Systems and Methods for Ballasting Covers for Gas-Holding Sludge Digestors

Abstract

A method of ballasting a cover of a sludge digester that is comprised of a storage tank and the cover. The method includes placing a ballast into the storage tank in a first predetermined position, placing the cover onto the storage tank, lowering a lifting member of a lifting device through an access port in the cover and into the storage tank, securing the lifting member to the ballast, using the lifting device to lift the lifting member and the ballast until the ballast is in a second predetermined position that is substantially above the first predetermined position, engaging a support bracket attached to the cover with a support member; and securing the ballast to the cover with the support member while the ballast is in a third predetermined position that is substantially below the second predetermined position.

1 . A method of ballasting a cover of a sludge digester that is comprised of a storage tank and the cover, the method comprising:
 placing a ballast into the storage tank in a first predetermined position;   placing the cover onto the storage tank;   lowering a lifting member of a lifting device through an access port in the cover and into the storage tank;   securing the lifting member to the ballast;   using the lifting device to lift the lifting member and the ballast until the ballast is in a second predetermined position that is substantially above the first predetermined position;   engaging a support bracket attached to the cover with a support member; and   securing the ballast to the cover with the support member while the ballast is in a third predetermined position that is substantially below the second predetermined position.   
   
   
       2 . The method of  claim 1 , wherein the access port is positioned substantially above the first, second and third predetermined positions. 
   
   
       3 . The method of  claim 1 , wherein the support bracket is attached to a side skirt of the cover. 
   
   
       4 . The method of  claim 1 , wherein the support member is substantially rigid, and includes a portion having a shape that is complimentary to the shape of the ballast. 
   
   
       5 . The method of  claim 1 , wherein the support member is flexible. 
   
   
       6 . The method of  claim 1 , wherein securing the ballast to the cover includes at least partially wrapping the support member around a bottom portion of the ballast. 
   
   
       7 . The method of  claim 1 , wherein the support member includes an engaging member, and engaging the support bracket with the support member includes engaging the support bracket with the engaging member. 
   
   
       8 . The method of  claim 7 , wherein the engaging member includes a hook adapted to hook onto the support bracket. 
   
   
       9 . The method of  claim 7 , wherein the engaging mechanism includes a clip adapted to clip onto the support bracket. 
   
   
       10 . The method of  claim 7 , wherein the cover includes a second support bracket, and the support member includes a second engaging member, and wherein securing the ballast to the cover with the support member includes engaging the second support bracket with the second engaging member. 
   
   
       11 . The method of  claim 10 , wherein the second support bracket is attached to a side skirt of the cover. 
   
   
       12 . The method of  claim 1 , wherein the support member includes two engaging members, and wherein engaging the support bracket with the support member includes engaging the support bracket with each of the two engaging members. 
   
   
       13 . The method of  claim 12 , wherein the support bracket is attached to a side skirt of the cover. 
   
   
       14 . The method of  claim 1 , further comprising:
 disengaging the lifting member from the ballast;   using the lifting device to lift the lifting member through the access port and out of the storage tank; and   sealing the access port with a removable sealing member.   
   
   
       15 . The method of  claim 14 , wherein the access port includes a threaded hole, and the sealing member includes a threaded cover that can be selectively engaged and disengaged from the threaded hole of the access port. 
   
   
       16 . The method of  claim 14 , further comprising:
 removing the sealing member from the access port, thereby unsealing the access port;   lowering a lifting member of a lifting device through the access port and into the storage tank;   securing the lifting member to the ballast while it is secured to the cover;   unsecuring the ballast from the cover;   lowering the ballast to a base; and   disengaging the lifting device from the ballast.   
   
   
       17 . The method of  claim 16 , further comprising removing the cover from the storage tank. 
   
   
       18 . A method of ballasting a cover of a sludge digester that is comprised of a storage tank and the cover, the method comprising:
 moving a ballast from a first predetermined position to a second predetermined position that is substantially above the first predetermined position;   attaching a portion of a support member to the cover, wherein another portion of the support member includes an engagement member that is not attached to the cover;   selectively engaging a support bracket attached to the cover with the engagement member while the ballast is in the second predetermined position;   allowing the weight of the ballast to settle into the support member whereby the ballast is secured to the cover by the support member.   
   
   
       19 . The method of  claim 18 , further comprising:
 disengaging the engagement member from the support bracket;   moving the ballast to a base; and   removing the cover from the storage tank.   
   
   
       20 . A method of ballasting a cover of a sludge digester that is comprised of a storage tank and the cover, the method comprising:
 lowering a lifting member through an access port in the cover and into the storage tank;   securing the lifting member to the ballast;   using the lifting device to lift the lifting member and the ballast until the ballast is in a predetermined position relative to the cover; and   selectively engaging a support bracket attached to the cover with a support member while the ballast is in the predetermined position relative to the cover, whereby the support member secures the ballast to the cover;   wherein the access port is positioned substantially above the predetermined position.