QH Series Submersible Mixed Flow Pump

Submersible pumps and traditional long shaft pumps have significant advantages in terms of usage scenarios, inlet and outlet conditions, and characteristic parameters, as well as the following:
Save over 30% of the total investment in pump station engineering:
★ Save over 40% in construction period:
★ Unit installation time saved by over 95%;
Reduce the weight of the unit by more than 50%:
★ Save investment in flood control walls for pump stations:
★ Low maintenance costs:
★ No operating noise, easy to operate, and easy to automate:
The low height of ground buildings can eliminate the need for pump room construction, and even allow for the construction of pump stations below ground level.
Therefore, new and old customers of axial flow pumps and mixed flow pumps can easily replace submersible pumps in new pump station projects, and can be updated with submersible pumps in old pump station renovation projects. This type of pump is mainly suitable for the following situations:
★ Irrigation and Drainage of Farmland:
★ Municipal discharge of rainwater and mild sewage:
★ Process water and cooling water in industry:
★ Water conservancy middle note project.

Our company's submersible pumps come in ten nominal outlet diameters, including 350, 500, 600, 700, 800, 900, 1000, 1200, 1400, and 1600. The flow range is 0.12-12m3/s, the head range is 2-14m, the power range is 7.5-630kW, and the voltage levels are 380V, 660V, 3kV, 6kV, and 10kV.

Model Description

1. Submersible axial flow pump

2. Submersible mixed flow pump

Structural Description

The QZB submersible axial flow pump and QH (B) submersible mixed flow pump are composed of four major parts: the inlet horn mouth, impeller components, impeller housing, and guide vane body. The submersible motor is a fully sealed dry-type asynchronous motor. The motor is enclosed by a casing, and there is a static sealing device at the cable outlet on the upper end of the motor. There is a rotating sealing device at the shaft cover on the lower end of the motor. The submersible motor has all the safety and reliability performance for submersible operation. There are monitoring, alarm and protection devices for sealing leakage, coil and bearing temperature rise, which do not affect the early leakage of the motor's normal operation (only alarm). When the coil temperature exceeds 135 ℃ and the bearing temperature exceeds 90C, power-off protection is used, and all protectors are monitored by a dedicated submersible pump protector to ensure the safe use of the submersible pump.

General drawing of QHB submersible mixed flow pump structure

1. Terminal box cover
2. Upper cover
3. Leakage alarm
4. Upper bearing
5. Thermal protector
6. Stator
7. Rotor
8. Lower bearing
9. Leakage alarm
10. Lower end cover
11. Upper mechanical seal
12. Electrode probe
13. Lower mechanical seal
14. Guide vane body
15. Impeller components
16. Water inlet horn

Layout of internal sensors for submersible axial flow pumps and mixed flow pumps

The sensor output signal is received by the submersible pump protector. The protector outputs a switch signal for each output signal, including switch or analog signals, and displays an alarm flashing signal on the protector.

Performance parameters and spectra

Performance parameters and spectrum of mixed flow pump QH (B)

1. Performance parameters of blade integral submersible mixed flow pump (QH type)

2. Performance parameters and performance curves of blade semi adjustable submersible mixed flow pump (QHB type)

500QH-50 Performance Table

600QH-50 Performance Table

700QH-50 Performance Table

(Five leaf blade)

700QH-40 Performance Table

900QH-40 Performance Table

900QH-50 Performance Table

1000QH-40 Performance Table

1000QH-50 Performance Table

1200QH-40 Performance Table

1200QH-50 Performance Table

1400QH-40 Performance Table

1400QH-50 Performance Table

Installation form and size

The smaller QZB series submersible axial flow pump and QHB series submersible mixed flow pump adopt open inlet, and the installation forms include wellbore bend installation, steel wellbore installation, and concrete prefabricated wellbore installation. The installation of bent pipes and steel shafts is provided by our company as a complete set of shafts. The installation of precast concrete shafts is provided by our company with installation bases (including anti rotation devices) and covers. During installation, lift the submersible pump into the wellbore until it reaches the bottom. The inclined surface on the guide vane body matches the inclined surface of the support, and the water stop rubber (O-ring) plays a sealing role. Larger submersible pumps (with impeller diameters generally above 1 meter) are installed in a form with a closed inlet channel.

1. Installation and size of wellbore bend pipe

1. Minimum water level
2. Trash rack
3. Wall penetrating pipe
4. Tap the door

Note:
(1) The dimensions in the table refer to the installation dimensions of the pump and the hydraulic control dimensions designed for the pump station. The hydraulic dimensions designed for the pump station are only for reference.
(2) Dimension A is determined based on the flow rate to control the flow rate and reduce hydraulic losses. The dimensions in the table are reference values and can be appropriately increased if necessary. Dimensions E and J are determined based on the specific conditions of the pump station. Dimension R is the minimum reference size and can be appropriately increased if conditions permit. The above dimensions are determined according to user requirements.
(3) The distance between the pump center and the rear pool wall is ≤ K.
(4) The center distance between two pumps in the same pool is ≥ L.

Installation Dimension Table for Shaft Bend (QHB)

1. Minimum water level
2. Trash rack
3. Wall penetrating pipe
4. Tap the door

Note:
(1) The dimensions in the table refer to the installation dimensions of the pump and the hydraulic control dimensions designed for the pump station. The hydraulic dimensions designed for the pump station are only for reference.
(2) The size A is determined based on the flow rate to control the flow rate and reduce hydraulic losses. The dimensions in the table are reference values, and if necessary, they can be appropriately increased. The size E.J.R is determined based on the specific conditions of the pump station. The above dimensions are determined according to user requirements.
(3) The distance between the pump center and the rear pool wall is ≤ K.
(4) The center distance between two pumps in the same pool is ≥ L.

Steel shaft installation dimension table (QHB)

3. Prefabricated concrete shaft installation and dimensions

1. Minimum water level
2. Wall penetrating pipe
3. Tap the door

Note:
(1) The dimensions in the table refer to the installation dimensions of the pump and the hydraulic control dimensions designed for the pump station. The hydraulic dimensions designed for the pump station are only for reference.
(2) Size A is determined based on the flow rate to control the flow rate and reduce hydraulic losses. The dimensions in the table are reference values and can be appropriately increased if necessary. Size E is determined based on the specific conditions of the pump station. The above dimensions are determined according to user requirements.
(3) The distance between the pump center and the rear pool wall is less than ≤K.
(4) The center distance between two pumps in the same pool is greater than  ≥L.

Size Table for Concrete Prefabricated Shaft Installation (QHB)

4. Installation and Size of Concrete Prefabricated Shaft with Closed Inlet Channel
① Dustpan shaped inlet channel

1. Cleaning machine
2. Minimum water level
3. Valve maintenance
4. One time pouring of embedded parts
5. Secondary pouring of embedded parts, pouring after on-site welding
6. Second pouring
7. First pouring
8. Floating box flap door
9. Valve maintenance

Note:
(1) The inlet channel can be equipped with elbow shaped, bell shaped, and dustpan shaped channels. The channel dimensions in the installation dimension table are dustpan shaped channels (for reference only).
(2) In addition to meeting the requirements in the table, the submergence depth must also be at least 500mm higher than the upper edge of the inlet of the channel.
(3) Generally speaking, the installation dimensions of the pump section are provided by the supplier, and the submergence depth is jointly determined by the supplier and the design party, and then verified through device testing. The geometric dimensions of the inlet and outlet water channels are calculated by the design unit according to the specifications through numerical modeling, and after preliminary determination, device model testing is carried out. The geometric dimensions of the flow channel provided by the manufacturer are used as a reference for the design unit during design.
(4) The geometric dimensions of the flow channel proposed by the supplier are for reference only by the user and the designer.

Size Table for Installation of Concrete Prefabricated Shaft with Closed Inlet Channel

②Bell shaped inflow to size chart

1. Truck crane
2. Concrete activity cover plate
3. Manhole cover
4. Diving wire lead out
5. Minimum water level
6. Submersible pump
7. Concrete shaft
8. Inlet water
9. Maximum water level
10. Minimum water level
11. Water outlet
12. Floating box flap door

Other installation forms and accessories

1. Floor standing installation of wellbore

1. Minimum water level
2. Wall penetrating pipe
3. Tap the door

Explanation:
(1) Floor standing installation is an installation method developed on the basis of steel wellbore installation, which has the characteristics of stability and reliability. The pump seat can be fixed by pre embedded anchor bolts.
(2) The elevation of the vertical pipe between the pump seat and the electric pump can be adjusted, and a middle auxiliary support can be provided when the vertical pipe is long.
(3) The position of the water outlet pool can be adjusted by extending the horizontal water outlet pipe.

2. Distributed installation of wellbore

1. Minimum water level
2. Wall penetrating pipe
3. Floating box flap door

Explanation:
This installation method is preferred for the installation of low head submersible electric pumps.

3. Diagonal installation
① Sled installation
Features:
1. Suitable for small and medium-sized units, flexible and convenient, especially suitable for flood control and emergency rescue or situations where temporary pump stations need to be established.
2. Directly using pipelines to transport media, with reliable sealing and no leakage.
3. The civil engineering is simple, the construction amount is small, and the existing ramp construction can be utilized. The construction period is short and the investment is low.

② Pipeline direct installation
Features:
1. It is suitable for Rivers and Lakes where the water level changes frequently.
2. Directly using pipelines to transport media, with reliable sealing, no leakage, and no need to build inlet and outlet water tanks. This method is particularly space saving for the structure of a separate sand room.
3. The civil engineering is simple, the construction amount is small, and the existing ramp construction can be utilized. The construction period is short and the investment is low.
Points to note:
To prevent tipping over, there should be sufficient span in the design.

4. Attachment:
① Floating box flap door
Installation dimension table of floating box flap door

② Rubber slow closing check valve

Outline drawing of built-in connection

Outline drawing of sleeve type connection

Outline drawing of flange type connection

Connection size table:

Scope of complete supply and ordering instructions

1. Scope of complete supply

2. Ordering Notice
(1) The accurate product model and name, installation form, performance parameters (flow rate, head, motor power), and operating voltage (380V, 660V, 3KV, 6kV, 10KV) should be specified in the contract.
(2) The control cabinet should indicate its starting method (direct starting, autotransformer pressure reducing starting, thyristor soft starting), liquid level control method (floating ball liquid level, pressure transmitter digital liquid level, ultrasonic liquid level), and installation form (indoor or outdoor).
(3) If a terminal box is required, it should be indicated whether it is a control type or a wiring type: indoor or outdoor.
(4) The dimensions that need to be determined by the user in the "scope of supply" should be provided in a timely manner, and the user should also provide equipment installation and construction drawings.
(5) The normal supply length of our company's submersible pump cable is 10m. If the user has special requirements, please specify.
(6) If there are any other special requirements, please contact our technical department before signing the contract.

Scope of complete supply and ordering instructions

1、 Open type inlet (inlet pool)

Open type inlet (water tank) has a simple structure and easy construction, and is widely used in small and medium-sized pump stations. The hydraulic design of this type of channel is highly valued both domestically and internationally, and extensive experimental research has been conducted. Many researchers have proposed design criteria for open inlet tanks in the form of empirical coefficients based on experimental results. However, there are significant differences in the criteria proposed by various parties, and there is still no unified or optimal hydraulic design criterion. Below are general design reference criteria.

1. Minimum water level
2. Polygonal rear wall
3. Semi circular rear wall

Comprehensive dimension diagram of inlet pool (different shapes of rear wall)

Geometric dimensions of forward inlet straight inlet pool

The hydraulic design of an open inlet (inlet pool) is generally based on the inlet diameter D of the horn pipe. The main reason for this is that the water flow into the pump first passes through the cylindrical surface between the horn pipe mouth and the flow channel bottom plate, and then enters the pump through the horn pipe mouth. It is natural to determine the size of the inlet channel based on the diameter of the horn tube as the basic parameter. But the problem is that the current design of the horn tube has not been standardized, and the inlet diameter of the horn tube is a variable. The ratio of the inlet diameter of the horn tube to the diameter of the pump impeller may not be the same. If D. is used as the basic parameter, it will cause confusion in hydraulic design criteria and appear inappropriate. If the horn tube can be standardized, the hydraulic design of the inlet channel should be based on the horn diameter or impeller diameter as the basic parameters. Otherwise, the pump impeller diameter should be used as the basic parameter.

According to the data "Optimization of Hydraulic Design for Pump Station Inlet Channel", the recommended design for open inlet is as follows

(1) Suspended height M

The recommended suspended height is M=(0.68~1.2) D. For larger or smaller horn tube inlet diameters (1.67D.), take the smaller value, and for smaller horn tube inlet diameters (1.46D.), take the larger value: For larger or smaller horn tube inlet diameters, the value of suspended height can still be within this range.

(2) Rear wall distance T

The determination of the distance between the rear walls is basically not affected by the use of a horn tube for water suction. Some water flow must enter the pump from the rear of the horn tube, so a certain distance between the rear walls is necessary; However, the excessively large distance between the rear walls increases the degree of freedom of water flow in the rear wall space, increases the possibility of vortex generation, and requires a corresponding increase in submergence depth. According to the optimization calculation results, the rear wall distance is taken as (0.8-1.0) D. It is sufficient to meet the requirements.

(3) Pool width Bj

In order to allow a portion of the water flow to smoothly enter the pump from both sides and behind the horn pipe, a certain pool width is required: excessively large pool widths can suddenly increase civil engineering investment. The diameter of the horn tube inlet to some extent affects the determination of the optimal pool width. Based on the optimization calculation results, it is recommended that the pool width be (3.5-4.5) D. The inlet diameter of the larger horn tube is taken as the smaller value, and the inlet diameter of the lighter horn tube is taken as the larger value.

(4) Pool length X

In the case of forward inflow, sufficient pool length is necessary to achieve a generally uniform water flow before reaching the horn pipe. The pool length can be determined according to the layout requirements of the upper structure of the pump room, generally taking (7.0~8.0) D. In the case of lateral inflow, the pool water needs to be appropriately increased or necessary rectification measures need to be taken. The determination of pool length is independent of the size of the inlet diameter of the horn tube used.

(5) Flat shape

The calculation results show that the planar shape of the inlet pool has little effect on the working state of the pump: according to experimental data, the planar shape has a certain impact on the hydraulic loss of the inlet pool, with the heart-shaped hydraulic loss being the smallest and the rectangular hydraulic loss being the largest.

2、 The issues that need to be noted in the design of the inlet pool include:

(1) Make the flow in the inlet pool close to natural flow, and the flow should be able to evenly suction each pump.

(2) The configuration of the pump, the position of the inlet, and the design of the shape of the inlet pool should not cause backflow.

(3) The flow velocity entering the inlet of the water tank should be slow, with a value below 0.7m/s. In addition, it is advisable to maintain a flow velocity of 0.3m/s or less near the pump suction inlet located in the inlet pool.

(4) The flow channel cannot suddenly expand or change direction sharply.

(5) The design size of the inlet pool should not be too large or too small relative to the flow rate of the pump.

(6) Avoid installing another pump upstream of one pump.

(7) There should be sufficient submergence depth to avoid the generation of air intake vortices.

(8) Lower the bottom of the inlet pipe to smoothly connect it to the inlet pool. At the same time, the ends of the inlet and return pipes in the inlet pool should be submerged in the water, which is beneficial for smooth drainage. In this way, the water flowing in from the inlet pipe will not be sucked into the air and flow into the inlet pool.

(9) To prevent the occurrence of vortices, appropriate anti vortex walls and partition walls should be installed.

The following table provides examples of incorrect and correct water intake

Bad example	Precautions	Excellent example
	(2)
	(2)、(4)
	(5)
	(2)、(4)
	(1)、(4)、(6)
	(1)、(2) (4)、(6)
	(1)、(2)、(4)
	(8)
	(8)
	(8)

3、 Reference diagram for closed inlet channel

1. Elbow shaped inlet channel

The elbow shaped inlet channel is commonly used and the design and research are relatively mature. The cross-section of the elbow shaped inlet channel gradually shrinks, and the water flow state inside the channel is good with small hydraulic losses; The width of the channel plane is relatively small, usually B/D=2-2.5 (D is the diameter of the pump impeller, B is the width of the channel). In addition to the insufficient elbow shaped inlet channel, the height of the channel is relatively high, which may increase the excavation depth of the pump station foundation pit. Usually Hw/D=1.6~1.8 (Hw is the vertical distance from the center of the impeller to the bottom of the flow channel), and secondly, due to the complex profile, high construction technology requirements are required.

The main contradiction in hydraulic design of elbow shaped inlet channels is the inability to increase the average angle of water flow into the pump, while the uniformity of flow velocity generally meets the requirements. The geometric parameter that has the greatest impact on the average angle of water flow into the pump is the center height Hw of the pump impeller. Its value should not be too small, preferably not less than 1.6 Do. Without significantly increasing civil engineering investment, it is recommended to use a diameter of 1.8D with an impeller diameter of Do=1m, an impeller chamber inlet diameter of D1=0.97D, and a distance of Hp=0.167D from the center of the pump impeller to the inlet of the impeller chamber. As an example design, for different pump impeller diameters and pump impeller chamber diameters, corresponding conversions can be made based on the ratio of pump impeller diameters.

Recommended elbow shaped inlet channel single line diagram (Hw=1.8Do)