Coolant Delivery

Abstract

A coolant delivery device ( 100 ) comprises a coolant outlet ( 124 ) and an exhaust ( 140, 160 ). The coolant outlet ( 124 ) is contained within a housing ( 150 ) that has an opening provided with sealing means ( 180 ), to which opening the coolant outlet ( 124 ) is arranged to direct a coolant. In use of the device, coolant is delivered to a surface to be cooled, and the coolant vaporises at the surface so as to produce coolant gas. Since the sealing means ( 180 ), in use of the device, form a seal between the housing ( 150 ) and the surface, the coolant gas is constrained to escape the device through the exhaust ( 140, 160 ), and does not disturb or disrupt the ambient environment. The device is particularly useful for applying thermal tensioning to welds through the delivery of a cryogenic spray to a weld line.

1 . A coolant delivery device comprising a coolant outlet within a housing; the housing defining an opening and an exhaust, the opening being provided with sealing means; and the coolant outlet being arranged to direct a coolant towards the opening; such that, in use of the device to deliver the coolant to a surface to be cooled, at which surface the coolant vaporises to produce coolant gas, the sealing means are operable to form a seal between the housing and the surface, thereby constraining the coolant gas to escape the device through the exhaust. 
   
   
       2 . A device as claimed in  claim 1  wherein the exhaust is connectable to extraction means operable to extract coolant gas from the device. 
   
   
       3 . A device as claimed in claim or  claim 2  wherein the exhaust comprises primary and secondary exhausts. 
   
   
       4 . A device as claimed in  claim 3  wherein the sealing means comprises first and second sealing members, each operable to form a seal between the housing and the surface. 
   
   
       5 . A device as claimed in  claim 4  wherein the first and second sealing members define a space therebetween, which space provides a part of a passageway through which coolant gas can reach the secondary exhaust. 
   
   
       6 . A device as claimed in  claim 5  wherein the second sealing member encloses the first sealing member. 
   
   
       7 . A device as claimed in  claim 3  wherein the primary and secondary exhausts are independently connectable to extraction means. 
   
   
       8 . A device as claimed in  claim 3  wherein the exhaust comprises adjustment means operable to adjust the rate of extraction of coolant gas from the device. 
   
   
       9 . A device as claimed in  claim 8  wherein the adjustment means are provided in the primary exhaust. 
   
   
       10 . A device as claimed in  claim 1  wherein the housing is generally cylindrical, and the exhaust and the sealing means are located at opposite ends of the housing. 
   
   
       11 . A device as claimed in  claim 1  wherein the sealing means comprises a flexible seal. 
   
   
       12 . A device as claimed in  claim 1  fabricated at least partly from teflon. 
   
   
       13 . A device as claimed in  claim 1  adapted for use with welding apparatus. 
   
   
       14 . A device as claimed in  claim 13  further comprising attachment means for attaching the device to a welding rig comprising a welding tool. 
   
   
       15 . A device as claimed in  claim 14  wherein the attachment means are configured such that the position of the device relative to the welding tool is adjustable. 
   
   
       16 . A device as claimed in  claim 1 , wherein the coolant is a cryogen. 
   
   
       17 . (canceled) 
   
   
       18 . A method of cooling a surface comprising the steps of:
 delivering coolant to the surface, such that coolant gas evolves; and   extracting coolant gas from the vicinity of the surface through an exhaust, so as to provide mitigation of the effects of leakage of coolant gas into the ambient environment.   
   
   
       19 . A method as claimed in  claim 18 , further comprising the step of balancing the rate of delivery of coolant with the rate of extraction of coolant gas so as to provide the mitigation. 
   
   
       20 .- 21 . (canceled)