Chlorine Atmosphere

[gadfly56]

I have a customer that processes grey water for use in process cooling. This involves treatment with chlorine, among other things. The exhaust fans they had in the treatment building have corroded to unusable. They ventilate the building by opening a man door on each side off the building 24/7/365. Into this mix we have a fire alarm panel that went into a Hoffman box, but since they were ventilating it with the corrosive atmosphere, the components didn't last long. We are relocating the new panel to an enclosure at ground level in a breezeway under the building. Although not a part of the current work, eventually we need to replace the devices. We are going to go with conventional devices hooked up to monitor modules in the environmental cabinet. The EMT for the fire alarm devices in the building is completely wrecked and should be replaced. Does anyone have a recommendation that doesn't involve plastic coated RMC?

 

[don_resqcapt19]

Chlorine + humidity = hydrochloric acid.
They do make stainless steel EMT and fittings but it will be pricey.

In reworking some controls for potable water storage where they added chlorine to the water, I saw that any of the electrical parts that made a little bit of heat were fine, but parts that stayed at room temperature were damaged fairly quickly. We ended up moving the control panels outside like you are doing, but there were still things inside like pressure sensors and push buttons were an issue.

 

[gadfly56]

For an idea of what we're dealing with, here's an example.

 

[don_resqcapt19]

Unless you can make that vapor tight, that will be an ongoing problem.

 

[gadfly56]

Unless you can make that vapor tight, that will be an ongoing problem.

Yes, we are going to have to have a conversation with the customer about how we can make this work going forward, The monitor modules will be OK. We can relocate them into the new environmental enclosure. The real trouble is the relay modules. They are supposed to be within 3 feet of the controlled device which means being in the chlorine atmosphere. I'll have to put my thinking cap on for this.

 

[don_resqcapt19]

Yes, we are going to have to have a conversation with the customer about how we can make this work going forward, The monitor modules will be OK. We can relocate them into the new environmental enclosure. The real trouble is the relay modules. They are supposed to be within 3 feet of the controlled device which means being in the chlorine atmosphere. I'll have to put my thinking cap on for this.

It seemed that a small amount of heat eliminated the problem in the control panels I worked on....maybe a small heat pad?

 

[xformer]

Yes, we are going to have to have a conversation with the customer about how we can make this work going forward, The monitor modules will be OK. We can relocate them into the new environmental enclosure. The real trouble is the relay modules. They are supposed to be within 3 feet of the controlled device which means being in the chlorine atmosphere. I'll have to put my thinking cap on for this.

Purged and Pressurized?