What are the various types of Batch Reactor and their Applications?

In the chemical and pharmaceutical sectors, a common vessel type is called a batch reactor. This sort of jar is employed for many different processes despite its misleading name, including dissolving solids, mixing products, undergoing chemical reactions, distilling in batches, crystallising substances, extracting liquids from other liquids, and polymerizing substances. They may not always go by the title "realtor," but rather a term that better describes their work.

As a rule, a batch reactor is indeed a storage tank that comes with an agitator and a built-in heating/cooling system. Their capacity ranges from a few ounces to over fifteen thousand gallons. Glass-lined steel, stainless steel, glass, steel, as well as unusual alloy are the most common materials used in their construction. The reactor's top cover often has ports for charging liquids and solids. Connections at the top allow gases and vapours to be released. When discharging liquids, they often go out the bottom.

 

The flexibility of a robust batch reactor manufactured by an excellent batch reactor manufacturer in India is where its greatest strength lies. Multiple operations can be performed in succession within a single vessel without compromising containment. This is especially helpful when working with extremely powerful or dangerous chemicals.

Agitation:

A driveshaft in the middle of the agitator and a motor installed on top of the agitator is the standard setup. The blades of the impeller are attached to the shaft. There are many different blade designs, but generally speaking, the blades will cover around two-thirds of the reactor's diameter. Anchor-shaped paddles, with minimal space between the vessel walls and the blade, are commonly employed for transporting and manipulating viscous goods.

 

Baffles are a common component of reactors that operate in a batch mode. These are fixed blades that disrupt the flow generated by the agitator's rotation. These can be attached to the inside of the vessel's walls or to the vessel's outside cover.

 

Although advancements in agitator baffle and blade design have helped, the amount of energy available remains the limiting factor when it comes to mixing in big batch reactors. If the mixing energy is higher than 5 W/l, the cooling system may struggle to keep up with the load on a large vessel. Problems with shaft stability can also be caused by excessive loads on the agitator. In cases where thorough mixing is essential, a batch reactor is not the best choice. The use of high-speed agitators, ultrasonic mixing, or static mixers in conjunction with reduced-scale, flowing systems allows for significantly greater mixing rates than is possible with conventional methods.

Cooling as well as Heating systems:

During processing, the products within a batch reactor may either release or absorb heat. Stirring heated liquids around in storage containers is a waste of energy. It is necessary to either supply heat to or remove heat from the reactor's contents via a cooling jacket or pipe in order to maintain the proper temperature. Batch reactors can be heated and cooled using either internal coils or external jackets. To either add or remove heat, fluid is circulated through the jacket and coils. External cooling jackets are typically chosen in the pharmaceutical as well as chemical sectors due to their convenience when cleaning the vessel.

 

The coefficient of heat transfer is a variable that may be considered crucial. However, it is important to remember that large batch reactors equipped with external cooling jackets are subject to severe heat transmission restrictions due to their unique architectural configuration. Even with perfect heat transfer, it is challenging to go above 100 Watts/litre. A cooling capacity of more than 10,000 W/litre can be produced by continuous reactors. However, batch reactors are not the best option for procedures that generate a lot of heat.

 

When working with a temperature-sensitive product, such as during crystallisation, a quick response time from the temperature control system and uniform heating and cooling from the jacket is crucial. It is possible to choose from a variety of batch reactor cooling jackets mentioned below by Ablaze Glass Works - the most reliable Batch reactor manufacturer and supplier in Gujarat.

1.   Single external jacket:

The exterior shell of the vessel is protected by a single jacket in this configuration. High-velocity heat transfer fluid is sprayed from nozzles at high pressure all the way around the jacket. The jacket's interior temperature can be set to either warm or cool the wearer.

 

A single jacket is the most conventional form of outer layer for temperature regulation. However, there are still some drawbacks to this tried and true approach. Adjusting the fluid temperature in a large ship's cooling jacket can take several minutes. This leads to a lack of responsiveness in regulating temperature. Heating or cooling can be inconsistent around the dish's sides and bottom because of poor heat transfer fluid distribution. Heat transfer fluid input temperature can vary widely, leading to hot and cold spots at the jacket inlet sites.

2.   Half coil jacket:

To build the half coil jacket, a half-pipe is welded around the vessel's outside to provide a semicircular flow channel. Plug flow characterises the movement of the heat transfer fluid through the channel. To transport the heat transfer fluid, a big reactor may employ more than one coil. Similarly to how one may adjust the heating or cooling in a single jacket, this system allows for individual jackets to have their own individual temperature settings.

 

Faster heat transfer fluid displacement is possible in a half coil jacket due to its plug flow properties. Good temperature regulation requires this. As a bonus, the even supply of heat transfer fluid between the dish's walls and its base solves the issue of temperature differences between the two. To the same extent as the input heat transfer fluid is susceptible to large temperature swings, the single jacket design is as well.

3.   Constant flux cooling jacket:

Constant flux cooling jackets have only been around for a short amount of time. It's not just one jacket, but rather a collection of twenty or more separate ones. The valve's ability to regulate temperatures is based on the ability to open and close these passageways. The process temperature can be controlled without affecting the jacket temperature by adjusting the heat transfer area in this way.

 

The heat transfer fluid’s high velocity as well as the small length of the flow channels provide the constant flux jacket with an extremely fast temperature control response (usually less than 5 seconds). The cooling /heating flux is also consistent, much like the half coil jacket. However, unlike other jackets, this one maintains a very stable inlet temperature throughout operation. This jacket is unique in that it allows for precise measurement of process heat. By keeping tabs on the reaction rate, the user can keep tabs on addition rates, regulate crystallisation, and find the endpoints of reactions.

Applications:

The process sector frequently makes use of batch reactors. There are a wide variety of uses for batch reactors in the lab, including pilot-scale manufacturing and inducing fermentation in beverages. In addition, they have extensive application in the pharmaceutical industry. Running batch reactors can be costly and their reliability in producing consistent results is often questioned. Moreover, they are put to use in studies of reaction kinetics, volatiles, and thermodynamics. Wastewater treatment is another common application for batch reactors. They effectively decrease the biological oxygen demand (BOD) of raw water being used as an input (influent).