Edit post

Edit your reply below.

Post Body
Enter your post below.
Yes the powder flows very well under air pressure... dont EVER have water anywhere in the system. We sometimes sprayed a regular garden hose on a leaking fitting that is blowing a cloud of powder all over the place to create a bond that will seal off the leak. A bulk tanker needs to unload cement and it can be done one of two ways. Option one... a Exhaust driven turbine blower mounted behind the tractor cab to feed air into the trailer. It is basically a minature Jet and will pressurize a tanker to about 16 pounds max.. although 11-13 PSI is where I want it at. Advantage... if it screams constantly without change in the sound pitch and your tank pressure is constant everything is going well. If it =goes "Cough cough cough" (literally... with a metallic clank) you are on the way to backing up the entire unloading system and need to shut off the product flow and increase the air flow before you hit total "lock up" The second option would be to have the customer use thier own air pressure to unload you. This enables you to shut off your engine and unload the product very very fast. If you drive the tank air with your engine it can take you about 1.5 hours. IF the customer's powerful air system sucks the product out of your tank you could be empty in about 40 minutes. Lehigh Cement on the Baltimore Harbor depends on trucks to recieve portland cement from Lime Kiln Maryland at the old Essoroc (Name spelling? or new name change?) facility. They can create enough pressure to unload about 30 trucks at a time. However you need to watch every truck that is unloading, if one should go empty and left unattended.. it becomes a drain on the customer's air system that will rob all the other trucks of pressure and possibly threaten lock up of the material in the system. I did this work for a period of time, it is very "easy" to do while you really have to monitor the gauges to prevent blockage or loss of product/pressure the rest of the day it is a matter of staying awake as you made several trips to and from the cement supplier. You would see drivers hitting the bottoms of the pots with rubber mallets. A dull thunk thunk thunk means there is still product in the bottom pot. A musical ringing "CLANG!!" that echoes means that your pot is empty and it's time to open the next one. Never ever ever use a regular hammer on a bulk tank under pressure. It stands a real danger of actually going thru the metal skin of the tank and releasing the pressure with lethal results to YOU and damaging problems to all nearby objects. Railroad cars are unloaded with air driven shakers to ensure that the product is shaken out of the cars without wearing out the elbows of the personel that needs to determine if the pots are empty. Hatches are very simple affairs that literally "Clip" into place to create a sealed hatch capable of holding pressure. The tanks usually have some kind of pressure blowdown that relieves ALL pressure inside the tank. That is the very first valve you will open before you ever go to the top to open the hatch to load the product from above. Once a year or so.. someone forgets and opens a tank under pressure. The hatch will throw the driver's body for 50-100 feet up and away from the rig's 12'6" deck with very damaging injury or lethal results. To me opening hatches and connecting hoses are the two most dangerous moments in cement hauling. I am not sure about covered hoppers but they probably share the same problems.
Tags (Optional)
Tags are keywords that get attached to your post. They are used to categorize your submission and make it easier to search for. To add tags to your post type a tag into the box below and click the "Add Tag" button.
Add Tag

Update Reply

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Model Railroader Newsletter See all

Sign up for our FREE e-newsletter and get model railroad news in your inbox!

Subscriber & Member Login

Edit post

Post Body

Tags (Optional)

Subscriber & Member Login

Users Online

Search the Community