A system comprising: a first screen having an upper site and a lower side for separating drill cuttings and drilling fluid within a shaker; a pressure differential generator configured to pull air or vapor through the first screen to enhance the flow of drilling fluid through the first screen with respect to a second screen within the shaker in which the pressure differential generator does not create a pressure differential between an area above and an area below the second screen; and a sump located below the first screen and configured to collect the air or vapor and the drilling fluid that passes through the first screen; and a degassing chamber in fluid communication with the pressure differential generator and the swap and located external to the shaker for collecting all of the air or vapor and the drilling fluid in the sump and removing air or vapor from the drilling fluid. view more

The system of claim 16 wherein the pressure differential generator is located, external to the shaker.

The system of claim 16 wherein the air or vapor pulled through the first screen is adjustable to prevent stalling of drill cuttings on the first screen.

The method of claim 10 further comprising: intermittently interrupting the first pressure differential applied to the first screen.