Speaking of a monoblock pump, a standard model of this equipment is implied. The only difference is that the body of the centrifugal device, as well as the electric motor, are combined in one unit.
General unit design
The fluid enters this device in the axial direction, but leaves it already in the radial direction. In order to reduce the loss of friction efficiency, the following design is used. The impeller from the centrifugal device is mounted directly on the motor shaft. Due to this, the friction that goes to the connection with the bearings is reduced. In addition, this assembly method saves additional space. In order to create cooling of a monoblock pump, a rotating impeller is used, which is also located on the end of the motor shaft, on the opposite side of the wheel. The type of cooling used in this unit is air. The impeller is also additionally protected by a grill.
Pros, Cons, and Scope
The characteristic of monoblock pumps allowed this device to find quite wide application in many fields. The rapid and confident spread was also facilitated by the fact that the device has a universal design. A pump is used to circulate fluid in a heating, cooling, hot water supply system. It is used at boosting pumping stations to extinguish fires.
If we talk about the positive qualities of this device, then it has quite a lot of them. The first and most important quality is a wide range of operating parameters. The second important quality is the design, which is very compact. At their low cost, monoblock pumps have a significant indicator of efficiency - from 30 to 80%. In addition, the device is considered unpretentious to the quality of the incoming fluid. The temperature indicator of the liquid can exceed the mark of 100 degrees Celsius.
However, there are a number of several disadvantages:
- the design uses rolling bearings, as well as mechanical shaft seals;
- the level of noise and vibration created by this device is much higher than, say, for units with a wet rotor;
- the installation of this device can be performed in only one position, so that the axis of the shaft is horizontal;
- installation of a monoblock pump is permitted either on the foundation or on the frame;
- demanding maintenance due to the presence of stuffing box shaft seals.
Unit Operation
The fluid moves through the suction pipe in axial direction. Having passed the pipe, water enters the working area of the wheel, which is supplied with several curved blades. Due to the action of inertia forces, the direction of movement changes - from the center of the wheel to its periphery. A fluid that swirls in the direction of its movement accumulates in an element such as a spiral casing, from which it leaves the pump. This part is called a "snail", and its main purpose is to divert incoming fluid from the impeller, as well as the process of converting the dynamic pressure created by the movement of water into static. The shape of the spiral casing is very similar to an element such as a diffuser.
In a centrifugal monoblock pump, this sequence is observed. If there is a twofold increase in the speed of rotation of the wheel, then the supply will also double, the pressure force will increase four times, but the consumed electricity will increase eight times.
Cantilever Type
The main purpose of this equipment is to pump fluid by rotating one or more wheels. It is also important to note that all devices are designed for various purposes. The main difference between them is the design, which determines the further operation of the device.
Currently, two of the most common types of monoblock pumps are distinguished, which belong to the centrifugal type in their design.
The first place belongs to the equipment group, which is represented by single-stage pumps having a horizontal shaft arrangement, as well as a one-way input for such an element as an impeller.
In second place are centrifugal monoblock cantilever pumps. These units are marked with the letter "K" and are also driven by an electric motor. The main task of the device is to pump clean water in the system.
The use and advantages of the pump type "K"
These units are used for pumping purified liquid for industrial or technical purposes. This is the main industry of their use. However, they are also used for some other purposes:
- ensuring water circulation in the heating and water supply system, as well as in buildings for household and residential purposes;
- used in industrial water supply systems;
- It is used to ensure the supply of water to summer cottages;
- It is used during fire fighting in residential buildings.
Among the positive qualities of this equipment, several of the following parameters can be distinguished. The design of the unit is designed so that the housing has its own supports. This will allow you to remove the device without disconnecting it from the pipeline system. The diameter of such an element as an impeller can be any. It is made at the request of the customer. There is the possibility of individual selection of characteristics, based on the location and purpose of operation of the device.
TYPE OF KM MODEL
The main difference between the cantilever and monoblock from the conventional type is that the impeller is located on the shaft. The inclusion of this part is due to the efforts of the electric motor. If the model has a mechanical seal, then the temperature range for the working fluid is from 0 to +105 degrees Celsius. If the seal is of a packing type, then the range is reduced to 0-80 degrees Celsius. If we talk about the maximum allowable pressure at the inlet to the pump, then in the presence of a mechanical seal - it is 6 atmospheres. When using stuffing box packing it is 3,5 atmospheres. It is also important to note that during the operation of the KM pump model, an insignificant content of mechanical impurities in the working fluid is allowed.
Monoblock circulating pumps
This type of equipment belongs to the low-pressure device category. The design of this device uses the usual model of an electric motor with air-type cooling, as well as a constant speed. As in other models, the electric motor, as well as the working part of the device are made in one block, and therefore belong to the group of monoblock equipment. The design is very easy to maintain, as well as repair work.
One-piece pumps GRUNDFOS
This company is engaged in the production and supply of models such as console-monoblock and console devices.
Serial number monoblock and console-monoblock NB models. The main characteristic of these units is 2900 revolutions per minute. Structurally, these devices are made of single-stage centrifugal with pressure pipes, axial suction and radial types. The main purpose of these models is to increase pressure, as well as pumping fluid through systems such as district heating or heating equipment.