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Screw Chiller: The Ultimate FAQ Guide

This guide has all information you’re looking for about screw chillers.

It covers everything, from components, working principles, features, classification criteria, and installation, just to mention a few.

Keep reading this guide to learn more.

What is a Screw Chiller?

Screw chillers are industrial types of cooling systems that use a screw-type of the compressor.

You will compress the refrigerant using the screw compressor as one of the processes leading to fluid chilling.

Screw chiller

How Do the Screw Compressors in Screw Chillers Work?

Twin-screw compressor

Screw compressors have both female and male parts or rotors that rely on a timing gear to produce compression.

Apart from that, the male and female rotors also work in conjunction with one another to produce compression.

You will have the male rotor which connects directly to the motor which acts as the driving rotor.

On the other hand, the female driver will be the part that receives the driving action (it will be driven).

As the male and female rotors rotate, the volume within their grooves will decrease and compresses the refrigerant.

The refrigerant fluid will flow into the compressor through the inlet forcing the compressor to reduce the tooth space.

It will force the seal line of the scroll compressor to move in the discharge port direction as the compression continues.

Finally, the refrigerant will leave the compressor when the pressure is too high and the seal line is at the discharge point.

How Many Types of Screw Compressors can You Use in the Screw Chillers?

You can choose from the list of two types of scroll compressors to use in your screw chilling applications.

Here are the two types of screw compressors that you can choose from.

• Single Screw Compressor
• Twin Screw Compressor

What is the Difference Between the Single Screw Compressor and Twin-Screw Compressors?

You can either choose to use the single screw compressor or the twin-screw compressor depending on your application requirements.

Here is a comparison between the two main types of screw compressors.

· Single Screw Compressors

In the single screw compressor, you will find the main rotor and two gate rotors.

It uses the main rotor as the driving rotor in conjunction with the gate rotor thus producing a compression effect.

· Twin Screw Compressors

Twin-screw compressors have helical grooved twin rotors which help in producing the compression effect.

As the two helical grooved rotors mesh, it will force the refrigerant to compress and flow in the other direction.

What are the Main Parts of the Screw Compressors?

Screw compressors are positive displacement machines that have various working chambers and parts.

Here are the main components of the screw chillers that you need to pay close attention to.

· Rotor

It comes complete with two main rotors which include the smaller male rotors and the bigger female rotors.

The female rotor has a connection to the prime mover which basically rotates the male rotor.

· Suction Valve

The suction valve is responsible for controlling the movement of the gases within the scroll compressors.

You can either use electrical power or pneumatic power to control the movement of gases.

· Electrical Motor (Prime Mover)

This is the main source of power for the screw chillers that comes in various forms depending on the design.

It has varying power transmission systems that will vary depending on the design or the model of the screw compressor.

· Lubricant Section

This is the part of the screw compressor that lubricates the moving parts and reduces the effects of friction.

It comprises the oil or lubricant tank, oil separators, and oil filters.

How Does an Air-Cooled Screw Chiller Compare to a Water-Cooled Screw Chiller?

Well, among the different types of screw chillers, we have the air-cooled screw chiller and water-cooled screw chillers.

 Air-cooled screw chiller

Water-cooled screw chiller

The working principles of the air-cooled and water-cooled screw chillers are similar and produce the same chilling effect.

Apart from that, they have the same components that help in the chilling of different equipment.

The main difference is the fact that air-cooled chillers use air as the main chilling agent and are often noisy.

On the other hand, water-cooled chillers use water as the main chilling agent and are often quiet.

You will also install the air-cooled chiller outside the building and the water-cooled chillers inside a mechanical room.

What are the Main Components of the Screw Chillers?

Successful operations of the screw chillers to produce a chilling effect require a combination of efforts from different components.

Here are the main components of the screw chillers that you ought to pay close attention to.

· Compressor

In this case, the main compressor is the screw compressor which is responsible for compressing the refrigerant and increasing pressure.

There are two types of screw compressors which include the single-screw compressor and twin-screw compressor.

· Evaporators

This is the part of the screw chiller which will collect the heat that comes from the system.

It consists of different pipes that contain the liquid that delivers the hot water and heat from the system.

· Condensers

The condenser is responsible for eliminating the heat which the refrigerant collects from the evaporators in the screw chillers.

It has a system that increases the residence time of the refrigerant as it condenses the refrigerant to eliminate heat.

· Expansion Valves

In the expansion valves, various components will assist in controlling the amount of refrigerant.

It will help in reducing the pressure of the refrigerant and supply it in various quantities towards the screw compressors.

· Control Unit

You will use the control unit to configure, program, and even monitor every move that occurs within the screw chillers.

It has systems that allow you to connect to the screw chilling system even from a remote location.

· Lubrication System

You will depend on the lubrication system to lubricate the moving parts of the screw chillers to reduce the effects of friction.

It has different parts such as a lubrication tank, and filters that are capable of providing sufficient and clean oil.

What is the Working Principle of a Screw Chiller?

You will have to set the screw chillers according to the right chilling specification that you need.

As soon as you press start on the machine, the refrigerant will move from the refrigerant cylinder to the compressor.

In the screw chillers, we have screw compressors which are responsible for the compression of the refrigerant.

It will compress the refrigerant and increase the pressure as well as the speed of movement.

With that velocity, the refrigerant will flow from the compressor through pipes and delivery systems straight to the evaporator.

While in the evaporator, the refrigerant will collect the heat that comes from the system your intent to cool down,

The evaporator has a series of pipes that will deliver the heat from the system in pipes that contain flowing water.

The refrigerant will collect the heat from the water and leave them cool while the refrigerant heats up changing into gas.

Loaded with enough heat and pressure, the refrigerant will flow from the evaporator all the way to the condenser.

While in the condenser, the refrigerant will encounter cool water or air which will eliminate the heat it holds.

At the same time, it will change form from the gas into a liquid after losing the heat through the condensation process.

The air or water will eliminate the heat and dispose of it properly as the liquid refrigerant moves to the expansion valve.

At the expansion valve, the liquid refrigerant will go through a process of pressure reduction.

It will flow at a slower speed as the expansion valve delivers the liquid refrigerant in bits back to the compressor.

What is the Best Place for Locating a Screw Chiller?

You can locate the screw chillers at any part of the production facility depending on the type of screw chiller.

Water-cooled screw chillers are best located in a mechanical room away from the weather elements that can cause damages.

On the other hand, you will locate the air chillers outside the production facility where it has proper access to enough air.

It is also a very strong machine that can withstand the weather elements and survive for a very long time.

It also produces a lot of noise thus locating it outside in an open space will help in reducing noise irritation.

You can also locate the air-cooled screw chillers in a mechanical room with plenty of ventilation to provide enough air.

What are the main Quality Specifications for the Screw Chillers?

Screw chillers have particular quality specifications that assure you of very high-quality, safe, and durable screw chiller machines.

You must ensure that your screw chillers adhere to all the quality specifications such as:

• AHRI Quality Certifications certifies the machine according to the coefficient of performance.
• DIN EN Quality Certifications such as DIN EN ISO 9001:2015 for quality management systems.
• CE Quality Certifications for labeling certifications such as EU regulation no. 765/2008.
• ELT Quality Certifications for the North American Market Certifications
• RoHS Quality Certifications according to the 2011/65/EU
• ANSI Quality Certification such as ANSI/ASHRAE

Which Industrial Applications Employ the Use of the Screw Chiller?

You can use the screw chillers in different types of industrial applications to cool different types of equipment.

Here are some of the industrial applications where the screw chillers come in handy.

· Construction Industry

You can use screw chillers in the construction industry to cool different types of equipment.

For instance, you can use the screw chillers to change concrete molecular structures or supply chilled water for mixing concrete.

· Food Industry

You can also use the screw chillers in the food and beverage industry for several chilling functions.

It will help in cooling food faster before you fill the food in different packages for storage or subsequent distribution.

· Central Air Conditioning HVAC Systems

You can use screw chillers in big factories since they have higher chilling effects than other chillers such as scroll chillers.

It will come in handy in ink printing plants, chemical plants, and automobile factories to chill different types of applications.

Screw chiller regulate the temp of food industry

What are the Benefits of Using the Screw Chillers?

Screw chillers are one of the best types of chilling systems that you can use in the cooling of different machines.

Here are some of the advantages of using screw chillers in different cooling applications.

· Occupies Less Space

Screw chillers are smaller in size and will occupy less installation space in residential and commercial buildings.

They have smaller components that occupy less space thus making them smaller even though the effect is great.

· High-Efficiency Levels

You will also use the screw chillers to cool different equipment efficiently according to the capacity of the industrial application.

You have the freedom of customizing different sizes of screw chillers that can comfortably cool different building installations.

· Energy Efficient

You will experience great energy efficiency by using screw chillers as they use very little energy to produce proper results.

They have proper control on the optimal levels of cooling and never go beyond specific cooling capacities thus conserving energy.

· Emits Minimal Noise

The main type of screw chiller is the water-cooled screw chiller which does not make a lot of noise.

In addition to that, you will house it inside a mechanical room which will help in absorbing the noise.

· Requires Minimal Maintenance Work

You will spend less time and money in the process of maintaining the screw chillers because it requires minimal maintenance.

Screw chillers have fewer parts that are very strong and durable that will take ages before they are up for maintenance.

Are There Any Disadvantages of Using the Screw Chillers?

Unfortunately, screw chillers have some limitations despite the numerous benefits that come with them.

Here are some of the limitations that you might experience using the screw chillers.

· High Cost of Purchase

You will spend a lot on the purchase of the screw chillers as they are quite expensive and have high-quality materials.

The cost of manufacturing the scroll chillers is high because it uses very high-quality materials that are not cheap.

· Not Easy to Repair

Since the scroll chillers are hermetic systems, you might go through a difficult time trying to repair them.

You will have to purchase original parts for performing repairs which are often quite expensive.

· Difficult to Disassemble

In addition to that, you will find a lot of difficulty in bringing the hermetic screw chillers apart.

You will have to hire professionals or install the clean-in-place system which is often costly to acquire.

What is the Difference Between the Screw Chillers and the Scroll Chillers?

Chillers have different types of compressors which help in the compression of different types of refrigerants.

Among the chiller compressors that you can choose from including the scroll compressors and the screw compressors.

A screw chiller is, therefore, a chiller that uses the screw compressor to compress the refrigerant and increase pressure.

On the other hand, scroll chillers use the scroll compressor to compress and increase the pressure of the refrigerants.

 Scroll chiller

What are Some of the Features of the Screw Chillers?

Different types of screw chillers come complete with common features which you must pay very close attention to.

Here are the main features that you will find in most of the screw chillers.

· Different Components

Screw chillers have various components such as unit compressors that have semi-closed screw compressors.

It also has electronically controlled components with heat exchangers and high-quality copper tube condensers and evaporators.

· Security Features

You must also ensure that it has security features that will help in keeping the machine as well as the operators safe.

· Stable Performance

Your screw chillers must also exhibit stable performance with very low noise and high levels of durability.

Most of them have very simple operations with an LCD on the control panel for proper programming and monitoring.

· Open and Attractive Appearance

It has a very simple, beautiful, and open structure that you can easily install into the production facility.

· Flexible Operations

You can also enjoy the flexibility of operating the screw chillers as you can change compressors accordingly.

Implying that you will have to program the machine and the screw compressors to function according to the product specifications.

How Do You Maintain the Screw Compressor Unit of the Screw Chillers?

When you are maintaining the screw chiller units, you need to focus purely on the main parts.

In the screw chiller compressor unit, we have for main parts including:

• Air Suction Valve
• Oil Components
• Air End
• Electric Motor

Since the screw chillers have very few parts, you don’t have to perform a lot of maintenance on the machine.

In that case, all you have to do is disassemble the parts and clean them very well to eliminate the debris.

The oil components have oil tanks and oil filter systems which you need to clean regularly.

Apart from that, you must also fill the tanks regularly and ensure that the reservoirs are up to the right limits,

In addition to that, you must maintain proper lubrication of the moving parts and replace the broken parts regularly.

Finally, you should treat the refrigerant and any fluids on the screw chillers to eliminate the possibility of fouling the system.

Screw compressor maintenance

What is the Difference Between the Screw Chillers and the Centrifugal Chillers?

Screw chillers and centrifugal chillers are types of chillers that you can use in different industrial applications to cool equipment.

Despite the similarity in function, screw chillers and centrifugal chillers differ when it comes to the type of compressor.

Screw chillers have screw compressors while the centrifugal chillers come complete with the centrifugal compressors.

Centrifugal chillers are the most efficient option that you can use when you intend to run the chiller at full load.

Centrifugal chiller

It uses centrifugal force which helps in the compression of the refrigerant to produce enough pressure and speed.

On the other hand, you will use the screw chillers to squeeze the refrigerant between two rotating helical screws.

How do you Choose the Right Type of Screw Chillers?

Since we have different environmental and industrial aspects, you need to choose a screw chiller that will fit your operation requirements.

Here is a step-by-step process that you can follow to assist you in choosing the perfect screw chiller.

Step One: Determine Heat Load

You must know the specific heat load you expect to be chilling using the screw chillers.

With this knowledge, you will be able to choose the right type and size of screw chillers to handle the whole process.

Step Two: Determine Coolant Type

In this case, you will choose between the air-cooled screw chiller or the water-cooled screw chiller.

In other words, you will choose the coolant type that will provide you with the perfect flow rates to cool the target temperatures.

Step Three: Know Installation Environment

You must also have proper knowledge of the environment where you will install the screw chillers.

This information will help in getting the right size of screw chillers that you need and the accessories to fit.

Step Four: Check Performance Curves

At this point, you will look at the chiller as well as the pump performance curves among different models.

You should settle for the chillers that have the best types of chilling and pump performances to give the best results.

You will complete the process by selecting the best type of screw chiller to suit your application requirements.

Screw chiller coolant

How Much Does a Screw Chiller Cost?

You will purchase the screw chillers at various prices depending on the different types of screw chillers.

The prices vary due to the different sizes of the screw chillers in the market where larger screw chillers cost more.

Apart from that, you will also realize that the better the quality of screw chillers the higher the cost.

In some instances, the minimum order quantity also makes a difference in price as you might have a discount.

You will spend between 3000 and 50,000 US dollars to acquire a screw chiller depending on the type of screw chiller.

What are the main Technological Trends and Alternatives for the Screw Chillers?

Well, there are a lot of improvements in terms of developing the screw chillers for better performance.

Here are some of the technological alternatives and trends that you should consider looking at.

· Increased Energy Efficiency

In a bid to reduce the cost of energy, there are new technological advancements in the industry such as variable frequency drives.

As the cooling load decreases, the VFD will also reduce the energy output and increase when the cooling load increases.

Om that note, you will be able to save a lot of energy that could be even when the cooling load is low.

· Gas Driven Systems

You can opt for gas-driven screw chillers especially in areas where the cost of power is very high.

Despite that alternative, you should use gas-driven screw chillers in areas where electric power is a problem.

· 2-Phase Turbines

You can replace the expansion valve using the 2-phase turbines in very large screw chiller applications.

This will help in maintaining the energy potential that is often lost with the use of an expansion valve.

· Larger Sizes of Screw Chillers

You will also replace the small types of screw chillers with modern large-size screw chillers.

The large size of screw chillers will not only increase the capacity of the chiller but increase the overall efficiency.

Large size screw chiller

Which Factors Do You Look at When Calculating the Life Cycle Cost of the Screw Chillers?

You should do a proper calculation to know just how long you will take by using the screw chiller.

In other words, you should know the durability of the screw chillers by calculating the life cycle cost considerations.

Here are the main factors that you should look at when calculating the life cycle cost of screw chillers.

· Capital Costs

Here, you will look at the final cost of purchasing and installing the screw chillers with costs such as electric bills.

· Operating Costs

You will look at the amount of money you will spend in paying for energy, treatment, and overall maintenance.

· Programmed Servicing and Maintenance Cost

In this case, you will look at the amount of money you will spend in servicing and maintaining the screw chillers.

How Does a Screw Chiller and a Reciprocating Chiller Compare?

Well, the main difference between the screw chillers and the reciprocating chillers is the type of compressors.

Reciprocating chillers have reciprocating compressors while the screw chillers have the screw type of compressors.

Despite that difference, most of the factors such as working principles are similar for both types of chillers.

You can also have air- and water-cooled screws or reciprocating chillers for cooling different applications.

Reciprocating chiller

What are Some of the Faults that You will Experience with the Screw Chiller?

Screw chillers also work efficiently up to a point where it begins developing a few problems.

You can identify the issue affecting the machine through proper troubleshooting procedures.

Here are some of the problems that you might identify with the screw chillers.

· High- and Low-Pressure Alarms

High-pressure alarms go off when the pressure within the screw chillers is very high than usual.

Low-pressure alarms will also go off when the pressure within the screw chiller system is low.

You can sort this out through proper control of the pressure systems from the control panel.

· Compressor Overheat

You might also experience issues with very high temperatures within the compressor systems.

In such a case, you will activate the thermal protection module to help you in controlling the temperatures well.

At TopChiller, we design and manufacture a range of chiller systems such as air chillers and water chillers.

Contact us today for all your screw chiller needs.

Screw Chiller-The Ultimate Buying Guide By TopChiller

What is Screw Chiller?

A Screw Chiller is a type of cooling machine that is based on a screw-type compressor.

Its screw-based compressor comes with several innovative and unique features that make it preferable for many specific applications.

A Screw Chiller is a more efficient, less noisy, durable, and lightweight cooling device. It can perform efficiently under harsh environmental conditions.

Screw chiller manufactured by TopChiller

What are the Main Components of a Screw Chiller?

1. Screw Compressor:

This is the major and most important component of a Screw Chiller. It is responsible for the pressure, flow rate, and speed of the refrigerant.

2. Evaporation Unit:

It performs the evaporation process by which it sucks all the heat content in an excessive amount.

3. Advanced Control Unit:

This advanced microprocessor-based control unit is the heart of the Screw Chiller and controls everything in it. It has all the control options and features needed.

What are the Additional Components of a Screw Chiller?

1. Temperature Sensors:

Although a Screw Chiller has all the sensors built-in, you can add an extra set of sensors if needed in the tank, compressor, or any other component.

2. Alarm System of Fluid Levels:

A fluid level alarm system can be added to Screw Chiller, which will notify you when the fluid has reached a certain level. Like, the alarm will ring when fluid is too low or too high.

What are the Characteristics of an Ideal Screw Chiller?

1. Simple and Compact Structural Design:

Its parts should have protective features, less erosion, and wear, be corrosion-resistant, high-grade compressor piston, and have less probability of failure.

2. Smooth Operation:

All its rotating and moving parts are should be designed to move smoothly and quietly. It creates less noise and less vibration. This makes parts last longer without any kind of damage.

3. More Efficiency:

An ideal Screw Chiller can provide 25-30% more chilling efficiency. It is possible due to its screw-based compressor design.

What are the Outstanding Advantages of a Screw Chiller?

1. Modern Semi-Hermetic Compressor Design:

It is the heart of a Screw Chiller that is consisted of a 5 to 6 screw-based compressor. This modern type of compressor is a highly efficient compressor.

2. Fully Automatic Control Unit:

Its highly innovative microprocessor-based Control Unit manages and controls all its functions automatically.

3. Long-Lasting Protective Design:

Its parts contain protective covers, sensors, lubrication, and other kinds of features for the protection of the components.

Screw chiller control Unit

What is the Advanced Control Unit System of a Screw Chiller?

There are several innovative features of the control unit of a Screw Chiller that makes it an advanced control unit. These features are given below.

1. It has the most advanced PLC-based controller. It controls all the operations to the highest possible accuracy.
2. It has a big sensitive touch screen that promotes human to machine interface for better handling of the control unit.
3. One of its advanced features is the ease of control and simplicity. Anyone can learn and operate it with a little amount of training.

What is the Advanced Operating Feature of a Screw Chiller?

The advanced operating feature is the most beneficial feature that is made to make your operation easy and simple.

The advanced PLC-based control unit of the Screw Chiller is the backbone of the advanced operating feature.

In this, your setting and programming of parameters are made easy and simple so that you can set your data precisely with ease.

This feature makes all the operations most accurate. It does not fluctuate to a very minor degree from the programmed parameters. This feature makes the process faster and safer.

How does a Screw Chiller Work?

The working mechanism resembles the working mechanism of other kinds of chillers. In a Screw Chiller, the cooling cycle begins by cooling of refrigerant.

Then refrigerant is sent to the compressor for pressure, and flow rate regulations.

From the compressor, it enters the refrigeration unit where it collects all the heat and finally in condenser it discards all the heat to maintain optimum chilling by the following process of condensation.

Finally, the whole cycle is repeated from time to time for continuous cooling.

What are the Unique Applications of a Screw Chiller?

The food industry and the central cooling system of big rooms are the two most unique applications of a Screw Chiller.

1. Food Industry:

It is used for necessary temperature control during food processing, baking, etc. It is also used for post-production functions. These functions include storage, packaging, preservation, etc.

2. Central Cooling System:

In large industrial plants, where a central cooling system is needed for the whole area or room, a Screw Chiller is utilized there. With its characteristics, it efficiently handles the central cooling of the big areas.

Screw chiller is used for food industry

What is the Importance of a Screw Chiller in Construction Industries?

In construction industries, its importance is related to the concrete processing and curing process.

Concrete is the most vital part without which a construction industry is incomplete and it is manufacturing includes a vital role of Screw Chiller.

When concrete is manufactured it needs constant curing of chilled water. A Screw Chiller provides this constant supply with an accurate set-point of temperature.

It is also used for temperature regulation during setting required hardness and strength of many construction industry products.

What is a Low, Medium, and High-Temperature Level Screw Chiller?

1. Low-Temperature Level:

The low-temperature level is the range between -45 °C to -110 °C in which it operates.

2. Medium Temperature Range:

It is the temperature range between -5 °C to -45 °C.

3. High-Temperature Range:

This is the highest range of temperature and it is between 5 °C to 15 °C.

What is The Lubrication Oil Temperature of a Screw Chiller and How to Maintain it to Optimum Degree?

Lubrication oil temperature is very crucial to keep it working properly. A temperature range lower than the optimum range will cause the lubricant to freeze and becomes dense.

This will increase the friction and heat of friction. The high temperature will cause the lubricant to become less dense and it will not able to tackle friction and perform other functions.

A temperature range from 19 to 22 °C is the optimum temperature range of lubrication oil of a Screw Chiller. It has built-in features that automatically manage this range of temperature.

In case of any fault, extract the lubrication oil and change it will the new one.

What is the Lubrication Protocol and Principle of a Screw Chiller?

Lubrication protocol and the principle is a set of guidelines that must be followed to keep your lubrication oil and lubrication safe and efficient.

1. The lubrication oil temperature should be kept in the optimum range. The optimum temperature range generally used is 19 to 22 °
2. Always prefer natural mineral lubrication oil for your applications. These are more heat efficient and last longer.
3. Lubrication oil should be changed after 25 to 30 days. In case it has burned or worn out you may change it when needed.
4. Do not overfill the Screw Chiller with lubrication oil. Use precisely the amount needed.

What is the Difference Between a Screw Chiller and Other Type of Industrial Chillers?

1. An Industrial Chiller can use different kinds of compressors, while a Screw Chiller uses a screw-type compressor.
2. It can be applied to both process application as well as central chilling. On the other hand, an Industrial Chiller is not always applicable to both applications.
3. A Screw Chiller is much easier to install and maintain than an Industrial Chiller.
4. Its structure is highly protective and durable as compared to an Industrial Chiller.

Industrial Chiller

How a Screw Chiller is Different from Reciprocating Industrial Chiller?

1. A Reciprocating Industrial Chiller contains a moving piston-based compressor design, while a Screw Chiller has a rotating screw-based compressor design.
2. Reciprocating Industrial Chiller work by the movement of the piston that creates a vacuum and estimated degree of pressure, flow rate, and temperature is achieved.
3. Screw Chiller works by the rotation of screws in certain fixed paths that creates pressure and temperature of desired values.
4. Screw Chiller is more fast, efficient, and lightweight than a Reciprocating Industrial Chiller.

Reciprocating industrial chiller

What is the Three Major Type of Evaporators Used in a Screw Chiller?

1. Dry Shell Evaporator:

This cylindrical-shaped evaporator is simple to use and operate. The oil return value of the dry shell evaporator is much higher than other evaporators.

2. Flooded Evaporator:

In this cold refrigerant is passed through heat exchanger tubes. On passing through tubes it collects heat and evaporates.

3. Film Evaporator:

In this refrigerant is sprayed on the heat exchanger to form a film. This film refrigerant gets evaporated and desired heat collection is achieved.

What is the Composition and Structure of the Screw Compressor of a Screw Chiller?

A screw compressor is mainly made of rotor, screws, air filters, suction valves, rotation bearings, motor, and discharge valve. Rotors are moving high-speed cylindrical rollers.

These are the most important parts and are responsible for creating the required pressure. Air filters are used to filter the oil and air so that it does not cause any kind of damage to the compressor.

Suction valves are used to create suction and discharge valves are used to release the pressure.

What is the Working Principle of the Screw Compressor of a Screw Chiller?

A screw compressor works by sucking the air into it and compressing it to a small volume. As a result of this compression, changes happen in the pressure and temperature of refrigerants.

It works either by reciprocating piston mechanism or rotating screw mechanism. A Screw Chiller generally follows a rotating screw mechanism.

A screw compressor is composed of two screws called make rotor and female rotor. These two screws move at different speeds in opposite directions to each other to create pressure differences.

What is the Difference Between a Screw Chiller and Piston Chiller?

1. A Piston Chiller is based on a piston-type compressor, while a Screw Chiller is based on an advanced screw-type compressor.
2. Both differ in the working mechanism. Piston Chiller work by the movement of the highly tightened piston that moves up and down to create pressure. a Screw Chiller performs by the movement of screws.
3. Piston Chiller is used where a higher level of pressure range is required.

What are the Benefits of Using Dry Evaporators in a Screw Chiller?

1. It has the highest heat exchange efficiency. It is possible because it has a set of highly durable heat exchanger tube units.
2. Lubrication oil control is relatively simple and efficient. You can easily transfer and return oil in dry evaporators of a Screw Chiller.
3. It gives high efficiency at a low volume of refrigerant up to 55 to 70%.
4. The heat collection is simple and durable. It does not cause any kind of damage to the component in which the refrigeration process is taking place.

What are the Advantages of Water-Cooled Screw Chiller?

1. All parts are made with materials that can tackle high thermal expansion. All components can resist high thermal shock and undergo a minimum of thermal expansion.
2. The water circulation cycle through different components is smooth and less noisy. This results in a minimum amount of noise that is below safe limits for human health.
3. Fewer vibrations are produced, which makes components remain safe and sound for a long time.

Water cooled screw chiller designed by TopChiller

What are the Advantages of an Air-Cooled Screw Chiller?

1. It is based on the semi-hermetic design of screws with 2-3 screws. It has the highest degree of temperature control efficiency.
2. It is based on the most advanced frosting type microprocessor that makes all the control systems of the Air Cooled Screw Chiller perfect and fast.
3. It has a highly qualitative and efficient set of tubes for heat exchange operations. These are thermal resistant and durable with a thermal heat coefficient of less than 5%.

How to Select Between Air Cooled and Water Cooled Screw Chiller for your Industry?

Following facts and tips can help you to make a selection between these two.

1. The most important selection factor is the application. An air-cooled is mostly used as a central Screw Chiller. A water-cooled is used for process cooling.
2. Even though both are screw compressor-based, their cooling efficiency may be different. Usually, water-cooled is more efficient.
3. Water-cooled are mostly easy to install as compared to Air Cooled Screw Chiller.
4. Air Cooled contains more noise levels and vibration levels.
5. Air Cooled are usually costlier than the Water Cooled Screw Chiller.

How to Select Suitable Screw Chiller for your Industry?

Following are the major factors and features that you should take into consideration while selecting a Screw Chiller for your industry.

1. Cooling capacity should be the first factor here. The range of cooling capacity should match your required range. It should not be less than the required range.
2. The temperature difference between the inlet and outlet of the refrigerant should be optimum. Too much difference means low chilling efficiency.
3. Select one that is small in size, requires less amount of maintenance.
4. It should have the most advanced control unit.

Water cooled screw chiller

What is the Efficient Energy Control Mechanism of a Screw Chiller?

The efficient energy control mechanism is one of the most unique and beneficial features of the Screw Chiller.

This mechanism is based on a four-stage capacity control mechanism of 25%, 50%, 75%, and 100%. This mechanism works by two methods.

First, you can program the required set of capacity so that enough energy is provided and it saves your energy from being overused or leaked.

Secondly, it has an automatic load switching mechanism. You can set direction and it will switch to one of the four capacities automatically according to the needs of the process.

Both of the methods are very energy efficient and save a huge amount of your energy expenses.

What is the Multi-Level Protection Feature of a Screw Chiller?

The multi-level protection feature is a set of advanced features described below.

1. The Screw Chiller screw compressor has an internal protective layer system. Usually, 2 layers are mounted to protect the compressor and make it last longer.
2. Its parts are highly resistant to corrosion, chemical reactive agents, liquid spills, and dust accumulations.
3. Screw Chiller has a highly compact surface that can withstand any kind of wear and erosion from sharp, heavy other kinds of items.
4. Its automatic loading switching feature also keeps Screw Chiller safe and sound from high and low-temperature fluctuations and thermal expansions.

How a Screw Chiller is Easy to Install?

Ease of installation is one of its major features. You can easily install it on your own by following simple guidelines given by the manufacturers.

All the parts are already assembled and you just need to unpack them and join them according to the guidelines. After joining parts, filling the tank is easy too.

Just fill it to the optimum level prescribed. Connect to a power source and start it. programming parameters on the control unit is very easy and you can do it in a short time.

How to Size a Proper Screw Chiller for your Applications?

Sizing of a Screw Chiller can be done on the following considerations.

1. Estimate the cooling capacity required for your application. Estimate it in tons.
2. Calculate the process cooling load by diving the cooling capacity with the time unit.
3. Decide your operating load range. The generally used range is 50% to 75%

Based on the above three factors, one can properly size the Screw Chiller for the industry.

Why Lubrication Oil is Important for the Screw Chiller?

1. Reduction in the Friction:

Applying layers of lubrication oil on components, joints, etc of the Screw Chiller will reduce the friction produced. It will help to keep it long-lasting and healthy.

2. It Makes Operation Smooth:

Lubrication oil makes movements of the components smooth and easy. On the whole, it makes the process faster and quiet.

3. It Covers Leakages:

It helps in covering small leakages in the surfaces of components.

Screw chiller oil system parts

What Type of Lubrication Oil is used in a Screw Chiller?

1. Mineral Oil:

This is petroleum-based lubrication oil. It is extracted as the byproduct of the petroleum refining process.

2. Artificial Oil:

It has the same composition as mineral or natural oil. It is made synthetically for the lubrication in Screw Chiller. Is available in many varieties suitable for different compressors.

The two most common types of artificial oil are Polyester Oil and Polyether Oil.

What are the Four Load Capacities of a Screw Chiller?

The four load capacities are t 25%, 50%, 75%, and 100%. 25% load capacity is generally used at the start of the process.

It is used to give starting load to the Screw Chiller so that it can be prepared for further process. at 50% and 75%, the solenoid valve system is activated and high-temperature oil is entered into the system.

It is the optimum range of load used. At 100% load capacity, the Screw Chiller is at high risk. If operated at this for a long time, it may face a huge failure.

What are the Precautions for a Screw Compressor of a Screw Chiller?

1. Always choose the proper size of screw compressor that can fit well with the whole Screw Chiller.
2. Proper lubrication is necessary for a screw compressor. Without lubrication, it will wear out from friction and you may have to replace it frequently.
3. All the screws of the screw compressor should be aligned properly on their optimum motion path. They should be aligned properly with each other.
4. Always install the screw compressor in an environment that contains a normal level of moisture. High moister will affect if cooling efficiency negatively.

What is the Difference Between Screw Chiller and Scroll Chiller?

The major difference is that they both use different kinds of compressors. A Scroll Chiller uses a scroll-type compressor, while a Screw Chiller uses a screw-type compressor.

Secondly, there is a difference in performance efficiency. Generally, the Screw Chiller is 20 to 25% more efficient than the Scroll Chiller.

A Scroll Chiller follows a rotation-based scroll mechanism and a Screw Chiller follows a moving screw-based mechanism that creates suction and pressure.

Scroll chiller

How to Maintain your Screw Chiller for Longer life?

1. Keep the daily record of temperature, pressure, and flow rate of refrigerant in condenser, compressor, and refrigeration unit.
2. Daily inspection should be done of the compressor.
3. Lubrication oil should be changed when needed. Generally, it should be changed over 25 to 30 days.
4. Flow rate, temperature, suction pressure, pump pressure, and other parameters should be set on optimum values.

Screw chiller maintenance

What are the Low-Pressure and High-Pressure Alarm Systems of the Screw Chiller?

1. Low-Pressure Alarm System:

A low-pressure alarm is the notification alarm when the suction pressure of the screw compressor is very low.

This low level is below the safe limit and can cause a range of problems. Low suction pressure means a lower amount of air returned and it will cause efficiency to decrease.

2. High-Pressure Alarm System:

When the pressure of discharge in s screw compressor is too high, it is called a high-pressure situation. This situation is notified by an alarm system.

How to Overcome Communication Fault of a Screw Chiller?

Communication fault generally happens because of some kind of problem in the control unit line or the external device connected.

Due to excessive moister the communication line may get affected by an oxidation reaction and it stops working for a while. To solve this kind of problem, expert help is a must.

You can keep the communication line and circuit board protected by certain measures so that it can be safe from this kind of fault.

What is the Proper Monitoring Practice for a Screw Chiller?

A proper monitoring practice is based on following guidelines.

1. Inspection of pressure or flow rate of refrigerant on daily basis.
2. Visual inspection of all the parts for any kind of big or minor fault.
3. Inlet and outlet temperature and pressure range of condenser.
4. The monitoring of lubricant density, temperature, health, and pressure daily.
5. Daily checking for any kind of abnormal noise or vibration in the Screw Chiller.

Screw chiller monitoring

How to Solve the Compressor Overheating Problem of a Screw Chiller?

The first reason for the overheating of a compressor is friction between the shell and screws.

Originally screw compressor of a Screw Chiller is made highly frictionless but over time due to some problem, it might create friction that causes overheating.

You can solve this problem by simply replacing the compressor or repairing it. Secondly, when the electric resistance of the winding of the screws compressor crosses 141 kilo-ohms, it will cause overheating. Use windings with low electric resistance.

How to Solve Low Exhaust Pressure Problem of a Screw Chiller?

1. Is your Screw Chiller Maintained Properly and Timely?

In case of delayed or improper maintenance, it might cause some level of exhaust pressure problem. Maintain it properly and regularly so that this problem never happens.

2. Inspect the Inlet Valves of Screw Chiller:

The inlet valves may get chocked or blocked sometimes and that results in an abnormality in exhaust pressure. Clean them regularly and check the valves properly before starting your Screw Chiller.

3. Failure of Motor:

This problem might happen due to a faulty motor or any kind of sudden problem in the motor. Repair the motor and always use the high-quality motor in Screw Chiller.

Screw chiller inlet valve

How to Solve the Problem of Unusual Vibrations in a Screw Chiller?

Following are the major problems and their solutions regarding unusual vibrations in a Screw Chiller.

1. Bolts and Joints are Loose:

These loosened parts may create unusual vibrations and unbearable sounds when running. Tight the joints and nuts to get rid of this problem.

2. Improper Flow Rate of Refrigerant:

When the flow rate is too high or contains fluctuation it creates vibration in pipes, condenser, and other units. Set your flow rate to an optimum value.

What are the Troubleshooting Guidelines for your Screw Chiller?

1. When you Cannot Unload the Screw Chiller:

It can be because of the improper setting of pressure parameters or the pump pressure switch. Correct the setting and start again.

2. When Oil Temperature Decrease Sharply:

It can happen when the compressor sucks excessive moist air, or too cooled refrigerant into it. Improper setting of expansion valves may also cause this problem.

Inspect the valves and refrigerant temperature to maintain it optimum. Install your Screw Chiller under optimum environmental conditions.

Screw chiller troubleshooting