Small Port Additions


The solids addition process for chemical reactors can be a complicated and very dangerous process. Due to the presence of solvents, there is often a potentially explosive environment within vessel. The addition of dry solids introduces risk of static discharge and entrained oxygen which completes the highly dangerous fire trial and risk of a major deflagration event at the manway. EHS offers many options for safe solids addition into your chemical reactor.

The EHS Nitrogen Purge Hopper is a manway charge hopper that provides dust and vapor control while using a nitrogen purging system to maintain low oxygen concentrations throughout the solids addition process.

The small port configuration of our nitrogen purge hopper is attached on a tank nozzle, typically above a pressure rated isolation valve. This set-up is good for small quantity solids addition.


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<20μg/m³
Containment

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<8%
Oxygen Concentration in Vessel

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450cfm
Point Source Capture


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Small Port Nitrogen Purge Hopper

The Small Port Nitrogen Purge Hopper facilitates the addition of large quantities of powders or other solids through small vessel ports. This design can be configured to facilitate the charging of bag stock, bulk sacks, or drums.

The Small Port Nitrogen Purge Hopper serves as an engineering control to help maintain low oxygen concentrations within a process vessel during the manual addition of solids. This device utilizes a safe, pneumatically-powered butterfly valve that reduces the amount of time the tank is opened to the room environment. Split valve technology can also be used instead of the pneumatically-powered butterfly valve for high-containment applications. A full perimeter annular ring injects nitrogen at dual flow rates to dilute oxygen concentrations in the manway region of the tank. This engineered system has proven to maintain oxygen levels to below 5% for the duration of a charging process.



Mobile Transport Cart (Supporting Product)

The Mobile Transport Cart allows for easy transportation and cleaning access for all hopper components.



Air Filtration Unit (Supporting Product)

EHS offers a complete line of portable and stationary Air Filtration Units that provide a local HEPA filtration device to serve Local Exhaust Ventilation (LEV) systems. The EHS Air Filtration Unit is designed to meet the utility requirements of multiple EHS Ventilation Sleeves; it is also a good fit for any application with similar extraction utility requirements.

Each system is configured to comply with international electrical standards. The GMP compliant design features a small footprint and noise rating of 76 dBa. Safe Change filters and activated carbon filters for VOC’s are also available.

EHS Air Filtration Units are a cost effective alternative to upgrading house exhaust systems that have become over utilized or where there is a need to prevent the contamination of the house exhaust system ducting.



Tank Dynamics

In order to reduce the risk of deflagration within a process tank, an inert gas must be injected in the correct quantity, location, and time of the product transfer. Understanding the tank dynamics of each application is critical to implementing the best engineering control for this process. Existing nitrogen blanketing systems frequently do not apply the gas at the correct quantities, location, or timing during the solids addition process. This results in elevated oxygen concentrations in the manway region of the tank which increases the likelihood of a deflagration near the chemical operator.

Our inerting systems provide an effective control to reduce and maintain oxygen concentrations during the solids charging process. The dual rate injection system is adjustable and can be integrated with an oxygen level sensor to provide a precise control system.

The two figures to the left illustrate how a properly designed inerting system can change the tank dynamics and reduce the risk of deflagration. The first figure demonstrates a common tank system that allows elevated oxygen levels near the manway region during the solids addition process. All three components of the fire triangle [oxygen, ignition source, and fuel] are established in this scenario. The entrained air delivers oxygen to the headspace of the tank and mixes with the dry dust and solvent vapors. Static charge can generate the energy to ignite this volatile mixture resulting in a dangerous deflagration event, injuring the chemical operator and causing significant equipment damage. The second figure to the left shows a tank where the inert gas is added at the proper quantity, location, and timing of a solids addition process. A properly located 02 sensor can provide accurate O2 concentrations to confirm a safe work environment.



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