Motion Solutions Improve Breathing Quality Air with Powered Air-Purifying Respirator Systems

When you hear the phrase “air contamination,” what comes to mind? More often than not, it’s the air outside your home that continues to be contaminated by industrialization, such as growing amounts of unwanted and hazardous gases and other elements. However, there’s another important space where “air contamination” occurs – hazardous environments related to healthcare procedures and pandemic situations. Exposure to this contaminated air can negatively impact human health, aggravate existing underlying medical conditions, and cause allergies that affect the respiratory tract. Consequently, there is a significant need to safeguard employees who are working in such settings against contaminated air by providing quality breathing air.

This can be accomplished through the use of a powered air-purifying respirator (PAPR), or a device with a blower and filter system that safeguards workers by removing contaminants such as fumes, dust, and vapors from the air. The PAPR system is battery operated and consists of a half or full facepiece, breathing tube, battery-operated blower, motor driver system, and particulate filters. The PAPR uses a blower to pass contaminated air through a HEPA filter, which removes the contaminant and supplies purified air to a facepiece. This process creates airflow inside either the tight-fitting facepiece or loose-fitting hood or helmet, providing a higher assigned protection factor (APF) than the reusable elastomeric non-powered air-purifying half facepiece (half masks) or N95 filtering facepiece respirators (or FFRs).

Blower Motor Design Considerations and Selection

The heart of the PAPR system is the blower’s motor unit, which drives the blower itself. Each PAPR system is different and features unique application specifications; to meet these specific parameters and reliability requirements, the motor design and selection, as well as the blower design and assembly, become wholly unique to each use case. Below are six key criteria for designing a miniature motor solution for the blower:

1. Efficiency. Since the system is battery operated, the efficiency of the blower motor should be high enough to ensure extended battery life.
2. Flow Rate. A PAPR system typically requires a flow rate of 110 lpm (liters per minute) to 250 lpm with the lowest possible power input.
3. Lifetime. The typical lifetime required for the blower motor can vary from 2,000 to 5,000 hours, depending on application parameters.
4. Material Selection. Because the PAPR system works and interacts with the human body, the materials used must be medical grade.
5. Noise. Because of the sensitive environments in which the PAPR system operates, noise is also an important criterion. Less than 50 dB at 100mm distance at maximum air flow is the ideal noise level.
6. Weight. Due to the portability and wearable nature of the PAPR unit, motor weight should be at a minimum. The motor design should also be compact design.

Note: Approval from a competent authority/organization is required for PAPR devices, such as the National Institute for Occupational Safety and Health (NIOSH), CE, etc.

A brushless flat DC motor (either a brushless slotless flat motor or brushless slotted flat outer rotor motor) is the most suitable motor technology for this type of blower application. There are various advantages of using these BLDC motors for PAPR applications, including: the electrical commutation of brushless DC flat motors, eliminating the chances of a spark; longer lifetime; increased reliability; minimal noise levels; high efficiency; and optimal power-to-weight ratio. A motor driver can also be available as part of the larger motor & blower solution package.

Portescap offers a variety of best-in-class motion solutions for PAPRs. These dedicated and fully customized solutions not only meet the application-level specifications, but do so in a compact and lightweight envelope that operates in the most critical environmental conditions. For more details on our miniature motors for PAPR applications, reach out to us directly here!