Retrofitting Dryers and Nutsche Filter Dryers

Retrofitting Dryers and Nutsche Filter Dryers

The Challenge

It can be easy to jump to the conclusion that an old dryer needs to be replaced, especially if the process changed, either partially or entirely, from the initial one for which the machine was purchased. 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, it may make more sense to retrofit existing machinery instead of replacing the installed one. This can often better meet budget or schedule constraints. In these cases, a strict and rigid procedure must be implemented to create 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 modifications on machines, both originally supplied by Delta and by 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 the equipment was manufactured, a simple stuffing box or a lip seal was enough in terms of performance. 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 change of the seal can require either a simple component change or a deep 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 machine in question was built with a manual discharge and featured a manhole. 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 safety of the operator 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 control system of the equipment, added an interlocks component, which made it safer to operate.

Discharge System Revamping
  1. Containment

Delta dealt with filter dryers and dryers that needed to process a high-potent product, in instances where the machines were not originally equipped with a high-containment device. Two components are typically critical in this situation: the dust filter and the discharge nozzle.

By assessing the machine and the requested containment level, different solutions can be proposed:

  • If a continuous liner head is not sufficient, a connection plate can be included in order to enable the installation of an isolator at the discharge nozzle.
  • If the dust filter cartridge needs to be replaced, an additional isolator or a groove for a bag-in-bag-out procedure can be added.
  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 consist of the dust filter housing and the discharge valve body.

By simply adding spray nozzles with the correct layout, the issue can be solved in a short period of time.

Washing System
  1. Certifications

Delta has been involved with cases where the dryer installation area was classified in such a way that did not allow for explosives or other potentially dangerous situations, and where the machine was relocated from one country to another and therefore needed a different certification for the pressure vessels.

Starting from the existing documents, it is possible to certify the machines according to different Codes and Directives. In some cases, only minor changes are needed, whereas, in others, major modifications are required. 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.