Patent Application
20170051746
The following relates to a pump and in particular to a corrosion-resistant and wear-resistant chemical centrifugal pump.
Chemical centrifugal pumps are widely applied in industries such as petroleum, chemical industry, metallurgy and pharmacy. Currently, the common chemical centrifugal pumps in the market can only transport media having physical properties similar to those of water (without impurities and particles). In addition, after a period of time of use, wear from material on pump vanes leads to internal leakage between the pump vanes and the pump body, and thus leads to an increase in noise and an obvious power loss. When repaired, the centrifugal pump must be taken out to be machined again and reassembled for the purpose of leakage and noise prevention.
Structures of traditional chemical centrifugal pumps belong are known. For example, in document CN202047988U, a chemical centrifugal pump is disclosed, including a stationary mechanical sealing ring, a stationary ring seat and a mechanical sealing spring, characterized in that an impeller placed at a left end of a shaft is provided in a sealing cavity formed of a pump body and a pump cover, and a top end of the impeller is locked tightly by an impeller nut, and a moving mechanical sealing ring is provided in a slot at a right end of the impeller; a shaft sleeve, a mechanical sealing spring and a sealing box are, from inside to outside, successively sleeved on a shaft at a junction between the pump cover and a bracket; the stationary ring seat is sleeved at the left edge of the sealing box, a spring base is provided in the stationary ring seat, the stationary mechanical sealing ring is provided at a left end of the spring base, and a water nozzle is provided at a bottom right end of the sealing box; and a bearing set is provided on a shaft inside an internal cavity at a right end of the bracket, a grease nozzle is provided above the bearing set, and a suspension support is provided below a right end of the bracket. When implemented specifically, due to difference in media, different kinds of material can be employed to manufacture the chemical centrifugal pump. Usually, the chemical centrifugal pump is made of 324, 304, 316, duplex steel, CD4Mcu and the like. The cooling water is opened before the pump is started. The volume and pressure of the cooling water are preferably modest as long as there is water flowing. If the temperature is lower than 60° C., no cooling water is required. A pressure gauge and a valve on a discharge conduit are closed, if there is a bypass pipe, the bypass pipe should also be closed first. A motor is started, and the pressure gauge on the discharge conduit is opened slowly. When the revolving speed of the pump is normal, a valve on the discharge conduit is opened slowly, and the pressure is adjusted to a desired pressure. In a case where the valve on the discharge conduit is closed, the pump can only be continuously used for not more than three minutes. When the pump is operating, a temperature rise of the bearing should be within 75° C. The flow cannot be controlled with a valve on a suction conduit, in order to prevent cavitation corrosion; the pump cannot be continuously used at a flow which is lower than 30% of the designed flow; if the flow is too large, a bypass should be provided on the discharge conduit to discharge an excessive flow. When the pump is stopped, the valve on the discharge conduit is closed slowly. If the pump is used in a case of flow intrusion, the valve on the suction conduit and all the instruments should also be closed. The cooling water is closed. If an ambient temperature is lower than the freezing point of the transported liquid, liquid inside a pump cavity should be emptied to prevent the pump from being frozen off If the pump is out of service for a long period of time, apart from emptying liquid inside the pump cavity, components especially the sealing cavity should be detached and cleaned.
In document CN200943607Y, a high-temperature and multi-stage chemical centrifugal pump is disclosed, including a pump shaft, an impeller set, a mechanical seal, an inlet segment, an outlet segment and a bearing body. The bearing body is fixed at one end of the outlet segment of the pump, and the other end of the outlet segment is fixed with the inlet segment by the impeller set. The pump shaft is fixed on the bearing body by the bearing, and two sets (a front set and a rear set) of bearing sleeves and a mechanical seal are provided on the pump shaft. Balancing drums are provided in gaps between the impeller set, and the rear shaft sleeve and the mechanical seal. The balancing drum is sleeved on the pump shaft. Helical grooves are provided on an outer circumferential surface of the balancing drum. Since helical grooves are provided on the outer circumferential surface of the balancing drum, when the pump is in use, the balancing drum is driven by the pump shaft to rotate at high speed. In this way, the liquid inside the balancing drum groove generates a forward axial force offset by a backward axial force generated by the impeller set, so that no axial force is generated at a rear end of the pump shaft. Thus, the service life of the bearing is improved fundamentally, and the efficiency of the pump is greatly improved.
In document CN2168972Y, a mechanical seal of a petrochemical multi-stage centrifugal pump applied on a centrifugal pump is disclosed, including a gland sealing ring (1), a gland (2), a press plate (3), a protection sleeve (4), a sealing ring for a floating ring (5), a floating ring (6), a spring (7), a rotating ring (8), a sealing ring for a rotating ring (9), a cotter (10), a driving ring (11), a fastening washer (12) and a set screws with dog point (13). A ring-shaped hard alloy sheet (14) is beset inside the floating ring (6), and a ring-shape hard alloy sheet (15) is beset inside the rotating ring (8) or the rotating ring (8) is completely made of graphite. When in use, after the gland sealing ring (1) is mounted inside a slot for the gland (2), they are altogether mounted inside end cover fill openings of a suction segment and an extrusion segment of the pump and their end surfaces are leveled. The protection sleeve (4) is mounted inside an end surface slot for the gland (2). The press plate (3), the protection sleeve (4) and the gland (2) are fastened on the end cover by screws. The spring (7) is mounted inside an end surface hole for the gland (2). The sealing ring for a floating ring (5) is mounted inside an outer circumferential slot for the floating ring (6) beset with the hard alloy sheet (14), and then they are altogether mounted inside a hole of the gland (2) and against the spring (7). A ball head of the protection sleeve (4) is mounted inside the outer circumferential slot for the floating ring (6), and then the rotating ring (8) and the sealing ring for the rotating ring (9) are altogether mounted on a pump shaft sleeve. The cotter (10) is mounted on the driving ring (11) and then mounted on the shaft sleeve, so that the cotter (10) is inserted into an end surface hole for the rotating ring (8) to bring a besetting end surface of the floating ring (6) into contact with a besetting end surface of the rotating ring (8), and the pressure (i.e., a sealed pressing force) between the two besetting end surfaces can be calculated according to requirements of the pump. After the driving ring (11), the rotating ring (8) and the floating ring (6) are pushed so that the pressure of a counterforce generated by the compression of the spring (7) meets the design requirement, the fastening washer (12) and the set screws with dog point (13) are mounted to the driving ring (11) and the driving ring (11) is fastened on the shaft sleeve by the set screws with dog point (13). When a transport medium flows into the fill opening, since a gap between the fill opening and the gland (2) is sealed by the gland sealing ring (1) and a gap between the gland (2) and the floating ring (6) is sealed by the floating sealing ring (5), the transport medium can only flow from a gap between an internal hole for the floating ring (6) and the shaft sleeve to a gap between the floating ring (6) and the rotating ring (8). The gaps are sealed by a contact-type sealing end surface, thus the transport medium cannot overflow. However, a gap between the rotating ring (8) and the shaft sleeve is sealed by the sealing ring for the rotating ring (9). A predetermined sealing pressure between a sealing end surface of the floating ring (7) and a sealing end surface of the rotating ring (8) is generated in combination with the counterforce generated by the compressed spring (7) and the pressure of the sealed medium. When the predetermined sealing pressure is reached, the floating ring (6) is fitted with the rotating ring (8), with the friction end surfaces coming into close contact with each other. When a shaft (a shaft sleeve) rotates or remains still, the sealed medium can be prevented from leaking from the friction sealing end surface between the floating ring (6) and the rotating ring (8). In this way, the functions of sealing and shaft sealing by a multi-stage centrifugal pump can be realized.
Traditional chemical centrifugal pumps can only transport media having physical properties similar to those of water (without impurities and particles). Unreasonable sealing structures can easily lead to obstruction due to a high content of solid of the medium and also leakage due to wear and corrosion.
An aspect relates to a corrosion-resistant and wear-resistant chemical centrifugal pump. According to a first aspect of embodiments of the present invention, the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention includes a pump body, an impeller nut, an impeller, a pump cover, a mechanical sealing set, a sealing box, a shaft sleeve, a bracket, a bearing gland, a bearing, a pump shaft and a suspension support; the pump body is connected to the suspension bracket by a bolt and a base; the pump body is fixed on the bracket by a bolt; the mechanical sealing set includes a moving mechanical sealing ring and a stationary mechanical sealing ring, wherein the moving mechanical sealing ring is provided on the impeller; the pump cover, together with the sealing box and the mechanical sealing set, is provided on a pump shaft, wherein the pump cover is connected to the sealing box by a bolt; the stationary mechanical sealing ring, a stationary ring seat and a spring are arranged between the pump cover and the sealing box; the shaft sleeve is sleeved on the shaft; and the bearing gland is connected onto the bracket by a bolt; and the shaft and the bracket are detachably connected.
According to a second aspect of embodiments of the present invention, the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention further includes a water-cooling system which includes a cooling water nozzle and a cooling water pipeline connected to the cooling water nozzle.
According to a third aspect of embodiments of the present invention, the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention is a single-stage and single-suction horizontal centrifugal pump.
According to a fourth aspect of embodiments of the present invention, a diameter of the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention is between 25 mm and 500 mm.
According to a fifth aspect of embodiments of the present invention, a flow of the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention is between 1.6 m3/h and 3000 m3/h.
According to a sixth aspect of embodiments of the present invention, an overflow component of the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention is made of duplex stainless steel.
According to a seventh aspect of embodiments of the present invention, an applicable temperature of the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention is between −20° C. and +150° C.
According to an eighth aspect of embodiments of the present invention, an applicable medium for the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention is acid, alkali and/or salt of any concentration with a content of solid being lower than or equal to 40%, medium particles being hard and/or soft.
According to a ninth aspect of embodiments of the present invention, the applicable medium for the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention is lime slurry, mud slurry, cinder liquid, slag liquid, waste acid and/or sewage.
According to a tenth aspect of embodiments of the present invention, a method for mounting the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention is provided, including the following steps:
A. checking whether the net positive suction head when the pump operates exceeds the maximum net positive suction head permitted by the pump or not; if the net positive suction head when the pump operates does not exceed the maximum net positive suction head, continuing the following steps; and if the net positive suction head when the pump operates exceeds the maximum net positive suction head, stopping the mounting process;
B. providing a separated support for a liquid inlet and a liquid outlet of the pump;
C. making a foundation plane for mounting the pump by foundation concrete; after the concrete is solidified, placing the pump on the foundation plane; checking whether the pump is leveled with a motor shaft or not by a level; if the pump is not leveled with the motor shaft, aligning them with a sizing block until they are leveled with each other; and then, grouting concrete into a base and an anchor bolt hole by a grouting hole;
D. after the concrete becomes dry and solid, checking whether the base is loose from the anchor bolt hole; if the base is not loose from the anchor bolt hole, tightening the anchor bolt, and checking the levelness again; checking the concentricity between the pump shaft and the motor shaft, and measuring an excircle of a coupling, with a difference between up and down, right and left being lower than or equal to 0.1 mm, and a difference between a maximum gap and a minimum gap of a gap between end surfaces of two couplings on a circle being not more than 0.3 mm; and
E. when a mounting position of the pump is higher than a liquid level, mounting a bottom valve on a bottom end of a liquid inlet pipe, and providing a threaded grouting hole or a valve on a liquid outlet pipe to fill the pump before startup; and when a mounting position of the pump is lower than a liquid level, mounting a control valve and a filtering device on the liquid inlet pipe of the pump to prevent large sundries from being sucked into the pump.
The method for mounting the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention relates to components or process steps well-known in the art, for example, the structure of a coupling, the structure of a bottom valve, the structure for controlling a valve and the structure of a filtering device. Since the structures of these components are well-known in the art and can be obtained by those skilled in the art who are familiar with technical common sense in the art, no further description will be given in this description to these well-known techniques.
Before the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention is started, it is required to check whether the inside of the pump bearing is filled with lithium-based grease or not. If the inside of the pump bearing is not filled with lithium-based grease, the lithium-based grease should be filled into the pump bearing from the grease nozzle. Then, whether the rotation direction of the electromotor is right or not is checked; and idling and inverting of the electromotor are prohibited. The coupling is rotated with hands to check whether the coupling is smooth with an even weight or not. Besides, whether there is a friction noise inside the pump should be distinguished. If there is a friction noise, the friction noise should be eliminated. Then, a protection shield for the coupling is mounted. If the temperature of the medium exceeds 60° C., cooling water must be connected to the cooling water nozzle of the pump. The cooling water plays a role of thermal insulation and temperature reduction. The flow and the flow rate of the cooling water are preferably modest. When the foregoing steps are all set, the valve on the liquid inlet pipe is opened, and the valve on the liquid outlet pipe is closed. The electromotor is started. The pressure gauge of the liquid outlet is opened, and the valve on the liquid outlet pipe is opened slowly to adjust the pressure to a desired pressure. It is undesirable to operate the pump for a long period of time at a flow which is lower than 30% of the designed flow. If the pump must be used at such a condition, a bypass pipe should be mounted on the discharge conduit, and a bypass valve is provided on the bypass pipe to adjust the flow of the pump, so that the flow of the pump can meet the specified range of use. During the use, a temperature rise of the bearing of the pump and of the motor bearing should be checked, and the temperature rise of the bearing should be within 75° C. It is absolutely not permitted to use the valve on the liquid inlet pipe to adjust the flow, in order to prevent cavitation corrosion. During the operation, if abnormal sounds or other failures are detected, the pump should be stopped and checked immediately. The pump can operate continuously only when the failures are completely removed.
With regard to the corrosion-resistant and wear-resistant chemical centrifugal pump according to embodiments of the present invention, when the pump is stopped, the valve on the liquid outlet pipe should be closed slowly. If the mounting position of the pump is lower than the liquid level, the valve on the liquid inlet pipe and all the instruments should be closed. The power supply is turned off If the cooling water is connected to the pump, the cooling water should be closed only when the pump is stopped completely. If the ambient temperature is lower than the freezing point of the liquid, the liquid inside the pump should be emptied to prevent the pump from being frozen off If the pump is out of service for a long period of time, apart from emptying the liquid inside the pump, the pump should be cleaned by clean water. Especially, the sealed chamber should be cleaned completely. The best way is to take the pump apart to clean it and then reassemble the pump, and store the pump properly.
The corrosion-resistant and wear-resistant pump according to embodiments of the present invention, due to its advantages such as wide application range, long service life, wear-resistance, corrosion-resistance and obstruction-free, can be applicable to media such as acid, alkali and/or salt of any concentration with a content of solid being lower than or equal to 40% and without restriction on hardness or softness of the particles.
Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:
As shown in
The corrosion-resistant and wear-resistant chemical centrifugal pump further includes a water-cooling system which includes a cooling water nozzle and a cooling water pipeline (not shown) connected to the cooling water nozzle. If the temperature of the medium exceeds 60° C., cooling water must be connected to the cooling water nozzle of the pump. The cooling water plays a role of thermal insulation and temperature reduction. The flow and the flow rate of the cooling water are preferably modest.
The corrosion-resistant and wear-resistant chemical centrifugal pump is a single-stage and single-suction horizontal centrifugal pump with a diameter being between 25 mm and 500 mm and a flow being between 1.6 m3/h and 3000 m3/h.
An overflow component of the corrosion-resistant and wear-resistance chemical centrifugal pump is made of duplex stainless steel.
An applicable temperature of the corrosion-resistant and wear-resistant chemical centrifugal pump is between −20° C. and +150° C.
An applicable medium for the corrosion-resistant and wear-resistant chemical centrifugal pump of embodiments of the present invention is acid, alkali and/or salt of any concentration with a content of solid being lower than or equal to 40%, medium particles being hard and/or soft.
The applicable medium for the corrosion-resistant and wear-resistant chemical centrifugal pump according to embodiments of the present invention is lime slurry, mud slurry, cinder liquid, slag liquid, waste acid and/or sewage.
Whether the mounting of a pump is reasonable or not exerts significant influence on the normal operation and service life of the pump. As for the corrosion-resistant and wear-resistant chemical centrifugal pump according to embodiments of the present invention, since the mechanical seal is applicable to particle-resistant conditions and the mechanical seal is a mechanical component having an extremely high precision, in order to promise excellent sealing effects, the pump should be mounted and used strictly according to the mounting method provided by embodiments of the present invention.
The method for mounting corrosion-resistant and wear-resistant chemical centrifugal pump includes the following steps:
B. providing a separated support for a liquid inlet and a liquid outlet of the pump;
C. making a foundation plane for mounting the pump by foundation concrete; after the concrete is solidified, placing the pump on the foundation plane; checking whether the pump is leveled with a motor shaft or not by a level; if the pump is not leveled with the motor shaft, aligning them with a sizing block until they are leveled with each other; and then, grouting concrete into a base and an anchor bolt hole by a grouting hole;
D. after the concrete becomes dry and solid, checking whether the base is loose from the anchor bolt hole; if the base is not loose from the anchor bolt hole, tightening the anchor bolt, and checking the levelness again; checking the concentricity between the pump shaft and the motor shaft, and measuring an excircle of a coupling, with a difference between up and down, right and left being lower than or equal to 0.1 mm, and a difference between a maximum gap and a minimum gap of a gap between end surfaces of two couplings on a circle being not more than 0.3 mm; and
E. when a mounting position of the pump is higher than a liquid level, mounting a bottom valve on a bottom end of a liquid inlet pipe, and providing a threaded grouting hole or a valve on a liquid outlet pipe to fill the pump before startup; and when a mounting position of the pump is lower than a liquid level, mounting a control valve and a filtering device on the liquid inlet pipe of the pump to prevent large sundries from being sucked into the pump.
The method for mounting the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention relates to components or process steps well-known in the art, for example, the structure of a coupling, the structure of a bottom valve, the structure for controlling a valve and the structure of a filtering device. Since the structures of these components are well-known in the art and can be obtained by those skilled in the art who are familiar with technical common sense in the art, no further description will be given in this description to these well-known techniques.
Before the corrosion-resistant and wear-resistant chemical centrifugal pump described in embodiments of the present invention is started, it is required to check whether the inside of the pump bearing is filled with lithium-based grease or not. If the inside of the pump bearing is not filled with lithium-based grease, the lithium-based grease should be filled into the pump bearing from the grease nozzle. Then, whether the rotation direction of the electromotor is right or not is checked; and idling and inverting of the electromotor are prohibited. The coupling is rotated with hands to check whether the coupling is smooth with an even weight or not. Besides, whether there is a friction noise inside the pump should be distinguished. If there is a friction noise, the friction noise should be eliminated. Then, a protection shield for the coupling is mounted. If the temperature of the medium exceeds 60° C., cooling water must be connected to the cooling water nozzle of the pump. The cooling water plays a role of thermal insulation and temperature reduction. The flow and the flow rate of the cooling water are preferably modest. When the foregoing steps are all set, the valve on the liquid inlet pipe is opened, and the valve on the liquid outlet pipe is closed. The electromotor is started. The pressure gauge of the liquid outlet is opened, and the valve on the liquid outlet pipe is opened slowly to adjust the pressure to a desired pressure. It is undesirable to operate the pump for a long period of time at a flow which is lower than 30% of the designed flow. If the pump must be used at such a condition, a bypass pipe should be mounted on the discharge conduit, and a bypass valve is provided on the bypass pipe to adjust the flow of the pump, so that the flow of the pump can meet the specified range of use. During the use, a temperature rise of the bearing of the pump and of the motor bearing should be checked, and the temperature rise of the bearing should be within 75° C. It is absolutely not permitted to use the valve on the liquid inlet pipe to adjust the flow, in order to prevent cavitation corrosion. During the operation, if abnormal sounds or other failures are detected, the pump should be stopped and checked immediately. The pump can operate continuously only when the failures are completely removed.
With regard to the corrosion-resistant and wear-resistant chemical centrifugal pump according to embodiments of the present invention, when the pump is stopped, the valve on the liquid outlet pipe should be closed slowly. If the mounting position of the pump is lower than the liquid level, the valve on the liquid inlet pipe and all the instruments should be closed. The power supply is turned off If the cooling water is connected to the pump, the cooling water should be closed only when the pump is stopped completely. If the ambient temperature is lower than the freezing point of the liquid, the liquid inside the pump should be emptied to prevent the pump from being frozen off If the pump is out of service for a long period of time, apart from emptying the liquid inside the pump, the pump should be cleaned by clean water. Especially, the sealed chamber should be cleaned completely. The best way is to take the pump apart to clean it and then reassemble the pump, and store the pump properly.
The structure and the mounting method of embodiments of the present invention have been described and explained with reference to the illustrative process flowcharts. On the basis of the foregoing description, the additional variations and modifications are apparent for a person of ordinary skill in the art, and those variations and modifications are within the protection scope of the present application. The protection scope of embodiments of the present invention is defined by the appended claims.
Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.
For the sake of clarity, it is to be understood that the use of ‘a’ or ‘an’ throughout this application does not exclude a plurality, and ‘comprising’ does not exclude other steps or elements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014107482486 | Dec 2014 | CN | national |
This application claims priority to PCT Application No. PCT/CN2015/087499, having a filing date of Aug. 19, 2015, based off of Chinese Application No. 2014107482486, having a filing date of Dec. 10, 2014 the entire contents of which are hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2015/087499 | 8/19/2015 | WO | 00 |
