Lance holder with multiple-tolerance clamping head

Abstract

A lance holder 1 characterized by a high level of operating safety is equipped with a holder or tube fixing system which reliably prevents even a bent lance tube 2 from turning in the lance holder 1 . The clamping head 3 has a fixing part 4 and a clamping part 5 which ensure punctiform fixing by means of suitably-displaceable pressure elements 16 in the form of balls 20 . Three such balls 20, 20′ are distributed around the circumference and provide for secure fixing and a wide tolerance range in respect of the dimensions of the lance tubes 2 . Said wide tolerance range is also ensured by the possibility of using sealing sleeves 6 with a large internal diameter, which are pressed securely and directly against the wall 18 of the lance tube 2 without compression by insertion of a wedge 22.

1 . A lance holder for lance tubes ( 2 ) used in the iron and steel industry with a clamping head ( 3 ), which has a fixing part ( 4 ) and a clamping part ( 5 ) and to which a sealing sleeve ( 6 ) interlocking the inserted lance tube ( 2 ) and thus sealing it is allocated, wherein the fixing part ( 4 ) comprising the inserted lance tube ( 2 ) is provided with a leading bevel ( 14 ), in which pressure elements ( 16 ) distributed around the circumference are guided which can be displaced at right angles to the longitudinal axis ( 15 ) of the lance tube ( 2 ) and by means of which fixing part a clamping part having a pressure bevel corresponding to the leading bevel is arranged and formed in an influenceable manner. 
   
   
       2 . The lance holder according to  claim 1 , wherein the pressure elements ( 16 ) are all formed and arranged to be displaced simultaneously and uniformly by the pressure bevel ( 17 ) against the wall ( 18 ) of the lance tube ( 2 ). 
   
   
       3 . The lance holder according to  claim 2 , in that wherein the pressure elements ( 16 ) are formed so as to generate a punctiform and/or linear pressure load on the wall ( 18 ). 
   
   
       4 . The lance holder according to  claim 1 , wherein the pressure elements ( 16 ) are formed as balls ( 20 ). 
   
   
       5 . The lance holder according to  claim 1 , wherein three balls ( 20 ,  20 ′) acting as pressure elements ( 16 ) are arranged in the leading bevel ( 14 ) of the fixing part ( 4 ), evenly distributed around the circumference. 
   
   
       6 . The lance holder according to  claim 1 , wherein the fixing part ( 4 ) on the side ( 21 ) opposite the leading bevel ( 14 ) has a wedge ( 22 ) insertable between the outer wall ( 23 ) of the sealing sleeve ( 6 ) and the surrounding protective casing ( 9 ). 
   
   
       7 . The lance holder according to  claim 1 , wherein the clamping part ( 5 ) of the clamping head ( 3 ) has a clamping sleeve ( 25 ) which is formed so as to enclose the clamping part ( 5 ) and to be displaceable on an external thread ( 27 ) of the protective casing ( 9 ). 
   
   
       8 . The lance holder according to  claim 7 , wherein a ball bearing ( 30 ) is arranged between the front wall ( 28 ) of the clamping part ( 5 ) and the clamping wall ( 29 ) of the clamping sleeve ( 25 ). 
   
   
       9 . The lance holder according to  claim 1 , wherein a check valve ( 32 ) is arranged between the sealing sleeve ( 6 ) and a backburn safety device ( 7 ), which is affected by the lance tube ( 2 ) inserted as far as the stop ( 33 ) and which is formed so as to release the gas flow ( 34 ) when open. 
   
   
       10 . The lance holder according to  claim 1 , wherein a non-return valve ( 36 ), to be opened by the gas flow ( 34 ), is provided on the opposite side ( 35 ) of the backburn safety device ( 7 ). 
   
   
       11 . The lance holder according to  claim 1 , wherein the backburn safety device ( 7 ) with the valves ( 32 ,  36 ) is allocated to a safety casing ( 9 ) removably connected to the protective casing ( 10 ). 
   
   
       12 . The lance holder according to  claim 1 , wherein the fixing part ( 4 ), clamping part ( 5 ) and sealing sleeve ( 6 ) are formed with tube tolerances of 3-4 mm for group dimensions admitting both metric and imperial tubes.