How does television EHT Transformer (that connected to anode) operates in DC?
The rectifier diode is built into the flyback transformer. Then the pulsating output is smoothed into DC by the giant capacitor formed by the CRT itself. You can't typically SEE the diode because it is inside the potted secondary winding and high-tension cable exit. 

Television CRTs typically have a conductive coating ("Aquadag") on the INSIDE which accelerates the electron beam towards the phosphor coating on the face of the CRT.  But there is ANOTHER coating of Aquadag on the OUTSIDE which is typically connected to circuit ground. The conductive surface on the INSIDE, and the conductive surface on the OUTSIDE form a giant capacitor with the glass tube envelope as the dielectric between the capacitor plates.

For this reason, most CRTs are significant shock hazards even after the power is turned off and the connections are removed. It is recommended to discharge the CRT before handling it or working on adjacent circuits.