CONSTRUCTING A DREDGE HOT WATER SYSTEM.
Nov 14, 2008 8:50:32 GMT 12
Post by RKC on Nov 14, 2008 8:50:32 GMT 12
CONSTRUCTING A DREDGE HOT WATER SYSTEM.
Plans for constructing a dredge hot water system (HWS) can be found below.
Some additional aspects that need to be considered when constructing a HWS are as follows:
Motors of less than 5hp do not produce enough heat to run a HWS. And motors of about 5hp just produce enough heat to only run a Coil HWS ... Water-jacket HWSs are not as suitable as Coil HWSs for 5hp motors. Larger motors produce sufficient heat to run either a Coil HWS or a Water-jacket HWS. And for the larger stationary motors, such as the 16 or 18hp motors, a Water-jacket HWS is probably the best choice. And on the larger motors with two exhaust outlets, a dual HWS can be employed.
Highly corrosive condensation will be present in a HWS cylinder and water will collect at the bottom of the cylinder. To prevent water collecting a small hole should be drilled in the bottom of the HWS cylinder. If the HWS is made from mild steel the hole can block with rust and will need to be regularly cleared. A HWS made from stainless steel will obviously not have the rust problem ... and stainless steel is the preferred material to construct a HWS.
It is very important to use a suitable hose to deliver the heated water from the HWS to the diver. A thin walled hose should not be used as such a hose can easily kink ... a kink in a hose can produce a sudden blast of super-heated steam that could badly burn the diver. The type of hose used by most professional dredgers is a hose made for transferring hot water on washing machines. This type of hose is thick walled and will not kink, and the thick wall will provide some insulation against the heated water being cooled by the river water as it travels along the hose.
A hose of about 25' in length would suit most dredging situations.
One of the most important aspects of a HWS, of any style, is the use of a filter ( img.photobucket.com/albums/v521/NZGOLD/Equipment/0ff964ea.jpg?t=1248049608 ) (as positioned in the diagrams below). The filters used are plastic garden hose filters and can be bought from most hardware stores. If a filter is not used, small pieces of vegetation will plug the copper coil or the hose. A blast of super heated steam will then result. Filters need to be cleaned every day at least once, and only take a few minutes to clean. Some dredgers use a reservoir as the means of preventing a dangerous blast of steam. However a filter is much more effective. A reservoir could be added as an extra precaution, but its probably unnecessary and a reservoir can cool the water. A reservoir is also bulky and takes up space unnecessarily.
The end of a HWS hose should 'never' be securely attached to the divers wet suit! The hose must be positioned so it can be removed in seconds if the water overheats. And the hose should be positioned at the top half of the divers body so the heated water can circulate through the wet suit as the diver moves about.
The temperature of the water from the HWS can be altered to suit by adjusting the small tap (positioned as shown in the diagrams). A means of adjusting the temperature is essential as the temperature of the river water varies considerably depending on the time of year the dredging is being carried out.
A HWS needs to be solidly constructed and well supported as it is subject to severe vibration from the motor. A mounting bracket should be added (as in the diagram) to securely hold the HWS in place.
A flange (as in the diagram) is preferable to use where the HWS cylinder exhaust inlet connects to where the muffler normally mounts. A flange will stand up to vibration much better than a threaded pipe. And remember, in use, the HWS will be heavier as it will have water moving through it.
Most HWSs will only produce enough hot water for one diver.
A copper coil HWS uses a length of copper tube apx 25' or 30' long ... obviously, the more coil you can fit in a cylinder the more efficient the HWS will be. The diameter of the copper tube usually used in a HWS are either 5/16" or 3/8" in diameter. The cylinder is steel tube that can be either 4" or 5" in diameter (or even possibly 6"). Rolling the copper tube is easily done by wrapping it by hand around a solid steel tube of the appropriate diameter. But ... before the copper tube is rolled, it will make the rolling much easier if the copper tube is filled with sand and each end sealed so the sand stays in the tube when its being rolled. Filling the tube with sand will guard against the tube being flattened by mistake as its being rolled.
Where the copper tube enters and exits the HWS cylinder a sleeve of steel needs to be added, or maybe a nipple, to hold the tube solid so a hole will not wear in the soft copper where it is vibrating against a sharp surface. Or a threaded steel coupler can be positioned over the copper tube where it enters and exits the HWS cylinder. And the coupler could be threaded tight to hold the tube soil. Experiment!
Usually, the HWS that replaces the muffler will reduce engine noise equal to the muffler it replaces. However, if it is found that noise levels need to be reduced, a small (Briggs type) muffler can be attached to the HWS cylinder at the cylinder exhaust outlet.
Some dredgers have made copper coil HWSs that can be easily dismantled so the copper coil can be regularly cleaned. There is significant carbon build up in a HWS. However its doubtful if its worth dismantling the HWS cylinder every so often, to clean. Carbon build up probably does not impact on the efficiency of the HWS.
The outside of the HWS can be painted regularly to held reduce rust build up. Obviously the paint must be heat resistant.
Some HWSs have had spark arresters added at the exhaust outlet.
And, as with most gear made for production dredging, always keep in mind the KISS principal when designing equipment.
Regards,
Rob (RKC)
--------------------------------------------------------------------------------
Plans for constructing a dredge hot water system (HWS) can be found below.
Some additional aspects that need to be considered when constructing a HWS are as follows:
Motors of less than 5hp do not produce enough heat to run a HWS. And motors of about 5hp just produce enough heat to only run a Coil HWS ... Water-jacket HWSs are not as suitable as Coil HWSs for 5hp motors. Larger motors produce sufficient heat to run either a Coil HWS or a Water-jacket HWS. And for the larger stationary motors, such as the 16 or 18hp motors, a Water-jacket HWS is probably the best choice. And on the larger motors with two exhaust outlets, a dual HWS can be employed.
Highly corrosive condensation will be present in a HWS cylinder and water will collect at the bottom of the cylinder. To prevent water collecting a small hole should be drilled in the bottom of the HWS cylinder. If the HWS is made from mild steel the hole can block with rust and will need to be regularly cleared. A HWS made from stainless steel will obviously not have the rust problem ... and stainless steel is the preferred material to construct a HWS.
It is very important to use a suitable hose to deliver the heated water from the HWS to the diver. A thin walled hose should not be used as such a hose can easily kink ... a kink in a hose can produce a sudden blast of super-heated steam that could badly burn the diver. The type of hose used by most professional dredgers is a hose made for transferring hot water on washing machines. This type of hose is thick walled and will not kink, and the thick wall will provide some insulation against the heated water being cooled by the river water as it travels along the hose.
A hose of about 25' in length would suit most dredging situations.
One of the most important aspects of a HWS, of any style, is the use of a filter ( img.photobucket.com/albums/v521/NZGOLD/Equipment/0ff964ea.jpg?t=1248049608 ) (as positioned in the diagrams below). The filters used are plastic garden hose filters and can be bought from most hardware stores. If a filter is not used, small pieces of vegetation will plug the copper coil or the hose. A blast of super heated steam will then result. Filters need to be cleaned every day at least once, and only take a few minutes to clean. Some dredgers use a reservoir as the means of preventing a dangerous blast of steam. However a filter is much more effective. A reservoir could be added as an extra precaution, but its probably unnecessary and a reservoir can cool the water. A reservoir is also bulky and takes up space unnecessarily.
The end of a HWS hose should 'never' be securely attached to the divers wet suit! The hose must be positioned so it can be removed in seconds if the water overheats. And the hose should be positioned at the top half of the divers body so the heated water can circulate through the wet suit as the diver moves about.
The temperature of the water from the HWS can be altered to suit by adjusting the small tap (positioned as shown in the diagrams). A means of adjusting the temperature is essential as the temperature of the river water varies considerably depending on the time of year the dredging is being carried out.
A HWS needs to be solidly constructed and well supported as it is subject to severe vibration from the motor. A mounting bracket should be added (as in the diagram) to securely hold the HWS in place.
A flange (as in the diagram) is preferable to use where the HWS cylinder exhaust inlet connects to where the muffler normally mounts. A flange will stand up to vibration much better than a threaded pipe. And remember, in use, the HWS will be heavier as it will have water moving through it.
Most HWSs will only produce enough hot water for one diver.
A copper coil HWS uses a length of copper tube apx 25' or 30' long ... obviously, the more coil you can fit in a cylinder the more efficient the HWS will be. The diameter of the copper tube usually used in a HWS are either 5/16" or 3/8" in diameter. The cylinder is steel tube that can be either 4" or 5" in diameter (or even possibly 6"). Rolling the copper tube is easily done by wrapping it by hand around a solid steel tube of the appropriate diameter. But ... before the copper tube is rolled, it will make the rolling much easier if the copper tube is filled with sand and each end sealed so the sand stays in the tube when its being rolled. Filling the tube with sand will guard against the tube being flattened by mistake as its being rolled.
Where the copper tube enters and exits the HWS cylinder a sleeve of steel needs to be added, or maybe a nipple, to hold the tube solid so a hole will not wear in the soft copper where it is vibrating against a sharp surface. Or a threaded steel coupler can be positioned over the copper tube where it enters and exits the HWS cylinder. And the coupler could be threaded tight to hold the tube soil. Experiment!
Usually, the HWS that replaces the muffler will reduce engine noise equal to the muffler it replaces. However, if it is found that noise levels need to be reduced, a small (Briggs type) muffler can be attached to the HWS cylinder at the cylinder exhaust outlet.
Some dredgers have made copper coil HWSs that can be easily dismantled so the copper coil can be regularly cleaned. There is significant carbon build up in a HWS. However its doubtful if its worth dismantling the HWS cylinder every so often, to clean. Carbon build up probably does not impact on the efficiency of the HWS.
The outside of the HWS can be painted regularly to held reduce rust build up. Obviously the paint must be heat resistant.
Some HWSs have had spark arresters added at the exhaust outlet.
And, as with most gear made for production dredging, always keep in mind the KISS principal when designing equipment.
Regards,
Rob (RKC)
--------------------------------------------------------------------------------