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If you have an application that employs batch reactors and you are looking for a way to improve the efficiency of your operation, seeing what process automation you have (and don’t have) in place is a good way to start.  When automation technologies are integrated into your system, they not only improve process control but they can also be an effective way to increase productivity, minimize costs and make your facility operate more ergonomically.

There are many different aspects of a reactor that can be measured and regulated via control systems; the ones you select to have automated should be based on your application-specific requirements.  Items that can be controlled/monitored through a control system include:

1. Measuring and recording process variables

The ability to measure and record process variables such as temperature, pressure, and pH is critical in many applications that require precise measurements in order to maintain the reactive environment.  Keeping track of multi-variables electronically instead of manually not only saves time and increases organizational record-keeping but also minimizes miscalculations that can have a potentially detrimental effect on batch quality.

2. On/Off functionality of valves

Valves are critical components of a process, as they control the starting and stopping of product from one piece of equipment to another.  Regardless of the type, their basic function is to regulate the flow of liquid or gas.  When choosing between a manual or actuated valve, there are a few factors you’ll need to take into consideration.  There is an additional cost associated with an automated valve versus a manual design, but it’s important to ask yourself how frequently does the valve need to be turned on/off?  And where is it located?  (Some valves are in difficult to reach locations, making automation a practical option.)  When you considering the labor costs of personnel having to perform the job manually in addition to possible human error it might make more sense to go for the automated option where you can be assured that your control system will provide reliable shutoff over a wide range of service conditions.  Can a person give you the same high integrity, repeatable tight shutoff performance?

3. Reactor temperature control

It’s one thing to be able to measure and record temperature, but controlling it through automation gives you the power to change the temperature remotely or maintain a set point.  This capability will optimize the reaction rate of your process, resulting in better overall efficiency and an improvement in product yield.

DDPS reactors can be integrated with the Director Series temperature control module, which delivers accurate and reliable temperature control to your process vessel across a wide temperature range from -85° to 200°C.  The PLC controls even give you the ability to store temperature recipes, which can help standardize your operational procedures, a really handy feature for batch processes.  Data collection and trending are also available.

4. Agitator on/off and speed control

The agitation speed has a major impact on batch reaction rate and mixing efficiency.  Depending on the process objectives (e.g. homogenization, suspension) and the characteristics of the products involved (e.g. viscous fluid, fragile crystals) and the liquid level of the batch, it is important to regulate when the agitator is on and at what speed it is running.  Automating this part of your process can ensure optimal mixing times and speeds are adhered too.

5. Pressure/Vacuum control

There are many applications where the internal vessel atmosphere needs to be sustained under specific pressure or vacuum conditions with set-points that can vary throughout the lifecycle of the process. In many cases, catalysts are used to accelerate the rate of a reaction.  This often requires a product to be introduced in a precise portion and at a specific time into the vessel.  Also, many processes run their reaction unit under vacuum because the chemistry requires it or it lowers the boiling point of a solvent.  All of this needs to be accomplished while maintaining a specific pressure or vacuum within the reactor.  If the pressure/vacuum of the vessel isn’t maintained it will cause inaccuracy in the reaction.  The easy solution to this problem is simple pressure control automation.

6. Recipe function

As we alluded to earlier in the post, recipes are a great tool for batch processes that allow you to pre-program certain parameters.  In addition to temperature control that we already touched upon, other functionalities like valve opening/shutoff, agitation speed, and timing of other variables in conjunction with one another can be set for multiple batches without any operator interaction.  Having a recipe in place is especially useful when you are evaluating a process.  Once the run has been analyzed, you can make recommendations and fine tune the recipe to help optimize the process for future runs.

7. Record variables to form a batch record

I can remember over a decade ago working for a pharmaceutical company and having to go into “the cage” from time to time.  This was the nickname given to the documentation room that was a library of shelves filled floor to ceiling with batch records on printed paper arranged alphabetically and chronologically.  While this still might be the standard practice for some facilities, most processes are trending towards paperless, electronically-documented records.  Automated controls can give you the functionality needed for recording all of this important information seamlessly as it is recorded by the control system.  This not only streamlines the data but it eliminates human error that can happen when numbers are observed and transcribed manually onto paperwork.  It also makes looking up batch records a lot easier.

There are so many advantages to having a control system integrated with your reactor system.  Because process parameters, operator manipulations and other variables need to be continuously measured and recorded, automation enables the unattended running of a system through tried and true solutions that are built from technical expertise, knowledge and experience.  When processes can be standardized it facilitates up-scaling from laboratory to pilot plant and production scale; and since control functionality can be tailored to your specific needs, you can select what aspects of your process need automation.

Through automation, De Dietrich Process Systems can help you achieve better batch management.  Our control systems can be seamlessly integrated into your new or existing reactor as well other equipment/systems that are in need of automation upgrade.  Whether you already know your project goals or need help defining them, we can establish the hardware design specifications, software, and programming around those objectives.  DDPS’ project management encompasses all phases of engineering and design including process mapping for performance specification, control panel and HMI development, electrical design, equipment and component recommendations and selection, as well as documentation, validation and testing, start-up assistance, training, and technical support.  Contact us to find out more about how we can work together to automate your reactor; or for more information about other upgrades that are available for glass-lined steel reactors download our free ebook on Optimizing the Glass-Lined Reactor.

If you are new to glass-lined steel equipment, it can be intimidating when it comes time to determine the specifications of the vessel.   Especially when filling out our Reactor Specification Form, you might find yourself with more “don’t know” and “not sure” responses than actual specs…and that’s okay.  Our team of experts can help to identify what is the best type of reactor to suit your needs (that’s what we’re here for, after all).  But if you’re like me, you want to be an educated consumer and make some informed decisions on your own or at least have a basic understanding of what you need and why.

Even if you are well versed in glass-lined equipment, you still may not be sure about the fundamental differences between reactor models, baffle designs, agitator blades, and so on.  For those reasons, we’ve developed this post to help distinguish the differences between the three main types of vessel designs.  A simple comparison like this is handy if you are looking for a vessel and aren’t sure what model to choose.  In this article, we will refer to the different models by DDPS-branded terms; however, other glass-lined manufacturers may have comparable designs.

How to Select a Reactor Model for your Process

If you are in need of a new reactor for an existing process, chances are you’ll go with the same design that is currently employed in your operation.  If equipment is needed for a new process, there are two initial questions you’ll want to ask yourself:

• What is the volume of product per batch? (Note: all reactor sizes are labeled according to working capacity not total volume, so a 300 gallon vessel can process a maximum of 300 gallons of product per batch)
• What are the temperature and pressure ranges you will be operating under?

By answering these two simple questions you will already be able to eliminate some designs.  Once you have narrowed it down from there, you can identify more specific objectives, such as:

• How concerned are you with cleaning between batches and overall cleanability?
• How many nozzles do you require for installation of ancillary equipment/instrumentation?

Based on the answers to these fundamental questions, you can begin to narrow down your options.

To successfully convey solids, there are a number of factors that need to be considered.  This includes transfer rate, transfer distance, product characteristics, quantity, and level of containment required (just to name a few).   Given the range of issues involved, it’s easy to see why there is no single solution that will apply to all applications.  And while each one is important in its own right, the quantity of material involved can be especially important when considering all the options available.

When transferring a sizeable volume of solids, it usually involves integrating three components to create a complete solution:

1. Some type of container that temporarily stores the material in need of being transferred
2. A mechanism or station to assist in facilitating the discharge from the primary location
3. An apparatus that carries out the transfer of material (empties the container/fills the secondary vessel)

Let’s focus on what your best options are for each of these components when you need to move a significant amount of material from one place to another in a safe, contained manner.

Bags/Containers

When you need to transfer large volumes of material, it is too labor intensive to rely on an operator to stand for long periods of time and introduce materials to the system through a charging lance.  Plus, this arrangement would require using multiple drums or containers which not only adds unnecessary clutter to the work area, but transferring by lance from open containers also reduces the level of containment that is achieved, which can lead to dust exposure and other housekeeping issues.

When transferring larger quantities of powders, many companies incorporate FIBC’s or “Bulk Bags” to carry out both single powder and multiple powder transfer.  These containers can be used for relatively small batch operations as well as larger production campaigns, and can provide a high level of containment during transfer.  These types of containers, when integrated into a closed transfer system, provide an ideal solution for applications that require large quantity transfer with minimal labor.

There are many advantages in using flexible bulk containers in your transfer solution (one of which – flexibility – is mentioned in its name!).  Bulk bags are extremely cost effective and even customizable, taking into account material properties as well as filling and discharge conditions.  And unlike drums and other rigid containers that take up a large amount of space regardless of if they are full or empty, FIBCs take up very little space when empty.  They have a low packaging weight with the ability to carry up to a thousand times their own weight.  Additionally, there are recycling and recondition opportunities, making big bags a green choice (that of course depends on the material they are being used for; some that contain hazardous material don’t have that capability).

Big Bag Stations/Bag Discharge Systems

With all due respect to the bag, it really is only as good as the station that facilitates its discharge.  There are various arrangements and options, but essentially a big bag discharge system is comprised of:

• Loading mechanism – there are various methods that can be used including an integral hoist system, customer supplied hoist, or forklift
• Impactors – to help with material flow from the bulk bag into the discharging system, impactors are often incorporated to push the material towards the center of the bag to prevent bridging or rat-holing.
• Massagers – these frames raise and lower the bottom of the bulk bag from both sides to push material into the flow path.
• Discharge Gate – this feature safely and quickly closes bulk bag discharge spouts for operator tie off, allowing partial bag discharging of your materials.
• Bag Sealing System – to enable dust-tight discharge at the spout interfaces
• Material Conditioning – de-lumping, granulation, preventing ratholes and bridging, fluidizing gas introduction and discharge pressure control.
• Controls – bring automation to your transfer solution with a control package that can be custom designed for your application requirements. From loss in weight scale systems and fully automated PLC controls to intrinsically safe or explosion-proof controls for hazardous locations, many options are available.

Transfer Technology

A major part of any powder handling system is the apparatus that transfers the material from its source container, and delivers it into the secondary receiving vessel.  For larger volumes that utilize a Big Bag System and require a high level of containment, pneumatic conveying is often the most suitable technology to accomplish transfer.  Typically, the pneumatic transfer unit is mounted on the receiving vessel, and a flexible hose connects it to the Bulk Bag Discharger.  Then, using a series of vacuum and/or pressure sequences, the apparatus moves the material into the vessel.

Observing an operation like this in action, it’s clear to see that while all the components play an essential role in creating a complete solution, the transfer unit is really the heart of the process.  De Dietrich Process Systems’ powder handling solutions all incorporate the Powder Pump, a device that safely and efficiently transfer powder from one location to another.  When installed together, the Big Bag Station and the Powder Pump offer a comprehensive solution for large volume transfer by creating a complete, integrated system with a modular design that offers the flexibility needed to accomplish a variety of powder transfer requirements.

Halloween may be over, but we still thought it would be a good time to ressurrect an old post of ours about reglassing, especially since we recently published a new Introduction to Reglassing brochure.  It’s a great resource to learn more about the subject and how it can help bring new life to your old, used, or damaged glass-lined steel equipment.  

The vessel shown above is actually a reactor that was sent to us by a customer for reglass (embellished with some of my amateur Photoshop skills).  Here is the actual “before picture” without the special effects, taken during the reglass evaluation at our Corpus Christi, Texas plant:

This image may even look familiar to you if you have old, worn or damaged glass-lined equipment currently in your facility.  If not, this is an example of what can happen to a reactor that has suffered from extremely harsh working conditions including corrosion caused by chemical attack, environmental effects such as erosion and oxidation, and fractures to the glass lining due to mechanical stresses.  While it’s far from picture perfect, upon further inspection of the vessel, DDPS actually assessed this reactor as being a great candidate for our reglass service.

If reglassing is a new technology to you, check out our reglass web page or read this post that will familiarize you with the process (or check out that new brochure we mentioned above).

All caught up or already an expert on the subject?  Great!  Now we can talk about why reglassing is a “frightfully” good idea.

1. It’s Faster

Fabricating a glass-lined vessel is an intricate process involving many steps that take a considerable amount of skill and time to complete (click here if you’d like to learn more about how glass-lined vessels are made).  Due to the variety of sizes and specifications such as nozzle locations, glass-lined equipment manufacturers typically don’t keep a large inventory of stock vessels.  Because vessels are manufactured on demand, the order process can take months from the time an order is placed to the time the vessel is delivered and installed onsite.  Reglassing, on the other hand, offers a turnaround time that can be measured in weeks versus months since the framework or “skeleton” of the unit already exists.  And take it from us, while it may take a customer some time making a purchasing decision, once the contract is signed they usually would like delivery to be “yesterday”, so anything that shortens the delivery time is advantageous to the buyer.

2. It’s “Like New”

A vessel that is reglassed undergoes the same glassing procedure as a new vessel.  The refurbishment process to the steel substrate of an existing vessel is so meticulous that if you were to put a brand new vessel next to the refurbished one you wouldn’t be able to tell the difference.  Why is that?  Because essentially, a reglassed vessel is the same as exact quality as a brand new one.  So much so that most glass-lined equipment manufacturers (including De Dietrich Process Systems) will provide a warranty for a reglassed vessel that is identical to the standard warranty that comes with new vessels.  If you have any reservations about reglassing from the standpoint of it resulting in a second-class piece of equipment in terms of quality, you can rest assured that is a complete misconception.  Refurbished units are just as good as new ones.

3. It’s Cost Effective

With reglassing, you are using the frame of an existing vessel, and that saves on the cost of steel as well as the labor needed to build the vessel.  Less materials and work equates to substantial price cuts – as much as 50% off the list price of a new vessel.  Considering today’s most common-sized reactors, that would mean reglassing can provide a 4,000 gallon vessel at approximately the cost of a new 2,000 gallon vessel.  Rarely is there a company that is not looking to save money wherever they can, so this is definitely a good selling point if you are trying to win the support of your plant manager.

Reglassing is also cost effective in terms of cash flow.  Many companies find reglassing, which is considered a maintenance budget expenditure, preferable to a new capital expenditure.  Capital spending is usually more difficult to get approved too so it’s often less of a hassle for you to get a purchasing order generated for reglass service.

4. It’s Environmentally Friendly

In a world where everyone is continually taking more effort to reduce waste through recycling and repurposing materials, reglassing is a great way to minimize your company’s carbon footprint (not to mention, this environmental consciousness pairs perfectly with a company’s objective to minimize capital costs).  Reactors and tanks may not be buried in graveyards like we depicted above, but far too many vessels prematurely end up in a junkyard.    But how can you tell if your vessel is a reglass contender or if it is beyond repair?  If you are unsure, a qualified service technician can inspect it for you.

Instead of throwing out your vessel and buying a brand new one, you can actually refurbish your existing one and restore it to “like new” condition at a fraction of the cost.  How amazing is that?!  So if any of your equipment looks like the image at the beginning of this post, fear not.  It has potential to look like this:

Or like this, if you want to upgrade to a HemiCoil jacket (reglassing is the time to think about any additional upgrades you’d like to include in your vessel’s refurbishment):

De Dietrich Process Systems offers an affordable reglass service on our own vessels as well as on competitors’ equipment.  Even if you’re unsure if your equipment qualifies for reglassing, it’s an affordable solution worth looking into.  Check out our Introduction to Reglassing brochure for additional information.  Or, for a complimentary quote, fill out our Return Equipment Questionnaire to provide us with more information about your equipment so we can better assess if this is a viable choice for your equipment.