 62, the effective working length of the spring 53 can be changed, so as to accurately control the pressure applied to the sealing surface.

[0056] Please refer to Figure 10 The exhaust fan 3 is also designed in a split type for easy installation, including two clamping arc plates 31. The two clamping arc plates 31 are connected by bolt fastening and clamped on the shaft body. A plurality of fan blades 32 are uniformly distributed on the outer periphery of the clamping arc plate 31 for generating air flow during rotation.

[0057] Please refer to Figure 14, the air warehouse 7 is also convenient for installation, and is spliced by two half ring warehouses 76. The ends of the two half ring warehouses 76 are connected and fixed by the fastening plate 75 and the screw rod 73. A plurality of air holes 72 are formed on the side of the air warehouse 7 facing the exhaust fan 3, and cold air flows out from the air holes to cool the spring set 5.

[0058] Please refer to Figure 12 and Figure 13 , the semiconductor refrigeration piece 4 and the sleeve shell 41 are connected by a convenient buckle type. The outer frame of the semiconductor refrigeration piece 4 is provided with a buckle groove 42, and the inner wall of the sleeve shell 41 is provided with a corresponding buckle column 43. During installation, the buckle column 43 is embedded in the buckle groove 42 to realize quick fixing. The ventilation pipe 71 is connected to one end of the sleeve shell 41, and the other end is provided with an air inlet gap to ensure smooth airflow.

[0059] In terms of control, the semiconductor refrigeration piece 4 can be connected to an electrical control box, and the controller (such as PLC) can intelligently control according to the real-time temperature collected by the temperature sensor arranged near the spring set 5. When the temperature exceeds the preset threshold, the controller starts the semiconductor refrigeration piece 4 to work for strong cooling; when the temperature drops to a safe range, the power is stopped or reduced to realize energy saving and precise temperature control.

[0060] Embodiment 2

[0061] As shown in Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 6 , in order to timely discharge the heat in the space where the mechanical seal is located, reduce the temperature of the spring, and slow down the performance change rate, the application provides a new mechanical seal device. The mechanical seal device comprises a ring seal set 2, a spring set 5, an end plate 6, an air warehouse 7, an exhaust fan 3 and the like. The mechanical seal function of the pump shell and the shaft body of the water supply pump (such as a multi-stage centrifugal pump 1) is realized under the cooperation of the ring seal set 2, the spring set 5 and the end plate 6. The shaft body of the water supply pump is connected with the motor 12, so that the water supply pump can be controlled to work under the action of the motor 12. The exhaust fan 3 is installed on the shaft body, and then the exhaust fan 3 rotates synchronously with the shaft body, so that the gas in the space where the ring seal set 2, the spring set 5 and the end plate 6 are located can be discharged under the action of the exhaust fan 3, and then the heat is taken away to realize the heat dissipation treatment of the ring seal set 2, the spring set 5 and the end plate 6. In order to realize the continuous circulation of other spaces where the ring seal set 2, the spring set 5 and the end plate 6 are located, the air warehouse 7 is arranged in the space where the ring seal set 2, the spring set 5 and the end plate 6 are located, and the ventilation pipe 71 is arranged on the side of the air warehouse 7. The other end of the ventilation pipe 71 away from the air warehouse 7 is located outside the space where the ring seal set 2, the spring set 5 and the end plate 6 are located, so that under the cooperation of the exhaust fan 3 and the air warehouse 7, the gas can be drawn to pass through the space where the ring seal set 2, the spring set 5 and the end plate 6 are located, and then the continuous heat dissipation treatment of the ring seal set 2, the spring set 5 and the end plate 6 is realized.

[0062] As Figure 2 shown, here simply introduce the installation mode of ring seal group 2, spring group 5, end plate 6 and feed water pump. The ring seal group 2 is arranged in the gap between the end shell 11 of the multi-stage centrifugal pump 1 and the shaft body, and the spring group 5 is arranged at the side of the ring seal group 2, and the end of the spring group 5 away from the ring seal group 2 protrudes from the end shell 11, the end plate 6 is sleeved on the shaft body, and the protruding end of the spring group 5 is in contact with the end plate 6, so that the ring seal group 2 can be stably installed to realize the sealing function under the cooperation of the end plate 6 and the spring group 5.

[0063] As Figure 2 shown, under the premise of stable installation of the ring seal group 2, the spring group 5 and the end plate 6, the air warehouse 7 is arranged in the gap formed by the spring group 5 and the shaft body, and there is a gap between the end plate 6 and the shaft body and the end shell 11, so that the gas inside and outside the end shell 11 can be stirred to provide convenience for the circulation under the condition that the exhaust fan 3 rotates with the shaft body.

[0064] As Figure 11 shown, in order to introduce gas through the air warehouse 7 to realize continuous cooling when the exhaust fan 3 works and the gas in the space where the ring seal group 2, the spring group 5 and the end plate 6 are located is exhausted, the air warehouse 7 is arranged as an annular warehouse structure, and a plurality of air holes 72 are arranged on the side of the air warehouse 7 facing the exhaust fan 3, and the air warehouse 7 is connected with the ventilation pipe 71.

[0065] As Figure 14 shown, in order to facilitate disassembly of the air warehouse 7 according to needs, the air warehouse 7 comprises two half-ring warehouses 76, the central angles of the two half-ring warehouses 76 are both arranged as 180°, and the end portions are both arranged as openings, and the two half-ring warehouses 76 are connected in communication. Under the condition that the two half-ring warehouses 76 are connected in communication, the air warehouse 7 can be conveniently disassembled by the staff. In order to tightly connect the two half-ring warehouses 76, a fastening plate 75 is arranged at the joint of the two half-ring warehouses 76, a screw rod 73 is arranged on the side wall of the half-ring warehouse 76, the fastening plate 75 is sleeved on the screw rod 73, and a nut is sleeved on the screw rod 73. Therefore, the two half-ring warehouses 76 can be stably connected under the action of the fastening plate 75, and the air warehouse 7 can be conveniently moved to the outside of the end shell 11 for disassembly.

[0066] In order to stably install the air warehouse 7 in the end shell 11, the ventilation pipe 71 is arranged as a hard pipe structure, so that the air warehouse 7 can be stably installed under the support of the ventilation pipe 71.

[0067] As Figure 10As shown, in order to be able to install the exhaust fan 3 stably on the shaft body, and to provide support for disassembling the exhaust fan 3 according to the needs, the exhaust fan 3 comprises two clamping arc plates 31 and a plurality of fan blades 32, the plurality of fan blades 32 are evenly arranged on the outer side of the two clamping arc plates 31, and the two clamping arc plates 31 are symmetrical and sleeved on the shaft body, and the bolts are arranged through the intersection of the two clamping arc plates 31, and the two clamping arc plates 31 are stably connected under the action of the bolts. Therefore, after the clamping arc plate 31 is stably installed on the shaft body, when the water pump is working, the exhaust fan 3 works synchronously, and under the action of the plurality of fan blades 32, the gas in the space where the ring seal group 2, the spring group 5 and the end plate 6 are located is pumped out.

[0068] As shown in Figure 3 , Figure 11 , in order to be able to transport the gas with lower temperature to the space where the ring seal group 2, the spring group 5 and the end plate 6 are located, a semiconductor refrigeration sheet 4 can also be arranged on the outer side of the end shell 11, and a sleeve shell 41 is sleeved on the cold end of the semiconductor refrigeration sheet 4, and a narrow gap is formed between the sleeve shell 41 and the semiconductor refrigeration sheet 4. One end of the sleeve shell 41 is connected with the ventilation pipe 71, and the end of the sleeve shell 41 away from the ventilation pipe 71 leaves a ventilation gap with the semiconductor refrigeration sheet 4, so that under the working condition of the semiconductor refrigeration sheet 4 and the exhaust fan 3, the gas in the space composed of the sleeve shell 41 and the semiconductor refrigeration sheet 4 can be cooled, and the low-temperature gas flows to the ventilation pipe 71 and the air warehouse 7, and finally is discharged from the space where the ring seal group 2, the spring group 5 and the end plate 6 are located. Under the working condition of the exhaust fan 3, it also stirs the gas around the end shell 11 to flow, so that when the semiconductor refrigeration sheet 4 is installed on the side of the end shell 11, the gas on the hot end of the semiconductor refrigeration sheet 4 will also be stirred by the exhaust fan 3, realizing the heat dissipation treatment of the semiconductor refrigeration sheet 4. Even the heat sink can be installed on the hot end of the semiconductor refrigeration sheet 4, and the heat is dissipated to the surrounding environment in time.

[0069] As shown in Figure 12 , Figure 13 , in order to be able to disassemble the sleeve shell 41 and the semiconductor refrigeration sheet 4 according to the needs, a buckle groove 42 is arranged on the outer frame of the semiconductor refrigeration sheet 4, and the end of the buckle groove 42 is arranged as an opening. The sleeve shell 41 is sleeved on the outer frame, and a buckle column 43 is arranged on the side wall of the sleeve shell 41 in contact with the outer frame, and the buckle column 43 is installed in the buckle groove 42, so that under the cooperation of the buckle groove 42 and the buckle column 43, the sleeve shell 41 and the semiconductor refrigeration sheet 4 are stably connected. In addition, a bolt can also be arranged through the top of the sleeve shell 41, and a threaded groove is arranged on the outer frame, and the end of the bolt is screwed into the threaded groove, so that the sleeve shell 41 can be stably installed under the action of the bolt.

[0070] In order to control the mechanical seal device, it needs to be connected to the electrical control box. The electrical control box includes at least circuit breaker, contactor, relay, controller (such as PLC), port, etc., and the semiconductor refrigeration piece 4 is connected with the electrical control box. Temperature sensors can also be arranged at the space where the ring seal group 2, spring group 5 and end plate 6 are located, and the temperature sensors are also connected with the electrical control box.

[0071] Two wires are led out from the DC power output end in the electrical control box, and according to the positive and negative polarity requirements of the semiconductor refrigeration piece, the positive wire is connected to the positive electrode of the refrigeration piece, and the negative wire is connected to the negative electrode of the refrigeration piece. Usually a circuit breaker is connected in series in the circuit, which is used to automatically cut off the power supply when the circuit has overload or short circuit fault, etc. to protect the refrigeration piece and other circuit elements. The working state of the semiconductor refrigeration piece is controlled by the contactor or the relay. The normally open contact of the contactor or the relay is connected in series with the power supply line of the semiconductor refrigeration piece. When the contactor or the relay is energized, the normally open contact is closed, and the semiconductor refrigeration piece is connected to the power supply and starts to work; when the contactor or the relay is de-energized, the normally open contact is disconnected, and the refrigeration piece stops working.

[0072] The temperature sensor generally has two or three wires, two wires are usually thermocouple type, and three wires may be thermistor type, etc. The signal line of the temperature sensor is connected to the analog input port of the controller in the electrical control box. If the sensor outputs a digital signal, it is connected to the digital input port of the controller. If the temperature sensor needs external power supply, the appropriate power supply line is led out from the power module in the electrical control box and connected to the power pin of the sensor to provide stable working voltage for the sensor.

[0073] The temperature sensor monitors the temperature of the environment or object that needs to be controlled in real time, and converts the temperature signal into an electric signal. For example, the thermocouple will generate a thermoelectric potential according to the temperature difference, and the thermistor will change the resistance value with the change of temperature. These electric signals are transmitted to the controller in the electrical control box.

[0074] The controller processes and analyzes the received temperature sensor signal and compares it with the pre-set temperature value.

[0075] According to the comparison result, the controller sends a control signal. If refrigeration is needed, the controller will energize the relay or contactor coil, so that the contact connected in series with the semiconductor refrigeration piece is closed, and the semiconductor refrigeration piece starts to work. Its cold end absorbs heat, and its hot end dissipates heat, achieving refrigeration effect and reducing the temperature of the environment or object.

[0076] As the semiconductor cooler operates, the temperature sensor continuously monitors temperature changes and feeds the new temperature signal back to the controller. When the temperature approaches or reaches the set point, the controller adjusts the control signal based on a specific control strategy, such as a PID control algorithm, causing the semiconductor cooler to reduce cooling power or stop operation to maintain a stable temperature near the set point.

[0077] Example 3

[0078] like Figure 5 As shown, based on Example 1, in order to effectively seal the shaft and end shell 11, the ring seal assembly 2 includes a stationary ring 21, a dynamic ring 22, and a sealing sleeve 23. The stationary ring 21 and the dynamic ring 22 are in close contact with each other to achieve their sealing configuration. The dynamic ring is made of cemented carbide material, which has excellent wear resistance and corrosion resistance. The stationary ring is made of ceramic material, which has high hardness and low friction coefficient, further improving the service life of the sealing device. The sealing sleeve 23 is mounted on the outside of the stationary ring 21 and the dynamic ring 22, and a second sealing ring 25 is provided on the outer side of the dynamic ring 22. The second sealing ring 25 acts to achieve a sealed connection between the dynamic ring 22 and the sealing sleeve 23. A positioning hole 27 and a third sealing ring 26 are provided on the side of the stationary ring 21 away from the dynamic ring 22. The positioning pin inserted in the positioning hole 27 is inserted into the end shell 11, and the third sealing ring 26 contacts the side wall of the end shell 11. A first sealing ring 24 is provided on the outer side wall of the sealing sleeve 23 , and the first sealing ring 24 fills the gap between the sealing sleeve 23 and the end shell 11 .

[0079] The connection between the stationary ring 21 and the end shell 11 can also be set to interference fit, adhesive fixation, etc. In short, the stationary ring 21 and the end shell 11 are stably connected using existing technology.

[0080] like Figure 7 As shown, to force the dynamic ring 22 to fit tightly against the static ring 21, the spring assembly 5 includes a spring 53, a first push plate 51, and a second push plate 52. The first push plate 51 and the second push plate 52 are respectively disposed at both ends of the spring 53. The first push plate 51 and the second push plate 52 are in contact with the dynamic ring 22 and the end plate 6, respectively. Therefore, under the action of the spring 53, the dynamic ring 22 is forced to be stably positioned relative to the static ring 21. To enable the spring 53 to rotate synchronously with the dynamic ring 22 and the end plate 6, protrusions are provided on the side walls of the first push plate 51 and the second push plate 52 that are away from each other. The protrusions are respectively inserted into grooves in the dynamic ring 22 and the end plate 6.

[0081] like Figure 8As shown, in order to be able to disassemble the spring 53 according to the demand, the spring 53 comprises a plurality of arc-shaped splicing segments 54 connected end to end, and a connecting pipe 55 is sleeved at the joint of adjacent two splicing segments 54, and the connecting pipe 55 is also provided in an arc-shaped structure. When the connecting pipe 55 and the splicing segments 54 are installed, the connecting pipe 55 is deformed by extrusion of a hydraulic clamp or other external force extrusion equipment to be sleeved on the splicing segments 54, so that the adjacent splicing segments 54 are stably connected. Therefore, when a new spring 53 needs to be installed on the shaft body, the complete spring 53 can be composed by splicing the splicing segments 54 one by one.

[0082] As shown, Figure 9 Similarly, in order to be able to quickly disassemble the end plate 6 according to the demand, the end plate 6 comprises two splicing plates 61 connected by bolts and provided symmetrically, a plurality of convex plates are fixedly provided on the inner side wall of each splicing plate 61, the end surface of the convex plate is provided in an arc-shaped structure, and the end of the convex plate is attached to the shaft body, so that the two splicing plates 61 are stably installed on the shaft body under the cooperation of the plurality of convex plates and the bolts. Conversely, the bolts can be disassembled to release the restriction of the two splicing plates 61, thereby providing convenience for disassembling the end plate 6, the spring 53 and other devices.

[0083] As shown, Figure 9 In order to be able to adjust the compression degree of the spring 53 according to the demand, a pressing plate 62 is further provided on the inner side of each splicing plate 61, the side edge of the pressing plate 62 is fixedly provided with a limiting column 64 and a threaded column 63 connected by a bearing, the limiting column 64 penetrates the convex plate, and the threaded column 63 is threadedly penetrated through the convex plate, so that the pressing plate 62 is stably installed under the action of the limiting column 64 and the threaded column 63, and the movement of the pressing plate 62 can be controlled by rotating the threaded column 63. Since the pressing plate 62 is in contact with the second push plate 52, the relative position of the first push plate 51 and the second push plate 52 can be adjusted when the pressing plate 62 moves, and the compression degree of the spring 53 can be adjusted.

[0084] In summary, by providing the exhaust fan on the shaft body, the exhaust fan rotates synchronously with the shaft body when the water pump is working, and can actively exhaust the hot air in the space where the spring group is located, thereby achieving forced air cooling. At the same time, by providing the air warehouse and the ventilation pipe connected thereto, external cold air is introduced into the space, thereby forming a continuous gas circulation passage. This active and continuous cooling method can significantly reduce the working temperature of the spring group, effectively slow down the problems of material performance degradation, permanent deformation and fatigue fracture of the spring caused by long-term high-temperature environment, thereby ensuring that the spring group can continuously provide stable sealing force, and greatly improving the reliability and service life of the mechanical sealing device. In addition, by providing the semiconductor refrigerating sheet at the air inlet end to pre-cool the sucked air, the cooling effect is further enhanced, thereby providing more reliable protection for the stable work of the spring.

[0085] While certain specific embodiments of the application have been described in detail herein for the purposes of exemplification and to provide a thorough and enabling disclosure, it will be understood that the application is not limited to the particular embodiments described. Any modifications of the methods and materials described herein, which come within the scope and spirit of the application, are to be considered within the scope of the application. The scope of the application is to be determined by the claims appended hereto, which are to be construed in accordance with the principles of patent law.

Claims

1. A mechanical sealing device for a boiler feed water pump, characterized in that: include: A ring seal assembly (2) is arranged in a gap between the water feed pump end housing (11) and the shaft; A spring assembly (5) is arranged on the side of the ring seal assembly (2), and one end of the spring assembly (5) away from the ring seal assembly (2) protrudes from the water pump end housing (11); An end plate (6) is sleeved on the shaft and contacts the protruding end of the spring assembly (5); An exhaust fan (3) is sleeved on the shaft and arranged on the side of the end plate (6); an air chamber (7) disposed in the gap between the spring assembly (5) and the shaft; and A ventilation pipe (71) is arranged in communication with a side of the air bin (7); The end of the ventilation pipe (71) is connected to a space formed by a semiconductor refrigeration plate (4) and a set shell (41).

2. The mechanical sealing device of a boiler feed water pump according to claim 1, characterized in that: The ring seal assembly (2) comprises a stationary ring (21), a dynamic ring (22) and a sealing sleeve (23); the stationary ring (21) and the dynamic ring (22) are in close contact with each other; a second sealing ring (25) is provided on the outer side of the dynamic ring (22); and the sealing sleeve (23) is sleeved on the outer sides of the stationary ring (21) and the dynamic ring (22).

3. The mechanical sealing device of a boiler feed water pump according to claim 2, characterized in that: A positioning hole (27) and a third sealing ring (26) are provided on the side of the static ring (21) away from the dynamic ring (22); a positioning pin inserted into the positioning hole (27) is inserted into the water supply pump end shell (11); the third sealing ring (26) contacts the side wall of the water supply pump end shell (11); a first sealing ring (24) is provided on the outer side wall of the sealing sleeve (23), and the first sealing ring (24) fills the gap between the sealing sleeve (23) and the water supply pump end shell (11).

4. The mechanical sealing device of a boiler feed water pump according to claim 2, characterized in that: The spring group (5) includes a spring (53), a first push plate (51) and a second push plate (52); the first push plate (51) and the second push plate (52) are respectively arranged at two ends of the spring (53); the first push plate (51) is in contact with the movable ring (22), and the second push plate (52) is in contact with the end plate (6); convex columns are provided on the side walls of the first push plate (51) and the second push plate (52) that are away from each other, and the convex columns are respectively inserted into the grooves of the movable ring (22) and the end plate (6).

5. A mechanical sealing device for a boiler feed water pump according to claim 4, characterized in that: The spring (53) comprises a plurality of arc-shaped splicing sections (54), wherein the plurality of splicing sections (54) are connected end to end; and a connecting tube (55) is sleeved at the junction of two adjacent splicing sections (54).

6. The mechanical sealing device for a boiler feed water pump according to claim 4, characterized in that: The end plate (6) includes two splicing plates (61) connected by bolts and symmetrically arranged, and a plurality of convex plates are fixedly arranged on the inner side walls of the two splicing plates (61), and the ends of the convex plates are arranged in contact with the shaft body; a pressure plate (62) is also arranged on the inner side of each splicing plate (61), and the pressure plate (62) is in contact with the second push plate (52) and can move axially to adjust the compression amount of the spring group (5).

7. The mechanical sealing device for a boiler feed water pump according to claim 1, characterized in that: The exhaust fan (3) comprises two clamping arc plates (31) and a plurality of fan blades (32) connected by bolts; the two clamping arc plates (31) are spliced ​​and sleeved on the shaft; and the plurality of fan blades (32) are evenly distributed on the outsides of the two clamping arc plates (31).

8. The mechanical sealing device for a boiler feed water pump according to claim 1, characterized in that: The wind bin (7) comprises two interconnected semi-annular bins (76); a plurality of air holes (72) are provided on the side wall of the wind bin (7) adjacent to the exhaust fan (3).

9. The mechanical sealing device for a boiler feed water pump according to claim 8, characterized in that: The wind bin (7) further comprises two fastening plates (75); a screw rod (73) is provided on the side wall of the semi-ring bin (76); the fastening plate (75) is provided at the intersection of the two semi-ring bins (76), and the fastening plate (75) is sleeved on the screw rod (73).

10. The mechanical sealing device of a boiler feed water pump according to claim 1, characterized in that: A snap groove (42) is provided on the outer frame of the semiconductor refrigeration plate (4); the sleeve shell (41) is sleeved on the outer frame, and a snap column (43) is provided on the side wall of the sleeve shell (41) in contact with the outer frame, and the snap column (43) is installed in the snap groove (42); the ventilation pipe (71) is installed in communication with one end of the sleeve shell (41), and a ventilation gap is left between the other end of the sleeve shell (41) and the semiconductor refrigeration plate (4).

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