MD Multi-Stage Pump (for mine)

This product is a segmented multi-stage centrifugal pump, supported by foundations, and the suction section, middle section and discharge section are connected with tightening bolts.

MD series products comply with the GB/T5657-2013 centrifugal pump technical conditions (III) standard;

MD series products comply with the MT/T 114-2005 “Wear-resistant Multistage Centrifugal Pumps for Coal Mines” standard. Each model of the MD series has obtained the mining product safety mark certificate issued by the Anbiao National Mining Product Safety Marking Center. Inquiry website: www.agbz.org;

DF series products comply with the GB/T5656-2008 centrifugal pump technical conditions (II) standard; the design, production, and service processes of this product have a strict control system, fully ensuring product quality.

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D type horizontal multi-stage centrifugal pump MD type wear-resistant multi-stage centrifugal pump for coal mines DF type corrosion-resistant multi-stage centrifugal pump

The D-type horizontal multi-stage centrifugal pump uses a fully enclosed self-fan-cooled squirrel-cage three-phase asynchronous motor: voltage: 380V, 6kV or 10kV; frequency: 50Hz; protection level: IP44; insulation level: B; installation form: B3.

The MD horizontal multistage centrifugal pump uses YB3 or YBXN series flameproof three-phase asynchronous motors: voltage: 380V, 6kV or 10kV; frequency: 50Hz; protection level: IP55 or IP54; insulation level: F; installation form: B3.

The DF-type corrosion-resistant multi-stage centrifugal pump uses a fully enclosed self-fan-cooled squirrel-cage three-phase asynchronous motor: voltage: 380V, 6kV or 10kV; frequency: 50Hz; installation mode: B3.

Note: The mine flameproof three-phase asynchronous motor and water pump unit used in the company’s MD pump must not be used in mining working surfaces. Specia

Working conditions
Model description
Standard basic type
Maximum suction height
Rotation direction and installation form
Structure diagram

Nominal speed: 2980/1480r/min

Transmission medium: D-type horizontal multi-stage centrifugal pump is used to transport clean water without solid particles or liquids with physical and chemical properties similar to clean water.

MD type coal mine wear-resistant multi-stage centrifugal pump is used to transport neutral mine water or other similar sewage with a solid particle content (volume concentration) not greater than 1.5% (particle size less than 0.5mm) and a temperature not higher than 80°C.

DF type corrosion-resistant multi-stage centrifugal pump is mainly used to transport acid, alkaline mine water or other similar weakly corrosive chemical wastewater.

Liquid temperature: 0-80℃

Flow range: 3.75~1200m²/h

Lift range: 50-1550m

Number of stages (number of impellers)

Single stage lift (m)

Pump flow (m²/h)

The first stage is double suction, and the one without S is single suction.

D type horizontal multi-stage centrifugal pump

MD type wear-resistant multi-stage centrifugal pump for coal mines

DF type corrosion-resistant multi-stage centrifugal pump

The D-type pump has the suction section flange to the right when viewed from the coupling end; the discharge section flange is upward; the motor is arranged at the suction end. The suction section, middle section, discharge section, guide vane, and impeller are made of cast iron; the shaft is made of 45 steel or 40Cr; the balance ring and sleeve are made of 3Cr13; the balance plate is 2Cr13; and it is sealed with packing. Viewed from the coupling end toward the pump, the pump rotates clockwise.

The MD type pump has the suction section flange facing to the right when viewed from the coupling end; the discharge section flange faces upward; the motor is arranged at the suction end. The material of the suction section and the middle section is francium iron; the material of the discharge section, guide vane and impeller is ductile iron; the material of the shaft is 45 steel or 40Cr; the material of the sealing ring is stainless steel or copper alloy; the material of the balance ring and sleeve is 3Cr13; the balance plate is 2Cr13 ; Seal with packing. Viewed from the coupling end toward the pump, the pump rotates clockwise.

The DF-type corrosion-resistant multi-stage centrifugal pump has the suction section flange facing to the right when viewed from the coupling end, the discharge section flange upward, and the motor is arranged at the suction end; it adopts packing seals; when viewed from the coupling end toward the pump, the pump rotates clockwise.

When users use it, they should consider the impact of various factors on use. The maximum suction height H should be lower than the calculated value below (negative values should indicate backflow), otherwise the water pump will not work properly.

H=Pb×10.2-NPSHr-Hf-Hv-Hs

Pb = local atmospheric pressure bar (sea level 1bar) NPSHr=necessary NPSH m

Hf=loss of water inlet pipe m

Hv = liquid saturated vapor pressure m (converted to water column height)

Hs = safety margin m (usually 0.5m)

Example: Atmospheric pressure Pb=1bar, pump NPSHr=2m, pipeline loss Hf=2m, safety margin Hs=0.5m saturated vapor pressure when liquid temperature is 40℃

Hv=Pv/pg=0.7m (converted into water column height)

H=1×10.2-2-2-0.7-0.5=5m

D / M D pump main parts selection material table
name		D type pump	MD type pump		D type pump		MD type pump
suction section		HT200	HT200		ZG270-500		ZG270-500
spit out segment		HT250	QT500-7		ZG310-570		ZG310-570
middle section		HT250	HT250		ZG310-570		ZG310-570
guide vane		HT200	QT500-7		ZG270-500		ZG270-500
impeller		HT200	QT500-7		ZG230-450		ZG230-450
axis		40Cr	40Cr		40Cr		40Cr
Shaft seal		Packing seal	Packing seal		Packing seal		Packing seal
Remark		Suitable for single stage lift<80m			Suitable for single stage lift≥80m
DF pump main parts selection material list
Material category	I			Ⅱ		Ⅲ
Main parts Media	Resistant to minor corrosion			Resistant to moderate corrosion		Resistant to strong corrosion and sea water
suction section	ZG230-450			1Cr13、304 or 316		316Lor duplex steel
spit out segment
middle section	ZG230-450
guide vane
impeller
cooling body
axis	2Cr13 or 40Cr					2205 or 17-4PH
Note: 1. In addition to the above three types of materials, it can also be produced according to the media characteristics and customer requirements. 2. The material of the shaft is configured according to the specific characteristics of the conveying medium and the shaft power. 3. Because the characteristics of corrosive media (especially mixed corrosive media) vary widely, please verify before signing such an order. Material configuration and other related matters

Note: The standard configuration of the pump is a self-flushing structure. If the medium at the customer’s site is poor and contains particles or chemically corrosive media, the customer needs to change the self-flushing structure to an external flushing structure. Flushing water requirements:
Water quality: clean industrial water
Flow:2m³/h
Pressure: ≥ pump inlet pressure + 0.2MPa, if the pump has a first-stage double-suction structure pressure ≥ pump single-stage lift + inlet pressure + 0.2MPa

Safety warning

1) Before using this product, you must carefully read the instruction manual of this product and the instruction manuals of related supporting products. During installation, use and maintenance, the safe operating procedures for this product and related equipment must be followed.

2) The pump must not be operated at low or zero flow for a long time, otherwise it will cause the pump unit to vibrate or even vaporize the pumped liquid, causing personal injury and equipment damage.

3) The pump is a rotating device, and the power supply must be cut off before installing or repairing the pump unit, otherwise personal injury may occur.

4) Before using the pump, you must check whether the cable is damaged or broken and whether it is well grounded. When the pump unit is running, it is strictly prohibited to enter or remove the protective cover with hands, otherwise personal injury may occur.

5) Before using the pump, please turn on the power, “click the start switch button” and make sure the rotation direction is correct before use.

6) For explosion-proof motors used underground in coal mines, YB2 and YB3 series motors can be used underground, but cannot be used in mining working surfaces. Y series motors cannot be used underground.

7) A coupling protective cover must be installed to prevent personal injury or death.

8) In order to prevent accidents such as shaft breakage or even motor burning due to the collision between the pump shaft and the motor shaft after the pump is running, before adjusting the clearance between the pump and motor couplings,

The pump shaft must first be pulled out as far as possible in the direction of the pump coupling, and then the clearance adjustment must be performed according to the instructions.

9)Neither the user nor the company shall arbitrarily change the configuration of standard installation kits and zero (element) parts.

Typical applications

D-type horizontal multi-stage centrifugal pump is mainly used for water supply and drainage in factories, cities and mines;

MD type coal mine wear-resistant centrifugal pump is mainly used to transport neutral mine water and other similar sewage;

The DF-type corrosion-resistant multi-stage centrifugal pump is mainly used to transport moderately corrosive media in metallurgy, mining, brine mining, chemical industry and other occasions. It can also be used to transport seawater and highly corrosive media when the flow-passing parts are made of duplex stainless steel and other materials.

Installation

Check that the water pump and motor are not damaged.
The local atmospheric pressure minus the installation height of the water pump, the hydraulic loss of the suction pipeline, the speed energy and the vaporization pressure at the operating temperature

That is, the cavitation head of the device is NPSHa, and NPSHa is greater than NPSHr. The foundation dimensions should comply with the installation dimensions of the pump unit.

Installation sequence (unit):

(1) Place the water pump on a concrete foundation with embedded anchor bolts, and calibrate the level (it is recommended that the unevenness per 1000mm length is less than

0.5mm), and tighten the anchor bolts appropriately to prevent movement.

(2) Pour concrete between the foundation and base. The external concrete surface is level with the surface of the anchor bolts, and concrete is poured inside the base to increase the rigidity of the unit and reduce vibration.

(3) After the concrete is dry, tighten the anchor bolts and recheck the level of the water pump.

(4) Correct the concentricity of the motor shaft and the water pump shaft. To align the two axes in a straight line, the misalignment tolerance on the outer circles of the two couplings

0.1 mm, the unevenness tolerance of the end gap along the circumference is 0.1 mm (check it again after connecting the inlet and outlet pipes and trial operation, and it should still meet the above requirements);

When installing separately, pull the pump coupling to the motor side to the end, leaving a gap of 5~8mm between the pump coupling and the motor coupling.

(5) After checking that the steering direction of the motor is consistent with the steering direction of the pump, install the connecting pin of the coupling.

The inlet and outlet pipes should be supported by separate brackets and should not be supported by the pump body.
The joint surface between the water pump and the pipeline should ensure good air tightness, especially the water inlet pipeline, which must be strictly air-tight, and there should be no possibility of air escaping from the device.
If the water pump is installed above the inlet water level, in order to start the pump, a bottom valve can generally be installed, or a vacuum water diversion method can be used.
Gate valves and check valves must be installed in the outlet pipeline of the water pump.

Starting, stopping and running

1.Start and stop:

(1) The machine must be manually turned for at least one turn before starting, and it can only be operated after there is no jamming.

(2) Close the water outlet gate valve and inject water into the pump (if there is no bottom valve, use other vacuuming devices to draw water). Make sure that the pump is filled with water and there is no air trapped; it is strictly prohibited to start without water.

(3) Install a vacuum gauge and a pressure gauge on the inlet and outlet of the pump, close the valve connected to the pump, then start the motor, and then open it again after the speed is normal.

Then open the outlet gate valve (the outlet valve should not be closed for too long, otherwise the pump body will easily heat up and be damaged) to make the lift match the nameplate lift. If the lift is too low, you can close the gate valve appropriately for adjustment; conversely, if the lift is too high, Open the gate valve wide.

(4) Tighten the compression nut on the packing gland evenly to allow the liquid to leak out in drops, and pay attention to the temperature rise in the packing cavity.

(5) When stopping the operation of the water pump, first close the valves of the vacuum gauge and pressure gauge and the gate valve on the water outlet pipe, and then cut off the power supply to the motor. If the temperature of the environment is low,

Then the plug at the bottom of the pump body should be opened and the remaining water should be removed to avoid freezing and cracking.

(6) When using variable frequency or soft start mode, the time required to start from zero speed to rated speed is less than 10 to 15 seconds. At the same time, the frequency should be fixed and the pump outlet valve should be used to adjust the flow to prevent frequency changes from causing severe fluctuations in the head. The pump is damaged.

(7) When the pump is shut down for a long time, drain the accumulated water in the pump to prevent rust or freezing of the pump body, and rotate the rotor 180 degrees every 15 days.

Operation

(1) The maximum temperature of the water pump bearing should not exceed 75°C.

According to the oil cup refueling method).

(3) When the packing is worn, the packing gland can be properly pressed. If the packing is worn too much, it should be replaced.

(4) Regularly check the elastic coupling components and pay attention to the temperature rise of the motor bearings.

(5) During operation, if noise or other abnormal sounds are found, stop the machine immediately, check the cause, and eliminate it.

How to refill the oil cup

Type of lubricating oil: 32# or 46# turbine oil;
When adding oil to the bearing box for the first time, open the bleed plug on the bearing box and add oil into the box through this hole. At the same time, open the oil cup chassis (as shown in Figure 2). From the open oil level gauge, you can see that when the oil flows out along the oil level gauge pipe, stop refueling, wait for the oil level to stabilize, then slowly refill the oil to surface A, and stop refueling;
As shown in Figure 3, remove the oil cup and add about 2/3 of the oil into the oil cup;
As shown in Figure 4, carefully install the oil cup (with oil inside) onto the oil cup chassis and tighten it;
Quickly close the oil cup together with the oil cup chassis (as shown in Figure 1), and the refueling is now completed;
After running for a period of time, when the oil cup is out of oil, follow steps 2 to 4 to add oil.

Possible faults and their elimination methods

Fault

reason

Elimination method

(1) The pump does not absorb water, and the pointers of the pressure gauge and vacuum gauge jump violently.

1. Insufficient water injection;

2. There is air leakage in the pipeline or instrument.

1. Then inject water into the pump;

2. Tighten and block the air leakage.

(2) The pump does not absorb water and the vacuum gauge shows a high vacuum.

1. The bottom valve is not open or blocked;

2. The resistance of the water suction pipeline is too great;

3. The water absorption height is too high.

1. Correct or replace the bottom valve;

2. Clean or replace the water suction pipeline;

3. Reduce the water absorption height.

(3) The pump does not discharge water, but the pressure gauge shows pressure.

1. The water outlet pipeline has too much resistance;

2. The rotation direction is wrong;

3. Impeller blocked

4. The speed is not enough.

1. Check or shorten the water outlet pipe;

2. Correct the rotation direction of the motor;

3. Clean the impeller;

4. Check the power supply voltage and increase the rotation speed.

(4) The flow rate is insufficient or the head is too low.

1. The impeller or water inlet pipe is blocked;

2. The sealing ring is too worn or the impeller is damaged;

3. The rotation speed is lower than the specified value.

1. Clean the impeller or pipeline;

2. Replace damaged parts;

3. Adjust to the rated speed.

5) The power consumed by the pump is too large.

1. The filling is pressed too tightly;

2. Friction between impeller and sealing ring;

3. The traffic is too large.

1. Unscrew the packing gland

2. Check the cause and eliminate mechanical friction;

3. Reduce the gate valve opening.

6) The sound inside the pump is abnormal and the pump cannot supply water.

1. The resistance of the water suction pipe is too large;

2. The water absorption height is too high;

3. There is air inhalation at the water absorption point;

4. The temperature of the liquid being sucked is too high;

5. Cavitation occurs due to excessive flow.

1. Clean the water suction pipeline and bottom valve

2. Reduce water absorption height;

3. Check the bottom valve, reduce the water absorption height, and block the air leakage;

4. Reduce the liquid temperature;

5. Adjust the outlet gate valve to operate within the specified performance range.

(7) The pump vibrates abnormally.

1. Cavitation has occurred in the pump;

2. The impeller is unbalanced;

3. The pump shaft and the motor shaft are not concentric;

4. The foot screws are loose.

1. Adjust the outlet gate valve to operate within the specified performance range;

2. Impeller correction static balance;

3. Correct the concentricity of the pump shaft and the motor shaft

4. Tighten the foot screws.

(8) Bearing overheating

1. There is no oil in the bearing;

2. The pump shaft and the motor shaft are not on the same center line.

1. Check and clean the bearing body and add lubricating oil;

2. Correct the concentricity of the two axes so that they are on the same center line.