How cable blowing machine works

Posted by Fatih Batal on January 9th, 2021

How Does A Cable Blowing Machine Work and what is Cable blowing machine also called Jetting machine or fiber optic cable blowing machine. The fiber optic cable blowing machines are engineered and manufactured for deploying and installing the fiber optic cables into ducts (micro-ducts or HDPE telecom ducts) by the help of of pressurized air or compressed air. After that, Cable is put into a motorized cable blower head that is plugged to a duct via a one-way air valve.

The pusher head provides the initial pushing force that drives the cable into duct when air source like compressor is introduced to the duct through the one-way air valve. Then Hydraulic or Pneumatic motors will help to push the cable into ducts and compressed air will decrease the friction of cable by preventing the cable contacting ducts. Therefore, the cable can be pushed through thousands of kilometer of pre-installed duct. Such long distances are possible with the high air drag and low friction generous. So it will be good to use Lubricant Oil. To reduce friction between cable and duct, you can consider to add special lubricant into ducts.

On the other hand it might be good idea to use an Air Cooler for more safe cable blowing. 

Air Cooler: 

Air Cooler remarkably effects and increases the “blowing” performances and protects the cable from the high temperature with the cooling feature of this accessory when climate temperature exceeds 20°C. 

Air Cooler Machine is very much recommended making a safe cable deployment in long distances without or with less friction and this will protect your cable from the potential damages that are mainly high temperature on the cable jacket surface. This heat may cause to melding of cable jacket and cost you high.

Special mechanism of machine changes the high temperature air with the air outside. The pressurized cool air will drive the fan that propels the air outside with low temperature.

This machine should be between the air-compressor and the cable blowing machine, which limits the pressurized air’s temperature up to max around 10°C more than the air in the climate in order to prevent the overheating problems.

Without air cooler, the temperature of compressed air exiting the compressor is around 35°C above the ambient temperature.

In case no air cooler, then the air temperature compressed may exceed the environment temperature by 30 or 35C.. This means that total temperature may go up to 70C. Such a temperature will meld the outer jacket of cable.

Any temperature more than 50°C, will soften the outer sheath of cable and also pre-installed duct walls. Due to aforesaid reasons your cable deployment time and cost will remarkably increase, length of cable you install will be much less. This will bring the risk of bursting of ducts. 

Blowing machine design

Fiber Optic cable blowing machine mainly consists of following parts

1. Adjustment and lubrication mechanism
2. Mechanical or digital cable meter counter
3. Pressurized air plug or connection
4. Cable router
5. Base line plate or basement
6. Pallet and or belt feeder mechanism
7. Pushing head

A Fiber cable blowing machine consists of the following components:

• a head that is assuring secure fitting of the duct that we will install the cable inside. It is going to be providing the medium (Air/Pneumatic or Oil/Hydraulic) to the HDPE telecom ducts. Afterwards the fiber cable pushed into the HDPE duct through the head goes inside a sealing system preventing the medium from getting into the machine;
• a pallet or belt feeder which pushes the cable forward the head;
• a basement plate or a frame onto which the cable blowing machine’s subsystems are assembled
• cable router, which is a system of bushes or rolls routing the cable forward the blowing head;
• air or oil supply is ensued to the blowing machine securely;
• a digital or mechanical meter counter which shows the length (in some cases the cable velocity) of the installed cable
• and control unit which helps you to control cable speed blown and the propelling power of the feeder.

Types

Machines are classified with regard to the diameter of the cable they can handle and the type of drive system (track feeder, roller feeder, belt feeder or blower heads without feeders). The machines are of 2 types.

1. Hydraulically powered
2. Pneumatically powered.

The hydraulically blowing machine consists of 2 parts.

1. Cable feeding unit: – This is the main component and it pushes the cable into the HDPE duct with the help of compressed air.
2. Hydraulic Power pack: – This unit provides the power to cable feeding unit and it is because of hydraulic power pack, the cable feeding unit operates.

How does a cable blowing machine work?