DOUBLE SCREW PUMP

Best solution for high viscous fluid transport

The double screw pump can completely replace other pumps, such as centrifugal pumps, sliding vane pumps for high-viscosity liquid transportation. 

Screw pumps are widely used in food, oil & gas, shipbuilding,  metallurgy, papermaking, printing and dyeing, chemical industry, fertilizer, pharmaceutical and other industrial sectors.

Advantage of Double Screw Pump

In recent years, our company has developed a helical structure with independent intellectual property rights, and it is at the leading level of the world.

Heat Presevation

It can be designed as a heat preservation and sealed cooling system, suitable for medium transportation in high temperature, corrosion, abrasion and other occasions.

Energy-Saving

It can realize flow regulation under constant pressure, suitable for frequency conversion control, and the effect of energy saving and consumption reduction is remarkable.

various mediums

If the external structure is selected, the transmission system is independently lubricated and does not contact the conveyed medium, and can convey lubricating and non-lubricating mediums.

①In the structure, a certain gap is maintained between the two screws, and between the screw and the bushing, and there is no direct mechanical wear. Low noise and long life.

②If the external structure is selected, the transmission system is independently lubricated and does not contact with the conveyed medium, and both lubricating and non-lubricating media can be conveyed.

③It can be designed as a heat preservation and sealed cooling system, which is suitable for medium transportation in high temperature, corrosion, abrasion and other occasions.

④Compared with other pumps, the conveying viscosity range of double screw pump is wide. When conveying high-viscosity medium, it has high efficiency and energy saving, low failure rate, and can convey extremely high-viscosity chemical materials; and when conveying low-viscosity medium, it has outstanding advantages such as smooth conveying, no stirring and no pulsation. Different materials are used to transport materials of different properties, including gas-liquid mixed transport and liquefied gas transport.

⑤ It can realize flow regulation under constant pressure, suitable for frequency conversion control, and the effect of energy saving and consumption reduction is remarkable.

Twin screw pump manufacturing expert

Our Typical Products

also known as: sewage pump, loading pump, sweeping pump, marine ballast pump, fuel transfer pump, fuel injection pump, etc.

Tower bottom pump, high temperature oil slurry pump, coking high temperature pump, etc.

also known as: corrosion-resistant pump, viscose pump, food pump, etc.

also known as: multi-phase pump, oil-gas-water mixed pump, etc.

also known as: tower bottom pump, high temperature slurry pump, coking high temperature pump, etc.

also known as: chemical raw liquid pump, viscose pump, corrosion-resistant pump, food pump, etc.

LPG pump in gas station, liquefied petroleum gas pump

High viscosity raw liquid pump, viscose pump

diesel injection pump, heavy oil injection pump, low viscosity medium delivery pump, etc.

asphalt pump, heavy oil pump, unloading pump

fuel high pressure delivery pump, oil high pressure delivery double screw pump

multiphase pump, twin screw pump manufacturer, pump oil and gas, subsea multiphase pump, multiphase pump oil and gas
twin screw pump

Types of the Double Screw Pump

The twin screw pumps are structurally divided into single-suction twin-screw pumps and double-suction twin-screw pumps.
These two major products’ features:

There is a pair of left-right spiral sleeves in the pump unit, which are divided into cantilever type (see Figure 1) and A-line (see Figure 2). The product has a simple structure and is easy to use and maintain. It is mainly used in occasions where the flow rate is not large and the pressure is not high.

There are two pairs of left and right spiral sleeves in the pump unit, as shown in Figure 3. The product structure is more complex than the former, and the use and maintenance are more difficult than the former. It is mainly used in the occasions with large flow or (and) high pressure. The double-suction twin-screw pump has been carefully built by our company’s R&D department for 10 years, and has achieved effective measures such as quick replacement of seals and quick adjustment of helical surface gap.

Where are double screw pumps used?

Driving technology for leading brands

The viscosity range of the material conveyed by the  double screw pump is wide, and the conveyed medium is stable. The viscosity of the medium it transports is as low as liquefied gas and as high as toothpaste-like and close to solid. Not only that, because the screw pump moves the medium in axial translation, it conveys the medium smoothly and without pulsation, which is suitable for conveying those easily vaporized liquids, high-viscosity materials, and media that require self-priming; during the conveying process, the double screw pump also shows excellent energy saving effect.

Because the surface of the screw rod is not in contact, it overcomes the defects of easy wear and aging of the single-screw pump’s rubber bushing. Our company has also carried out a lot of technical research and development according to various working conditions, forming our company’s unique twin-screw pump products, which are widely used in the market.

Crude oil transportation, oil and gas mixed transportation, polymer transportation, used as multiphase pump.

Heavy oil, crude oil, asphalt, fuel oil, grease, lubricating oil, petroleum additives, gasoline, kerosene, diesel oil, various resins, etc.

Coal tar, coal tar transportation. The twin-screw pump is also the most ideal pump for conveying coal-water slurry, and has a longer service life than the single-screw pump.

Syrups, health products, pharmaceuticals. Papermaking: pulp, adhesives, auxiliaries, etc.

lubricating oil pumps, fuel oil transfer pumps, cargo oil pumps.

glycerin, sorbitol, cosmetics, shampoo, facial cleanser, toothpaste, soap, washing powder slurry, titanium dioxide, ink, paint, latex paint, white glue, various high-viscosity materials, polymers.

Viscose, polyester, etc. High-viscosity PVA, aramid fiber, spandex and other raw solutions have high efficiency.

Chocolate, milk, dairy products, fruit juice, jam, pasta sauce, syrup, honey, beverages, condiments, vegetable oil, soybean protein, xanthan gum, starch, yeast liquid.

Heavy oil transfer pump, heavy oil fuel oil pump.

Lubricating oil pump.

LPG tanker loading and unloading, tank dumping, etc.

Lubrication pump, oil supply pump, fuel injection pump, water glycol and other delivery pumps.

Unloading oil pump, loading pump, unloading pump, loading pump.

Dalian BaoSteel Metallurgy

Dalian BaoSteel Metallurgy Group Co., Ltd. is affiliated with LMM Group. Since our establishment 15 years ago, we have focused on the iron and steel metallurgy industry, high-end equipment manufacturing industry, green food industry and other energy-saving and emission-reduction health industries. We independently develops and designs of energy-saving screw pumps with professional intellectual property rights.

We have many overseas warehouses in Europe, the United States, Mexico, etc., and partners all over the world. Our goal is to contribute to a sustainable future together.

Services

We pay much attention to the spirit of the contract, and we can unconditionally solve any quality problems with the pumps sold. 

Pre-sales consulting service

Recommend suitable products according to the actual working conditions and needs of customers. It can also be developed and designed according to needs, and customized services can be provided. During the epidemic, provide remote detection technical support

Strict quality control

From raw materials, to the production process and before leaving the factory, all performance indicators are strictly tested, and the professional QC team controls according to the process.

After-sales service

The product is sold, the quality is tracked throughout the process, and the installation and use are guided throughout the process.

How to choose the right double screw pump?

It should be noted that the performance parameters corresponding to each series are different. When selecting models, it is necessary to consult for the corresponding product series of our company according to the working conditions.

First of all, the speed of the pump should be determined according to the viscosity of the medium being conveyed. At different working temperatures, the viscosity of the medium is different, and it is necessary to determine the maximum medium viscosity that may occur at the current working temperature. If the actual viscosity is higher than the estimated viscosity, there may be insufficient power.

According to the viscosity of the medium at the working temperature, the rotation speed n of the pump is determined: generally, when V≤1000mm2/s, n=1450r/min is allowed; when V≤3000mm2/s, n=750~950r/min is allowed. When V>3000mm2/s, n=600~750r/min is allowed.

Please carefully consider the NPSH value of the pump and the NPSH value of the pipeline; the higher the viscosity, the more attention should be paid. Generally speaking, when the viscosity exceeds 1000mm2/s, the inlet resistance of the pipeline should be calculated before selection. If the inlet resistance does not meet the requirements, it will cause damage to the pump. Therefore, remind the user to calculate or submit it to the technical department of our company for calculation.

When high-viscosity materials are transported in the pipeline, it should be noted that if the pipeline resistance is too large, the load will increase sharply, and the conventional shaft power calculation will cause the problem of insufficient power. When handing over to our company for calculation, the user should provide the corresponding inlet pipeline information, including the pipeline length, height difference, filter elbow tee and other accessories, and our company’s technical department will provide the selection.

In order to facilitate users to configure pipelines, the R&D department of our company has developed pipeline selection software, which saves a lot of calculation time and provides convenience for users.

The model of the pump can be determined according to the flow rate, the pressure difference between the inlet and the outlet, the viscosity of the medium and the speed of the pump.

How to determine the model of the pump is further explained as follows:

2.1 According to the flow rate and pressure, determine whether to choose a double-suction product or a single-suction product.

Note that as long as the conditions are met, try to use single-suction products, because single-suction products have a simple structure and are easy to load and unload.

Generally speaking, when the flow rate is not large and the pressure is not high, the single-suction product (ie BY2G type or BY2GX type) is used; on the contrary, when the flow rate is large or the pressure is high, the double-suction product (ie the BY2GS…series) is used. . The single-suction product has a simple structure and is easy to maintain. It is preferred to use it as far as possible.

2.2 Determination of sealing form.

What kind of sealing form is adopted depends in many cases on the needs of the working conditions or the user’s preference. However, it should be noted that the use of packing seals will produce more or less trace leakage. Leakage that meets the requirements of industry standards and national standards is allowed, but when transporting toxic and harmful liquids, it is forbidden to use packing seals. such substances, double mechanical seals should be used to achieve long-term zero leakage. For the transportation of high-viscosity chemical materials, if there is no suitable sealing liquid, the packing seal should be used to realize it. Otherwise, the mechanical seal may be scrapped in a very short period of time due to the inability to obtain timely cooling, or be affected by high-viscosity material’s effect and fail.

2.3 The heat preservation method and installation method are the relevant structures of the pump selected by the user according to the conveying needs of the medium. When the user does not make a request, our company will produce according to the content of the default item.

2.4 Bypass valve, which plays the role of overload protection in the pump unit. It is configured according to the user’s needs. Our company will not configure the bypass valve if the user does not ask for it. We recommend using other methods to protect the pump unit from overload, such as: automatic shutdown of the motor when the motor is overloaded, pressure relays in the pump discharge pipeline system and installation of solenoid valves, etc., which are simpler, more reliable and more sensitive.

The motor is the most commonly used driver for the pump unit. After selecting the pump specification, find out the shaft power N corresponding to the flow rate of the pump of this specification under the working pressure P from the table according to the corresponding viscosity V. With the shaft power, the motor power can be determined.

The optional motor power Nm should be slightly larger than the found shaft power N. When the power is relatively small and the pressure is relatively low, the reserve should be larger. The applied power reserve is Nm≥K·N, and the K value is shown in the table below. With the motor power, the model and specifications of the motor (or geared motor) are determined according to the explosion-proof requirements and other conditions required by the user. After the user selects the pump, please ask us for the unit size of the pump and motor required for the foundation construction design.

Determine the model of the drive

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