Plate heat exchanger

A plate heat exchanger comprising:

• a plurality of heat exchanger plates;
• a first end plate;
• a second end plate spaced apart from the first end plate, the plurality of heat exchanger plates being positioned between the first and second end plates;
• a plurality of motors that collectively define a drive unit;
• a plurality of threaded tightening bolts that each extend between the first end plate and the drive unit, each of the threaded tightening bolts also extending through the second end plate;
• the threaded tightening bolts each including a respective bolt head that bears directly or indirectly against either the first end plate or the second end plate;
• a plurality of nuts, each in threaded engagement with a respective one of the threaded tightening bolts and arranged to bear directly or indirectly against either the second end plate or the first end plate so that the bolt head and the nut associated with each respective threaded tightening bolt bear directly or indirectly against different ones of the first and second end plates;
• the threaded tightening bolts and nuts being arranged for relative movement of the first and second end plates towards or away from each other;
• and
• each of the plurality of motors being operatively connected to a respective one of the threaded tightening bolts so that each of the threaded tightening bolts is rotatable independently of others of the threaded tightening bolts, the bolt heads and the nuts being operatively coupled to the respective end plates in a manner such that operation of the respective motors and rotation of the threaded bolts in one direction decreases a distance between the end plates while operation of the respective motors and rotation of the threaded bolts in an opposite direction to the one direction increases the distance between the end plates.