For the purpose of cooling liquids, special devices are used, which are called heat exchangers. They are able to work with juices, milk and various oils. The main device partners are performance and bandwidth. Additionally, the dimensions of the device are taken into account. In order to learn more about heat exchangers, it is worth considering their structure and principle of operation.
Tubular heat exchangers: device and principle of operation
A conventional heat exchanger consists of tubes and a compensator. There is a cover on the side of the case. The tubes of the models are fixed on the racks. The heat-insulating layer is attached under the tubular heat exchanger. The principle of operation of the devices is based on the removal of liquid through the coolant. Initially, the substance enters the inlet pipe. The cooling rate in this case depends on the initial temperature of the liquid. Additionally, the length and diameter of the pipes are taken into account. To increase the tightness of structures, special clamping rings are used.
Types of heat exchangers
The design distinguishestubular-lamellar, cross-flow, direct-flow, and counter-flow models. Pipes can be in vertical or horizontal position. Additionally, the separation of devices occurs along the width of the compensators.
Tubular-plate modifications
Tube-plate heat exchangers have good performance. Models are quite often used for pasteurization of juices. They are mainly produced with small diameter tubes. In this case, the covers are made of steel. In some cases, models have three racks. The throughput is on average 20 liters per minute. It is also worth noting that modifications with adapters are presented in stores.
Casings are usually used with pads. The devices differ greatly in the diameter of the nozzles. In front of the modifications are small flanges. O-rings are used to protect models. There are tubular heat exchangers (market price) about 120 thousand rubles.
Features of horizontal modifications
Models of this type are the most common. For industrial enterprises, a tubular (horizontal) heat exchanger is great. The conductivity indicator for models, as a rule, does not exceed 130 liters per minute. A tubular heat exchanger is often found in dairy enterprises. The tubes in this case are fixed on special plates.
Some enterprises install modifications on wide stands. Heat exchange tubes are useddifferent diameter. Flanges are usually found at the front of the structures next to the covers. The coolant temperature in this case depends on the throughput of the model. Branch pipes of branch connect with adapters. Tubular heat exchangers are mainly manufactured in the USA.
Vertical device parameters
The vertical tube heat exchanger is only suitable for pasteurization of viscous oils. Models have very low throughput. It is also worth noting that in stores there are modifications for two racks. In some cases, models are supplied with stands. The flanges are installed behind the covers. Directly heat exchange tubes are made of steel. Many models have multiple o-rings. It is also worth noting that clamps are installed on the tubular heat exchanger to fix the casing. The cost of equipment depends on the dimensions of the device, as well as the material of the cylinder.
Countercurrent modifications
Tubular counterflow heat exchanger operates at a pressure of 4 Pa. The tubes of the models are installed in a horizontal position. On average, the throughput is at the level of 140 liters of liquid per minute. It is also worth noting that there are modifications with two racks. The lids are usually made in small diameters. Pipes are used from stainless steel, but there are also brass counterparts.
Many modifications boast excellent performance. Heat exchangers of this type are well suited forvegetable oil pasteurization. Some experts claim that the models have good tightness. However, they have several disadvantages. First of all, we are talking about large sizes. Additionally, it is important to consider the complex maintenance of these units, since the racks must be replaced periodically. It is also required to constantly check the strength of the flange.
Device of once-through heat exchangers
Direct-flow heat exchangers are characterized by good throughput. Their outlet pipes are installed with a diameter of 2 cm or more. In some cases, wide expansion joints are used. It is also worth noting that there are modifications on the covers in stores.
The capacity they have is 130 liters of fluid per hour. If we consider a tubular water-water heat exchanger, then its limiting pressure is 4 Pa. Protection systems in devices are used in different classes. According to experts, the conductivity depends not only on the diameter of the pipes, but also on the length of the cylinder. Housings in devices are used in high density.
Models with wide expansion joint
Heat exchangers with wide expansion joints are great for running oils. Their limiting pressure starts from 3 Pa. Protection systems are mainly applied in class P23. Separate removal from the modifications deserve adapters. The lids are made of stainless steel and screwed together. Very rarely there are devices on two racks. First of all, they have unstable plates. AlsoIt is worth noting that there are modifications with front flanges. O-rings lock behind adapters.
Reviews on models with a narrow compensator
Heat exchangers with a narrow expansion joint are well suited for milk pasteurization. The tubes are in a horizontal position. Many experts say that devices are most often produced for 6 handsets. Their casings are of medium density. Performance deserves special attention. The specified parameter generally does not exceed 120 liters per hour.
Additionally, the conductivity of the model, which depends on the diameter of the cylinder, is taken into account. In order to choose a high-quality heat exchanger, you should pay attention to sealing devices. Many heat exchangers are manufactured with multiple fixing rings. This achieves a high degree of security.
Modifications for 6 tubes
Heat exchangers for 6 tubes are able to show good performance. If their diameter is less than 2.3 cm, then certain problems with conductivity may occur. The operating temperature in heat exchangers of this type is on average 10 degrees. Cylinders are most often made from brass. There are also cast iron models on the market that weigh a lot and are bulky.
Parameters of models for 8 tubes
8-tube heat exchangers are suitable for cooling not only oils, but also liquids of high density. The performance of the models is on average 110 liters per hour. As a rule, the diameter of the pipes for modifications is 3.3 cm. Many models are produced with several flanges. Seals, which are fixed on the rings, deserve special attention in the devices. Modern heat exchangers are made on three rings. In this case, the flange should be located in the front of the modification.
Double Insulated Heat Exchangers
What is the difference between double insulated heat exchangers? First of all, they have a very low operating temperature. It is also worth noting that they are great for working with oils and milk. Many modifications are used in large enterprises. To date, devices for 6 and 8 pipes are produced. In the first case, the average productivity is 120 liters per hour with a diameter of at least 2.2 cm.
Modifications for 8 pipes with a double seal can boast good conductivity. They are best suited for high density liquids. Modifications for two racks are used for pasteurization of milk in large quantities. There are also models with a vertical arrangement of pipes.
Modifications without compensator
Tubular stainless heat exchangers without compensator are unable to work with oils. It is also worth noting that they have low performance. However, the advantage of the models is the rapid cooling of liquids. The devices are well suited for juice pasteurization.
Their flanges are installed in front of the cover. It is also worth noting that models are available for two and three racks. Cylinders are manufacturedfrom cast iron or steel. The average diameter of the pipes is 2.4 cm. The sealing nuts are fixed on the racks. High performance devices come with optional brackets.
