What pump is used for methanol?

Shielded pumps are a good choice; the ones from Dalian Empire are quite good. Our unit uses them

Shielded pump, right~ That’s the one we use. .

Use a shielded pump; if the flow rate is low, a pneumatic diaphragm pump is also a good option, as it provides good sealing and generally does not leak

For high flow rates, either centrifugal pumps or magnetic drive pumps can be used. Of course, if your factory has high requirements for precision, then go with a diaphragm pump! 1

Some people say that a regular centrifugal pump will do, but I dare not use it; has anyone who is an expert used it?

Use a leak-free magnetic pump or shielded pump.

Of course, it should be a magnetic pump without leaks; I haven’t used shielded pumps, so I’m not familiar with them.

A magnetic pump is a centrifugal pump without mechanical seals, ensuring absolutely no leakage. Its key advantage lies in the use of the best magnetic materials available in the world (rare earth magnets), bearings that are highly resistant to wear (silicon carbide materials), as well as isolation covers made of Hastelloy stainless steel; these elements ensure safety and reliability during use. Requirements for installing HMD magnetic pumps: 1. The pump should be installed as close as possible to the liquid supply source, and preferably below the liquid level in the supply tank. 2. The pump’s mounting base should have a solid and suitable foundation to prevent vibration during operation. 3. The installation of the pump’s inlet pipeline should take into account the resistance at the liquid inlet, by increasing the length of the straight section in the inlet pipeline. (Minimum length = 10 × pipe diameter) to ensure NPSH (Net Positive Suction Head). 4. Ensure that all connections of the inlet pipeline are airtight and leak-free. 5. The inlet and outlet pipes of the pump should be properly supported to prevent the pump casing from being affected by changes in stress. 6. A section of straight pipe should be installed at the inlet and outlet, with a corresponding pressure gauge on each, to help monitor the operation of the pump. 7. Install a check valve on the outlet pipeline, and provide a venting facility between the pump and the check valve to ensure the pump can start properly. Preparations before debugging: 1. This pump must be tested and operated in strict accordance with the operating conditions specified in its manual. If there are significant discrepancies in the operational data, it is necessary to recalculate to avoid damaging the pump. 2. It is absolutely not allowed for this pump to operate dry; dry operation can cause the silicon carbide bearings, shaft sleeves, and thrust washers inside the pump to break down due to a lack of lubrication from the fluid. Therefore, special attention must be paid during testing. 3. Before using the pump for the first time or again after maintenance, it is necessary to fully drain the steam to ensure that the pump chamber is filled with the medium before starting the pump. 4. Before trial operation, it is necessary to pay attention to cleaning and purging the pipes; in particular, iron filings in the pipes must not be present at all, as the magnetic force of the internal magnetic cylinder could attract these iron filings to the isolation cover, thereby jamming the pump and causing damage. 5. Before starting up the pump for trial use, it is advisable to install a temporary filter with a mesh size of 40–60 before the pump’s inlet. (This filter can be removed after it is confirmed that there are no other debris in the pipes.) This measure is intended to prevent debris present in the pipes from entering the pump. However, it is important to monitor the pressure changes before and after the filter, in order to avoid a situation where the pump’s NPSH (net positive suction head) becomes insufficient, which could lead to damage to the pump. 6. Centrifugal pumps must not be operated with the valve closed, and the same applies to magnetic drive pumps; running them with the outlet valve closed can cause the fluid inside the pump to vaporize. When stopping the pump, it is important to note that the inlet valve must not be closed first and then the pump stopped, as this can cause a sudden loss of fluid inside the pump. 7. When the pump is not equipped with protective devices, attention should be paid to changes in the medium being transported, especially changes in the level and temperature inside the tank (which are often overlooked by end users); these factors can also affect the operation of the pump. 8. For magnetic pump units equipped with couplings, it is necessary to realign the couplings before starting the pump. To meet the alignment requirements, a dial indicator is used to adjust the upper and lower edges of the coupling on the motor side and that on the pump side, with the maximum allowable deviation to be 0.4 millimeters or less. If the vertical error is significant, shims can be added at the bottom of the motor or pump; for the horizontal error, the position of the motor or pump can be adjusted. Care should be taken to ensure proper alignment during this process. 9. For pumps equipped with bearing housings, it is important to pay attention to the oil level inside the bearing housing and any changes in that level, in order to prevent the bearings from being damaged due to a lack of oil. This could also lead to damage to the pump as a whole. The oil level should not be too high either, as excessive oil levels can cause the temperature of the oil inside the bearing housing to rise. 10. During operation, pay attention to changes in outlet pressure and flow rate; if these changes are excessive, immediate action should be taken to stabilize the pressure and maintain the flow rate. It must under no circumstances operate at low flow rates. It is also hoped that the traffic volume will not exceed the limit, thereby preventing the motor from operating with excessive current. Trial operation steps: 1. Open all the inlet valves to fill the pump with liquid, then slowly open the outlet valve; if there is an exhaust port, use it to ensure thorough exhaust from the pump. 2. Turn on the motor to verify that its rotation direction is consistent with the direction indicated by the arrow. The jogging time must not exceed three seconds, and jogging is allowed only when there is fluid inside the pump; under no circumstances should the pump be run in reverse for an extended period of time. 3. Open the outlet valve to about 25% of its full opening. 4. Start the motor, and pay attention to the changes in the outlet pressure gauge. Once the pressure rises normally and stays stable, adjust the valve so that the pump operates within its designed operating range. If the outlet pressure is unstable and drops rapidly, the pump must be stopped immediately; exhaust work must be carried out again before restarting it. If the outlet pressure is normal, it indicates that all the gas inside the pump has been removed. 5. If the pressure remains unstable after exhaust is completed, if there is noise or a rumbling sound of stones bouncing inside the pump casing, this is cavitation. The pump should be stopped immediately for inspection, and it should be checked whether the effective NPSH (net positive suction head) meets the operating requirements of the pump. Only after the cause of cavitation is identified and corrected can the commissioning proceed. Note: The pump must not be operated continuously under cavitation conditions. 6. Ensure that the pump operates at normal flow rates; even if the flow rate changes due to process variations, it is necessary to prevent the pump from operating for extended periods at its minimum flow rate. If it is difficult to ensure this, a return line should be installed on the outlet pipeline to regulate the flow rate and ensure the proper operation of the pump. 7. For special pumps (such as high-temperature pumps, low-temperature pumps, high-viscosity pumps, self-priming magnetic pumps, and those that need to operate in parallel due to process requirements), please read the operation manual carefully; if there are any uncertainties, feel free to consult by phone

Depending on the flow rate, if it is high, a centrifugal pump is used; if it is low, a canned motor pump is used

Our facility uses shielded pumps for methanol.

Our factory uses ordinary centrifugal pumps, but high requirements are placed on mechanical seals; imported mechanical seals are employed for this purpose. Considering the amount of work involved in daily maintenance and repairs, we are gradually switching to dry gas seals.

Shielded pumps are the preferred choice, or centrifugal pumps (but maintenance work is extensive); our factory has already modified them; now P is much easier to use

Magnetic pumps or shielded pumps are generally more suitable. A conventional centrifugal pump can also be used, but it requires higher standards for mechanical seals and their supporting systems, and it is more expensive. If the flow rate is high or the head is high, a conventional centrifugal pump can be considered.

Use magnetic pumps, shielded pumps, diaphragm pumps, etc. – in short, those that require no dynamic seals

Our company uses centrifugal pumps and pneumatic diaphragm pumps