Retrofitting Dryers and Nutsche Filter Dryers

Retrofitting Dryers and Nutsche Filter Dryers

The Challenge

Replacing an old dryer may seem like a natural conclusion when the process has changed, either partially or entirely, from its original intended use. After all, there are certain features in vacuum dryers and nutsche filter dryers that are added to the equipment according to customer specifications identified during the design phase. As we all know, over the course of a machine’s life, those initially requested characteristics can change because of a variety of external factors:

  • changes in process or production needs;
  • safety or regulation issues;
  • new technology solutions; or
  • the incorrect original design of the machine.

Our Solution

In some instances, retrofitting existing machinery may make more sense than replacing the installed one. This can often better meet budget or schedule constraints. In these cases, implementing a strict and rigid procedure is necessary to ensure the creation of a safe and effective modification. For Delta Costruzioni Meccaniche, this retrofitting process typically includes:

  • A customer’s needs analysis;
  • On-site data collection;
  • A solution proposal;
  • Implementation; and
  • Test and feedback.

Over the years, Delta has received several requests for machine modifications, both originally supplied by Delta and other manufacturers. Below are some examples of retrofits Delta has done.

  1. Agitator Seal Change

A typical situation involves process machines (reactor, dryer, filter dryer) equipped with an agitator seal that is no longer suitable for the scope of work. For example, when manufacturing the equipment, performance requirements were satisfied with a simple stuffing box or a lip seal. Now, however, the customer requires new technology that allows them to achieve a lower vacuum level or a higher containment of pollution in the area around the machine.

The seal change can require either a simple component change or a profound modification to the entire structure of the machine, depending on the machine’s features and constraints. Delta has undertaken both solutions for different customers.

Agitator Seal Change
  1. Discharge System Revamping

In this case, the manufacturer built the machine with a manual discharge and incorporated a manhole as a feature. The company decided that the discharge process was too time-consuming, especially since it relied on the manual operation performed by an employee. The customer wanted to improve the work conditions – for the operator’s safety and to reduce the discharging time. As a result, Delta installed an automatic side discharge valve at the manhole’s blind flange. This solution, integrated into the equipment’s control system, added an interlocks component, making it safer to operate.

Discharge System Revamping
  1. Containment

Delta handled instances where filter dryers and dryers needed to process a high-potent product, even if the machines lacked an original high-containment device. Two components are typically critical in this situation: the dust filter and the discharge nozzle.

After assessing the machine and the requested containment level, we can propose different solutions:

  • Include a connection plate to enable the installation of an isolator at the discharge nozzle if a continuous liner head is insufficient.
  • Add an additional isolator or a groove for a bag-in-bag-out procedure if the dust filter cartridge needs replacement.
  1. Washing System

Sometimes the dryer or nutsche filter dryer is equipped with a washing system that doesn’t satisfy the required performance. Typical critical points include the dust filter housing and the discharge valve body.

The issue can be solved in a short period of time by adding spray nozzles with the correct layout.

Washing System
  1. Certifications

Delta has encountered cases where the dryer installation area had classifications that prohibited explosives or other potentially dangerous situations. In some instances, the machine had to be relocated to a different country, requiring a new certification for the pressure vessels.

Starting from the existing documents, certifying the machines according to different Codes and Directives is possible. In some cases, the required changes are minor, while in others, substantial modifications are necessary. Delta can suggest the least impactful structural changes in order to fulfill the Customer’s needs and the reference Code requirements.


The Results

Delta’s experience in the industry has given it the knowledge to approach a revamping solution from any angle. We know what it takes to meet customer requirements and can advise on if a machine can be repurposed, or if a new machine would better suit your needs. This saves our customers time and money.