CN115405535A - Protection method for mechanical seal of tetrafluoro pump - Google Patents
Protection method for mechanical seal of tetrafluoro pump Download PDFInfo
- Publication number
- CN115405535A CN115405535A CN202211034069.7A CN202211034069A CN115405535A CN 115405535 A CN115405535 A CN 115405535A CN 202211034069 A CN202211034069 A CN 202211034069A CN 115405535 A CN115405535 A CN 115405535A
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- Prior art keywords
- current
- mechanical seal
- pump
- tetrafluoro
- motor
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- 238000000034 method Methods 0.000 title claims abstract description 17
- 239000000463 material Substances 0.000 abstract description 19
- 238000001816 cooling Methods 0.000 abstract description 13
- 230000000694 effects Effects 0.000 abstract description 3
- 238000012423 maintenance Methods 0.000 abstract description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 15
- 238000001514 detection method Methods 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 4
- 239000004810 polytetrafluoroethylene Substances 0.000 description 4
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 4
- 239000000498 cooling water Substances 0.000 description 3
- 238000003825 pressing Methods 0.000 description 3
- 230000005611 electricity Effects 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000005856 abnormality Effects 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000012916 structural analysis Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
- F04D15/0077—Safety measures
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
- F04D15/0088—Testing machines
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
- F04D15/02—Stopping of pumps, or operating valves, on occurrence of unwanted conditions
- F04D15/0245—Stopping of pumps, or operating valves, on occurrence of unwanted conditions responsive to a condition of the pump
- F04D15/0254—Stopping of pumps, or operating valves, on occurrence of unwanted conditions responsive to a condition of the pump the condition being speed or load
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/02—Selection of particular materials
- F04D29/026—Selection of particular materials especially adapted for liquid pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/58—Cooling; Heating; Diminishing heat transfer
- F04D29/586—Cooling; Heating; Diminishing heat transfer specially adapted for liquid pumps
- F04D29/588—Cooling; Heating; Diminishing heat transfer specially adapted for liquid pumps cooling or heating the machine
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- General Physics & Mathematics (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
The invention relates to a method for protecting a tetrafluoro pump mechanical seal, which is characterized in that a module for detecting the current of a main circuit is arranged on the main circuit of a motor for controlling the action of a tetrafluoro pump, a switch is connected in series with a control circuit of the motor for controlling the action of the tetrafluoro pump, the switch is controlled to be disconnected when the module for detecting the current of the main circuit detects that the current is less than a set value, so that the control circuit of the motor for controlling the action of the tetrafluoro pump is disconnected, and the motor stops. In the invention, the conventional that an external cooling mode is adopted to cool the mechanical seal is broken through, the on-off control of a switch caused by current change is applied to the cooling of the mechanical seal, and meanwhile, the change of the current when the pump body is in no-load and full-load is utilized to skillfully control the motor of the tetrafluoro pump to stop in time when the material is insufficient to circulate or idles, so that the risk of damage is avoided, and the problem of cooling the mechanical seal is solved from the aspect of the electric appliance principle; the technical scheme is simple and easy to implement, has outstanding effect, improves the service cycle of the mechanical seal, and reduces the maintenance cost.
Description
Technical Field
The invention belongs to the technical field, and particularly relates to a method for protecting a mechanical seal of a tetrafluoro pump.
Background
The PTFE pump is a plastic pump for short, is named after the material of the PTFE pump, and the pump shell, the impeller and the pump are made of PTFE plastic, are internally provided with steel inserts and are molded at high temperature, so that the PTFE pump has the characteristics of deformation resistance, ageing resistance, cracking resistance, corrosion resistance, leakage resistance, acid and alkali resistance and the like, and is widely applied in the chemical industry.
The tetrafluoro pump is usually provided with a tetrafluoro mechanical seal to ensure the sealing performance in the operation process, when the tetrafluoro pump runs at a high speed, the tetrafluoro pump generates high temperature, and when materials flow through the tetrafluoro pump, the materials can cool the mechanical seal when flowing through a pump body, so that the phenomenon that the mechanical seal is damaged due to high temperature is avoided; however, when the pump body is short of materials or sudden abnormality occurs, because sufficient material circulation is not available to cool the mechanical seal, the mechanical seal is damaged by high temperature in actual work for 3-15 minutes, and the seal fails, in the current stage, the cooling of the mechanical seal is usually realized by adopting an external cooling water mode, for example, a patent document with the publication number of CN 101149065A discloses a high temperature resistant lining tetrafluoro pump mechanical seal cooling water device, wherein a water cooling cover is arranged on the mechanical seal pressing cover, and a water inlet and a water outlet are arranged on the water cooling cover to cool the mechanical seal, although a certain cooling effect is achieved, some defects still exist in the use process, for example, a water cooling cover and an external water circulation device are additionally arranged, so that the installation is very inconvenient, and in addition, because the water cooling cover and the mechanical seal pressing cover are mechanically matched, the structural strength of the mechanical seal pressing cover is changed; in addition, a cavity formed by the water inlet and the water outlet wraps a gap between the original machine seal and the pump body, if accidental leakage of materials occurs at the gap, due to the existence of water circulation damage, the gap cannot be found outside completely, certain economic loss is caused, and meanwhile, the accurate production cannot be ensured, so that a novel machine seal protection method is provided urgently.
Disclosure of Invention
The invention aims to provide a method for protecting a mechanical seal of a tetrafluoro pump, which aims to solve the problem that the mechanical seal cannot be effectively cooled due to material loss caused by small material circulation or accidental faults of the tetrafluoro pump.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for protecting the mechanical seal of a tetrafluoro pump is characterized in that a module for detecting the current of a main circuit is arranged on the main circuit of a motor for controlling the action of the tetrafluoro pump, a switch is connected in series with a control circuit of the motor, and when the module for detecting the current of the main circuit detects that the current is smaller than a set value, the switch is controlled to be disconnected, and the motor is stopped.
Preferably, the module for detecting the current of the main circuit is a current transformer, and the current transformer is electrically connected with one phase of the main circuit; the switch is a normally closed switch; the output end of the current transformer is connected with the input end of the operation module, and the output end of the operation module is connected with the normally closed switch.
Preferably, the number of the current transformers is three, the three current transformers are respectively and correspondingly electrically connected with three phases, and output ends of the three current transformers are connected with an input end of the operation module; when the current detected by any two of the three current transformers is smaller than a set value, the signal output by the operation module drives the normally closed switch to be switched off.
The invention has the beneficial effects that:
in the invention, the conventional method of cooling the mechanical seal by adopting an external cooling mode is broken through, the on-off control of a switch caused by current change is applied to the cooling of the mechanical seal, and meanwhile, the change of current when a pump body is in no-load and full-load is utilized to skillfully control the motor of the tetrafluoro pump to stop in time when materials are not circulated sufficiently or idling, so that the risk of damage is avoided, and the problem of cooling the mechanical seal is solved on the basis of the principle of an electric appliance; the technical scheme is simple and easy to implement, has outstanding effect, improves the service cycle of the mechanical seal, and reduces the maintenance cost.
Drawings
Fig. 1 is a circuit diagram of a main circuit and a control circuit of a motor according to the present invention.
Names corresponding to the marks in the figure:
1. the device comprises a starting switch, 2 a stopping switch, 3 a contactor, 4 an auxiliary contact, 5 a current transformer, 6 and a normally closed switch.
Detailed Description
The technical solutions in the embodiments of the present invention are clearly and completely described below.
The embodiment of the invention comprises the following steps:
the tetrafluoro pump is usually provided with a tetrafluoro mechanical seal to ensure the sealing performance in the operation process, when the tetrafluoro pump runs at a high speed, the tetrafluoro pump generates high temperature, and when materials flow through the tetrafluoro pump, the materials can cool the mechanical seal when flowing through a pump body, so that the phenomenon that the mechanical seal is damaged due to high temperature is avoided; however, when the pump body lacks the material or the proruption is unusual, because do not have sufficient material circulation to cool off the machine and seal, will be damaged by high temperature in the actual work 3-15 minutes, cause sealed inefficacy, adopt usually at present stage to cool off like external cooling water, this mode needs extra set up water circulation bad equipment, need dock with the machine seal shell simultaneously, influence the structural strength of machine closing cap, the cavity that forms simultaneously still can shelter from the clearance between machine seal and the casing, in case the weeping takes place, also can't discover at the very first time, thereby cause certain economic loss, also influence the normal clear of work.
When the tetrafluoro pump works normally, the materials are fully loaded, and the mechanical seal is cooled to a certain degree when the materials flow through the pump body and the mechanical seal; when the flow in the tetrafluoro pump is reduced, the circulation of materials is not enough to sufficiently cool the mechanical seal, and the mechanical seal is damaged after long-time operation; when the pump body idles, no material circulates in the pump body, and the mechanical seal cannot be cooled completely, so that the pump body is damaged finally; the following experiment was performed to verify the change in the motor current, considering the presence and amount of the material load.
Experiment 1: the running detection is carried out on a tetrafluoro pump with the motor power of 11KW, in the process, the circulating medium is water, the temperature is 23.3 ℃, the tetrafluoro pump runs for 1 hour simultaneously and collects the passing current of each phase of electricity on the main circuit of the motor, and the detection result is shown in the table 1:
| run time | A current | B current | C current of |
| 10min | 17.9A | 18.4A | 18.3A |
| 20min | 18.0A | 18.3A | 18.2A |
| 30min | 17.8A | 18.3A | 18.3A |
| 40min | 18.2A | 18.4A | 18.1A |
| 50min | 18.3A | 18.5A | 18.0A |
| 60min | 17.8A | 18.0A | 18.2A |
TABLE 1
Wherein, the current A, the current B and the current C are respectively the current detected in each phase.
After that, the water supply to the pump body was stopped, and the current per phase was measured four times, and the results are shown in table 2:
| number of tests | A current of | B current of | C current of |
| 1 | 12.6A | 12.4A | 11.8 |
| 2 | 12.3A | 12.6A | 12.3 |
| 3 | 12.4A | 11.8A | 12.2 |
| 4 | 12.4A | 12.1A | 12.4A |
TABLE 2
Experiment 2: the running detection is carried out on a tetrafluoro pump with 5.5KW motor power, in the process, a circulating medium is water, the temperature is 23.3 ℃, the operation is carried out for 1 hour simultaneously, the passing current of each phase of electricity on a motor main circuit is collected, and the detection result is shown in a table 3:
| run time | A current of | B current | C current of |
| 10min | 9.8A | 10.1A | 10.0A |
| 20min | 10.0A | 10.1A | 10.1A |
| 30min | 10.2A | 10.3A | 10.1A |
| 40min | 10.0A | 10.2A | 10.2A |
| 50min | 9.8A | 10.3A | 10.1A |
| 60min | 9.9A | 10.1A | 10.1A |
TABLE 3
Wherein, the current A, the current B and the current C are respectively the current detected in each phase.
After that, the water supply to the pump body was stopped, and the current per phase was measured four times, and the results are shown in table 4:
| number of tests | A current of | B current of | |
| 1 | 7.3A | 7.2A | 7.5 |
| 2 | 7.5A | 7.3A | 7.4 |
| 3 | 7.1A | 7.2A | 7.3 |
| 4 | 7.2A | 7.2A | 7.4A |
TABLE 4
Structural analysis of two experiments shows that the current on a main loop of a motor for controlling the action of the tetrafluoro pump is reduced under the condition of idling of a pump body, and after the conclusion is obtained, the technical scheme of the invention is provided:
a module for detecting the current of a main circuit is arranged on the main circuit of a motor for controlling the action of the tetrafluoro pump, the detection module preferably adopts a current transformer 5 in the embodiment, a switch is connected in series on a control circuit of the motor for controlling the action of the tetrafluoro pump, the switch preferably adopts a normally closed switch 6 in the embodiment, the normally closed switch 6 is connected through an operation module, when the current transformer 5 detects that the current is less than a set value, the normally closed switch 6 is controlled to be disconnected, the control circuit of the motor for controlling the action of the tetrafluoro pump is disconnected, and the motor is stopped; specifically, the output end of the current transformer 5 is connected with the input end of the operation module, and the output end of the operation module is connected with the normally closed switch 6; in actual operation, as shown in fig. 1, when the starting switch 1 is closed, and the motor operates in a no-load state, the current transformer 5 detects that the current is reduced, the normally closed switch 6 is controlled to be opened through the operation module, the contactor 3 is lost, the auxiliary contact 4 is disconnected, and the motor stops operating; in the process, the normally closed switch 6 has the same function as the original stop switch 2 on the control loop, and the normally closed switch and the original stop switch both break the circuit.
In the table, because the current in each phase can be reduced and the phases are close, in order to ensure the accuracy of the operation module driving the normally closed switch 6 to act, three current transformers are specially arranged, when any two-phase current in the detected three-phase current is smaller than a set value, the operation module outputs a control signal, a coil in the normally closed switch 6 is electrified, and a normally closed contact is opened, so that a control circuit of a motor can be disconnected, the motor is stopped, and the problem that the machine seal is burnt due to the no-load operation of a pump body is avoided. It should be noted that in other embodiments, only one current transformer 5 may be provided to detect the current.
In other embodiments, the normally closed switch 6 may also be designed to be delayed according to the time from the beginning of idle running to the damage of the mechanical seal.
When it needs to be described, the control relationship and the delay design among the current transformer 5, the operation module, and the normally closed switch 6 in this embodiment are all the prior art, and are not described in detail herein.
The present invention is not limited to the above preferred embodiments, and any other various products can be obtained by anyone in light of the present invention, but any changes in shape or structure thereof, which are similar or identical to the technical solution of the present invention, fall within the protection scope of the present invention.
Claims (3)
1. A method for protecting a mechanical seal of a tetrafluoro pump is characterized by comprising the following steps: the method comprises the steps that a module for detecting the current of a main circuit is arranged on the main circuit of a motor for controlling the action of a tetrafluoro pump, a switch is connected in series with a control circuit of the motor, and when the module for detecting the current of the main circuit detects that the current is smaller than a set value, the switch is controlled to be disconnected, and the motor stops.
2. The method for protecting the mechanical seal of the tetrafluoro pump according to claim 1, characterized in that: the module for detecting the current of the main circuit is a current transformer, and the current transformer is electrically connected with one phase in the main circuit; the switch is a normally closed switch; the output end of the current transformer is connected with the input end of the operation module, and the output end of the operation module is connected with the normally closed switch.
3. The method for protecting the mechanical seal of the tetrafluoro pump according to claim 2, characterized in that: the three current transformers are respectively and correspondingly electrically connected with the three phases, and the output ends of the three current transformers are connected with the input end of the operation module; when the current detected by any two of the three current transformers is smaller than a set value, the signal output by the operation module drives the normally closed switch to be switched off.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211034069.7A CN115405535A (en) | 2022-08-26 | 2022-08-26 | Protection method for mechanical seal of tetrafluoro pump |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211034069.7A CN115405535A (en) | 2022-08-26 | 2022-08-26 | Protection method for mechanical seal of tetrafluoro pump |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115405535A true CN115405535A (en) | 2022-11-29 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211034069.7A Pending CN115405535A (en) | 2022-08-26 | 2022-08-26 | Protection method for mechanical seal of tetrafluoro pump |
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| Country | Link |
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| CN (1) | CN115405535A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000050487A (en) * | 1998-07-27 | 2000-02-18 | Toshiba Corp | Load control device |
| CN1885659A (en) * | 2006-06-14 | 2006-12-27 | 淄博永麒化工技术开发有限公司 | Electronic anti-slip protector |
| KR20160072461A (en) * | 2014-12-15 | 2016-06-23 | 전북대학교산학협력단 | Deepwater Pump Multi-Function Controller |
| CN215595898U (en) * | 2021-08-16 | 2022-01-21 | 云南效维节能科技有限公司 | Anti-idling multi-stage centrifugal energy-saving water pump |
| CN215949861U (en) * | 2021-09-06 | 2022-03-04 | 青岛天尧新材料有限公司 | Water pump capable of preventing machine seal from being burnt out due to idling |
| CN114914884A (en) * | 2022-04-26 | 2022-08-16 | 湖南柿竹园有色金属有限责任公司 | Overheat protection device and protection method for motor of sewage pump |
-
2022
- 2022-08-26 CN CN202211034069.7A patent/CN115405535A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000050487A (en) * | 1998-07-27 | 2000-02-18 | Toshiba Corp | Load control device |
| CN1885659A (en) * | 2006-06-14 | 2006-12-27 | 淄博永麒化工技术开发有限公司 | Electronic anti-slip protector |
| KR20160072461A (en) * | 2014-12-15 | 2016-06-23 | 전북대학교산학협력단 | Deepwater Pump Multi-Function Controller |
| CN215595898U (en) * | 2021-08-16 | 2022-01-21 | 云南效维节能科技有限公司 | Anti-idling multi-stage centrifugal energy-saving water pump |
| CN215949861U (en) * | 2021-09-06 | 2022-03-04 | 青岛天尧新材料有限公司 | Water pump capable of preventing machine seal from being burnt out due to idling |
| CN114914884A (en) * | 2022-04-26 | 2022-08-16 | 湖南柿竹园有色金属有限责任公司 | Overheat protection device and protection method for motor of sewage pump |
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