Author Topic: New Pre-Dryer  (Read 233 times)

Alan

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New Pre-Dryer
« on: October 12, 2018, 03:17:11 PM »
This is my new pre-dryer. It is simple to make using standard hardware PVC fillings, and a piece of acrylic tubing. The total cost in under $10, plus he cost of the silica gel.

(https://www.amazon.com/Premium-Indicating-Silica-Industry-Standard/dp/B013L31PQ0/ref=sr_1_4_acs_ac_2?ie=UTF8&qid=1539380655&sr=8-4-acs&keywords=silica+gel+desiccant)

Here is the rest of the story.

Silica gel is a wonderful moisture absorbing material, which can be reused hundreds of times, and comes in both blue and orange. Once it is depleted, the brilliant color turns translucent. A few minutes in the microwave, and you’re back in business.

Silica gel’s ability to absorb moisture, is based on the exposed surface area. It should be evident that the longer the air path, the more moisture it will absorb. In this case, 24 inches long. The 5/8 inch OD acrylic tubing came from Amazon, as my local supply house didn’t have any. A different size could be used with the appropriately sized fittings. You could even use vinyl tubing by using the correct fittings.

The fittings shown are for 1/2 inch PVC pipe, so the inside diameters are a bit too small for the 5/8 inch OD acrylic tubing. I used a 5/8 inch drill bit to open them up. I didn’t use my drill press, as PVC snatches very badly. I just clamped the drill bit in the vice, and twisted them by hand. I used a Dremel tool with a small sanding drum to smooth and taper the fittings. No glue is used, and none is needed if you do the job correctly. After all, you do have to recharge the silica gel once in a while, so you have to have at least one end removable. By the way, the inlet hole is 1/4 inch, allowing plenty of airflow.

The filter screens which keep the silica gel bead in place, are made from washing machine hose washers with a built in screen. With a bit of trimming with a pair of small side cutters, they fit in the fittings rather tightly. No glue here either.

My HPA compressor is a standard Omega Air Charger, and like most HPA compressors, the air is drawn in through a crank case fitting, which has a fritted brass filter screen (not shown). Its threads (in this case) are standard 1/2 inch pipe threads.

The question remains, does it work! The resounding answer is yes! Fact is, you can actually see the silica gel start to change color near the end of the inlet on the first refill! Not to shabby!
« Last Edit: October 12, 2018, 03:21:26 PM by Alan »


  • Roswell, New Mexico
Alan

I have an Omega compressor. If you're a fellow Guild member, and you pass through Roswell, NM, I'll fill your portable tank as a courtesy.

steveoh

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Re: New Pre-Dryer
« Reply #1 on: October 12, 2018, 04:02:51 PM »
Good job! Gonna think about doing the same on the Yong Heng.

This is my new pre-dryer. It is simple to make using standard hardware PVC fillings, and a piece of acrylic tubing. The total cost in under $10, plus he cost of the silica gel.

(https://www.amazon.com/Premium-Indicating-Silica-Industry-Standard/dp/B013L31PQ0/ref=sr_1_4_acs_ac_2?ie=UTF8&qid=1539380655&sr=8-4-acs&keywords=silica+gel+desiccant)

Here is the rest of the story.

Silica gel is a wonderful moisture absorbing material, which can be reused hundreds of times, and comes in both blue and orange. Once it is depleted, the brilliant color turns translucent. A few minutes in the microwave, and you’re back in business.

Silica gel’s ability to absorb moisture, is based on the exposed surface area. It should be evident that the longer the air path, the more moisture it will absorb. In this case, 24 inches long. The 5/8 inch OD acrylic tubing came from Amazon, as my local supply house didn’t have any. A different size could be used with the appropriately sized fittings. You could even use vinyl tubing by using the correct fittings.

The fittings shown are for 1/2 inch PVC pipe, so the inside diameters are a bit too small for the 5/8 inch OD acrylic tubing. I used a 5/8 inch drill bit to open them up. I didn’t use my drill press, as PVC snatches very badly. I just clamped the drill bit in the vice, and twisted them by hand. I used a Dremel tool with a small sanding drum to smooth and taper the fittings. No glue is used, and none is needed if you do the job correctly. After all, you do have to recharge the silica gel once in a while, so you have to have at least one end removable. By the way, the inlet hole is 1/4 inch, allowing plenty of airflow.

The filter screens which keep the silica gel bead in place, are made from washing machine hose washers with a built in screen. With a bit of trimming with a pair of small side cutters, they fit in the fittings rather tightly. No glue here either.

My HPA compressor is a standard Omega Air Charger, and like most HPA compressors, the air is drawn in through a crank case fitting, which has a fritted brass filter screen (not shown). Its threads (in this case) are standard 1/2 inch pipe threads.

The question remains, does it work! The resounding answer is yes! Fact is, you can actually see the silica gel start to change color near the end of the inlet on the first refill! Not to shabby!
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sixshootertexan

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Re: New Pre-Dryer
« Reply #2 on: October 12, 2018, 07:24:12 PM »
Nice.
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Alan

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Re: New Pre-Dryer
« Reply #3 on: October 31, 2018, 07:04:27 AM »
Here are two photos of the aforementioned dryer. The blue is unsaturated silica gel, near the compressor end. The pink is the saturated silica gel near the inlet end. Proof positive that it works!

  • Roswell, New Mexico
Alan

I have an Omega compressor. If you're a fellow Guild member, and you pass through Roswell, NM, I'll fill your portable tank as a courtesy.